A STUDY 0F THE RELATIONSHIP BETWEEN QCULAR DOMINANCE Am PERFORMANCE IN CERTAIN SELECTED MOTOR ACTIVITIES Thesis for II‘m Degree OI EcI. D. MICHIGAN STATE UNIVERSITY Jess Willard; FaIkenstine 1957 This is to certify that the thesis entitled A Study of the Relationship Between Ocular Dominance and Performance in Certain Selected Motor Activities presented bg Jess W. Falkenstine has been accepted towards fulfillment of the requirements for ECLD. degree inIQundaLiQns of Education £22294:“L¢/ /24gxy«3:au¢xr Major prolessflr Date )7” \I //f Q \T\\ 0-169 —-- w- fo—u— mvmw A STUDY OF THE RELATIONSHIP BETWEEN OCULAR DOMINANCE AND PERFORMANCE IN CERTAIN SELECTED MOTOR ACTIVITIES By JESS WILLARD FALKENSTINE A THESIS Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF EDUCATION Department of Foundations of Education 1957 /c,t, - U: ABST RAC T This study was an investigation of the relationship of the eye dominance of an individual to his performance in those motor activi- ties in which vision plays an indiSpensable role. Three investigations were made--an investigation of archery, one of baseball. and a con- trived-control examination of ball-catching-movement turns. Data were obtained of the eye dominance of the subjects and the positions taken by them to perform each of the activities; these were grouped accordingly and compared to the success attained in performance. The eye dominance of the subjects was determined by the hole-in-card test, which designates the "directionalizing" eye of binocular vision. The subjects for the archery phase of the study were the men and women competitors in the 1955 National Target Archery Championship Tournament, with their scores in the compe- tition being used as a measure of their performance. The subjects of the ball-catching investigation were members of a college physi- cal education class (the inexperienced group) and members of the varsity baseball and basketball squads (the experienced group). The measure of performance for this controlled experiment was the ob- servation of the turns taken to catch the ball, from a frontal ii standing position as in baseball, and from a running position as in basketball. The subjects of the baseball investigation were the reg— ular players on fifteen college baseball teams, with a season's batting, pitching, and fielding records used as measures of their success. The findings of the archery investigation showed that there was a specific pattern of eye usage followed by all subjects, with one unsuccessful exception. It was established that, when the shooting handedness of the subject corresponded to his eye domi- nance, both eyes were left open while shooting or the nondominant eye was closed. Those who used a shooting handedness opposite to their eye dominance closed the dominant eye and sighted with the nondominant eye. There was no significant difference in success shown between those who shot with only one eye open and those who had both eyes open. Nor was there a significant difference shown between those who shot with their shooting handedness cor- responding to their eye dominance and those who had an opposite eye dominance, or between those who used a shooting handedness which correSponded to their native handedness and those who did not. The fact that there were so few native right-handed and left-eye- dominant individuals in the tournament could indicate that individuals iii in this category are liable to have shooting problems if they do not follow the prescribed eye usage pattern. The findings of the ball-catching investigation showed that neither the experienced nor inexperienced players, as a group, turned according to their eye-dominance or handedness characteristics, al- though they did show specific turning habits, apparently selected by chance. The findings of the baseball investigation showed that. in batting, the groups which had their eye dominance opposite their batting handedness had a significant difference in group means in their favor for the measures of success in batting average, slugging average, and bases on balls received. For the pitching phase there was not a significant difference shown between the corresponding and opposite groups, according to their throwing handedness and eye dominance, for any of the five measures of pitching success used, which were won-lost average, earned-run average, hits allowed, bases on balls, and strike-outs. The fielding phase of the investi— gation showed a noteworthy, although not significant, difference in group means in favor of the group with the opposite characteristics of throwing handedness and eye dominance, using fielding averages as the measure of success. iv VITA Final examination, May 6, 1957, 10:00 a.m., Room 221, Physics- Mathematics Building. Dissertation: A Study of the Relationship between Ocular Dominance and Performance in Certain Selected Motor Activities. Outline of Studies Major subject: Education (higher education). Minor subject: Education (counseling and guidance). Cognate subject: Physical education. Biographical Items Born, November 28, 1916, Morgantown, West Virginia. Undergraduate studies, West Virginia University, 1935-1939. Graduate studies, West Virginia University, 1939-1946; Mich- igan State University, 1950-1957. Experience: Graduate assistant, West Virginia University, 1939-1940; teacher and coach, Junior High School, Morgantown, West Virginia, 1940—1941; officer in Physical Training Section, United States Navy, 1941- 1946; instructor of physical education, baseball coach, assistant coach of basketball and football, Rensselaer Polytechnic Institute, Troy, New York, 1946-1952; assistant director of physical education, basketball and baseball coach, assistant football coach, Kenyon Col- lege, Gambier, Ohio, 1952 to present. Member of: American Association for Health, Physical Edu- cation, and Recreation; American Football Coaches Association; The National Association of Basketball Coaches of the United States; The American Associa- tion of College Baseball Coaches; The American As- sociation of University Professors. V ACKNOWLEDG MENTS The author Wishes to express his indebtedness to the many persons Who have aided him in the completion of this study. He desires especially to express his gratitude to the chairman of his committee, Dr. Randolph W. Webster, who provided invaluable help and encouragement as the project progressed. In addition, he de- sires to thank Dr. Milosh Muntyan, Dr. Walter F. Johnson, and Dr. Cecil V. Millard for their helpful criticisms and assistance in for- mulating the thesis. Special gratitude is also expressed to James E. Steinway, the 1955 president of the National Archery Association, for his coopera- tion in the gathering of the statistics for the archery phase of the study. Grateful acknowledgment is also due the college baseball coaches who obtained the statistics for the members of their teams because of their interest in the study. They were: Arch Allen of Springfield College, Edwin Jucker of the University of Cincinnati, John Kobs of Michigan State University, Robert Sieman of the Uni- versity of Delaware, Ethan Allen of Yale University, William Lai of Long Island University, Paul Eckley of Amherst College, Raymond Coombs of Williams College, Evan Male of the University of Virginia, vi Dell Morgan of Rice Institute, Ralph Coleman of Oregon State Col— lege, Lovette Hill of the University of Houston, Frank Sancet of the University of Arizona, William Sharpe of the University of Nebraska, and George Wolfman of the University of California. The writer also extends his sincere appreciation to Dr. Daniel T. Finkbeiner of the Kenyon College Mathematics Department for his suggestions concerning the statistical aspects of the study; to William C. Stiles, director of physical education at Kenyon College, for his permission and cooperation in carrying out parts of the investigation; and to Technical Sergeant Dwight Perry of the Kenyon College ROTC Air Force detachment for his help. Also, the writer is indebted to the many subjects of the study who so graciously cooperated, and without whom this study would have been impossible. Finally, full credit. should be given to the author‘s wife, Helen Hebblewhite Falkenstine, for vital moral support, without which this project would have been impossible. vii TABLE OF CONTENTS CHAPTER I. INTRODUCTION ......................... Limitations and Scope of the Study .......... Definition of Terms .................... Organization of the Study ................ II. REVIEW OF THE LITERATURE ............. Int roduction .......................... The Concept of, and the Testing for, Ocular Dominance ..................... The Relationship of Ocular Dominance to Motor Activities ..................... III. METHODOLOGY AND PROCEDURE ........... Handedness Determination ................ Selection of Activities and Subjects ......... The Data ............................ Statistical Analysis of Data ............... viii IV. THE RELATIONSHIP OF OCULAR DOMINANCE TO ARCHERY SUCCESS ................... 78 Introduction .......................... 78 Individual Shooting Characteristics .......... 78 Shooting Characteristics and Tournament Success ............................. 84 Summary ............................ 89 V. THE RELATIONSHIP OF OCULAR DOMINANCE TO BALL-CATCHING MOVEMENTS ........... 91 Introduction .......................... 9 l Standing—turn Investigation ................ 91 Running-turn Investigation ................ 97 Summary ............................ 102 VI. THE RELATIONSHIP OF OCULAR DOMINANCE TO BASEBALL SUCCESS ........ . .......... 103 Introduction .......................... 103 Batting Investigation .................... 104 Pitching Investigation ................... 110 Fielding Investigation ................... 116 Summary ............................ 117 VII. SUMMARY AND CONCLUSIONS .............. 120 The Problem ......................... 120 ix Page Findings and Implications of the Archery Investigation ................... 121 Findings and Implications of the Ball-catching Investigation ................ 124 Findings and Implications of the Baseball Investigation ................... 126 BIBLIOGRAPHY ............................... 129 APPENDIX .................................. 138 TABLE II. III. VI. VII. VIII. XI. XII. LIST OF TABLES Shooting Handedness of Archers ............ Native Handedness and Eye Dominance of Archers .......................... Shooting Handedness and Eye Dominance of Archers .......................... Native and Shooting Handedness of Archers ...... Eye Usage by Archers .................. Shooting Characteristics and Tournament Success of Archers .................... Eye Dominance, Native Handedness, and Turning Directions for Standing-turn Test of Ball - catching Movements ............... Eye Dominance and Turning Direction for Standing-turn Test of Ball-catching Move- ments .............................. Native Handedness and Turning Directions for Standing—turn Test of Ball-catching Movements .......................... Summary of Standing-turn Test of Ball-catching Movements ................. xi 80 81 82 82 84 85 92 93 95 96 TABLE Page XIII. Eye Dominance, Native Handedness, and Turning Directions for Running-turn Test of Ball-catching Movements ................. 98 XIV. Eye Dominance and Turning Directions for Running-turn Test of Ball-catching Movements ............................ 99 XV. Native Handedness and Turning Directions for Running-turn Test of Ball-catching Movem ent s ............................ 1 0 0 XVI. Summary of Running—turn Test of Ball-catching Movements ................... 101 XVII. Batting Averages of Baseball Batting Subjects .............................. 105 XVIII. Slugging Averages of Baseball Batting Subjects .............................. 106 XIX. Bases on Balls Received by Baseball Batting Subjects ......................... 107 XX. Strike-outs of Baseball Batting Subjects ........ 108 XXI. Games-won-and-lost Percentages of Baseball Pitching Subjects .................. 111 XXII. Earned-run Averages of Baseball Pitching Subjects .............................. 112 XXIII. Hits Allowed by Baseball Pitching Subjects ...... 113 XXIV. Bases on Balls by Baseball Pitching Subjects 114 XXV. Strike-outs by Baseball Pitching Subjects ....... 115 XXVI. Fielding Averages of Baseball Fielding 117 Subjects .............................. xii CHAPTER I INT ROD UC TION Nature of the Problem This study was an investigation of the relationship of the eye dominance of an individual to his performance in motor activities. Studies were made of the Specific sports of archery and baseball, and of ball—catching movements through a contrived study. Eye dominance is defined by the Optometrist‘s Dictionagy as “the faculty which one of the eyes commonly exercises of dominat- ing, or leading the other, both in fixation and in attentive or per- ceptive function" (83:95). According to the most prevalent concept of the phenomenon, there are two types, motor and sensory (92). Motor dominance is designated as being functional, providing objec- tive direction to the vision process of an individual. This type of dominance is determined by sighting preference tests. Sensory dominance is determined by rivalry tests of the two eyes. It is also functional, but it is concerned with such activities of cerebral references as reading and writing. This latter type of eye domi— nance was not considered in this investigation. There has been and continues to be considerable controversy over the concept of eye dominance, with resultant confusion in the process of testing for it. Motor activities investigated in this study were only those in which vision plays an indispensable role. There are motor activi- ties which do not need vision in order to be performed successfully, others depending only slightly upon it, and still others that are com- pletely dependent. To be successful in a motor activity, the indi- vidual must pick up cues of position, movement, and balance. The cues come from two sources: vision; and that something called muscular kinesthesis, sometimes referred to as the sixth sense. It is defined by Scott as "a feeling of position and movement which makes possible the assuming and maintenance of a position or move— ment" (77:84). The vision cues give to the individual movement relationships in reference to other objects in the vision field, and aid in the judgment of distance and the anticipation of movements. The muscular action required to accomplish a particular motor activity will depend upon the Speed and resistance encountered and the action desired. This is determined largely from past ex- perience, both actual and associated, and is brought to bear by the stimulus received from the vision cues and kinesthetic sense. As the vision cues are acquired through the directional dominance of the vision process, this investigation was concerned with determining whether or not there was any significant relationship between this factor and success in performance. Motor activities were classified for the purpose of this inves- tigation into static position actions and dynamic movements. The static position actions refer to those in which the body does not move from the starting position and in which the action is accom- plished by the extremities. Activities of this type which are de- pendent upon vision cues would be those of the shooting type--rifle, field, revolver, and archery. The designation of dynamic movement action is applied to those activities in which there is movement of the body as well as of the extremities during the execution of ac- tivity skill. The activities of the dynamic type which are dependent upon vision cues are baseball, boxing, fencing, football, handball, hockey, lacrosse, polo, soccer, squash, and tennis. It was decided to investigate the sport of archery as repre- sentative of the static position activities, when permission was ob- tained from the National Archery Association to run the study on the participants in the 1955 National Target Championship Tourna— ment. The Sport of baseball was selected to be investigated as rep— resentative of the dynamic movement type of activity, because the primary interest of the writer in the subject of eye dominance was 4 fostered by the supposition that it was possibly a factor in baseball batting success. Theorizing on possible avenues of the relationship of eye dominance to performance success in motor activities, the writer came upon the problem of catching a ball while running. This is an action common to many activities, and a skill difficult to teach. It was decided to investigate this problem as a part of the study, and a control study was evolved to examine this Skill in the Sports of baseball and basketball. Statement of the Problem The main purpose of this study was to check whether or not a relationship existed between the eye dominance of an individual, the positions assumed to perform the activity, and the success ob- tained while participating in the selected motor activities. The ultimate goal was to ascertain if the eye dominance of an individual is worth consideration as a teaching point for those motor activity skills dependent upon vision perception for success. Specific prob- lems were of interest in each of the three phases of the study. Archeg. The general problem of the archery study was to ascertain if the eye dominance of the tournament archers had any bearing upon the shooting style that they used. The following ques— tions were answered by analyzing the data of the study: 1. Did the shooting handedness of the better archers cor— respond more with their eyedness or their native handedness? 2. What shooting styles did the dextrals use? The sinis— trals? The crossed dextrals? The crossed sinistrals? 3. What pattern of eye usage was followed by the dextrals? The sinistrals? The crossed dextrals? The crossed sinistrals? Ball-catching movements. The general concern of the ball- catching experiment was to ascertain if there was a relationship be- tween the individual's eye dominance and his turning habits in going straight back to catch a fly ball in baseball, or in turning to catch a ball while running in basketball. The following Specific questions were answered by analyzing the data: 1. Was there a difference in the turning habits of experienced and inexperienced players in baseball? In basketball? 2. Was there a uniformity of turning habits in starting back after a fly in baseball from the standing position, and in turning to catch the ball while on a run in basketball? Was there a difference in experienced and inexperienced players? 6 3. Did the individual player's handedness have any relation- ship to the turning habits of either the experienced or inexperienced, in either baseball or basketball? Baseball. The general problem of the baseball study was to ascertain if there was a relationship between the eye dominance of college players and their playing success in the phases of batting, fielding, and pitching. The following specific questions were an- swered by analyzing the data: 1. Did players who used a batting handedness which corre- sponded to their eye dominance have a higher batting average and a higher slugging average, receive more bases on balls, and strike out less than those who used a batting handedness opposite to their eye dominance? Was there a comparable difference between those who had correSponding eye dominance and those who did not, among the right-handed batters? The left-handed batters? Was there a difference between right- and, left-handed batters? Z. Did players who had a throwing handedness corresponding to their eye dominance have a higher fielding average than those with their throwing handedness opposite to their eye dominance? Was there a difference when the same comparison was made With only those who were right-handed? Left-handed? 7 3. Did pitchers who had a'throwing handedness correspond- ing to their eye dominance have a better won-lost percentage, have a lower earned- run average, allow less hits, give up fewer bases on balls, and strike out more men than those with their throwing handedness opposite to their eye dominance? Was there a compar- able difference between the correSponding and opposite right-handed pitchers? The left-handed pitchers? Limitations and Scope of the Study The statistical methods used in the investigation of problems of the study had a serious limitation in that the data were analyzed by groups, a procedure necessitated by the large differences in num- bers of subjects in the categories compared. Therefore, any con- clusions drawn from the study must be of general application. Sta- tistics in each of the three phases of the study were handled differ- ently, because of the differences in the types of data. The assumption was made that the subjects of each of the groups used for comparisons in each of the three phases of the Study had an approximate equalization of the factors of individual differences and experience in the activity. This was not investigated, as there was considerable doubt that such an investigation would be successful. 8 It was also assumed that the records used for success meas- ures were valid. They were objective upon consideration but were arrived at with considerable subjective judgment. It is believed that there will be an equalization of errors, pro and con. There was also the factor of "ups and downs" of motor activity perform— ance which was not investigated. The baseball study could be ques- tioned because of the differences in the number of games played by the members of the various teams. Definition of Terms The terms defined in this section are general in meaning in common usage, or are particular to the jargon of physical education, and are therefore explained according to usage in this study for common understanding. CorreSponding is a term used to designate that the eye domi- nance of an individual or group is on the same side of the body as a type of handedness; i.e., a person who is right-eye-dominant and bats right - handed . Opposite is a term used to designate that the eye dominance of an individual or group is on the other Side of the body from a type of handedness; i.e., a person who is left-eye-dominant and bats ri ght-handed. 