UVtRDUE FINES: 25¢ per day per new RETURNING LIBRARY MATERIALS: Place in book return to remove charge from circulation records THE USE OF THE SLEEP-WAKE CYCLE IN DETERMINING INDIVIDUAL DIFFERENCES IN NEONATES By Esther Dienstag A THESIS Submitted to Michigan State University in partial fuifiiiment of the requirements for the degree of MASTER OF ARTS Department of Psychology 1981 G //3‘fé\f ABSTRACT THE USE OF THE SLEEP-WAKE CYCLE IN DETERMINING INDIVIDUAL DIFFERENCES IN NEONATES By Esther Dienstag In studying the heritability of temperamental traits, researchers have discovered correlations between infant behavior from the second day of life through 4 months of age. The present study sought to dis- cover the stability of biological rhythmicity and behavioral state reg- ulation during the first two months of life using the sleep polygram. Ten infants were followed from 10 days of age through 6 weeks of age. At 10 days they were tested with the NBAS neonatal exam. At 6 weeks their mothers completed the MITS temperament scale. At 4 and 6 weeks infant heart-rate was monitored polygraphically during afternoon sleep sessions. Observers noted sleep state transitions by observing infant REM's, facial movement and body movement. Results indicate continuity from 2 days through 6 weeks of age. Ten day measures of physiological regulatory processes were correlated to infant biological rhythmicity at 6 weeks. Responsitivity to stimula- tion and susceptibility to impinging stimuli were also stable. The rhythmicity of the sleep cycle could not be studied due to limited sample size. Comparison of observational and physiological sleep state transition detection revealed strong negative correlations. Implications for future sleep research were discussed. ACKNOWLEDGMENTS I would like to thank my thesis committee, Dr. Hiram Fitzgerald, Dr. Helen Benedict, and Dr. William Crano for all of their assistance and support throughout this study. Special thanks go to my chairper- son, Dr. Hiram Fitzgerald, for his good advice, which sometimes went unheeded, and for his diligent editorial assistance. I must thank the agencies who distributed brochures which enabled me to recruit participants; the students who assisted in this study by spending many hours in a dark observation room observing infants; the mothers who volunteered to participate and gave of their time; and of course the infants themselves. I also wish to express my gratitude to Steven Gitterman whose help in the lab was invaluable and to Roger Buldain for his assistance in the statistical analysis. ii CHAPTER I CHAPTER II CHAPTER III TABLE OF CONTENTS INTRODUCTION LITERATURE REVIEW Infant Temperament State Criteria Sleep Cycle Ontogenesis The discovery of REM sleep Active Sleep Quiet Sleep waking State Sleep and the immature infant Environmental Effects on Sleep Maternal Variables and infant sleep rhythmicity Exogenous Stimulation and Sleep Psychophysiology and Sleep ' Heart rate Respiration Skin potential Intercorrelation among psychophysiological variables Summary: Procedure and Predictions METHOD Subjects iii 12 14 16 19 21 22 23 24 24 25 26 26 27 27 27 3O 3} 31 CHAPTER IV CHAPTER V REFERENCES APPENDIX A APPENDIX 8 APPENDIX C Procedure Data Reduction RESULTS AND DISCUSSION Behavioral Measures NBAS and MITS Summary of Behavioral Results Physiological Measures Characteristics of Infant Sleep: 4 Weeks Characteristics of Infant Sleep: 6 Weeks Determination of Sleep State Transitions Summary of Physiological Results SUMMARY AND CONCLUSIONS Summary of Results Conclusions iv 32 36 4O 42 47 48 48 51 54 69 71 71 75 79 88 95 114 #wN 01 0 LIST OF TABLES Research Protocol Brazelton (NBAS) Summary Scores of Neonates Results of the Michigan Infant Temperament Scale Pearson Product-Moment Correlations Between 10 Day NBAS Factors and 6-week MITS Scale Mean Duration of Sleep Mean Heart Rate During Sleep Sessions in Beats Per Minute Differential Indexes for Ascending State Changes Mean Differential Indexes 33 43 44 45 49 52 67 67 10. 11. LIST OF FIGURES Summary of Sleep Cycle Ontogeny Pre- and Post-Transition Means for Ascending Sleep States Pre- and Post-Transition Means for Descending Sleep States Ascending Transition from State 1 OS to State 2 AS Ascending Transition from State 1 OS to State 3 Drowsy Sleep Ascending Transition from State 1 OS to State 4 Awake Ascending Transition from State 3 Drowsy Sleep to State 4 Awake Descending Transition from State 2 AS to State 1 OS Descending Transition from State 3 Drowsy Sleep to State 1 OS Descending Transition from State 4 Awake to State 1 OS Descending Transition from State 4 Awake to State 3 Drowsy Sleep vi 114 55 56 58 59 60 61 62 63 64 65 CHAPTER I INTRODUCTION Ever since the 1930's, the question of early evidence of unique, individual traits which persist over time, has been discussed widely. Although often not in the form of the original traits themselves, some consistency was noted in behavioral style and in what was termed an "outgrowth" of the original traits (Shirley, 1933; Gesell, 1937). Neilon (1948) was able to identify Shirley's babies 15 years later based on personality profiles prepared when these babies had reached adolescence. Neilon's conclusion was that personality traits persist over time, but that some children are more readily identifiable than others, based on the uniqueness of their personalities. Trait consistency is an issue which still is discussed widely. The current study was designed to measure trait consistency from ten days postnatal age through six weeks of age. To date, discrete mea- sures have been used to study continuity with some measures being ap- propriate for the period of birth through two weeks, and other measures being appropriate from three months onwards. On the other hand, the sleep polygram is a dependent variable which can be used from birth on- wards, which reflects developmental changes in a predetermined sequence, and which manifests individual variations shown to be consistent over time. Consequently, infants were tested at ten days of age on the Brazel- ton Neonatal Behavior Assessment Scale (NBAS; Brazelton, 1973). At four weeks and at six weeks postnatal age, they then were measured poly- graphically and observationally during a sleep epoch. High correlations between certain factors of the NBAS and the sleep polygram would sup- port the use of this technique of sleep study in the examination of trait consistency. High correlations would indicate that the sleep polygram is a more sensitive measure of trait consistency than are the temperament questionnaires which are currently in use to study trait consistency from the three month period onwards. At six weeks of age, one such temperament questionnaire, the MITS (Bonem, 1978), was admini- stered. Correlations between the MITS and the NBAS also were examined as an additional measure of trait consistency during early infancy. In addition, the characteristics of the sleep of the full-term, four week old infant were studied. This review will survey the literature on individual differences in early infancy and their continuity over time. Most of the studies cited have been based on the use of infant assessment techniques and temperament questionnaires. Sleep, as a multi-dimensional variable will be examined and defined in terms of its component states. Since this study looks at sleep from a develOpmental perspective, a discus- sion will follow on the devel0pment of the sleep cycle in the infant from the fetal period through the first eights months. Sleep is di- vided into two major state categories, Quiet Sleep and Active-REM sleep. These two states will be examined in detail, including a description of the development of each sleep state in the fetus and young infant. Information about fetal development is derived from the study of im- mature infants. Therefore, a discussion of sleep in the premature and immature infant is included. The experimental study of sleep has pro- duced data on the nature of sleep. Thus literature on environmental effects on sleep will be reviewed briefly where it applies to the struc- ture of the sleep cycle itself. As the dependent measure which constitutes the sleep polygram is psychophysiological in nature, the physiology of sleep also will be summarized. ’6 TD! CHAPTER II LITERATURE REVIEW INFANT TEMPERAMENT Data from the New York Longitudinal study (Thomas, Chess, & Birch, 1968) suggest that children do manifest distinct individuality in tem- perament in the first weeks of life independent of their parents' hand- ling or personality style, and that these original characteristics of temperament tend to persist in most children over the years. Thomas et al defined temperament as behavioral style, including intensity of action, tempo, mood, adaptability, and rhythmicity. These categories were further defined as the child's activity level, rhythmicity, approach/ withdrawal tendency, adaptability, threshold of responsiveness, inten- sity of reaction, quality of mood, distractibility, attention span, and persistence. Most persistent were clusters of personality traits associated with temperament. These clusters were used to identify three types of children: the "Easy Child", the "Difficult Child", and the "Slow To Warm Up Child“. Easy children are described as exhibitors of' regular biological rhythms, positive approach responses, easy adaptabil- ity, general positive mood, and mild to moderate reactive intensity. The Difficult Child displays irregular biological rhythm, negative re- sponses to new stimuli, slow adaptability, frequent negative moods, and responses of high activity. The Slow To Warm Up Child is described as a combination of negative responses of mild intensity to new stimuli. These children are slow to adapt to new stimuli, even with repeated In t: presentation. The main difference between the Difficult Child and the Slow To Warm Up Child is the intensity of response, which is more di- luted in the latter. Dividing the children into appropriate categories lent greater predictability to the development of subsequent behavior disorders. Seventy percent of the infants who developed behavior problems at age ten were classified as Difficult Children. Only eighteen percent were classified as Easy Children. Moreover, Thomas et al's observations suggest that each of the three types of children described above were susceptible to distinct forms of environmental stress. This was con- firmed by the idiosyncratic distribution of behavior disorders among the three temperament categories. However, observations began when the infants were three months of age, allowing for the possibility that the first three months may have structured caregiver-infant interac- tion. Examination of the question must begin at an earlier age. There- fore, the present study began when infants were ten days of age. Birns, Barten & Bridger (1969), found that responsiveness to stimu- li differentiated babies consistently during the neonatal period. Vigor of response to a cold disc pressor on the abdomen was greater in some infants than in others. Additionally, some infants objected to the removal of a pacifier more vigorously than did others. The same was found for soothability, and each baby was found to have a hierarchy of soothing modalities. Some babies were soothed more readily by paci- fiers, others by rocking or sound. Moreover, some infants were more easily soothed by any soothing technique than were others. Longitudi- nally, neonatal irritability was significnatly correlated to tension, sensitivity, and soothability at three and four months of age and nega- tively correlated to sociability and positive affect. Activity level at one month of age was