9 Sinistral is a term used to designate that the native handedness and eye dominance of an individual or group are both on the left side. Crossed sinistral is a term used to designate native left- handedness and right-eye dominance of an individual or group. Dextral is a term used to designate that the native handedness and eye dominance of an individual or group are both on the right side. Crossed dextral is a term used to designate native right- handedness and left-eye dominance of an individual or group. The following terms are concerned with the baseball study measures of success. Batting average is a percentage figure used as a measure of hitting frequency, secured by dividing the official number of times at bat into the number of base hits made. Slugging average is a percentage figure denoting both hitting power and frequency, secured by dividing the official number of times at bat into the total number of bases accumulating from base hits made. Per plate appearance is a term used to show the number of times the individual came to the plate as a batter, secured by adding together the official number of times at bat, the bases on balls, the times hit by the pitcher, and the sacrifices. Earned- run average is a term denoting the pitcher's effective- ness, secured by dividing the total number of innings pitched into ‘ I 10 the number of runs given up by the pitcher, discounting errors, and then multiplying the result by nine. Fielding average is a percentage figure used to denote field- ing success, and is secured by dividing the total fielding chances handled (put-outs, assists, and errors added) into the number of successful chances (put-outs and assists added). Organization of the Study Chapter II contains a review of the literature. The first section is concerned with the concept of ocular dominance and the testing for the phenomenon. The second section is concerned with the literature that could be found which discussed ocular dominance and various motor activities. Chapter III consists of a discussion of the methodology and procedures used in the study. It is concerned with the selection of the test used, the selection of the activities and subjects, and a description of the data gathered for analyzation. Chapters IV, V, and VI are concerned with the analyzation of the data of the three phases of motor activities used in the study. Chapter VII gives the findings of the three phases of the study, with accompanying implications, and suggestions for further study. CHAPTER II REVIEW OF THE LITERATURE Introduction The literature on the subject of ocular dominance could be divided into four main classes. They are (a) the concept of ocular dominance, (b) testing for ocular dominance, (c) ocular dominance as it concerns clinical work, and (d) ocular dominance as it con- cerns various human functions. This study was concerned only with the concept, testing, and motor activity performance relationships. The literature on concept and testing is reviewed chronologically in the first part of this chapter. The various motor activity performances which are re- ferred to in the literature are reviewed in the second half of this chapter with the corresponding activity. Reports of studies concerning clinical work have not been reviewed here except as they may refer to concept or testing. There have been few studies in this category, as the subject has not been considered important by oculists (36). ll 12 There has been considerable literature written on the rela- tionship of ocular dominance. to the functions of reading and writing. There has also been some work done in the field of such anomalies of functions as stuttering, poor emotional control, awkwardness, and generally low-level performance. Literature in these areas has not been referred to in this study, except as applicable to motor activity performance. The Concept of, and the Testing for, Ocular Dominance Early studies. The first known mention of ocular dominance in the literature was in 1593 by loan Batista Porta in his book 23 Refractione. According to the translation by Durand and Gould in 1910, he reviewed the opinions of "the ancients and the moderns" concerning binocular vision and gave his own thinking from personal observations. Concerning eye dominance, Porta observed: Nature has bestowed on us eyes in pairs, one at the right hand and one at the left, so that if we are to See anything at the right hand we make use of the right eye. . . . Whence we always see with one eye, although we think that both are Open and that we see with both. This thesis he attempted to prove with two experiments. Between the two eyes let there be placed a partition to divide the one from the other, and let us place a book before the right eye and read. If anyone shows another book to the left eye it will not only be unable to read, but it cannot even .13 see the pages, unless in a moment it withdraws the visual vir- tue from the right eye and changes it to the left. . . . If any- one places a staff before him and brings it directly opposite some crack that exists in the opposite wall and notes the place, when he closes his left eye he will not see the staff removed from the Opposite crack. The reason being that everyone looks with his right eye as he uses his right hand. [68:369] Numerous references are made in the literature to the book written in 1861 by Humphrey, who discussed the "correspondence of function between hand and eye, advancing the theory that eyed- ness is the cause of handedness" (44:157). Donders wrote in 1889 of eye preference, stating that "we abstract from one eye more easily than the other" (28:559). He advocated, as Porta had, the use of the alignment test to Show the preferred eye. In endeavoring to connect eyedness and handedness with cere- bral laterality, Wray in 1903 suggested foot-preference tests along with eye and ear testing. If the footedness were distinguishable and on the same side as the eye and ear, then cerebral dominance was indicated. He discounted handedness as a determinant, reason- ing that it was subject to change by training or imitation. He advo- cated the ring test for eye dominance, and he was the first to use the term "master eye": It is common knowledge that though the vision is perfect in each eye and the refraction is normal nearly eyery person has a ”master eye." This is determined by holdinga ring at arm's length with both eyes open and covering an objectlla f.feziw yards away. A left-eyed person shutting his left eye W1 1n 14 the ring far to his left. If, on the other hand, he shuts his right eye he finds he is "dead on" his object. [100:683] In an article written in 1910, Durand and Gould made the ob- servation that the question of ocular dominance did not seem to be of any consequence to the medical profession, which opinion they believed to be unsound. They introduced a new test of eye domi- nance, the peephole test, as an improvement on the hole-in-card test, reporting their experiment as follows: During the fall of 1909 there appeared in a New York neWSpaper an article on the "master eye" in which the author shows that in the realm of sport the master eye directs and controls the marvelously quick and accurate movements of successful players. To demonstrate beyond doubt the fact of the existence of a "master eye" he directed that a round hole he cut in a piece of cardboard, the disc thus being cut out and placed on the floor in front of the person tested. The card- board is held at arm's length and the disc observed through the hole. Inasmuch as the disc can be seen with only one eye at a time, one will select his "master eye" to see it. The method was so simple, the demonstration so convincing that modifications and further improvements were immediately de- vised. The modification consisted simply in narrowing the field of vision by placing a tube in the center of the cardboard, and, second, in increasing the convenience of using the appara- tus by adding a handle, blackening the instrument, etc. The instrument we now use is Simple, light, homemade and ef- fective. [322370] The same authors, who were practicing ophthalmologists, collaborated on another article in 1910, which discussed the reason- ing behind their belief that an individual's native handedness Should never be changed. They believed that handedness was not hereditary, 15 but was caused by eye dominance, the preferred hand corresponding to that eye. Eye dominance they believed to be determined by the eye with the better vision. They suggested that the dominant eye is a stable entity, although such things as disease, injuries, and changing refraction may cause a change, in a small number of indi- viduals, to dominance of the other eye (33). In an article published in 1919, Dolman suggested the hole— in-card test for ocular dominance. He cited the difficulties of testing with a finger or pencil in the alignment test, and believed that the ring test was not consistent. He cautioned against accept- ing the premise that eyedness and handedness should agree, because there was no substantiating evidence. His discussion on testing was a forerunner of many discussions concerning the possible ef- fect of the testee's handedness on the results of testing for eye dominance. In the instructions on how to give the hole-in-card test, he insisted that the subject hold the card in both hands, so as to counteract possible handedness influence. He advocated the hole-in-card test because it eliminated negative results, gave con- sistent results over a period of time, and was simple to adminis- ter (27). 16 The Parson influence. Parson published a book on handed- ness in 1924, advocating with supporting evidence the theoretical concept that the eyedness of an individual was the cause of his handedness. The book marked a turning point in that it created considerable controversy and instigated numerous studies and tests by psychologists, who were more prolific in producing literature on the subject than the medical profession had been. Parson deduced that the over-all subject could better be understood if the indexes of eyedness and handedness were thought of as acts of the entire body, as necessitated by the structure and function of the body to cause unilateral action. He presented a complete survey of the theoretical handedness concepts and a summary of all prevailing tests for both eyedness and handedness, and collected eyedness and handedness data on 887 school children through the means of an eyedness test he devised. The test used an instrument called the manaptoscope, or manuscope, which was a cone-shaped funnel. The test procedure consisted of placing the wide end of the funnel over the face, and fixating the eyes on an object several feet in front of the narrow end. At a certain distance, the object being looked at cannot be seen simultaneously with both eyes; the dominant eye is the eye which can see it. The other eye will see something else located on the medial side of that eye. His testing results Showed 17 69.3 per cent right-eyed, 29.3 per cent left-eyed, and 1.3 per cent impartial-eyed (64). Concurrence with Parson's theory of handedness was the con- clusion of a study done by Mills in 1925. He devised and used a convergence test for ocular dominance. It consisted of the subject's fixing on a spot on a mirror held in front of him by the examiner; the mirror was then moved inward to the individual's nose at eye level. The test result was the observation by the examiner as to which eye was first to diverge from the spot, it to be designated the nondominant eye. He compiled the results of five different series of two hundred cases each, concerning the prevalence of handedness and eyedness. His results showed the total of 76 per cent right— handed and right-eyed, 13 per cent right-handed and left-eyed, 9.3 per cent left—handed and left-eyed, and 1.7 per cent left—handed and right-eyed (57). In 1928 Mills wrote a supplementary article analyzing the factors of handedness and eyedness. He theorized that: Handedness is caused by a functional limitation of binocu- lar vision which necessitates the exclusive use of one eye for all sight or aiming operations and therefore for many of the most important manual activities. The fact that these visual operations are carried on monocularly leads inevitably to the preferred use of one hand-—the hand nearer the sighting eye for the greatest anatomical and physiological advantage. Every consideration of speed, accuracy and economy of muscular 18 effort demands this intimate correlation of eye and hand on the preferred side. [582190] Mills believed, as did Durand and Gould, that the eyedness of an individual would persist throughout his lifetime, although handedness is subject to change. He stated that eye dominance was an indica— tion that cerebral hemisphere dominance was in keeping with the structure of the paired organs of the body. He further theorized that the dominant eye had significance in the visual pattern of an individual, by giving direction and position to binocular vision. The .nondominant eye then gives the individual, through its moving during convergence by nervous impulse and kinesthetic sense, the quality of stereoptic vision for use in making judgments of distance, depth, and relief. He also emphasized the necessity for early discovery of what the native handedness of an individual was, and for its con- sistent maintenance (58). As a modification of the Parson manoptoscope test, Miles devised a test in 1929 involving the use of the cone—shaped funnel. The narrow end was placed over the eye and the wide end toward the object being sighted. Holding the cone in both hands, the testee was asked to look at a card held by the examiner in front of him, and to tell what he saw on the card. The test result was secured by the observation of the examiner who observed the eye used for l9 sighting by the testee, who was unaware of the exact purpose of the test. The test was standardized and c0pyrighted, and is still being sold today, under the name of the A- B-C Vision Test for Ocular Dominance (55). Concerning the ocular-dominance concept, Miles stated, "Ocu— lar dominance tends to clear the visual field by giving the right of way to the image that belongs to the dominant eye, making it appear more substantial than the other which tends to be more or less sup- pressed" (552113). Miles did a comprehensive study of the subject of ocular dominance in 1930, emphasizing the fact that there were many problems of importance unanswered: Is dominance a thing to be encouraged or held back? Should the patient know his tendencies in this respect? Does the presence of a dominant eye actually work toward a physical or functional distortion of the face? Is dominance a favoring condition for the development of motor skill, fine visual dis- crimination, and high achievement in general? At what time in the individual's life does the preference begin and can it be ascribed to adaption to environment where minute visual detail is stressed? How readily and with what result can dominance be reversed in case of need? [56:414] Miles did, in this second article, come to some conclusions concerning a normal population and their ocular dominance charac- teristics. The A- B-C test results showed that 64 per cent of the population was right-eyed and 34 per cent was left-eyed, with 2 per cent impartial-eyed. Correlating handedness and eyedness in 20 individuals showed that, of the right-handed subjects, one in three was left-eyed, and that the left-handed subjects were about equally divided between right- and left-eyedness. Testing of women and children showed approximately the same results, as did a test run on Chinese men (56). In another effort to improve upon Parson‘s test, Cuff in 1930 devised the manoptometer. He stayed with the same test procedure, but the fixation points were picture slides which were moved around on an easel to attempt to secure quantitative measurements of an individual's dominance. The easel was marked off in centimeters for this purpose (20). Lund objected to the testing devices of both Parson and Cuff because there were no objects in indirect vision, because it was a matter of chance which eye was used, and because the examiner could not see the eyes of the testee and therefore had to depend upon his report. To correct these discrepencies Lund devised a test ap- paratus which he called the monoptometer. It required the subject to place his chin in a crevice devised for that purpose, and then to look through a projected ring two feet in front of him at a particular spot on a board four feet in front of‘him. The examiner then ob- served which eye was used to align the ring with the Spot on the board (53). 21 Crider wrote an article in 1935 discussing both the Cuff and Lund testing procedures. He reasoned that the Lund test was too similar to the Parson test in principle and did nothing to overcome the objections to that test. The Cuff effort at quantitative measures of dominance was judged by Crider to be merely an indication of the interpupillary distance (11). The post- Parson period. The controversy over Parson's work and that which immediately followed it caused a great variety of tests and discussion of concept of the subject. of ocular dominance in the 1930's. The particular interest of most investigators was with the effect that crossed eye and hand dominances had on learn- ing, emotional control, speech, and motor control functions of an individual. Linebeck did a study on the concept of vision in which he introduced a new test of dominance. The test procedure was the observation of the position of a shadow from a staff placed four feet in front of the testee, and observed according to a Spot on the wall sixteen feet away. He also reported upon measuring eighteen pairs of human eyes in an effort to determine if there were any structural condition in the dominant eye to account for the dominance. He found that in every pair of eyes examined the fovea was found 22 closer to the Optic disk in the right eye. He assumed that this would cause the right eye to reach the line of vision quicker than the left (51). Another test devised was a projection test by Snyder. It con- sisted of fixating a designated point on a test card, and, without moving the eyes, bringing the top of a pencil or the point of a finger in line with the line of sight about midway between the card and the eyes. Each eye was closed in turn to discover which was doing the sighting (87). Schneidemann and Robinette, using a variation of the peephole test of Durand and Gould, were able to get ocular-dominance results of infants as young as twenty months old (74). Schneidemann also reported on a practical variation of the hole-in-card test, which she called the paper-hole test (72). Washburn reported upon a test she and others devised at Vassar College, which involved retinal rivalry testing with a stereo- sc0pe, and compared such test data with results secured from the Miles A-B-C test. The procedure was to present to the subject a different field for each eye and then to alternate the two. The test measured the time each field remained in the consciousness; the eye that retained its image longer was the dominant eye. There 23 was no significant correlation of the test results with the Miles test (94). Jasper and Raney devised what they called the "phi test of lateral dominance." This test had two lights in a line inside a box, one light being 38 centimeters in front of an opening in the box big enough for the subject to look into with both eyes simultaneously, and the other light at 142 centimeters. The lights went on and off alternately every 1.5 seconds. This gave a movement pattern to the subject as he looked into the box. Left movement at the far point and right movement at the near point indicated right-eye dominance, and vice versa for left-eye dominance. This test had a high retest reliability but a low correlation with the manoptoscope and paper— hole tests of dominance. The phi test gave a figure of 86 per cent right—eye dominance for the test group, as compared to 68 per cent for the manoptoscope and 63 per cent for the paper-hole test (45). Downey reported on two studies concerning methods of de- termining ocular dominance. The first study was the testing of the belief that facial characteristics would give evidence of dominance. She was able to predict from photographs the dominance of individ- uals with from 48 to 76 per cent accuracy. The second study re— ported on was concerned with the voluntary eye-winking ability of ' ' st individuals, with the conclusion that in most cases the eye ea31e 24 to wink was the nondominant eye, and the observation that some per- sons were not able to wink their dominant eye (29). Crider reported upon a study he conducted concerning the effect of ocular muscle imbalance upon eye dominance. He found that only two individuals of 257 cases with muscular imbalance in one eye had that eye as their dominant eye (12). Crider also re- ported in another article on a new test of eye dominance which was similar to that of Mills. It was a mirror test, involving a small mirror with a one-inch black circle in the center. The