stable from one month through four months of age. Assessing neonates in the second and third day of life, Korner (Korner, 1973; Korner, Hutchinson, Koperski, Kraemer & Schneider, 1981) found differences between infants in the duration and frequency of crying, and in both crying and noncrying activity level. Korner and her associates also found variation in the ease with which infants may be soothed, in spontaneous oral activity such as sucking and mouthing, and in the degree to which they engage in self-comforting behaviors such as hand-to-mouth contact. Significant differences in sensory threshholds, both auditory and visual also were found. Individual variation in neonates has been widely confirmed and replicated in diverse populations and cultures (see Sostek, 1978). Hence it is predicted that in the current study, observ- able differences between infants will be present at ten days of age. Addressing the issue of continuity from the neonatal period on- wards, Bakow, Sameroff, Kelly & Zak (1973) found significant correla- tions between factor analytically derived NBAS factors and infant tem- perament assessed at four months using the Carey Infant Temperament Questionnaire (CIT: Carey, 1970). Sostek and Anders (1977) further found correlations between the NBAS scores at 8.6 days mean age and Bayley mental quotients (Bayley, 1970) at ten weeks. Both the NBAS and the Bayley scores correlate to elements of infant temperament at two weeks as measured by the CIT. Sostek and Anders' findings are based on an early a priori cluster analysis of the NBAS yielding four clusters of individual infants' performance. These are: I. interactive processes - responses to social stimuli; 11. motoric processes; III. or- ganizational processes - state control; and IV. organizational processes - physiological responses to stress (Adamson, Als, Tronick & Brazelton, 1975). Brazelton factor entitled "state control" was a predictor of the Bayley mental score, but not the motor score. Dividing the sub- jects into two groups based on Brazelton NBAS scores yielded an optimal and a worrisome group. These two groups differed significantly on Bayley mental performance at ten weeks. Temperament factor intensity, measured with the CIT, correlated with Bayley mental scores whereas distractibility correlated with motoric interactive processes and total Brazelton scores. This makes intuitive sense since both the NBAS test items and the CIT distractibility items involve the ability to shut down external stimuli. However, the sample size used in the Sostek and Anders study was too small for positive conclusions to be drawn. Others have found similarities in the patterns of relations be- tween scores on the Graham-Rosenblith Scales (Graham, 1956; Rosenblith, 1961) during the neonatal period and at eight months of age. For boys, gross motor development showed the strongest relationship to neonatal measures, particularly the motor score. For girls, social-emotional development was the best factor predicted (Rosenblith, 1974). Gesta- tional age in male two-day-old newborns proved to be a predictor of tonic activity at three months of age. Infants who were more mature at 2 days, were more highly vocal, alert and active at 90 days and had higher muscle tonus. Optimal functioning during the newborn period appears to be correlated to optimal functioning at three months of age (Yang & Moss, 1978). tC th ha err th. 1'5 0f tar Another source of information on the heritability on tempera- ment traits comes from twin studies (Goldsmith et al, 1981; Torgeson & Kringlen, 1978). Torgeson & Kringlen (1978) found higher correlations for temperament traits of monozygotic twins (MZ) than for dyzygotic twins (DZ) at both two months of age and at nine months of age, though by nine months the pattern of similarity was more clear than at two months. They found that MZ two-month-old infants are significantly more similar than DZ infants on three of the nine Thomas, Chess and Birch temperament categories; namely rhythmicity, threshhold, and in- tensity. By nine months, the MZ twins were more similar than the DZ twins on all nine of the temperament categories. For the purposes of this study it is especially interesting to note that the temperament category of rhythmicity is organized as a stable trait so early in infancy. The temperament trait rhythmicity may be compared to the individual differences found in the rhythmicity of the infant sleep cycle, as both refer to the biological rhythmicity of the infant. Hence there does seem to be a relationship between specific fac- tors in the neonatal period through early infancy. Unfortunately, the information is sketchy and no one pattern appears prominent at this point. Results of studies where the Graham-Rosenblith scales have been used are not concordant with results of studies which have employed the NBAS. The former was a predictor of motor performance, the latter of Bayley mental test performance. Perhaps the difficulty is with using static measures which are applicable to limited periods of infancy. There is little theoretical basis for assuming that fac- tors contributing to performance on neonatal exams are the same factors COO' EVE! shc per sta' IInI. of 1 die of- contributing to performance on infant exams. Moreover, there is not even face validity on the comparability of the various measures. In short, evidence of external validity is lacking. Therefore, use of a measure which is appropriate throughout the period involved and which takes into account changes in developmental status over time might produce a more composite picture of trait con- tinuity. Such a measure is found in the study of sleep-wake cycles. It was predicted that information provided by the continuous measure of sleep cycle study, known as the sleep polygram would be better pre- dicted by an infant