subject tried to keep his nose in the circle as the mirror was brought in close. The result was observed by the examiner, as the head of the subject would turn to give clearance to the dominant eye (13). Updegraff made a study which attempted to find the ocular dominance of children two to six years of age, using the Miles test. She found the test reliable from age three, but with more impartial- eyedness in children of preschool age than later, with no sex differ- ences, and a 75 per cent consistency of results (90). Gahagan made a study to discover whether a relationship existed between eye dominance and visual acuity. He tested one hundred university students and found that 60 per cent had unequal visual acuity. Of thirty-three cases with a superior right eye, twenty-six were right-eye-dominant. Of the twenty-seven cases 2.5 with a superior left eye, only seven were left-eye-dominant. The eye-dominance test used was the hole-in-card test. Gahagan con- cluded that eye dominance and visual acuity were independent visual phenomena (39). Wile published a book on handedness in 1934 which was a review of all preceding theories. He indicated that eyedness appeared to be in the same category as handedness, with possiblities of their being Mendelian recessives, with a proportion of six to one (96). Schoen discussed the role of ocular dominance in the vision of an individual. He pointed out that both the dominant and non- dominant eye could localize objects accurately in space. He con- cluded that ocular dominance was the necessary consequence of binocular vision and "must be regarded as a complex, dynamic, interactional process occurring somewhat above the lower nervous levels. The phenomenon is most readily understood in terms of binocular projection“ (75:134). McAndrews published a discussion of the subject in 1935 which called attention to some pertinent. theories which he deduced to em- phasize the importance of the phenomenon of ocular dominance. He defined ocular suppression as follows: The unequal function of the two eyes in binocular vision is not commonly known or recognized. One knows that if one 2.6 fixes both eyes on an object all other objects in front or behind this object should appear double. Actually this is not the case, because one suppresses one of these images, and in the case of most persons it is the image of the left eye. For this reason the right eye is said to be the dominant eye. [54.449] McAndrews also discussed the triangulation theory of vision, and stat ed“ In nearly all textbooks binocular vision is represented and discussed on the basis of triangulation. The line joining the nodal points of the eyes is considered the base of this triangle, and the object fixed by both eyes in the median plane is con- sidered equidistant from the two nodal points. However, in the majority of cases no such ideal or mathematical picture occurs. In fact, in all right-eyed persons this triangle is a right-angled triangle with the right angle at the nodal point of the right eye. Each eye has its definite function to perform. The dominant eye sights and fixes objects; the non-dominant eye attempts to estimate distance and the position of objects in space. [54455] Crider in 1937 conducted a study to see to what extent a num- ber of conditions were related to eye dominance. He found that the distance of the eye from the point sighted, and the hand used in hold- ing the sighting object, were not important in testing. He also con- cluded that visual acuity and eye closure facility were not highly related to eye dominance, and that. sex and I.Q. had no relationship to eye dominance (l4). Buxton and Crosland ran a study, also in 1937, to ascertain the statistical reliability of simple performance tests of eye domi- nance, and to determine the degree of relationship between the tests. They used the manoptosc0pe, hole-in-card test, ring-sighting, and 27 an aiming test of looking through two washers at a distant object. They discovered that the tests all had high statistical retest relia- bility, but low correlation with each other. The conclusion was reached that the existence of a unitary trait of eye preference was not shown, indicating that a battery of tests was needed to determine ocular dominance (70). The Pink study. In 1937 Fink, an ophthalmologist, published the most exhaustive study yet done on the subject of ocular dominance. He was dissatisfied with what he could find out from a review of the literature, as most of it had been done by nonmedical investigators. The research that had been done by oculists was largely opinion with- out the substantiation of actual case studies. After making a com- plete survey of the subject, he set up and conducted a study on 125 of his patients who successively appeared at his office. Actually he picked 200 patients who successively appeared, but had to discard 75 of them as not being able to lend themselves to the problem. His investigation was concerned with four phases of the sub- ject that were important to an oculist. They were: (a) the testing technique, (b) the nature of ocular dominance, (c) the influence of ocular dominance on the ocular mechanism, and (d) the influence of ocular dominance on the management of ocular problems. In the investigation of the literature on testing, he reached the conclusion that there was no perfect test. Therefore, he used 28 the following testing processes in his investigation, concerning each of which he stated a definite opinion. 1. 11. The tests and opinions were: The manoptoscopic method of Parson—-—was not objective, required too much explanation, and there was uncertainty as to answers . Dolman‘s hole-in-card method-—proved to be satisfactory, as it was practical, easily understood, and the results were uniformly accurate. A modified alignment method—-was not any more accurate than Dolman's method, but is very difficult to explain and carry out. Position of alignment at close range-~was not highly ac- curate, only suggestive. The convergence near point method-~was not considered accurate. Comparison coordination tests--were not practical, and sidedness could possibly influence the result. The winking reflex test--was judged unreliable. Ocular fatigue method--was judged not reliable. . Facial asymmetry method--did not seem significant. 10. Visual acuity method—-proved an indication of dominancy perc entagewise. Refraction--proved some indication of dominancy percent— agewise (36). 29 He concluded his testing report with the statement that "as a prac- tical method for office use the Dolman method appears to be more satisfactory because it is more easily understood, quickly performed, and inexpensive in construction" (362560). Fink made the following observations concerning the nature of ocular dominance: Qth—I CIDKJOU'I ll. 12. l3. 14. It is a characteristic of the ocular mechanism. A relation exists between it and sidedness. . It is stable. It promotes mental stability and better coordination when it is on the same side as handedness. It is independent of visual acuity and refraction. . It is established early in life. Anatomic evidence of it is not conclusive. It does not shift when the focus is changed from distant to near vision. Facial asymmetry is not a factor. . In cases of strabismus, the turned eye is usually the non- dominant eye. Ocular fatigue occurs more in the dominant eye but IS not conclusive. The length of time that glasses have been worn has no effect. The use to which the eyes are subjected is no criterion. Sex is not a factor. [36:561] Concerning the influence of ocular dominance on the ocular mechanism, Fink made the following statement: ence on the ocular mechanism. It seems evident that ocular dominance exerts some influ— There is some evidence that ocular dominance acts as a stabilizer on the ocular mechanism because it is suggestive that the greater the dominancy, the greater the ocular coordination. . . fact that ocular dominance must be maintained as is. fluence of dominancy on convergence is a fa ered. That certain per . . than the other was found in the subjects of his Object was not always alined Some evidence points to the The in— ctor to be consid- sons aline an object before one eye more study, but the before the dominant eye. [362574] 30 Fink studied the evidence in the literature and in the data from his study concerning the influence of ocular dominance in the management of ocular problems, and then concluded that it "is an interesting field but also a field in which actual facts concerning dominancy are few" (36:580). He also suggested that the lack of interest in the subject by ophthalmologists indicated that there was little clinical significance. The late 1930's and 1940's. Warren and Clark made a re- view of the literature of ocular dominance in 1938, concluding that limitations should be made on the use of the term "ocular domi- nance." They stated that eye laterality is determined by the situ- ation in which the test for dominance is made and is not an indica- tion of cerebral dominance. They further reasoned that: Sensory neural organization indicates that the problem of central functioning involves determining relationships of the two halves of the retina, rather than the two eyes as a whole. The motor functions of the two eyes are controlled by both hemispheres and cannot be studied from the point of View of cerebral dominance. [93:298] Schneidemann teamed with Kandle to produce a study in 1940 which advocated an ocular dominance test method of photographing an individual who was focusing on the camera. By checking the re- sulting picture, it could be determined which was the directionalizing eye, and the result would be free of handedness, accidental accom- modation, and head-position and head-movement interference (73). Crider, in 1941, ran a study on the relationship between eye closure 31 success and ocular dominance. He concluded that with children eye closure success was not a reliable or valid measure of checking eye dominanc e (15 ). Diehl reported on a test method that he devised in 1941 to measure eye dominance, which included building instructions for the testing apparatus. The apparatus suggested was similar to Cuff‘s manoptemeter, designed to give the degree of dominance possessed by an individual (24). Williams reported the same year on a sug- gested improvement of the hole—in-card testing method. This con- sisted of putting two arrow points at the top of the test card, with the subject fixing on these until the test letter was located through the hole in the card. The same procedure as advocated by Dolman was followed (98). Johnson conducted a very elaborate study of lateral dominance measurements in 1942 for the Society for Research in Child Devel- opment of the National Research Council. The principal problem of the study was to check the possible relationship of lateral domi- nance to reading disability. He discovered that there appeared to be no observable relationship. The statementthat he made concern- ing ocular-dominance testing appeared significant. He reached the conclusion that: The different tests of eyedness are not assumed to meas- ure the same type of function. A natural dichotomy occurs be- tween the eyedness tests which are based upon motor forms of response and those which involve sensory perception. [47:136] 32 He used a battery of tests in the study since he felt that no single test was sufficiently reliable for an individual diagnosis of children thirteen and fourteen years of age, the age of the subjects. In 1942, Crider reported upon Lebensohn's rifle-shooting study (50). and concluded that "to bring the entire problem out of its present confusion, it is necessary to agree on a method of de- termining the dominant eye" (16:149). He further stated that his belief was that a battery of tests whose reliability and validity had been established was necessary (16). In 1944 Crider compiled such a battery, consisting of seven tests with complete instructions and norms. Each of the tests was to be done three times, with the first attempt to count as practice. The seven tests were the ring test, hole-in-card test, box test, cone test, othoscope, the Spot test, and the mirror test (17). Gesell, of the Yale Clinic of Child Development, published a book in 1941 on the development of vision in infants and children. He emphasized the role of the cerebral cortex in the pattern of ocular action. Its development was explained thus: The cortex is . a kind of meeting ground where the pressures of native growth and of acquired experience are reconciled and assimilated. The cortex itself, as a protoplas— mic organ, is subject to maturational changes, which determine its capacity for learning and assimilation. With increasing age and experience, the cortex normally grows in the power of in- terpretation. It shows great adaptability in making use of cues and in compensating for limitations in the subcortical mechan~ isms of vision. It integrates and regulates. The cortex also 33 supplements bilateral balances with unilateral dominances; it offsets the disadvantages of rigid symmetry by eccentric but useful forms of functional asymmetry. The cortex is the true seat of handedness, eyedness, footedness, and sidedness. Lateral dominance, therefore is a functional trait which displays many interesting changes over a long cycle of growth. Although the physical organism, with its numerous paired or- gans, seems to be constructed on the basis of bilateral sym- metry, it shows a consistent trend toward functional unilateral- ity in handedness, eyedness, footedness, and torsal sidedness. The developmental forces generally favor the right ones over the left; but the organization of this rightwardness requires recurrent secondary inclusion of leftwardness, and also of simultaneous right and left capacities. In the development of ocular and manual behavior, this means recurrent alternation and reciprocal interweaving of right and left components and of monocularity and binocularity. It must be an extremely complex morphogenetic process; two pairs of opposing trends are in mutual rivalry--bilaterality versus unilaterality, the right versus the left. The organism solves the developmental problem by adapting temporary and mixed dominances along the way, with a basic trend which satisfies the principal of func- tional asymmetry. Directionality is a functional trait allied to laterality, and indirectly related to it. It concerns the preference which the organism exhibits in the directions of its limb-body movements and eye movements. The eyes, of course, are in some way involved in these directional tendencies of the action sys- tem. [41:169] Duke-Elder, in his textbook of Ophthalmology published in 1949, stated that the idea of a dominant cerebral hemisphere had been ac- cepted since about 1860. He called attention to the fact that there was not always a consistent association, as one hemiSphere may lead for speech and the other for other activities. He suggested that ”unilaterality of cerebral function" has evolved with a develop- ment in the direction of the most successfully coordinated muscular 34 action, because the necessity for thinking and communicating de— mands that the coordinating phases of the act be concentrated in one hemisphere, as is the case with speech (31). Penfield and Rasmussen brought out in their clinical study of the cortex, published in 1952, that the occipital cortex of one hemi- sphere played an essential role in vision but was not restricted to vision in the opposite field. Let us refer to the calcarine cortex, area 17 of Brodmann, as primary and the rest of the occipital cortex (areas 18 and 19) as secondary. Excision of the primary visual cortex produces complete homonymous hemianopic blindness. - Excisions limited to the secondary visual cortex do not produce such blindness. And yet electrical or epileptic stimu- lation in the primary and secondary fields produces visual ’ phenomena which are identical in character. It might therefore be suggested that the essential function of the secondary visual cortex cannot be demonstrated by stim- ulation. It might be suggested further that its function is related to vision in both fields so that loss of one secondary field does not produce an obvious defect in the total function of vision. It seems probable that the secondary visual cortex is a field for visual elaboration, elaboration of visual impulses coming in from both fields of vision. [66:146] Ogle published a book in 1950 based upon the reports of the research of the Dartmouth Eye Institute. In his discussion he gave a partial theory of how vision materialized in the human mechanism: The striking fact of normal vision with two eyes is that although there are two retinal images, we as individuals ex- perience only a single perception of Space. Without implications as to the ultimate nature of this phenomenon, we designate the anatomic, physiologic and psychologic mechanisms responsible as the fusional processes. The concept generally held is that answer the prevailing questions concerning ocular dominance. made an analytical d and then framed some opinions b to clarify the concept of ocular dominance. classification of eye dominance into two types, The motor type wa 35 normally the neurologic excitations that arise in the two retina's are transmitted to the cortex, where they terminate as ”corti- cal images" in rather localized regions of the occipital lobe. There fusion (unifaction) either takes place locally as a physi- ological process or takes place more diffusely entirely as a psychic response. This unifaction must occur prior to the conscious awareness of the images in the perceptional experi- ence. In either case the emergent sensation is one of single- ness. [62:59] Whenever diSparate images fall within Panum's areas and are fused, and therefore are seen in one subjective visual direc- tion, the primary subjective visual directions associated with the particular retinal elements on which diSparate images are falling, must to some extent be likely to lose, or capable of losing, their primary identity. . Two possibilities exist: 1) Both lose their identity in favor of an emergent compromise visual direction that lies between the two primary directions, or 2) the subjective visual direction of the fused image coincides with the primary direction of one of the eyes, while the other loses its identity entirely. From available data, both can occur, for the phenomenon differs among subjects. The second case probably occurs with individuals who have a marked ocular dominance. In these the subjective direction of the fused dis— parate images coincides with the primary subjective visual direction of the retinal element on which the image falls in the dominant eye. [62.86] The Walls study. The study by Walls in 1951 attempted to He iscussion of the past literature on the subject, y logical deduction in an attempt He concluded with the motor and sensory. s that which is motor by character, and expresses 36 itself by monocular sighting preference. He explained that "visual ego" determined the preference, and that an innervation record was kept only for the muscles of that eye. The sensory-type dominance was that to which the designation was made by eye-rivalry tests. Walls gave the opinion that brainedness had nothing to do with eyedness. In approaching the subject of ocular dominance, it is es- sential to strive to shed this attitude of expectation, this as- sumption that brainedness will be found to be the primary de- terminant. > The problems of both motor and sensory dominance are complicated--or potentially so--by the fact that the two eyeballs themselves do not constitute "the pair of structures," one member of which may be expected to be dominant in some way or several ways. Superficially, the retina in each eyeball is a complete and unitary sense organ. But two portions of each retina are respectively connected separately with the two lateral halves of the brain. The group of oculorotatory muscles inserted on one globe turns that globe only. Only in that one respect is the group a lateral unit--the left medial rectus is yoked with the right lateral rectus in the conjugate components of binocular movements but pairs with the right medial rectus in the disjunctive components. Both complete sets of muscles are involved when either eye is stimulated to move, for neither eye ever moves alone, except in some laboratory situation. As regards an inevitable determination of eyedness by brainedness, "all rules are off" and we should be prepared to find whatever we do find. {92337} To show the ambiguousness and irregularity of the meaning of the subject of ocular dominance, Walls composed a list of the criteria known to have been used for the determination of ocular dominance. They were: 10. ll. 12. 13. 14. 15. 16. 17. 18. 19. 