assessment scale than the,discontinuous measure of infant temperament scale. The sleep polygram includes polygraphic and behavioral monitoring of infants for extended periods. A cyclic presentation of the biobehavioral states of sleep and waking can be identified using state classification shcemes derived by Wolff (1959, 1966), Brackbill & Fitzgerald (1969), Anders et al (1971), or Prechtl (1968). A behavioral state is a relatively stable condition, and can be detected using such behavioral criteria such as eyes open or closed, regularity of respiration, gross body movements, and movements of the eyes under closed lids. More sophisticated techniques include poly- graphic monitoring of physiological variables such as heart rate, respiration, tonic activity of the submental muscles, rapid and slow eye movements, and skin conductance. There is some debate as to the continuity between states, with Wolff (1966) contending that the sleep- wake cycle is one arousal dimension with quiet sleep on one end of the continuum, and awake-crying on the other. On the other hand, Prechtl 10 (1974) proposes that state reflects nervous system functioning, with each state being a distinct and qualitatively different condition. All of the above classification schemes include two or more waking states and two or more sleep states. Waking states include quiet awake, active awake, and crying. Wolff further distinguishes between alert activity and alert inactivity. Sleep states include active sleep and quiet sleep. Active sleep has also been referred to as irregular sleep, REM sleep, and paradoxical sleep. Quiet sleep is also‘ known as regular sleep, and non-REM sleep. Others include a third sleep state konwn as indeterminate, intermediate or transitional state. A sixth state is often used to divide waking states from sleeping states and is known as drowsy state, because it contains some elements of a waking state and some of a sleep state. During the course of a sleep period, an infant typically will go through four to five 60-minute cycles in which active sleep, quiet sleep, indeterminate sleep, and brief periods of waking alternate. Although one cannot predict the state to which a transition will be made, the duration of each stage within a sleep period and the periodicity with which these stages will reoccur is fairly well circumscribed for most normal infants. Yet this is not true of all infants. The ability to maintain a sleep state for an extended period of time (approximately 10-20 minutes) is related to the maturity and intactness of the central nervous system. For example, a full term infant can maintain a quiet sleep state longer than can a premature infant. Moreover, the rhythmicity with which quiet and active sleep alternate is more finely tuned in the 11 full term infant than in the premature, brain damaged, or small-for- date infant (e.g., Fantalova, 1976; Dreier & Wolff, 1972). For this reason, the sleep polygram has been recommended as a clinical tool for distinguishing full term infants from prematures (Anders & Hoffman, 1973), high risk from low risk infants (Theorell, 1974), and other clinical populations as well (Prechtl, 1970; Fantalova, 1976; Rad- vanyi & Morel-Kahn, 1976). Even within the normal population, wide individual variation exists, with some evidence for individual continuity on variables such as state organization, the develOpment of state parameter synchrony, and duration of state maintenance. For instance, Thoman (1975) found that infants who are deviant on state behaviors prove to be deviant in later physical development. She also found extreme variability in her infants with evidence for continuity along state variable dimen- sions. In a series of long-term studies at the Institute for the Care of Mother and Child in Prague, infants were significantly correlated to themselves at ages 2 weeks through 20 weeks on variables such as the duration of active and quiet sleep at each age, number of REMs per minute during active sleep and the development of EEG patterns ontogenetically (Dittrichova, Paul & Von Dracek, 1976). Individual differences were found to be stable over this period and there was a positive correlation between total sleep duration and the duration of quiet sleep and active sleep states. More specifically, lower total sleep duration correlated with an increased duration of transitory sleep states. Additionally, infants who spend more time in quiet sleep could not maintain the waking state as long as other infants. 12 They also vocalized less and spent more time finger sucking, an activ- ity which replaces facial movements at about 12 to 16 weeks of age (Paul, Brichacek, & Kittrichova, 1978). Thus the sleep polygram appears to be an appropriate dependent variable for the assessment of individual variation in early life, with specific emphasis on the rhythmicity, state organization, and state maintenance during the sleep cycle. It was predicted that the sleep polygram would distinguish between highly rhythmic and arrhythmic in- fants, between infants with organized state parameters and infants whose disorganization reflects immature CNS functioning. STATE CRITERIA Although there is some controversy related to the definition of sleep and waking states, the standardized version of Anders, Emde, and Parmlee (1971) currently is preferred and therefore will be the version which will be used in the present study. Three sleep studies are de- scribed: active-REM sleep, quiet sleep, and indeterminate sleep. Sleep,States: 1. Active-REM sleep — Considerable behavioral activity can be ob- served. These include facial movements such as smiles, grimaces, frowns and bursts of sucking. Limb movements and gross body writhing occur and usually show a writhing quality. Rapid and slow eye movements can be observed under closed lids. Penile erections, blinks, and vocalizations are present. Physiological measures - EOG is positive for REMs, EEG is usually low voltage irregular or mixed high and low voltage, EMG of the submental 13 muscles is low and respiration is irregular. Quiet sleep - Characterized by behavioral quiescence. No body movements are present except for occasional startles. Physiolog- ical components - EEG is of a high voltage slow pattern, trace alternant with bursts of high voltage slow waves with occasional imposition of rapid low voltage waves with sharp waves of 2-4 Hz interspersed, or mixed high and low voltage waves, respiration is quiet and regular, EOG is negative for REMs, and the EMG is high. Indeterminate sleep - Certain epochs do not completely meet the above Active-REM and Quiet sleep criteria for more than a single 30 second to one minute epoch. Three wake states are described: crying, active awake, and quiet awake. The final state is an interim state between sleep and waking and is known as drowsiness. Non-Sleep States: 4. Crying - Characterized by crying vocalization, with vigorous and diffuse motor activity. Eyes may be open or closed with face flushed and grimacing. Active Awake - Gross body movements are present with limbs, trunk' and neck in motion. Eyes are open and moving. Quiet Awake - Little activity is observed. Eyes are open, face is relaxed, eyes follow a slow-moving object for a brief period of time. Drowsiness - Eyes open and close intermittently and are unfo- cused. Eye movements may or may not be present and may be similar to those observed during active-REM. Other criteria are variable, 14 there may or may not be body movements. Face may be relaxed or there may be fleeting frowns and grimaces or smiles present. SLEEP CYCLE ONTOGENESIS The most striking aspect of sleep is the biological rhythmicity which predominates. Initially, sleep is superimposed on a circadian rhythm of 23-25 hours. It is not until three to four months that a circadian rhythm of about 24 hours is established (Parmelee, 1969). However, by four hours of age, an ultradian rhythm is present which will predominate until the tenth week of life. Between ten and thir- teen weeks, circadian rhythms will again become dominant (Hellbrugge, 1974; Ullner, 1974) while a diurnal cycle is developing. The sleep of the neonate is characterized by three to four hour periods of sleep interrupted by periods of waking, which increases to eight and a half uninterrupted nightly sleep periods only by sixteen weeks (Parmelee, 1969; Webb, 1974). Total sleep in the newborn ranges from 11.76 hours for every 24 hours to 16.32 hours or from 49% of the time to 68% of the time. The mean for a 3-week-old infant is 15 hours of sleep per day. IFrom 14 to 26 weeks there is a gradual decline in total sleep time so that by the 26th week of life, the infant is sleeping only 13 hours, 48 minutes per 24 hours. By this time, day sleep has dimi- nished to only 3% hours per day (Kleitman & Engelman, 1953). However, the most dramatic changes do not occur in reduction of total sleep time, but rather in the ratio of active sleep to quiet sleep. By 37 weeks conceptional age (CA), the sleep rhythm is mature 15 and cycles range from 40-60 minutes. At birth in the full-term, healthy newborn, active and quiet sleep are present in equal amounts. By 8 months, twice as much quiet sleep as active sleep can be found. Therefore, the percent of active sleep declines while quiet sleep in- creases (Stern et al, 1969). The duration of quiet sleep episodes increases from 13.8 minutes at 2 weeks to 22.2 minutes at 20 weeks. Active sleep diminishes from 25.3 minutes at 2 weeks to 14.4 minutes at 20 weeks (Dittrichova et al, 1976). This translates into a longer sleep state periodicity in quiet sleep through three months of age, whereas at 8 months, this reverses and active sleep periodicity be- comes longer. Thus, greater time elapses between quiet sleep states during the first three months, and between active sleep states from 8 months onwards. However, no correlation exists at these ages be- tween the length of the active sleep and quiet sleep periodicities. Whereas an 8-month-old's active sleep periodicity is likely to be higher than his quiet sleep periodicity, the specific relationship, i.e., how much longer the lag between active sleep states than between quiet sleep states would be, cannot be predicted. These sleep states are maturing independently (Stern, Parmelee & Harris, 1973). In fact,’ evidence from the study of premature infants indicates that there is no progressive organization of sleep prenatally, and that each compon- ent of sleep matures independently (Dreyfus-Brisac, 1970). The first differentiation between active sleep and quiet sleep does not occur until 30 weeks CA. The active sleep pattern deveTOps at 32-34 weeks CA and is fully developed at 35 weeks, while quiet sleep patterns develop at 36-38 weeks CA (Parmelee, 1973; Dreyfus-Brisac, 1975). 16 Indeterminate (transitional) sleep remains relatively constant over the first year. There is only a small inverse relationship between quiet sleep and indeterminate sleep (Emde & Walker, 1976). The major shifts in indeterminate sleep occur prenatally. Most of the sleep time of the 30-week-old infant CA is not-clearly defined active sleep which resembles indeterminate sleep. By 35 weeks CA, active sleep begins to be more distinct and indeterminate sleep levels off to a rate which it more or less retains throughout the first year of life (Parmelee et al, 1967). (See Figure 1), (Appendix C). THE DISCOVERY OF REM SLEEP It was not until the notable observations of Aserinsky and Kleitman (1953) that the realization of successive stages of sleep occurred. These investigators discovered that eye movements during sleep were conjugate and regular and that they occurred in bursts of activity periodically throughout the