37 I. . The eye whose image in a rivalry situation is in conscious- ness for more of the time than that of the other eye. . The eye which alone sees movement in the JaSper-Raney ambiguous phi situation. II. . The eye with which one alines a finger or pencil in pointing at another object when both eyes are Open. The eye regularly chosen for sighting or looking when both eyes cannot be used. . The eye used for looking when the subject supposes he is looking binocularly but is not. The eye with which the subject notices the lesser "jump" in a cover test. The eye affording the better marksmanship (with rifle, pis- tol, etc.). The eye whose occlusion (as for the elicitation of latent hyperphoria) leads to a greater uneasiness, and less self confidence in locomotion, etc. The eye whose images of alined near and far objects do not appear to shift laterally when fixation alternates between the two objects, regardless of the eye with which they are alined. III. The eye which is actually fixating when fixating disparity exists. The eye in which no portion of any horizontal or vertical heterophoria resides. The eye which in strabismus is neither deviant nor amblyopic. The eye whose image is less readily ignored or suppressed, as in training in monocular microscopy, etc. The eye which with bifixation at twenty feet deviates less if covered. The eye which continues to fixate a target pushed up within the convergence near point. The eye which diverges les after a bifixation target has been inches from the face. The eye which having dive inch bifixation target recov again, or recovers fixation faster than the other e IV. olds a card to read it. s more nearly perpendicular to s, or not at all, when covered brought and held three rged under cover from a three ers its vergence when uncovered ye does. The eye before which one h The eye with which one look 38 a surface when asked to face that surface squarely. 20. The eye which is harder to close alone. V. 21. The eye having the higher visual acuity. 22. The eye which in physiological diplopia of an object affords the [more substantial seeing image. 23. The eye which in physiological diplopia of a light affords the brighter image. 24. The eye whose after-image of light persists longer. 25. The eye on the side of the dominant hand. [92:390] Walls classified the criteria listed according to general the- oretical groupings. Group one tests were called rival asymmetrical criteria, as they had no possibility of an oculomotor element, and could not be connected to brainedness or sighting dominance. These were the concept criteria which constitute "sensory dominance” as distinct from "motor dominance." Criteria three through nine went into the second grouping, which Walls described as one-eyed expres- sions of an asymmetrical but binocular phenomenon, proposing the term ”directional dominance." This group all had something “motor,“ but, as he stated. . it is this very elusiveness of just what it is that is motor about “sighting dominance" that has kept its motor na— ture from being unanimously agreed on, thus leaving room for such confusions as Washburn's [94], and has consequently kept its basis from being elucidated. [92:394] Group three criteria were not actually separable from those of group two, but were "secondary consequences of a dependence on one eye for the establishment of direction." Group four criteria 39 were evidences of "the dominance of the directionalizing eye assert- ing itself." The last five criteria, those of group five, were all meaningless according to Walls's opinion (92). From Walls to the present. Cohen published an article in 1952 on eye dominance in which he reiterated Walls's dual designa- tions of ocular dominance as sensory and motor. He defined motor dominance as that having to do with sighting or eye-directed body movements and sensory as that which had to do with tasks of fusion or rivalry (19). Francis and Harwood reported before the International Opti- cal Congress in 1951 upon a study of a comparison of the usual sighting tests of eye dominance and a rivalry method. They claimed that true dominance was determined by the latter method. Their rivalry method was new. consisting of the measurement of the pro- jection center of vision, a term given to the alignment of two disks with binocular vision being obstructed by a photometric wedge, used to change the illumination to each eye, in turn (37). Berner and Berner published a study in 1953 which advocated the designation of two types of eye dominance; namely, "sighting" and "controlling.“ The authors described it thus: As binocular vision develops, it becomes habitual to use two eyes as a unit for visual perception. But within the pattern 40 of binocular vision there is rivalry between the two eyes, and one eye controls binocular perception. This eye we have called “the controlling eye." The other eye plays an assisting rather than an equal role. The eye which controls binocular percep- tion is not necessarily the eye with which a person sights. The sighting, or dominant eye is selected for an essentially monocu- lar act; the controlling eye gains its mastery within the pattern of binocular vision. The dominant eye is stable from early life, but the controlling eye can be shifted, as the binocular pattern is easily influenced by changes in vision or controlled by train- ing. When a person has binocular vision, his motor reactions, speech, reading, and writing are initiated by binocular images. Our investigations have led us to believe that when the control- ling eye is on the side opposite that Of the handedness, the motor initiation is poor, and difficulties in Speech, reading and writing ensue. These difficulties can be relieved by shifting the control of the binocular pattern to the side of the handed- ness. Similar difficulties do not occur when the controlling eye is on the side of the handedness. [5:604] The Berners used a Keystone machine, the Telebinocular, to deter- mine the “controlling eye." The results of testing for the con- trolling eye did not correlate with the sighting eye results for their subjects. After working on over five hundred patients, they concluded that they had found a reliable answer to an Old problem (5). Using the same designation of types of eye dominance as did Walls, Pascal wrote a discussion on the subject in 1954. He cau- tioned that the subject was very complex, calling attention to the fact that a basis for the whole concept had never been agreed upon by the many authors on the subject. He disagreed with the common 42. indifferent or uncertain ability at golf, shooting, tennis, baseball and other branches Of sport. It is a foregone conclusion that in these games played with both eyes open, the crossed dextral and sinistral classes are at an anatomical and physiological disadvantage compared w th the pure dextrals and sinistrals, whose sighting line and preferred hand are on the same side and work together naturally. The intimate grouping of the prin- cipal motor centers is disarranged in the crossed classes and, in the transfer of part of their activities to the other cerebral hemisphere a certain amount Of indecision and awkwardness often is apparent. So long as the crossed dextrals do not strain or press and merely use muscle sense and two- eyed vision, they shoot and play games reasonably well and at times very well, but when they become particularly anxious, by the very nature of ocular dominance, they must pick up their alignment with the left eye and miss widely to the left. In other words, when exact sighting is necessary, binocular vision is replaced by monocular vision and the sight is brought into line with the Object by the master eye along its line of vision. [582191] Mills suggested that every effort should be made in earliest child- hood to discover what is normal for an individual and to maintain it According to his theory of eyedness, he believed that the handedness should conform to the eyedness, and that the 15 per cent of the pOpulation who were "crossed" should have their handedness trained accordingly (58). Obarrio, in discussing Mills's article, did not agree with the reasoning and conclusions reached by him. Now as to the relation of sight in Sports I claim that, generally Speaking, the question of sight is of relatively second- ary importance throughout the whole realm of sports and that the matter of muscle coordination, quick perception, adaptability, responsiveness, reaction to surroundings, temperamental nature and what not, plus other items, with or without regard to 43 "handedness," constitute a proficient player, and among these the champions are the few gifted and inSpired. [581194] After considering the problem of whether ocular dominance promoted better coordination when it corresponded with handedness, Fink concluded that “undoubtedly it is of some advantage and pro— motes better coordination to have the dominant eye and the domi- nant hand on the same side" (37:565). Garrison came to the same conclusion in his book, published in 1940, explaining, The hand on the same side as the preferred eye is nearer to the preferred eye and can be brought into position more quickly when hand and eye coordination are necessary. To use the other hand would mean the farther one would have to act in a more strained and awkward position. [40:286] Lund reported on a study he conducted using the activity of dart-throwing. His conclusions showed that better results were made by using the dominant eye for aiming rather than the non- dominant eye, but that the highest scores were made when using both eyes (52). Freeman and Chapman experimented with a study based on manual tracing using the dominant eye and hand and then switching about. They concluded that hand dominance was more important than eye dominance but suggested that the phenomena of dominance may be obscured in many tests, due to transfer or cross education. They also made the observation that a skill can only be acquired to a certain degree by those who are not well coordinated, 44 as compared to those who are (38). Smith reported upon a study he conducted of a reaction exercise involving tapping, in which he concluded that there was not a significant difference due to handed- ness but that right-handers who were right-eyed did better than right-handers who were left-eyed (85). Rifle-shooting. The first study of record concerning rifle- shooting was reported by Wray in 1903. He conducted an experiment with thirty professional men, all Of whom were experienced shoot— ers. Each man shot twenty shots from each shoulder, sighting with the corresponding eye, and alternating the sidedness with each shot. The results showed that left-eyed men who were left—handed did about 20 per cent better from the left side. He concluded, ”One thing is beyond all doubt: there was never what the left-handed men who had always shot from the right shoulder expected-~a very bad record for the left shoulder" (100-683). In the article previously referred to, Mills discussed the Shooting problems of eyedness and handedness: There is no reason why a left-eyed man cannot Shoot from the right shoulder with accuracy if the left eye be closed, provided that his arm, hand, and back muscle coordinations are eclual. His success as a shot under such conditions depends merely upon his visual acuity. However, as theyery fact :1); r handedness presupposes inequality or imbalance in the $510 Se girdle action, this skeletal imbalance makes for awkwar nes 31 and is the sole handicap. . Here, other things being equ , 45 the chief and almost only determining faCtor in the relative ability to shoot from the right or left shoulder is visual acuity. When rapid fire without exact aim is necessary the visual prob- lem is identical with that of the shotgun, i.e., the rifle is put into alignment with the right eye in the right-eyed and with the left eye in the left-eyed regardless of the shoulder from which the rifleman shoots. Granting then that a man has the temperament of a good shot, normal binocular vision and nor- mal visual acuity, his success as a shot will depend upon the harmony of action of the correSponding eye and hand, or the lack of it. [58:191] The first large-scale study of record on rifle-shooting was reported on in England by Banister in 1935. The subjects of his study were British army men. The results showed that 69 per cent of the right-eyed qualified for marksman, first class, as against 54 per cent of the left-eyed. The dextrals were considered the better soldiers, no doubt partly because they were better rifle shots. He also called attention to one soldier who lost several teeth when he attempted to shoot right-handed by aligning his weapon with the left eye (3). Simpson and Somner came out with a study in 1942 which concluded that the preferred eye, as well as other visual functions, was not related to the success of the shooter (81). In a very complete study of the subject of ocular dominance and marksmanship with the rifle, a Navy Ophthalmologist by the name of Lebensohn did a study of Naval recruits and their rifle- shooting in 1942. The study started out with the testing of 1,768 46 subjects, but only 856 were used, as those with previous rifle- shooting experience were excluded. His results showed that dex- trals were the best shooters, sinistrals the worst, with the crossed groups only a shade better than the sinistrals. He explained that the rifles were made for right-handed Shooters, a circumstance which inconvenienced those who were left-handed. He suggested that ocular dominance may play a subordinate role in a naturally good marksman (50). Crider reviewed the subject of rifle marksmanship and ocu- lar dominance in an article which came out in 1943. He reviewed the aforementioned studies and gave the opinions of several experts concerning eyedness in shooting. All stated, with one exception, that eyedness was to be considered over handedness in the shooting process. The one exception happened to be Walter R. Miles, the author of the A- B—C vision test for ocular dominance (56), who suggested that the adjustments should be made in the sighting in order to use native handedness (16). Only four rifle-Shooting textbooks were found which recog- nized the eye dominance of the shooter as being significant in his shooting success and made recommendations concerning it. The official Army pamphlet on rifle-shooting advocated using two eyes when shooting, but if the nonaiming eye is the master eye it is 47 "okay" to have a slight squint to dull the vision of the left eye (24). Chapel, the noted writer on all types of shooting, offered the align- ment test to check for the master eye, and suggested shooting with both eyes open unless the left eye is the master eye. In this case he recommended going to an oculist to have the right eye trained as the master eye, to wear a black patch over the dominant eye, or to place a cover over that lens in a pair of shooting glasses (10). The National Rifle Association handbook made the recommendation that, if the nonaiming eye is the master eye, the shooter should close it, or put tape over that lens of shooting glasses (2). Cross— man also suggested the alignment test to check the master eye, and cautioned shooters to watch for a changing of the master eye in their advancing years as a source of shooting difficulty (18). Field shooting. The problem encountered by a crossed dex- tral was explained by Nichols in his text on skeet shooting, as he had this problem to overcome in order to become a proficient shooter. He recommended that if the individual were a crossed dextral or crossed sinistral he should change his Shooting handed— ness to the side of the master eye, unless he were over the age of thirty-five, in which case he should learn'to wink the Off-side eye just before shooting (62). Johnson discussed a personal 48 novelty; he had an ocular diplopia and could willingly use either eye to Sight with. He emphasized the importance of the dominant eye, and recommended the paper hole test for determining the dominant eye, stating, "It should be understood that if you are going to be successful in your gun pointing, you will have to follow your master eye" (46:63). Chapel, in discussing skeet and trap shooting, emphasized that the right way to shoot was with the master eye wide open, and the other partly Open. He advocated that the shooting handedness should be determined by the master eye, recalling that "during World War II, the skeet instructors for the Armed Forces learned that it is better to let the man whose left eye is the master eye, learn to shoot left-handed" (9:78). Revolver- shooting. Weston, a well-known instructor and a shooting champion in his own right, came forth with a sighting system that disregarded the master eye. He stated, "It is merely a matter of effort, of practice, of aligning the sights with only one eye, and slowly opening the other eye" (95:29). By this method, it was claimed, both eyes are used with the advantages ensuing from binocular vision. He further stated that the use of one eye was sufficient for target shooting, but two eyes were needed for combat. 49 Shooting handedness was not believed important in pistol or revolver shooting as the weapon can be sighted before either eye, regardless of which hand is used to hold it (95). Archery. In the most complete textbook on archery exam- ined, Elmer advocated the use of the master eye as shown by the alignment test to determine the handedness the archer should use. He further recommended leaving up to the archer, with a considera- tion of the range at which he was shooting, the decision as to whether or not the nonaiming eye should be closed. He explained it thus: In general, distance is gauged much better by binocular vision than by monocular and so most archers keep both eyes Open from 80 yards up. At the short ranges it does not make much difference, though when sighting on a point of aim it is often safer to close the unused eye throughout the shoot or else wink it enough to be sure it is not intruding; for many an ar— row is diverted toward the side of the unused eye because it is caught and pointed by that eye without the archers being aware of the slip. [35:404] Later on in his discussion he made the recommendation that right- handers should shoot left-handed, because there was as much push- ing as pulling, but failed to state anything concerning the dominant eye when this method was used (35). Schmidt stated in his book, which was concerned with beginning archers, that the master eye, as determined by the alignment test, should determine shooting 50 handedness. He modified this statement by recommending that all archers should start right-handed, and then, after a trial, change to left-handed if desired (71). In an earlier book, Reichart and Keasy advocated closing the left eye and sighting with the right if the archer has trouble focusing on the point of aim. They mentioned that the likely source of trouble was that the right eye was not the master eye (69). Baseball. There has been considerable opinion eXpressed in baseball articles and books on the importance of vision to playing success, but only one reference was found which mentioned the dominant eye. This was in an article by DeGroat, who stated, There is no question of the importance of concentrating the sighting eye on the pitcher and the ball when at bat. Most certainly the eye should be given a full and direct view. [23:81] In a study done by Montebello at Ohio State University, he called attention to the fact that stereoscopic vision is necessary to play the game. By a testing procedure, he brought out the fact that if one of a player's eyes is occluded, either partially or fully, the efficiency of the player radically drops. This means that a one- eyed individual will not have any success at playing baseball (60). In a'talk before the College Physical Education Association's 1950 annual meeting, Sherman made an analysis of the vision 51 process in baseball batting. He summarized with a statement which was of importance to this study: . the batter does not follow the ball with the pursuit movement of the eye, but he assumes a directional locus for the fixationuprobably the pitcher's hand. Mastering this he commands the relative Speed and position of the ball, as it emerges in the field cues in terms of its apparent size-~and rate Of change in its apparent Speed. [80:16] Golf. Nearly all golf instructional books mention the same visional aspect of golf; namely, the necessity for keeping the eyes on the ball during the swing. Only one reference was found con- cerning the relationship Of the dominant eye to golf. That was by Banister, previously referred to, who stated in a discussion of ocu- lar dominance significance to marksmanship that "it is said that all good golfers are left eye dominant" (3.34). Several golf writers emphasized that the ball should be watched by the left eye during the swing, but they did not mention the dominant eye. Obarrio, in discussion of Mills's article on eyedness, made the following statement concerning "keeping the eye on the ball": ess a person than Bobby . have the authority of no 1 1927’ Jones, writing in the Oakland Tribune of September 30, in what part Of the ball I looked at when playing golf. In :m- swer I have always said that I did not look at it at all,dbumO was merely conscious of its presence. And I have trite“:le . as an experiment to gaze fixedly at the ball throughou hu 8 swing, and everytime without exception, I have dug utos 5e- masses of turf behind the ball. When 1 top a shot 1 1] cause my swing is out of its customary rhythm.8.uls;fi y because I am fearful of some other mishap. [5 . 52 This conforms to a statement made by Sherman, in the talk previously referred to, in which he maintained that "keeping the eye on the ball" is to insure stability Of the head during the swing, as the distance of the ball was not a perception clue, but orientation (80). Griffith conducted a study in which blindfolded individuals were taught to drive a golf ball. The result of the study showed that those subjects who were blindfolded had better success than those without the blindfold. The results of this experiment caused him to conclude that "the kinesthetic aspects of golf, par- ticularly the swing, are more effectively learned when unaided by visual perception" (43:10). The fact that blind people have learned to play effective golf was stated by Davis and Lawther (22). CHAPTER III METHODOLOGY AND PROCEDURE Introduction In this study the attempt was made to determine whether there was a relationship between the eye dominance of an individual and his performance in the motor activities of archery, baseball, and the Specific skill of catching a ball. The aim of this chapter is to present the methods and procedure used in gathering and analyzing the data of the study. The first consideration was the selection and validation of the test for eye dominance, and the method of determining handedness, to be used. The description of the activities investigated, the subjects, the data, and the statistical method of handling the data for each phase of the study are pre- sented. The Test for Ocular Dominance Method of selection. The hole-in-card test for eye domi- nance was selected for use in this study because it best met the criteria for tests as stated by Bovard. COZGTIS. and Hagman. They 53 54 state that the criteria to be kept in mind in the selection of a test include the following: validity, reliability, objectivity, administrative economy, and standardized directions (6). The simple instructions and minimal equipment requirements for this test were factors which would allow the test to be used by teachers and coaches as a teaching aid, in the event the findings of the study so warranted. A survey of the literature of testing for eye dominance was made to find the tests which had been used in other studies with favorable results. It was found that the hole-in-card test, the alignment test, and the Miles ABC Vision Test for Ocular Domi- nance were the three most used tests for motor eye dominance as distinct from sensory eye dominance, according to the definition Of Walls (92). The writer then proceeded to experiment with these three tests on the 1954 Kenyon College varsity basketball and baseball teams, of which he was the coach. Giving each test three times to each squad member resulted in several conclusions. The alignment test can be used over and over with satisfac- tory results, but a large amount of explanation was required; the Check on the results was made by questioning the subject. There was considerable difficulty in administering the test to most sub— jects, as the double-image effect caused considerable confusion. 55 It had an advantage in that it could be given anywhere without equipment or any preparation other than the explanation to the subject. The Miles test went off very well the first time it was given to the subjects, but upon repeat performances was not successful because the subterfuge that was called for by the test—~i.e., not telling them the object of the test--was not conducive to coopera- tion from college students the second time given. The results were uniform for the test, but the testing situation must be highly for- mal if the test directions are to be followed. It might be men- tioned that since the test was COpyrighted it was necessary to pur— chase the test, at a cost of two dollars, and it may be secured only by those known to be qualified test examiners. The hole-in-card test gave uniform results, was easy to explain, and could be given over and over with the subject‘s knowl- edge of what was being tested. The test was simple to administer, and, if the test card were not available a hole could be punched in a sheet Of paper with a pencil and the test run with reliable results. From this experiment and a comparable report by others who had used the test the decision was made to proceed with this test as the one for use in the study. 56 From the literature, the following pertinent statements were taken concerning the hole-in-card test. Schneidemann stated, The test is reliable. Its principles are those underlying complicated tests for eye dominance. Its accuracy is not de- creased when the subject knows the purpose of the test for it is only by special and readily detectable adjustment that the subordinate eye is accommodated. [722126] Fink came to the conclusion concerning the hole-in-card test, after giving all known tests to his subjects, that it . proved to be very practical and lends itself admir- ably to office routine as it is easily understood and the results are uniformly accurate. [362558] In a study of statistical reliability of tests of eye dominance by Buxton and Crosland, the hole-in-card test had the highest coef- ficient. of reliability of the four tests used in a retest situation, having an r = .97 corrected to .98 (7). Another reliability test by Jasper and Raney gave the figure of r = .93 for the paper-hole test, which is the same test (45). Further testing experiments. In order to learn as much as possible about the hole—in- card test, another experiment was con- ducted before the study experiments were accomplished. A testing group was set up consisting of seventy-seven male college students, forty- five of whom were members of two physical education classes, and thirty-two of whom were members of the 1955 Kenyon College~ 57 varsity basketball and baseball teams. The testing group was given a relay of tests, consisting of the Miles test as per instructions, and the hole-in-card test at near and far objects and from three positions. The following test procedure was used: The groups were informed that an eye examination was to be given to each individual, and they were asked for their cooperation. Each testee was called to the testing area in turn and given the following tests. Upon the completion of the testing for each individual, he was excused for the day and not allowed to converse with the subjects who had not been tested. 1. The Miles test, one trial at 10 feet. 2. The hole-in-card test, front position, one trial at 10 feet, looking at a penlight. 3. The Miles test, one trial at 10 feet. 4. The hole-in-card test, front position, one trial at 60 feet, looking at a baseball on floor straight ahead. 5. Miles test, one trial at 10 feet. (In each of the trials of this test, a different set of objects was used.) Two weeks later, the following procedure was used in giving the hole-in- card test to the testing group. They were 58 given an honest explanation of what they were being tested for: that a check was being made to see if their eye domi- nance shifted when their position changed. 1. The test at the frontal position, 20 feet from test Object, a four-inch red circle on the wall. 2. The test at left-side position (as a left-handed batter in baseball), looking at a baseball on the floor 60 feet away. 3. The test at right—side position (as a right-handed batter in baseball), looking at a baseball on the floor 60 feet away. The test results were conclusive, in that seventy-one of the seventy-two subjects taking all of the tests in both series used the same eye for sighting in every test. There was complete agreement with test results as gathered by the Miles test. The one exception was an individual who used a different eye when changing from the right to the left batting position in the second series of tests. All the other testings for this individual corresponded in results to the eye he used in the position simulating a right-handed batter. The contradictory result stood up on several retests. From personal experimentation with the hole—in-card test, the writer discovered only two methods by which the test would fail to give the dominant eye. These were (a) when the subject fixes on 59 the test object with the nondominant eye through closing the domi- nant eye and then opens it before the test card is brought up be- fore the face, or (b) when the subject brings in the test card from the side of the nondominant eye. After this experiment it was decided to rewrite the test in- structions before using the test to get the data for the archery and baseball phases Of the study. The original instructions were adapted by the writer, from those given by Crider (17), Schneidemann (72), and Dolman (27). Two changes were made. First, the number of test trials was changed from three to one, providing the directions were followed and there was no confusion by the subject or the examiner as to the result. This would save time in the adminis- tration Of the test, which was an important consideration when try- ing to get such organizations as the National Archery Association to agree to allow the test to be given. The second change was that for a particular motor activity--the position assumed by the indi- vidual to start the particular action of the activity would be the position used to get the test result. According to the test experi- mentation, just discussed, there should be the same test results with one trial as with several, and if there are impartial- eyed individ— uals encountered they would be tested for the eye being used in the 60 particular activity in which they are interested. The test instruc- tions used may be found in the Appendix. Retest Observations. There were two opportunities to check the results of the testing experimentation. First, the test results were compared with the previous year's results for the twenty members of the varsity basketball and baseball teams who were still available. The test result was the same in every case. The second chance to check results was when a test situation was set up at the Kenyon Rifle Range for those trying out forthe Air Force ROTC rifle team. There were twenty-seven members of this group who had also been members of one or the other of the testing groups in the experiments conducted by the writer. The test was given to the rifle group by the rifle instructor, a technical sergeant in the Air Force. He gave the test without Special instruction other than what he gained from simply reading the directions provided and from some experimentation upon his own initiative with the Air Force staff at the college. The test results were identical in every case with those given by the writer. The entire rifle group consisted of fifty students. The writer retested the remaining twenty-three individuals who had not been in one of the experi- mental groups by visiting them in their rooms. Again the test results were identical. 61 Handedness Determination Handedness characteristics of the subjects in this study were of concern in regard to the positions assumed to perform various motor activities. If there is such an entity as native handedness, it is commonly arrived at by giving a battery of tests, as many individuals have varying degrees of preference for the use of one hand over the other, depending upon the action being attempted. When considering handedness in a motor activity, the common practice is to refer to the throwing handedness of the individual con- cerned. As throwing is one of the fundamental motor skills, the preference for habitual usage of one particular extremity to do the act is established early in life. Once this preference is acquired, it is most difficult to change, since the neuromuscular pattern is established simultaneously. It was therefore decided to use throw- ing handedness as the determinant of native handedness of the subjects in this study. Throwing handedness was of direct concern in the baseball investigation, as it was instrumental to the performance Of the skills of pitching and fielding. The rules of the pitching action require the individual to throw the ball with his body facing a position 90 de- grees to the side of his throwing arm. The rules of fielding are 62 only restrictive to the individual pertaining to the type of glove which is worn on the nonthrowing hand. The fielding action is complex, in that it is determined according to how and where the ball is hit, for which reason the fielder assumes a frontal starting position. Shooting handedness is the term given to the position as- sumed by individuals to perform such a skill as the sport of arch- ery. The shooter is either a right- or left-handed shooter, de- pending on which side of his body he holds the bow. If he is a right-handed shooter, the how will be held on his right side, with the right side of his body facing approximately 90 degrees to the right of the target. The string of the how will be pulled with the right hand, while pushing against the bow with the left hand. If the shooter is left-handed, the opposite position and movements would prevail. Batting handedness is the term given to the position assumed by an individual to perform the skill of batting in the sport of base- ball. A batter is designated right-handed if he stands in the batter's box on the third base side of home plate. The right- handed batter holds the bat on the right side of his body in both hands, with the right hand on top. The right-handed batter will take a position facing from 45 to 90 degree to the right of the direction 63 of the pitcher. The player who elects to take the batting position on the first base side of home plate would be designated a left- handed batter and would use the Opposite characteristics of those used by the right-handed batter. Most players choose the same batting handedness unvaryingly, but there are a few who elect to be "switch hitters," a term indicating that they bat right-handed against left-handed pitchers and left-handed against right-handed pitchers. Selection of Activities and Subjects To best study the relationship of eye dominance to motor activities, it was decided to secure individuals at the highest pos- sible levels Of attainment in the particular activities selected to be studied. This was believed the better approach because of the rec— ognition of the psychological principle that individual differences in highly coordinated body movements tend to decrease with train- ing and instruction (35). The problem of securing subjects at the desired level of performance caused considerable difficulty. Archery. The decision to do a study on archery as a static- position activity was made because the National Archery Association gave the necessary permission and cooperation to do the study at their 1955 national tournament held on the grounds of Miami 64 University at Oxford, Ohio, between the dates of August 8 and 12. There were 155 archers who completed the three-day shooting sched- ule in the free-style championship tournament, which was considered the true test of shooting ability and was therefore used as the cri- terion of shooting success for the investigation. Personal and shooting characteristics were secured on 140 of this group, with the others failing to cooperate. There were nearly three hundred persons registered for the tournament, but those competing in only novelty events were not used as subjects. The archery competitors came from all over the country, the only requirement for entry being that they must be members of the National Archery Association, and it was possible for the individual to join at the time he registered. The ages of the competitors ranged from sixteen up into the sixties. As there was no qualifi- cation procedure, it was quite possible that several of the competi- tors entered for reasons other than the belief that they had a chance to win the championship. Ball-catching movements. The decision to do the investiga- tion of ball-catching movements was reached because it, is a skill dependent upon vision cues, thus suggesting that the individual's eye dominance could be a factor in his habits of turning to view the 65 ball, while getting in position to catch it. Two control situations were set up; the first involved the turn made to go straight back from a standing position to catch a fly ball in the baseball fielding situation, and the second was concerned with the turn made while running to look back to see the ball in order to judge where it was coming down and thus to catch it. The latter testing was done in the basketball situation. The turns are common to many Sports, such as tennis, soccer, lacrosse, squash, and handball. The subjects selected for the standing turn experiment were fifteen members of the Kenyon College 1955 varsity baseball squad as the experienced group, and sixteen members of a physical edu- cation class at the college as the inexperienced group. There were no criteria or qualifiCations set up, other than their willingness to participate in a class activity designed to aid them. The members of the baseball squad had had Specific instructions and practice at the (skill of going back to their right and left to catch balls, but not at catching those balls going straight back over their head. The physical education class members were a random selection of individuals electing to take the course at the particular time en- rolled. They had had no specific instructions during the class pro- gram on how to catch a ball going back, although they possibly could have had before coming to college. 66 The individuals selected for the running-turn study were thirteen members of the same physical education class used in the standing-turn study and sixteen members of the Kenyon College 1955 varsity basketball squad. None of the subjects had had while in college any particular instructions on how to perform the skill. Baseball. The interest of the writer in the subject of eye dominance was initiated by the possibility that it could be an im— portant factor, when considered with batting handedness, in the suc- cess of a player. Such a possibility was intimated by the batting averages of the 1954 Kenyon College baseball team, which showed that the tOp four batters were also those who had their dominant eye opposite to their batting handedness. The subjects in this study were the regular team players for fifteen college and university teams; namely, the University of Cincinnati, the University of Delaware, Yale University, Michi~ gan State University, Springfield College, Williams College, the University of California, the University of Houston, the University of Nebraska, the University Of Arizona, the University of Virginia, Amherst College, Kenyon College, Oregon State College, and Long Island University. The decision to participate in the study was made by the coach Of each team because of his interest in the 67 subject under investigation. It was hoped originally to run the study upon the professional level, but requests to do so were not honored. It was decided to do the study at the college level, after getting twenty-four coaches to agree to assist with the study, either by personal contact at the annual coaches' convention or by mail. Of the twenty- four agreeing, fourteen actually followed through and assisted with the study, which, added to the writer's team, made a total of fifteen teams. The college players were estimated to be in an age bracket between eighteen and twenty~two, with an average of six years' playing experience on organized teams. By virtue of their being on a college team, they were making progress toward a degree and were at least in their second year of college. It was believed that the players were the best baseball players in each of the respective institutions, although there was a considerable difference in the en- rollment figures of the different institutions. The Data The nature of the data obtained to Show possible relationships between the eye dominance Of the subject and his performance suc- cess in the three phases of the study precluded the handling of the data in the same way for each phase of the study. The measurement 68 of performance was of a different type for each activity; this neces- sitated different analyzation procedures for each. The procedure of gathering the data, and the method of analyzing it, are explained according to the problems of each of the three phases of the study. Archery. The data of eye dominance, shooting handedness, throwing handedness, and eye usage while shooting were secured from each contestant as he registered. An explanation Of the study, giving the purpose and procedure, and asking for their cooperation, was made and posted for the competitors to read before being inter- viewed by the writer. They were asked their names, which hand they used to throw with, their archery shooting handedness, and their eye usage while shooting; i.e., whether they kept both eyes open, or closed one eye while shooting. They were then given the hole-in-card eye-dominance test from a side position, assimilating their shooting handedness, and looking at a red circle, four inches in diameter, posted on the wall, twenty feet in front of them. During the competition, the writer Observed the contestants as a check on their shooting handedness and eye usage. During the course of the tournament, the writer also checked the handedness tendencies, specifically checking those who gave their handedness as 19“. and watching for any others. Several of the competitors did 69 not know their eye usage when asked, and they agreed to check them- selves while shooting and then report the result. This was done; this answer was left blank on the individual‘s card until it was re- ported. There also was the problem of whether a "squinted" (partially closed) eye was to be considered an open or shut eye, with the former decided upon. A systematic method of checking was used to make sure that all contestants were checked on the shooting line. The information received for shooting handedness and throwing handedness was correct in all cases. It is believed that after much discussion with the contestants and observation under difficult conditions the same could be said for eye usage. The competitors were ranked according to their tournament shooting record. The record is the total score of the contestant accumulated from shooting 468 arrows. The men shot two York rounds (consisting of seventy-two arrows at 100 yards, forty-eight at. 80, and twenty— four at 60) and two American rounds (consisting of thirty arrows each at 60, 50, and 40 yards). The women shot two American rounds (consisting of thirty arrows each at 60, 50, and 40 yards), two Columbia rounds (consisting of twenty- four arrows each at 50, 40, and 30 yards), and two National rounds (consisting of forty— eight arrows at 60 yards and twenty- four at 50). 