night. Systematic tests revealed that cortical evoked responses during rapid eye movement periods were similar to those obtained during the waking period. This led to the hypothesis that bursts of REM activity are necessary for heightened perceptual processes and may be the neurophysiological setting for halé- lucinatory repetition of accumulated experience. Aserinsky and Kleitman further suggested that REM sleep is phylogenically more primi- tive than non-REM (NREM) sleep since REM sleep matures earlier than NREM sleep and decreases in amount ontogenetically. Later, other behaviors were found to correspond to REM periods. Body movements were found to be associated with a return to the waking state during the sleep cycle. A periodicity then was discovered to be 17 present in movement during the sleep cycle. Decreases in ocular activity were seen to correspond to interruptions in body movement, and conversely, periods of eye movement paralleled increased motility. Five or more cycles of ocular and body motility were discerned nightly. Thus, it became apparent that organized cycles are present during sleep (Aserinsky & Kleitman, 1955). When these patterns were superimposed on citations of cyclic activity of the EEG (Loomis, Harvey & Hobart, 1935), coordination of behavioral and neurophysiological activity be- came evident. REM was found to be consistent with stage 1, or the low voltage fast wave pattern, of Loomis et al. Moreover, peaks of eye movement were found to correspond to peaks of the EEG cycle and to greater body movement (Dement & Kleitman, 1957a). When subjects were awakened at these times, a high incidence of dream recall was achieved. A low incidence of dream recall was found when subjects were awakened at other times. More convincingly, patterns of REMs were related to reported visual imagery of the dreams (Dement & Kleitman, 1957b). This still left open the question of the function of REM sleep. Several theories have been advanced since the discovery of REM sleep, including ontogenetic and phylogenetic theories. Among these, several relate to activation of regulator centers which respond to the absence of restraining influences on the REM center due to the immaturity of the system. An alternate theory is less passive in approach, and pos- tulates that REM is a response to a specific CNS requirement which originates in the pontine area of the brain stem (Roffwarg, Muzio & Dement, 1966). The phylogenetic theory proposes that REM sleep evolved to provide internal stimulation so as to serve a vigilance function. 18 Others offer that REM serves to increase “Cortical tonus" while pre- serving the basic rest cycle and the oculomotor innervation hypothesis suggests that the function of REM is to strengthen neuromuscular path- ways involved in conjugate binocular eye movements during early develop- ment (Berger, 1969). Whatever the function of REM, its discovery has largely contributed to the objective classification of sleep patterns. Five REM states have been identified: sucking, drowsy, fussy, crying, and sleeping REM. In the first two months of life, the EEG of these REM states are indis- tinguishable (Metcalf, 1970), but other classification criteria are not. In contrast to adult sleep which begins with a NREM period, REMs are generally present at the onset of infant sleep. The NREM-REM period begins to shift to the adult mode at 12 weeks, although the change may not be as dramatic as the literature seems to indicate. One possible reason for the reduced incidence of NREM sleep at the onset of sleep may be a confounding laboratory effect. At home, many naps begin with a 2 to 5 minute period of NREM sleep. This was not typically seen in the laboratory where only 3 out of 13 subjects tested during daytime naps began sleep with a NREM period. At home, many naps end in REM sleep as well, whereas in the laboratory, the final REM period is either shortened or omitted entirely. Although this initial NREM period is still substantially shorter than adult REM periods at sleep onsent which lasts between 50 and 70 minutes, 2 minute initial NREM periods are still an indication that the mode of sleep onset in early infancy is not as discrepant from the adult mode as is commonly thought (Bernstein, Emde & Campos, 1973). 19 The initial REM stage which has been observed in laboratory studies is also atypical of REM sleep commonly observed in newborns. Only part of the initial REM time corresponds to active sleep which is characterized by the disappearance of tonic activity of the chin muscles and low voltage fast wave EEG. Moreover, the first REM is shorter than other REM periods and sometimes differs in amplitude and rhythmicity of the EEG (Paul 8 Dittrichova, 1977). It probably corresponds to phase 'a' REM state in Petre-Quadens classification scheme, as phase 'd' REM state is described as being the more clearly defined of the two, with state 'a' being the more likely of the two to be discrepant from other aspects of active sleep (Petre-Quadens, 1966). ACTIVE.SLEEP Active-REM sleep is characterized by EEG activation, an increase in respiratory rate, eye movements and the disappearance of the EMG of the chin as well as an increase in body movement. In EEG, regular waves in- crease with age (Dittrichova, Paul & Von Dracek, 1976). Active sleep be- comes more coordinated towards term, but only becomes fully coordinated by 10 months of age. It is only at that point that the disappearance of chin movements perfectly coincides with the presence of rapid eye move; ments (Petre-Quadens; 1967; 1974). Sponteneous smiling is seen both in sleep REM and drowsy REM states. but the incidence of smiling during the transition from waking to sleep- ing diminishes at 12 weeks. Three months is the time when undifferen- tiated REM becomes less frequent. At the same time, the incidence of smiling levels