70 The method of analyzation used for this phase of the study consisted of first ranking the contestants by their tournament scores, and second of classifying the contestants into groups according to their personal and shooting characteristics. A comparison was then made by percentage of those in each group. A similar comparison was made of the top twenty- five archers in each of the men's and women's divisions. Through rank comparisons, the various differ- ences in shooting characteristics were analyzed. Ball-catching movements. All of the subjects for this phase of the study were also members of the experimental testing group, and their eye dominance was a matter of record. The one individual who was impartial-eyed had dropped from the physical education class and was therefore not in this phase of the study. The standing-turn study was set up to test the turn the indi- vidual subject took to go straight back to catch a fly ball thrown back over his head. To get the subjects' cooperation and also to have an educative experience, it was explained to the group mem- bers that they were being checked on how they went back at various angles to catch a fly ball. At the completion of the test, each was shown the results and his mistakes were explained. 71 The layout of the test area was on the side of the baseball diamond. The instructor, the writer, stood on a designated Spot 45 feet in front of the subject, who was also on a designated Spot. Three Spots were designated 30 feet behind the subject's spot, the first directly behind, and the other two 45 degrees to the right and left, measuring from the subject‘s Spot. On the day selected for the experiment, the subjects were called over to the test area, one by one, and given the test. The following procedure was used. Eleven throws were made to each individual, five to the middle spot and three each to the Spots to the right and left Of it. There was not a regular pattern followed, so that the individual could not guess, prior to the ball delivery by the instructor, where the ball was going. The throws were high over the head, such that the individual had to run to attempt to catch them, and not so high that he could back up and make the catch. If the throw was not approximately on a spot or was too high or low, it was not counted and another throw was made. The results were recorded for all the throws that counted, but only the five throws to the middle spot counted for this study. Each sub- ject used a regulation fielder's glove, and the ball used was a regulation baseball. They were recorded as taking a right turn if they dropped their right foot and started back to their right, which 72 meant that they were looking at the ball over their left shoulder. They were recorded as taking a left turn if they turned the other way. The running-turn experiment was devised to check the turn the subject took while running at near top speed to catch a ball thrown from behind to well ahead of him. The procedure followed was to explain the experiment to the groups as a basketball drill for long passes. Instruction was given as a part of the drill in how to make the long pass. Nothing was stated about catching the ball, except to catch it and shoot a ”lay-up" shot at the basket. Frequent corrections were made of the individual subject's passing form, as the drill progressed. The subject was told to take off at full speed running directly from under one basket for the other basket, and to look back for the ball which would be thrown as he reached the center line. He would then catch the ball and shoot the prescribed shot. The group was placed on the end line at one end of the basketball court, with the first man in line running, and the second throwing the ball. The thrower then became the receiver, the third man in line became the thrower, and the first man who had been the receiver returned to the end Of the line to await his next turn. This procedure was continued until each subject had thrown and caught, or attempted to 73 catch, three times. This was done at three successive class periods for the class group, and within a period often days with the basket- ball squad. This made a total of nine trials for each subject. If the individual looked back over his right shoulder, he was said to have turned right, and vice versa. The data from the two experiments were analyzed separately, then collectively, as twenty- one individuals were in both experiments. The relationship of eyedness to the turning habits as measured by the tests was investigated by checking the number with correSpon- dence Of the two factors, and whether there was a difference between the experienced and inexperienced. Percentages of the total are used as the comparison measure, with significance levels determined. Baseball. The task of testing the eye dominance of the play- ers on the fifteen teams participating in the study was done by the coach of each team. The test directions and test card (see Appen- dix) were sent to each coach before the start of the season, to allow him to give the test at his own convenience, such as on a rainy day. Two checks on the accuracy of the results were conducted. The Springfield College team was rechecked at the college testing lab- oratory, which was manned by professional testing men, and the test results of the coach were confirmed. The writer rechecked 74 the University of Cincinnati team and also confirmed the results of the testing by the coach, although one individual was found who was impartial-eyed. He was discovered because of a comment made to the writer by the coach, concerning a question that the impartial- eyed individual had brought up. He stated that upon playing around with the test in his room he usually got the opposite result from that recorded. Upon questioning him, it was discovered that he had done the test from a frontal position, which was comparable to the impartial-eyed subject found in the writer‘s testing experiment. For the purpose of expediency, the same test was used for the fielding and pitching subjects as used for the batting subjects. It was reasoned that the difference would be practically nil, in Spite of the fact that a different position is used, since there was a 98.6 per cent agreement in the test results in the writer's testing experiment. The performance of the players in the study was judged from their playing record for the season, as compiled by the official scorer of each team and turned in to the writer by the coach of each team at the conclusion of the season. To study the relation- ship of eye dominance to baseball success in batting, fielding, and Pitching, it was necessary to decide upon the measures of success of each. They were: 75 Batting: batting average, slugging average, bases on balls received, and strike-outs made per plate appearance (limited to those who had been officially at bat more than thirty times). Fielding: fielding average (limited to those of the batting study who had accepted more than twenty fielding chancesL Pitching: the games-won-and-lost percentage, earned-run average, hits allowed per inning pitched, bases on balls given up per inning pitched, and strike-outs per inning pitched (limited to those who had pitched more than twenty innings). Comparisons for the batting study were made from classifi- cations resulting from pairing the subject's batting handedness and eye dominance into corresponding and opposite groups of the total group, and then of the right-handed and left-handed groups. The same type comparisons were made for the fielding and pitching Studies, except that the throwing handedness was paired with the eye dominance of the subjects. the study. 76 Statistical Analysis of Data The data were analyzed statistically for the three phases of The methods used were the significance of difference between proportions for the archery and ball-catching studies, and the significance of difference between means for the baseball study. It was decided to use these methods after consultation with the members of the Mathematics Department of Kenyon College. The computation of the significance of difference in prOpor- tions involved the following steps: 1. Finding the p (percentage) and q (1 - p) of the categories being compared. . Formulating the hypothesis. For this study, the H : p : 1 p2 was used with the significance level of 10 per cent for acceptance. . The following formula was then computed for the data: +1645 13,3432 < < p1 p2 ' N N pl 102 1 2 Pq Pq ll 22 1 p2 N1 N2 If the limits of the computation did not cover zero, the hypothesis was rejected (25). 77 The computation of the significance of difference between means involved the following steps: 1. The following measures were computed for each group: Mean (2?) = ZX/N I 2 2 Standard deviation (cr) = X - (2X) /N N-l Standard error of the mean (crm) = cr/fl‘T 2. The standard error of the difference between the two means was then computed: 3. The difference in means (551 - 352), was divided by the ad, which gave the critical ratio (CR). 4. The CR was then checked on a normal-probability table to get the significance level (SL) for the comparison Of the two means (6). CHAPTER IV THE RELATIONSHIP OF OCULAR DOMINANCE TO ARCHERY SUCCESS Introduction The investigation of archery was concerned with the relation— ship of eye dominance, native handedness, shooting handedness, and eye usage to shooting success. The subjects of the investigation were the competitors in the 1955 National Target Archery Cham- PiOnShip Tournament. Each of the characteristics considered is discussed individually, then grouped according to usage by the sub- jects and compared percentagewise to the tournament success of the subjects. Individual Shooting Charact eri stics Eye dominance. The eye-dominance statistics of the archery SUbjects showed that 88 per cent of the men and 77 per cent of the women, or a total group occurrence of 81 per cent, were right-eye- ban would be dominant. This was a significantly higher percentage t E3Xpected from a normal population, according to the statistics 78 79 TABLE I EYE DOMINANCE OF ARCHERS Group Total RED LED Total ........................ 140 1 15 25 Men ........................ 84 71 13 Women ...................... 56 44 12 compiled by Miles, who gave the expectancy figure of 64 per cent of the population possessing right—eye dominance (56). Native handedness. The native handedness statistics for the archery subjects showed that 96 per cent of the total group were right-handed, with percentages of 97 for the men and 95 for the women. TABLE II NATIVE HANDEDNESS OF ARCHERS Group RH LH Total ............................... 127 13 Men ............................... 74 10 80 The normal population expectancy percentage for an adult group is between 93 and 95 per cent, which would indicate that the archery subjects could be considered normal as a group in this character- istic. Shooting handedness. The shooting handedness statistics of the archery subjects showed that 91 per cent of the total group shot right-handed, which included 95 per cent of the women and 88 per cent of the men. TABLE III SHOOTING HANDEDNESS OF ARCHERS Group RHS LHS Total ............................... 128 12 Men ............................... 75 9 Women ............................. 53 3 Native handedness and eye dominance. The expectancy figures of the coordination of the characteristics of handedness and eyedness in a normal population, according to Miles, was that 33 per cent of the right-handers would be left—eye-dominant, and one-half of the left-handers would be left-eye-dominant (56). The figures for the 81 TABLE IV NATIVE HANDEDNESS AND EYE DOMINANCE OF ARCHERS Grou RH, RH, - LH. LH. p RED LED RED LED Total ................. l 1 1 23 4 2 Men ................. 68 13 3 0 Women ............... 43 10 1 2 subjects of this study showed that 17 per cent of the right-handers were left-eye-dominant, which was a significant difference from that expected. This included 16 per cent of the men and 19 per cent of the women, which was significantly lower than that expected. The figures for the left-handers were near expectancy, although inconse- quential due to the few cases in this category. Shooting handedness and eye dominance. The coordination of the characteristics Of shooting handedness and eye dominance of the archery subjects showed that 83 per cent of the total group of right- handed shooters were right-eye—dominant, and 54 per cent of the left-handed shooters were left-eye-dominant. The figures showed that 91 per cent of the men and 81 per cent of the women who were I‘ight-eyeadominant shot right-handed. The statistics for the left- 82 TABLE V SHOOTING HANDEDNESS AND EYE DOMINANCE OF ARCHERS Gr RHS, RHS, LHS, LHs oup RED LED RED LED Total ................. 108 20 6 6 Men ................. 67 8 5 4 Women ............... 41 12 l 2 handed shooters, who were few in number, did not Show an eye- dominanc e t rend. Native and shooting handedness. The coordination of the characteristics of native and shooting handedness showed that 92 per cent of the native right-handers shot right~handed. TABLE VI NATIVE AND SHOOTING HANDEDNESS OF ARCHERS G RH, RH. LH. LH, rOUP RHS LHS RHS LHS 'Total ................. 124 10 3 3 Men ................. 73 8 1 Z 51 2 2 1 83 The figure was higher for the women than the men: 96 per cent to 90 per cent. The left-handers were few in number, but only half Of them followed their native handedness in shooting preference. Eye usage. The eye-usage pattern of the archery subjects, listed according to the other characteristics of concern, showed that a specific pattern of eye closure was followed by the subjects. Right- handed shooters who were right-eye-dominant shot either with both eyes open or with the right eye only open. The men in this cate- gory were about evenly divided between those keeping both eyes Open and those not, while the women by a proportion of about three to one preferred to keep only the right eye open. The right-handed shoot- ers who were left-eye-dominant were very consistent, there being only one exception, and that justifiable. They all closed the domi- nant left eye and sighted with the right eye. The one exception was a man who had lost his right eye, but still shot right-handed by compensating in his shooting form by bringing the bow string back and having his anchor point on his cheek to the left of his nose. The twelve left—handed shooters followed a comparable pattern re— gardless of their eye dominance, that of closing their right eye, and shooting with the left eye only open, with one exception. None of this group shot with both eyes open except the one individual 84 TABLE VII EYE USAGE BY ARCHERS Group RHS, RHS, LHS, LHS, RED LED RED LED Total Both eyes Open ........ 49 0 0 1 Right eye only open . . . . 59 19 0 0 Left eye only open . . . . . 0 l 6 5 Men Both eyes Open ........ 39 0 0 1 Right eye only Open . . . . 28 7 0 0 Left eye only open ..... 0 1 5 3 Women Both eyes open ........ 10 0 0 0 Right eye only open . . . . 31 12 0 0 Left eye only open ..... 0 0 1 Z M/ labeled an exception who was right-eye-dominant yet kept bO’th eyes Open, This latter exception was the only archer (of the 140 upon whom statistics were Obtained) who did not follow what would be the logical pattern of consideration of eye dominance. Shooting Characteristics and Tournament Success ' *‘ ment Investigation of the shooting characteristics and tourna nks in both the men's .. ' a Success as determined by the top twenty five r m aring and Women's divisions (see Table VIII) was done by CO P TABLE VIII OF ARCHERS 85 SHOOTING CHARACTERISTICS AND TOURNAMENT SUCCESS Pct. Pct. N Characteristics Ranks of in Top Total 25 Men 38 RHT, RHS, RED, both 1, 2, 3, 4, 8, 42.7 36 eyes Open 15, 23, 24, 25 28 RHT, RHS, RED, right 5, 7, 12, 16, 31.4 28 eye only open 19, 20, 21 7 RHT, RHS, LED, right 6, 22 7.9 8 eye only open 5 RHT, LHS, LED, left 13, 14, 18 5.6 12 eye only open 2 RHT, LHS, RED, left 11 2.2 4 eye only Open la RHT, RHS, LED, left 9 1.1 4 eye only Open 1 LHT, RHS, RED, both 17 1.1 4 eyes Open 1 LHT, LHS, RED. both 1.1 0 eyes open 1 LHT, LHS, RED, left 1.1 0 eye only open 5 unknown 10 5.6 4 Key: R, right; L, left; T, thrower; H, handed; S, shooter; E, eye; N, number of Shooters. aThis shooter had only one eye (See page 83). TABLE VIII (Continued) 86 Pct. Pct. N Characteristics Ranks of in Top Total 25 Women 10 RHT, RHS, RED, both 2, 10, 11, 12, 15.1 20 eyes open 22 31 RHT, RHS, RED, right 3, 5, 6, 8, 9, 48.5 44 eye only open 14, 15, 18, 20, 21, 23 10 RHT, RHS, LED, right 1, 7, 13 15.1 12 eye only open 2 RHT, LHS, RED, left 24 3.0 4 eye only Open 2 LHT, RHS, LED, right 4, 17 3.0 8 eye only open 1 LHT, LHS, LED, left 1.5 0 eye only open 10 unknown 16, 19, 25 15.1 12 87 percentages of the classifications of the number of each from the total group to the number in the top twenty- five ranks. The group comprising those with the dextral characteristics of native handed- ness, shooting handedness, and eye dominance matching, comprised 69 per cent of the total archers in the tournament, and won 64 per cent of the ranks in the men's and women's divisions. Those who kept both eyes Open in this group comprised 29 per cent of the contestants and won 28 per cent of the top ranks. The men's group who kept both eyes open comprised 42.7 per cent of the total and won 36 per cent of the ranks, including the top four, while only 15.1 per cent of the women fell into this classification but won 20 per cent of the rankings. Of those keeping only one eye open (the right eye) in this dextral group, there were 40 per cent of the total group who won 36 per cent of the ranks, including 31.4 per cent of the men who won 28 per cent of the rankings and 48.5 per cent of the women who gained 44 per cent of the rankings. The right-handers who shot right-handed and had left—eye dominance comprised 11.5 per cent of the total group and acquired 10 per cent of the top twenty— five ranks. The men of this category were 7.9 per cent of the total, with 8 per cent of the ranks of their group, while the women Of this group were 15.1 per cent of the 88 total women and they won 12 per cent of the ranks, including the women's championship. The right-handers who Shot left-handed comprised 5.9 per cent of the total, but picked up 10 per cent of the ranks. Of this group, those with left—eye dominance consisted of 3.6 per cent of the total archers, all of whom were men, winning 6 per cent of the total ranks, or 5.6 per cent of the men archers and winning 12 per cent of the ranks. Of this group, there were two men and two wo- men who were right-eye-dominant, a percentage of 2.6 of the total group, who won two ranks or 4 per cent of the total ranks. The native left-handers, six in number or 3.9 per cent of the total, won three ranks or 6 per cent, all by those shooting right- handed. The one individual who did not follow the pattern of eye usage logically expected was of this group. He was a left—handed thrower and shooter and right-eye-dominant, but kept both eyes open. He did not have any particular success in the tournament, as he ranked seventieth of the eighty-nine men participating. Those using the shooting side corresponding to their eye dominance were 73 per cent of the total, and picked up 72 per cent of the top twenty-five rankings in the men's and women's groups. Those using the shooting handedness corresponding to their throw— ing handedness comprised 83 per cent of the total, and won 76 per 89 cent of the top ranks. The men who used a shooting handedness correSponding to their eye dominance were 80.8 per cent of the total, with 80 per cent of ranks, and for the women the figures showed 65.1 per cent of the total and 64 per cent of the ranks. The men who used a shooting handedness corresponding to their throw— ing handedness were 85.3 per cent of the total with 76 per cent of the ranks, while in the women's division 80.2 per cent of the total were in this category, winning 76 per cent of the ranks. Summary There was a specific pattern of dominant-eye usage followed by all but one of the competing archers in the 1955 National Free- style Championship Tournament. The pattern was: 1. Those who used a shooting handedness corresponding to their dominant eye either shot with both eyes open or closed their nondominant eye. 2. Those who used a shooting handedness on the opposite side from their dominant eye closed the dominant eye and sighted with the nondominant eye. The tournament contestants showed a correspondence of Shooting handedness with throwing handedness of 83 per cent, and a 73 per cent agreement with their eye dominance. There was .not n a. 90 a statistically significant difference from zero between the success of the two groups, as shown by comparing the percentage of this category in the total group as compared with the percentage of this group in the tOp twenty- five ranks of each of the men's and women's divisions. The individuals who used a shooting handedness opposite to their throwing handedness had a higher percentage of their num- ber in the top twenty- five rankings than did the correSponding group, but the difference was not statistically significant from zero. CHAPTER V THE RELATIONSHIP OF OCULAR DOMINANCE TO BALL-CATCHING MOVEMENTS Int roduction This investigation was the consideration of the relationship Of eye dominance to the turning habits of individuals in the act of catching a ball in two experimental testing situations. It was a C o o . . - ontrol experiment of comparative experienced and inexperienced subjects whose turning habits were observed and compared as to the logical turning action expected according to their eye dominance. Standing—turn Investigation The standing-turn investigation involved simulating the act Of catching a fly ball in baseball. It would be expected that if the ey9dness of an individual had a relationship to his turning action to catch a ball a right-eyed individual would turn to his left so that he COUld more easily sight the ball after he starts running to catch up with the ball. If the handedness of the individual is the tell—tale, e nonthrowing band would be in the better so that the glove on th ed that the right-handed position to catch the ball, it would be expect 91 92 thrower would turn to his left. For these two reasons it would be expected that the individual who is both right-handed and right-eyed would turn to his left to go back to catch a fly ball, from the standing position. Turning habits. The results of the testing to determine the turning habits of the subjects showed that 84 per cent of the sub- jects demonstrated a consistent turning habit 80 per cent of the time or better, with the other 20 per cent showing a lesser percentage preference. TABLE IX EYE DOMINANCE, NATIVE HANDEDNESS, AND TURNING DIRECTIONS FOR STANDING-TURN TEST OF BALL-CATCHING MOVEMENTS Turn Direction *‘ No. Pct. No. Pct. NO. Pct. Eyedness Handedness Group -—_~ Experienced group Right ............ 10 67 13 87 7 47 Left ............ 5 33 2 13 8 53 Inexperienc ed group Right ............ 9 56 11 69 13 81 Left ............ 7 44 5 31 3 19 Total Right ............ 19 61 24 77 20 65 Left ............ 12 39 7 23 ll 36 93 The experienced varsity group did not show a particular difference as to which side they turned as a group, while the inexperienced class group showed an 81 per cent right-turn preference. The com- posite total showed that 65 per cent of the subjects showed a right- turn preference. Eyedness and Turning. The eyedness statistics for the total group are close to what would be expected in a normal population, as there were 61 per cent of the group right-eyed. TABLE X EYE DOMINANCE AND TURNING DIRECTION FOR STANDING- TURN TEST OF BALL-CATCHING MOVEMENTS Ex erienc ed Inex- IGrou perienced Total Item p Group No. Pct. No. Pct. No. Pct. - Right-eyed and right turn ............ 5 33 7 44 12 39 Right-eyed and left turn ............ 5 33 Z 13 7 23 Left-eyed and right turn ............ 2 13 6 38 8 26 Le ft- eyed and left turn ............ 3 20 1 6 4 13 94 It was somewhat higher for the experienced group, being 67 per cent right-eyed, as compared with 56 per cent of the inexperienced group. The experienced group was evenly divided as to turning habits according to their eyedness. The inexperienced group showed 82 per cent of them turning to their right, regardless of their eye dominance, with 77 per cent of the right-eyed turning right, and 86 per cent Of the left—eyed also turning right. For the composite group, 63 per cent of the right-eyed turned right and 67 per cent of the left-eyed also turned right. Handedness and turning. The handedness of the total group Showed considerably more left—handers than would normally be ex- pected, 23 per cent. This difference was largely in the inexperi- enced group, as 31 per cent of them were left-handed and only 13 per cent of the experienced group. The experienced group showed no particular difference as to handedness coordination with turning habits, as they were evenly divided. The inexperienced group showed 73 per cent of the right-handers turning right and 80 per cent of the left-handers turning left, or 75 per cent of them turning to the side of their handedness. The turning habits of the composite group showed that 61 per cent turned to the side of their handedness. 95 TABLE XI NATIVE HANDEDNESS AND TURNING DIRECTIONS FOR STANDING-TURN TEST OF BALL-CATCHING MOVEMENTS . Inex— EXIZ::;:nC ed perienc ed Total Item p Group NO. Pct. No. Pct. NO. Pct. Right- handed and right turn ............ 6 4O 8 50 14 45 Right-handed and left turn ............ 7 47 3 19 10 32 Left-handed and right turn ............ l 7 l 6 Z 7 Left-handed and left turn ............ 1 7 4 25 5 16 Handedness, eyedness, and turning habits. The experienced dextrals did not Show a turning preference as a group, but 77 per cent of the inexperienced group turned to the right. The composite dextral group showed a preference of 65 per cent of the group for turning to the right. There were no sinistrals in the experienced group, while all of those in the inexperienced group Showed a right- turn preference. The crossed dextrals did not show a turning Preference Of note for either group. The crossed sinistrals, 96 TABLE XII SUMMARY OF STANDING-TURN TEST OF BALL- CATCHING MOVEMENTS Experienced Inexperienced Characteristics Group Group Total Group (pct.) (pct.) (pct.) RH, RED, right turn . . . 27 44 36 RH, RED, left turn . . . . 27 13 19 RH, LED, right turn . . . 13 6 10 RH, LED, left turn . . . . 13 6 1 13 LH, LED, right turn . . . 0 31 16 LH, LED, left turn . . . . 0 0 0 LH, RED, right turn . . . 7 0 3 LH, RED, left turn . . . . 7 0 3 represented only in the experienced group, also did not show a turn- ing preference. The prevalence of handedness and eyedness coordination for the composite group of right-handers showed 72 per cent right-eye— dominant, with the figure of 62 [per cent for the experienced group and 82 per cent for the inexperienced group. The left-handers of the composite group were 71 per cent left-eyed, with all of those 97 left—eye—dominant being in the inexperienced group. All of the left- handers in the experienced group were right-eye-dominant. The differences from the expectancy figures for the dextrals were not significant. Running-turn Investigation In the running-turn investigation, which is the action of catch- ing a basketball thrown from behind while running, it would be ex- pected that, if the eye dominance had a relationship to the turning action, the right-eyed individuals would turn to the right, so that the ball could be sighted more easily. Handedness should not be of any consequence logically, as the catching of the ball in basketball is done with both hands, but it was investigated, nevertheless, as to Possible influence upon the turning habit. Turning habits. The data of the testing for this study showed ' f the that 93 per cent of the subjects were conSistent 67 per cent 0 . ' same wa tirne in their turning habits. With 53 per cent turning the y be sub— t of t every time. The experienced group showed 63 per cen 't rou jects turning to the left, as did 62 per cent of the compOSi e g p and the inexperienced group- 98 TABLE XIII EYE DOMINANCE, NATIVE HANDEDNESS, AND TURNING DIRECTIONS FOR RUNNING-TURN TEST OF BALL-CATCHING MOVEMENTS Turn E edness Ha dedn ss , , y n e Direction Group No. Pct. No. Pct. No. Pct. EXperienced group Right ............ ll 69 14 86 6 38 Left............ 5 31 2 14 10 63 Inexperienced group Right ............ 8 62 12 92 5 39 Left ............ 5 39 l 8 8 62 Total Right ............ 19 66 26 90 ll 38 Left ............ 10 35 3 10 18 62 Eyedness and turning. The eyedness characteristics statistics of the composite group showed that they closely approached the nor— mal p0pu1ation, as 66 per cent were right-eyed, with the experienced group having 69 per cent and the inexperienced group 62 per cent right- eyed. The right- eyed in the composite group had a turning Preference to the left in 68 per cent of the subjects, as did 64 per p and 75 per cent of the inexperienced cent of the experienced grou 99 TABLE XIV EYE DOMINANCE AND TURNING DIRECTIONS FOR RUNNING- TURN TEST OF BALL-CATCHING MOVEMENTS E r' nc d Inex- X32111): e perienced Total Item p Group No. Pct. No. Pct. No. Pct. Right- eyed and right turn ............ 4 25 2 15 6 21 Right-eyed and left turn ............ 7 44 6 46 13 45 Left-eyed and right turn ............ 2 13 3 23 5 17 Left-eyed and left turn............ 3 19 Z 15 5 17 group. The left-eyed in neither group showed a particular turning preference. Handedness and turning. The handedness figures for the ' ' ht- Composite group showed that 90 per cent of the subjects were rig . x- handed, which is near the normal population expectancy. The e . ' ' ced perienced group had 88 per cent right-handers, and the inexperien ' ent of group 92 per cent. Of those who were right-handed,_64 per c ' ’ , and the eXperienced group, 58 per cent of the Inexperienced group — reference. 62 per cent of the composite group showed a left turn P ' rence. The left-handers did not Show a particular prefe 100 TABLE XV NATIVE HANDEDNESS AND TURNING DIRECTIONS FOR RUNNING- TURN TEST OF BALL-CATCHING MOVEMENTS E ri nc ed Inex- x220: perienc ed Total Item p Group No. Pct. No. Pct. No. Pct. Right-handed and right turn ............ 5 31 5 39 10 35 Right-handed and left turn ............ 9 56 7 54 16 55 Left-handed and right turn ............ 1 6 0 0 l 4 Left-handed and left turn ............ l 6 1 8 Z 7 Handedness, eyedness, and turning. The dextral subjects of the composite group showed 68 per cent of their number preferring to turn left, as did 64 per cent of the experienced group and 75 per m- cent of the inexperienced group. The crossed dextrals of the co ning preference. Those in Posite group did not show a particular tur ' t fthe the experienced group all used the left turn, while 75 per cen o urn preference. The left- inexperienced group showed a right-t did not show a particular prefer- handers were few in number and ence. 101 TABLE XVI SUMMARY OF RUNNING-TURN TEST OF BALL-CATCHING MOVEMENTS Experienced Inexperienced Total Group Characteristics Group Group (pct.) (pct.) (pct.) RH, RED, right turn . . . 25 15 21 RH, RED, left turn . . . . 44 46 45 RH, LED, right turn . . . 0 23 10 RH, LED, left turn . . . . l9 8 14 LH, LED, right turn . . . 6 0 4 LH, LED, left turn . . . . 0 8 4 LH, RED, right turn . . . O 0 0 LH. RED, left turn . . . . 6 0 4 The composite group showed that, of the right-handed sub- jECtS. 73 per cent had right-eye dominancy, while the figure for the ' t for experienced group was 79 per cent right-eyed, and 67 per cen . ex ecta- the inexperienced group. This is somewhat above normal p - ‘ ormal. The tions, except for the inexperienced group. Wthh was n ed according to their eye dominance. left-handers were split as expect 102 Summary The results of the two tests conducted for this study con- cerned with the turning habits of the subjects in the act of catching a ball showed that the individuals did have a turning habit for the particular activities tested. There was no relationship indicated be- tween the eye dominance of the individuals and their turning habits, or between their throwing handedness and turning habits. There were no logically explainable differences shown between the ex- perienced and inexperienced groups in either test, or for handedness and eyedness tendencies. That the results were confusing is illus- trated by the fact that, of the twenty-one individuals who participated in both of the experimental studies, ten of them turned the same direction in both tests. If eyedness or the visional directional pat- tern were significant, it would be expected that the turning directions Would be reversed for the two tests. The total picture did indicate that for the standing-turn test 80 per cent of the inexperienced subjects had a right—turn prefer- ence, a preference not shown by the experienced group. The run- ning-turn study showed that two out of every three subjects, regard- less of experience, had a left-turn preference. CHAPTER VI THE RELATIONSHIP OF OCULAR DOMINANCE TO BASEBALL SUCCESS Int roduction The aim of this chapter was to investigate the relationship of eye dominance to the dynamic motor activity of baseball, by studyingthe playing success of the subjects as measured by their records in the three main facets of the game; namely, batting, fielding, and pitching. This was done through the medium of classifying the subjects into groups by their eyedness and batting handedness for the batting phase, and by their eyedness and throw- ing handedness for the fielding and pitching sections. Tables are presented in this chapter for each of the meas- ures of success of the categories of batting, fielding, and pitching. The tables present the data of the number of subjects (N), the range of the scores (R), the mean (X), the standard deviation (6), and the standard error of the mean (am). At the bottom of each table a statement of comparison is made between the groups, giving the difference in means, the critical ratio (CR), and the significance level (SL). The significance level is given for each comparison 103 104 made between groups, but only those exceeding the probability level of .90 were regarded as significant. Batting Investigation This phase of the baseball investigation was concerned with the subject's eye dominance and batting handedness. The resulting groupings are: right-handed batters who are right-eye-dominant (RHB-RED). right-handed batters who are left-eye-dominant (RHB- LED), left-handed batters who are right-eye-dominant (LHB-RED), and left-handed batters who are left-eye-dominant (LHB~LED). An- other more general grouping was used for each measure, that of correSponding and opposite groups. The corresponding (CORR) group was the total of the right-handed-batting, right-eye-dominant subjects added to the left-handed—batting, left—eye-dominant subjects. The Opposite (OPP) group was the total of the right-handed-batting, left-eye-dominant subjects added to left-handed-batting, right-eye- dominant subjects. Comparisons were made between the correspond— ing and opposite groups, between the two groups of right-handed batters, the right-eye—dominant and the left-eye—dominant, and the Same for the left-handed batters. The measures of batting success used were: batting average, slugging average, bases on balls, and strike-outs per plate appearance. 105 Batting average. The statistics concerning the batting aver- ages of the subjects showed that the differences in means of the three comparisons were all in favor of the crossed and Opposite groups. However, the only significance level high enough to be noteworthy was that of the comparison of the corresponding and opposite groups, in favor of the opposite group. The comparison between the two right-handed batter groups in favor of the left-eye- dominant batters was so close to the significance level that they were so considered. TABLE XVII BATTING AVERAGES OF BASEBALL BATTING SUBJECTS Group N R X 0‘ a __ EL RHB-RED ......... 80 .111 to .446 .274 .037 .004 RHB-LED ......... 24 .122 to .458 .303 .086 .018 LHB-RED ,,,,,,,,, 28 .095 to .433 .290 .071 .013 LHB-LED ......... 13 .173 to .447 .280 .072 .020 CORR ............ 93 .111 to .447 .273 .049 .005 Total ............. 145 .095 to .458 .281 CORR vs OPP; X difference is .012, CR of 1.92, SL of .946. RED vs LED, RHB; X difference is .029, CR of 1.61, SL of .894. RED vs LED, LHB; 3? difference is .010, CR of .42, SL of .326. 106 Slugging average. The measure of batting power, slugging averages, showed practically the same results as those in the bat- ting-average study, with the differences in comparisons in favor of the crossed and opposite groups. The differences were significant in two of three comparisons made, those being in favor of the left- eye-dominant group of the right—handed batters, and the composite opposite group. TABLE XVIII SLUGGING AVERAGES OF BASEBALL BATTING SUBJECTS _ Group N R X 0 am RHB-RED ......... 80 .133 to .699 .356 .279 .031 RHB-LED ......... 24 .200 to .644 .434 .145 .030 LHB-RED ......... 28 .095 to .755 .416 .127 .024 LHB—LED ......... 13 .207 to .627 .396 .127 .035 CORR ............ 93 .133 to .699 .362 .284 .029 OPP ,,,,,,,,,,,,, 52 .095 to .755 .424 .134 .019 Total ............. 145 .095 to .755 .384 CORR vs OPP; 2 difference is .062, CR of 1.77. SL of .924. RED vs LED, RHB; X difference is .078, CR of 1.73, SL of .917. BED vs LED, LHB; X difference is .020, CR 0f .48. SL of .366. Bases on balls. 107 The measure of judgment of pitched balls used, bases on balls per plate appearance for the subjects of the study showed that the differences in the groups were again all in favor of the crossed and opposite groups. The corresponding and opposite group comparison difference was significant, as was that between the two groups of left-handed batters. TABLE XIX BASES ON BALLS RECEIVED BY BASEBALL BATTING SUBJECTS v. Group N R X a 0m RHB-RED ......... 77 3.1 to 78.0 15.38 15.57 1.77 RHB-LED ......... 21 4.3 to 75.0 13.11 16.73 3.66 LHB-RED ......... 27 3.9 to 33.0 12.41 6.20 1.19 LHB-LED ......... 13 4.8 to 60.0 17.17 7.05 1.95 CORR ............ 90 3.1 to 78.0 15.64 14.66 1.54 OPP ............. 48 3.9 to 7.5.0 11.16 11.98 1.73 Total ............. 138 3.1 to 78.0 14.15 CORR vs OPP; i difference is 4.48, CR of 2.36, SL of .982. RED vs LED, RHB; X difference is 2.27, CR of .56. SL Of .425. RED vs LED, LHB; ‘X difference is 4.76, CR of 2.09, SL Of .963. 108 Strike-outs. The strike-outs, per plate appearance, inflicted upon the subjects Of the study showed that the difference in the two groups Of right-handed batters was in favor of the right-eye-domi- nant group, but was too small to be other than accidental. The difference in the two groups of left-handed batters was highly sig- nificant in favor of the right-eye-dominant group. The total picture shown by the comparison of the corresponding and Opposite groups showed a difference in favor of the Opposite group but was also small. TABLE XX STRIKE- OUTS OF BASEBALL BATTING SUBJECTS _ Group N R X 0 0m RHB-RED ......... 77 2.3 to 55.0 11.08 7.69 .88 RHB-LED ......... 21 4.7 to 27.5 10.92 5.02 1.10 LHB-RED ....... .. . 27 3.1 to 35.5 12.15 8.44 1.62 LHB-LED ......... 13 3.1 to 13.0 7.60 2.97 .82 CORR ............ 90 2.3 to 55.0 10.58 7.30 .77 OPP ............. 48 3.1 to 35.5 11.61 7.11 1.03 Total ............. 138 2.3 to 55.0 10.90 CORR vs OPP; 3? difference is 1.01. CR of .78, SL of .565. RED vs LED, RHB; Si difference is .16, OR of .11, SL of .088. RED vs LED, LHB; X difference is 4.55. CR of 2.50, SL or .983, 109 Eyedness, and throwing and batting handedness. The throw- ing handedness of the subjects in the batting study showed that 89 per cent were right-handed. The eyedness of the same subjects showed that 73 per cent were right-eye-dominant. Coordinating the traits in individual subjects showed that 74 per cent of the right- handed throwers were right—eye—dominant, and 64 per cent of the left-handed throwers were also right-eye-dominant. Comparing these figures with expectancy percentages of the normal population showed only slight differences which were not significant. This would indicate that the subjects approximate a normal p0pu1ation as to occurrence of the traits of eyedness and handedness, andthat college baseball players do not deviate from a normal population according to these traits. Coordinating the throwing with the batting handedness used by the subjects showed that 79 per cent of the right-handed throwers were right-handed batters, and that the same percentage prevailed for the left-handed throwers who batted left—handed. The coordination of the batting handedness of the subjects with eyedness showed that 75 per cent of the right-eye-dominant were right-handed batters, and 33 per cent of the left-eye—dominant were left—handed batters. There was not a significant difference between handedness and eyedness agreements with the batting 110 handedness used by the right-handed batters. There was a signifi- cant difference between the two traits for the left-handed batters, in favor of the batting position corresponding to the throwing hand- edness. The reason for the latter difference has nothing to do with the eyedness of the subjects, as there has not been a known situa- tion where it was used as the determinant for batting handedness. Players choose their batting handedness largely due to their throw- ing handedness, by imitation, or the belief of many that batting left- handed has an advantage in that most pitchers are right-handed and that their curve ball is not as great a problem batting from that side. Pitching Investigation This phase of the baseball investigation was concerned with the subjects' eye dominance and throwing handedness. The result- ing groups for comparisons of success were: right-handed throw- ers who are right-eye-dominant (REIT—RED), right-handed throwers who are left-eye—dominant (RHT-LED), left-handed throwers who are right-eye—dominant (LHT— RED), and left-handed throwers who are left-eye-dominant (LHT—LED). Another more general grouping was that of correSponding handedness and eyedness (CORR), compared with those of the opposite handedness and eyedness (OPP). The 111 measures Of pitching success decided upon were. games-won-and— lost percentage, earned- run average, hits allowed, bases on balls given up, and strike-outs made per inning pitched. Games-won-and-lost percentage. The differences between the groups compared in the measure of games won and lost all favored the corresponding groups but none were significant. TABLE XXI GAMES- WON-AND-LOST PERCENTAGES OF BASEBALL PITCHING SUBJECTS _ Group N R if a 0m RHT-RED ......... 26 .000 to 1.000 .632 .292 .057 RHT-LED .. . . . . . . . 8 .125 to 1.000 .567 .303 .107 LHT-RED . . . . . . . . . 8 .333 to 1.000 .643 .203 .072 LHT-LED ......... 6 .600 to .750 .656 .092 .038 CORR ............ 32 .000 to 1.000 .636 .259 .046 OPP ............. 16 .125 to 1.000 .605 .252 .063 Total ............. 48 .000 to 1.000 .626 CORR vs OPP; )7: difference is .031, CR of .40, SL of .311. RED vs LED-LHT; 32' difference is .013. CR of .16, SL of .128. RED vs LED-RHT; 3? difference is .065, CR of .54, SL of .411. 