off. There is about 4 to 5 times as much spontenaous smiling in prematures as in full terms, and more of a burst effect can be seen. Endogenous smiling decreases over the first five or six months 20 at which point it disappears or becomes a rarity (Emde & Metcalf, 1968; Emde & Harmon, 1972). Body movement, on the other hand, in- creases with age though variance decreases as movement becomes more regular (Tautermannova, 1973). Sucking movements are more frequent in active sleep than in quiet sleep (Dreier & Wolff, 1972). The rate of non-nutritive sucking during sleep is twice that of nutritive suck- ing and the sucking appears in bursts of 2% to 6 per second. They are interrupted by rest intervals of less than one minute which differs from the constant rate of nutritive sucking. Sucking bursts correlate to bursts of EEG activity (Wolff, 1968; Goldie & Svedsen-Rhodes, 1970). With regard to eye movements, they are observed only in active sleep. Slow eye movement appears first, increases in size and amount, then descreases toward the end of the active sleep epoch. Slow eye movements are observed only during sleep states. None can be seen during waking states (Prechtl & Lenard, 1967; Schulman, 1973). Further- more, no evidence can be seen for burst patterns using DC recording techniques. Prechtl and Lenard speculate that Aserinsky's reporting of a burst effect was probably due to less sensitive recording pro- cedures which failed to record slow eye movements. The use of DC re- cording, however, eliminates this error. Sleep REMs are less regular and less frequent than those observed in the waking states. REM epi- sodes shorten with age and become less interrupted. The rate of eye movements increases with age, and more REMs occur during early active sleep periods than during late active sleep periods (Dittrichova, Paul & Pavlikova, 1972; Schulman, 1973). 21 QUIET SLEEP During quiet sleep, eye movements disappear, tonic muscle activity of the submental muscles reemerges, respiration decreases while slow waves of the EEG increase and rapid waves disappear. Initially, quiet sleep is characterized by bursts of high amplitude slow waves alter- nating with low amplitude activity, or the trace alternant (Parmelee et al, 1967). Between two and six weeks of age, trace alternant de- creases and between 12 and 20 weeks higher frequencies are observed. The amplitude of slower waves increases and nearly doubles between 2 and 20 weeks. There is a concurrent increase in regular, continuous slow waves. Spindle-like bursts of sigma frequency (10-15 Hz) appear and are developed by 3 months (Parmelee, 1977). As for respiration, it becomes more regular and the frequency decreases over the first 20 ’ weeks of life (Dreyfus-Brisac, 1970; Paul, Dittrichova and Pavlikova, 1973; Dittrichova, Paul & Von Dracek, 1976). Heart rate reaches a maximum between 4 and 8 weeks of postnatal age and then rapidly declines for the remainder of the first half of the first year of life (Katona & Egbert, 1978). Behaviorally, activity is discontinuous in quiet sleep (Dreyfus- . Brisac, 1975) and eye movements beneath closed lids cannot be observed. Spontaneous mouthing is observed only in quiet sleep, and is similar in temporal organization to non-nutritive sucking (Wolff, 1968). The course of quiet sleep is as follows: first rapid eye movements disappear, then regular respirations appear followed by characteristic EEG patterns. At this point, the continuous tonic EMG activity in the chin is present. At the culmination of a quiet sleep period, these 22 features disappear in reverse sequence (Paul & Dittrichova, 1974). For the purposes of this study, characteristic changes in slow and rapid eye movements, mouthing activity, gross body movements, EMG, respiration, and heart rate will be the variables used to detect sleep state transitions. WAKING STATES Gesell and Ilg (1949) advised their readers that wakefulness exists only in the hungry neonate. Thus whenever a newborn was awake, he was presumed to be hungry. After a feeding, sleep much necessarily ensue, according to this assumption. The notion that wakefulness does not exist in the satiated infant has been refuted by more recent observa- tions. Behavioral wakefulness was found to occur immediately after birth and between sleep periods, even in the absence of feeding. The ability to sustain wakefulness is somewhat hampered by obstetrical medication, which also serves to increase NREM sleep. Moreover, wakefulness in the newborn period was demonstrated to be attentive (Emde, Swedberg, & Suzuki, 1975), as has been confirmed by newborn behavioral exams such as the NBAS which relies on an alert awake state in the infant for sev- eral of its test items. As fOr the development of behavioral concomitants of the waking states, vocalizations increase and become more regular over the first 6 months of life, whereas crying decreases at 2 to 3 months and is replaced by increased babbling and manual manipulation of toys. Crying reaches its peak frequency at 8 weeks. By 10 weeks, crying has decreased and by 12 weeks it occurs less than 5% of the time. On the other hand, babbling occurs rarely before 6 weeks and increases in frequency only from 8 weeks on. It becomes more prominent at 10 and 12 weeks 23 while toy manipulation does not increase significantly until about 12 weeks. SLEEP AND THE IMMATURE INFANT: SOME ONTOGENETIC CONSIDERATIONS. The sleep cycle of the premature at term is not as well organized as that of a full-term neonate. This suggests that there is an incom- plete catch-up phenomenon in the premature during the weeks of life be- fore the expected date of delivery. At term, prematures have a lower threshold of arousal than do full-term infants. They are more easily aroused and are less able to inhibit arousal. Sucking is not as sooth- ing to the premature, and