112 Earned-run average. The differences in the comparisons made of the measure Of each pitcher's earned—run average were practically negligible. The right-handed-throwing, right-eye-domi- nant group showed a slight difference over the left—eye-dominant group, but the left-handed-throwing, right-eye-dominant group showed a slight difference over the left—eye-dominant group, which added up to a scant difference in favor of the correSponding group. TABLE XXII EARNED- RUN AVERAGES OF BASEBALL PITCHING SUBJECTS Group N R X 0' (Ir—IL RHT-RED ......... 26 .79 to 5.76 2.98 1.51 .296 RHT-LED ......... 8 88 to 6.61 3.19 2.41 .852 LHT-RED ......... 8 1.32 to 6.19 3.04 1.65 .583 LHT-LED ......... 6 .42 to 5.93 3.15 1.88 .767 CORR ............ 32 .42 to 5.93 3.02 1.50 .266 OPP ............. 16 .88 to 6.61 3.12 1.90 .475 Total ....... 48 42 to 6 61 3 05 .10, CR Of .02, SL of .016. s .21, CR of .23, SL of .182. .11, CR of .11. CORR vs OPP; X difference is . RED vs LED-RHT; X difference 1 RED vs LED-LHT; X'difference is 113 Hits allowed. The differences showed by the comparisons of groups for the measure of hits allowed per inning pitched were not significant. The right-handed throwers who were right-eye-dominant and the left-handed throwers who were right-eye-dominant showed differences in their favor, which added up to a difference in favor of the opposite group. TABLE XXIII HITS ALLOWED BY BASEBALL PITCHING SUBJECTS X, 0’ U Group N R m RHT-RED ......... 26 .56 to 1.30 .856 .194 .033 RHT-LED ......... 8 .44 to 1.21 .859 .236 .083 LHT-RED ......... 8 .61 to 1.31 .741 .534 .189 LHT-LED ......... 6 .71 to .84 .771 .074 .030 CORR ............ 32 .56 to 1.30 .840 .192 .032 OPP ............. 16 .44 to 1.31 .800 .402 .101 Total ............. 48 .44 to 1.31 .826 ##7##”, . - 6 -' - ' CR 18 .38. SL 15 '29 ' CORR VS OPP; X dlfference ls .040'003, CR is .03. SL is .296. RED vs LED-RHT; X difference is . ' SL is .229. RED VS LED-LHT; X difference is .030, CR 15 .29. 114 Bases on balls. The differences in the groups for the meas- ure Of bases on balls given up per inning pitched were in favor of the corresponding groups. The difference in the left-handed throw- ing-groups was highly significant, although the difference between the right-handed—throwing groups was almost negligible. TABLE XXIV BASES ON BALLS BY BASEBALL PITCHING SUBJECTS ____________—-————- __.———-. Group N R "X L GEL RHT-RED ......... 26 .24 to .81 .476 .130 .025 RHT-LED ......... 8 .22 to 1.11 .494 .285 ‘ .101 LHT-RED ......... 8 .22 to 1.16 .523 .299 .106 LHT-LED ......... 6 .14 to .57 .355 .157 .064 CORR ............ 32 .14 to .81 .453 .147 .026 OPP ............. 16 .22 to 1.16 .508 .283 .071 Total ............. 48 .14 to 1.16 .471 M//’# nce is .018, CR of .17, SL of .135. is .069, CR of 2.43, SL of .985. CORR vs OPP; X difference RED vs LED-RHT; § differe RED vs LED-LHT; X difference 115 Strike-outs. The comparisons made of the measure of strike— outs made per inning pitched were all in favor of the crossed and Opposite groups, but were not significant. TABLE XXV STRIKE-OUTS BY BASEBALL PITCHING SUBJECTS Group N R X 0 0m RHT-RED . . . . . . . . . 26 .50 to 1.24 .775 .227 .045 RHT-LED ......... 8 .53 to 1.47 .816 .284 .100 LHT-RED ......... 8 .46 to 1.05 .741 .468 .165 LHT—LED ......... 6 .33 to .77 .583 .486 .198 CORR .. . . . . . . . . . . 32 .33 to 1.24 .739 .228 .040 OPP ............. 16 .46 to 1.47 .779 .229 .057 Total ............. 48 .33 to 1.47 .752 —_—-—- Jaw” . -— . ' .040, CR or .587 SL Of .439. CORR VS OPP' X dlfference ls CR of .38, SL of .296. RED vs LED-RHT; 2 difference is .041. f 411. RED vs LED-LHT; X difference is .158, CR of .54, SL o . The throwing handedness of the Eyedness and handedness. t of them to be right-handed throwers. pitchers showed 77 per cen 77 er cent of The eyedness characteristics of the group showed p ' ' dness and them were right-eye-dominant. Coordinating the hande r cent of the eYEdneSS in individuals, the results showed 77 pe 116 right-handed throwers to be right-eye-dominant, and 57 per cent of the left-handed throwers also to be right-eye-dominant. None of the figures have a significant difference in occurrence from normal expectancy percentages. This would indicate that college baseball pitchers have the same percentage occurrence of the traits of eyed- ness and handedness as a normal population. Fielding Investigation This phase of the study was concerned with the eye dominance and throwing handedness Of the subjects. The same comparisons and groupings as used in the pitching phase of the study were applied in this study. The measure of fielding success was the player's field- ing average. The differences between the groups were all in favor of the crossed and Opposite groupings, although none were significant. The subjects of the fielding study were 88 per cent right- handed throwers and 75 per cent of the group were right-eye dominant. Coordinating the two traits showed 76 per cent of the I‘ight-handed throwers were also right-eye-dominant. None of the differences were significant from that expected from a normal P0pulation. 117 TABLE XXVI FIELDING AVERAGES OF BASEBALL FIELDING SUBJECTS Group N R X a (r m RHT-RED ......... 87 .584 to 1.000 .921 .137 .015 RHT-LED ......... 27 .792 to 1.000 .926 .082 .016 LHT-RED ......... 10 .939 to 1.000 .979 .010 .003 LHT-LED ......... 6 .833 to 1.000 .916 .112 .046 CORR ............ 93 .584 to 1.000 .920 .104 .011 OPP ............. 37 .792 to 1.000 .940 .073 .012 Total ............. 130 .584 to 1.000 .926 CORR vs OPP; 3? difference is .020, CR of 1.23. SL of .782. RED vs LED-RHT; 2? difference is .005, CR of .23. SL of .182. RED vs LED—LHT; it difference is .063. CR Of 1.36, SL of .827. Summary The relationship between eye dominance and baseball playing success was investigated in this chapter. The factors investigated Were the records Of the subjects covering one season Of play. Batting. The batting investigation showed evidence that the general group of players whose batting handedness was Opposite to the side of their dominant eye had higher batting and slugging 118 averages, received more bases on balls, and struck out fewer times than did their counterparts, the corresponding group. The first three measures were significant at the 90 per cent level. The group of right-handed batters who were left-eye-dominant, upon being compared with those who were right-eye-dominant, showed a significant difference in two Of the measures investigated in their favor, and a difference in a third measure in their favor. In only the measure of strike-outs did the right-eye-dominant group show a difference in their favor, and it was not significant. The comparisons of the two groups of left-handed batters showed that the right—eye—dominant group held a difference in their favor for all four categories, but only the bases on balls and strike- out measures were significant. Pitching. The five measures of pitching success investigated did not follow a consistent pattern, as the group whose throwing handedness corresponded to their eye dominance had an advantage in won-and-lost percentage, earned—run average, and bases on balls. The Opposite group had the better record for hits allowed and Strike-outs. None of these differences were significant or close to it. 119 The group of pitchers who were right-eye-dominant held the advantage of the comparisons in four of the five measures, with the left-eye—dominant group leading the way only in strike-outs. Again none of the differences were significant or close to it. The group of left-handed pitchers were inconsistent as the right-eye-dominant group had better records for earned- run average, hits allowed, and strike-outs. The left-eye-dominant group showed a difference in their favor in the comparisons made for won-and- lost percentage, and bases on balls given up. Only the bases on balls comparison difference was significant, which was the only sig- nificant comparison in the pitching investigation. Fielding. The measure of fielding success used in the in- vestigation, the fielding average, showed a difference in favor of the group whose throwing handedness was opposite to the players‘ eye dominance in the general comparison with the correSponding group. The comparisons of the right-handed throwing groups showed a dif— ference in favor of the left-eye—dominant group, and in the left- handed throwers‘ comparison the difference was in favor of the right-eye-dominant group. None Of the differences were significant. CHAPTER VII SUMMARY AND CONCLUSIONS The Problem The determination of the relationship of eye dominance to motor activity performance was a difficult and complex problem. The only source Of investigation deemed likely was an analyzation of results of performance in activities having a complete dependency upon vision cues for success. The problems Of the study were to select the most appro- priate test of eye dominance for use in the study, to find motor activities with specific measures of success, and to find subjects to perform the selected activities with comparatively sufficient expe- rience to equalize individual differences. The test selected was the hole—in—card test of eye dominance. Motor activities were analyzed according to two classifications, static and dynamic. It was decided to select a sport from each group for study, archery as a static activity, and baseball as a dynamic activity. Later, it was decided to include also a control 120 121 study of a general skill movement used in many activities, that of catching a ball. Subjects for the archery study were Obtained when permission was secured to run the study on the contestants at the 1955 National Free Style Target Championship Tournament. Subjects for the base- ball study were obtained from fifteen college teams through the co- operation of the coaches. Subjects for the ball-catching experiment were obtained from members of physical education classes and athletic teams at Kenyon College. The main hypothesis of this study was that there is a Spe- cific relationship between motor activities and the eye dominance Of the individuals participating to the degree of success attained. It was believed that these relationships are pertinent teaching points that should be used in motor activity instructions. Findings and Implications of the Archery Investigation From a comparison of the individual traits of Shooting hand- edness, eye usage, eye dominance, and native handedness, groups were formulated for comparisons as to success Of the archers of each category. The following findings were evident from an analyz- ation of the data: 122 1. The tournament shooters, with one exception, followed a pattern Of eye usage relative to the dominant eye. Those who used a corresponding shooting handedness to their dominant eye either shot with both eyes Open or closed the nondominant eye. Those who used a shooting handed- ness on the Opposite side from their dominant eye closed the dominant eye and sighted with their nondominant eye. 2. The problem of selection of shooting handedness, which is controversial in the literature, whether to use the side indicated by the dominant eye or that indicated by the individual's native handedness, was not answerable from the success of the tournament archers. The implications of this phase Of the study were that a teacher of archery should ascertain the eye dominance of an archer so that the pattern of eye usage may be determined, regardless of Whatever shooting sidedness is used. The expectancy figures of the Population showed that native right-handers will have right— eye dominance two—thirds of the time. If this group shoots right- handed, they have only to decide if they will close the left eye ' th e es and shoot with the right eye only Open. or shoot Wlth b0 y '1 will Open. According to the results of the tournament success, 1 Ob'ect is he a matter of chance which is the better. so long as the J 123 target archery. The same would hold for those who are left-handed and are left-eye-dominant. There is approximately one-third of the population who have a dominant eye on the Opposite side from their native handedness. This group could have considerable sighting trouble unless the dominant eye is known and accounted for as indicated. That this group could have trouble is indicated by the tournament figures, in that only 18 per cent of the tournament shooters were in this "crossed" category, when the expectancy figure is 33 per cent. This is a highly significant statistical difference (.997). If this group shoots according to their handedness, they must close their dominant eye and sight with the nondominant one. If they elect to shoot according to their eyedness, they may keep both eyes open, as the other group does. The figure was not tabulated, but it seemed that a high percentage of the archers had no idea of which was their dominant eye. Therefore, for an individual to be "crossed" and not to know it could be a source of shooting diffi- culty, and perhaps the reason for so few of this group being con- testants in the tournament. 124 Findings and Implications of the Ball-catching Investigation The investigation of the turning movements involved in the ball-catching experiments showed that the subjects in the study did have turning habits, but. they were not consistent by group, or with the logical turning expectations for eyedness or handedness prefer- ences, by either experienced or inexperienced players. This study indicated that turning habits were selected by chance, and if it were determined that a specific direction of turning was necessary for a particular activity, it is likely that half the subjects would have to have their habits changed to conform. Findings and Implications of the Baseball Investigation Batting. The batting investigation was by comparisons of group performances, with the groups being formed according to the eye dominance of the subjects and their batting handedness. Using the general comparison of corresponding and Opposite groups, it was found that the subjects with their batting handedness opposite to their eye dominance were the better batters. The composite OPPoSite group showed significant differences in their favor for batting average, slugging average, and bases on balls received. The 125 left-eye-dominant group of right-handed batters showed a significant difference in their favor for batting average and slugging average. The right—eye—dominant group of left-handed batters showed signifi- cant differences in their favor for bases on balls received and fewer strike-outs per plate appearance. The indications of the study were that in baseball batting there could be an advantage in having the dominant eye on the side of the head closest to the pitcher in the batting position. The fact that the dominant eye is the “directionalizing eye" in binocular vision could be the reason. There is also a strong possibility that the occlusion of the eye farthest from the pitcher by the batter's nose on some inside pitches could interfere with the direction-giving powers of the dominant eye when it is the one farthest from the pitcher. Pitching. The pitching investigation was made by the com- parisons of group performance, with the groups formed according to the eye dominance of the subjects and their throwing handedness. The findings of this phase of the study showed that the differences between the groups are probably due to chance. as there was none of the comparisons significant or close to it, with some favoring one group and some another. The indications were that the eye dominance of a pitcher has no relationship to his success. 126 Fielding. The fielding study investigation was made by the comparisons of group performances, with the groups being formed according to the eye dominance of the subject and his throwing handedness. The findings of this phase of the study showed that there was a consistent difference in favor of the Opposite groups in all three comparisons. None of the comparisons were significant, but two of them were around the 80 per cent level. The indications are that, if there is a difference in fielding ability, it is more than likely in favor of the players with their eye dominance on the opposite side from their throwing handedness. If such is the case, the reason is advanced that it is because the glove is on the side Of the opposite eye, and therefore the direc- tionalizing of binocular vision from that side would cause a more accurate alignment of the ball into the glove. Implications for Further Research In the process of carrying out this investigation, a number of problems presented themselves which were beyond the scope of this study. The following problems, concerning static-type position activities, are presented as implications for further research. 1. There is the logical assumption that the same conclusions as indicated in the archery study also could be applicable 127 in the sighting process involved in rifle- shooting, skeet and trap shooting, and perhaps pistol- shooting. . The information concerning archery would be enhanced considerably by having control studies conducted on whether shooting handedness should be determined by personal preference, or selected according to native hand- edness, either corresponding to, opposite to, or selected by the eye dominance of the prospective archer. With the advent of field archery, it may be necessary to sight with both eyes, a fact which should be investigated. The dynamic—type movement presents a complex problem for investigation because of the varying individual differences and capa- bilities which complicate the measurement of success relationship for a specific part of the action. There is a need for investigation of eye dominance relationship in all the motor activities depending upon vision cues for success, by a carefully controlled handling Of the other success factors. The following suggestions are made for further research concerning the relationship of eye dominance to performanc e in baseball. . A study made on batting at the major league level would be enlightening, taking into account the factors used in this study plus an exact measurement of the stance of the 128 batters. This could perhaps determine whether adjust- ments in stance, such as the use of an “open" stance by batters with eye dominance corresponding to their batting handedness, would provide compensation sufficient to equal- ize the indicated advantage that batters have with eye domi- nance opposite to their batting handedness. . There is a need Of investigating upon the major league level the eye dominance of a player to his fielding suc- cess according to the position played. 10. 11. BIBLIOGRAPHY Adler, Francis H. Physiology of the Eye. St. Louis: The C. V. Mosby Co., 1950, 709 pp. Andrews, Robert C. Shooting the .22 Rifle. The National Rifle Association Of America, Washington, D.C., 1952, 74 pp. Bannister, H. ”A Study in Eye Dominance," 13_ritish Journal of Psychology, 26 (1935-1936), 32-48. Bender, Irving E., and others. Motivation and Visual Factors. Dartmouth College Publications, Hanover, N.H., 1942, 369 PP- Berner, George E., and Dorothy E. Berner. 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APPENDIX INSTRUCTIONS AND TEST CARD FOR THE HOLE-IN-CARD TEST OF EYE DOMINANCE 138 139 INSTRUCTIONS FOR TESTING EYE DOMINANCE OF BASEBALL BATTERS TEST AREA- An Open spot 60 feet long, indoors or outside TEST EQUIPMENT- A black 5x8 card with a 3/8" hole in center, and a regulation baseball TEST PROCEDURE- 1. Measure off 60 feet. Place the baseball at one [end of the distance on the ground (floor, if inside), and have the testee at the other end assimilating the batting situation. The testee would assume his batting stance, whether right or left-handed, then look at the ball, as if it were being held by the pitcher. 2. Hand the testee the black card with the hole in the center, requesting him to take it in both hands and bring straight up in front of the face at arm's length. Then request the testee to keep both eyes open and look through the hole in the card at the baseball sixty feet away. 3. Next ask the testee if he can see the baseball. When he so states, ask him to close his left eye and continue to look at the baseball, cautioning him not to move the card. Again ask him if he can still see the base all through the hole in the card. If he can see it, he is right eye dominant. New have him open his left eye and close the right one, still without moving the card. Again ask him if he can see the? baseball through the hole in the card, If he was unable to see it before and now can (with his right eye closed and the left Open), he is left eye dem- incnt. The Opening and closing procedure for both eyes should be done even if the first result is in- dicative of dominance. (Note, Some individuals can not close their dominant eye while keeping the other eye Open.) 4. The test supervisor should stand in front of the testee, just out of the line of his vision, so that he may observe what the testee is doing. It will be evident to the supervisor from this position which eye is being used for sighting in most cases. This serves as a check on the answers given by the testee. 5. If there is any confusion in the results, or the testee moves the card after the test has started, the test should be repeated. 6. If the testee wears eyeglasses while batting, he should wear them for the test. 7. In the case that the testee is a legitimate switch batter, have him repeat the test from both his left and right-handed stances, and enter the results sep- aratoly. 8. After the test has been satisfactorily completed for all squad members, the tosteos may be informed of the results. 140 I {Era iii}, MICHIGAN TATE UNIVERSI 1 M x M ‘, W W ; 1|? H v 3 1 Sumum 295 03056 limit?!” ~;