responses to neurological examinations are weaker. However, they cry less than full-terms and, overall, their activity state is lower (Parmelee, 1975). As for physiological concomitants of state, prematures display less regular respiration than full-terms, and periodic respiration is also more prevalent. Regular respiration becomes more rapid at 38-41 weeks CA (Dreyfus-Brisac, 1970) Respiratory rate is higher in pre- matures than in full-terms until 8 months postnatal age, when the two groups become equivalent (Katona & Egbert, 1978). Frequency is also higher in Small-for-Date infants during quiet sleep, indicating that higher respiratory rate is characteristic of immature organisms in general. This is true of periodic breathing as well. Periodic breath- ing constitutes 36.1% of respiration in normal newborns and 94.5% in low birth weight infants (Dittrichova & Paul, 1973; Fenner et al, 1973). 24 Premature cardiac rate is irregular. The regular rhythm increases in rapidity until 37 weeks at which time it stabilizes (Dreyfus-Brisac, 1970). Before 37 weeks CA, periodic variations appear in both active and quiet sleep. After that point, slow periodic variations in active sleep are superimposed by fast variations. In general, there is less variability in the heart rate of prematures than of full-terms. At birth, many of the prematures still do not display sleep cycling of the heart rate. In others, heart rate variability can be found only during the active sleep state (Radvanyi & Morel-Kahn, 1976). Before 30 weeks CA, changes associated with sleep stages do not appear at all (Watanabe, Iwase & Hara, 1973). Heart rate is consistently higher in prematures than in full-terms over the first 6 months of life (Katona & Egbert, 1978). Eye movements are absent in the non-viable premature infant. By 30 weeks CA, periods of eye movements of significant length appear (Parmelee, 1973). Prematures only show a reduction in localized mo- tility rate at 38 weeks CA. Until that point, body movements are con- tinuous (Dreyfus-Brisac, 1970; Parmelee, 1973) (See figure 1), (Appendix C). At this point, the examination of premature, immature and brain damaged infants is the primary source of knowledge on fetal development. Consequently, immature papulations have been studied in order to ob- tain information on the ontogenesis of sleep and sleep state parameters. ENVIRONMENTAL EFFECTS ON SLEEP Maternal Variables and Infant Rhythmicity Infant sleep cycling has been found to be independent both of mothers' preferences for infant sleep patterns (Friedman & Erich, 1978) 25 and mothers' own rhythmic activity. No temporal relationship has been observed between maternal and neonatal sleep patterns (Anders & Roffwarg, 1973a) or between maternal and fetal sleep using maternal and fetal heart rate as indicators (Happenbrouwers et al., 1978). Exogenous Stimulation and Sleep Dimmed light has the effect of stabilizing respiration rate ir- respective of sleep state. Noise level has no parallel effect on sleep (Ashton, 1971). Selective sleep stage deprivation could not be accom- plished during the newborn period through interruption of sleep during REM and NREM periods. The sole effect to this procedure was in increas- ing sleep time during the following sleep period. However, NREM sleep seemed to be preferred in recovery (Anders & Roffwarg, 1973b). The general response to stress in the newborn is the prolongation of NREM sleep. Following routine hospital circumcision, most infants show an increase in NREM sleep (Emde et al, 1971). Emde et al speculate that the increment in NREM sleep following this procedure is a conservation/ withdrawal response to stress. This is congruent with the notion of a passive stimulus barrior existing during the neonatal period which prevents the infant from being "overloaded" with excessive amounts of external stimulation (Tennes et al, 1972). The result is a stimulus shut down which often takes the form of a general suppression of be- havioral response to stimulation through rapid habituation, or more dramatically, through resorting to immediate periods of quiet sleep. NREM sleep is believed to be more restful than REM sleep. This is supported by the fact that the organism is less active during NREM sleep, but also less responsive to certain stimuli. Overall, infants' 26 responsivity to external stimulation is greater during REM than during NREM sleep (Paul & Dittrichova, 1973), hence it would be adaptive for the infant to retreat to prolonged periods of NREM sleep when overbur- dened with either painful or excessive stimulation. In the current study, infants were exposed to constant temperature, noise level, and lighting. External stimulation was limited to the laboratory environ- ment. PSYCHOPHYSIOLOGY AND SLEEP Heart Rate Heart rate tends to decrease between 21 and 30 days postnatal age, after which it increases. After 3 months of age, heart rate then de- creases rapidly in waking and more slowly thereafter. Heart rate vari- ability is greatest during REM sleep, and lowest during crying and bottle feeding. At week one, variability during wakefulness is not as great as during REM sleep but larger than during NREM sleep. Thereafter, variability is greatest during waking, next highest during REM sleep, and lowest during quiet sleep. Variability decreases rapidly from 2 to 4 months postnatal age, and less quickly from 4 to 6 months. Quiet sleep variability decreases at 1 month at which point it stabilizes. Heart rate during active sleep and quiet sleep are very similar, whereas heart rate variability during REM sleep is closer to that of the waking state (Watanabe, Iwase, & Hara, 1973; Harper et al, 1976) (See Figure 1) (Appendix C). 27 Respiration Mean respiration rate, respiratory variability, and amplitude of oscilations in volume and frequency are higher in REM than in NREM sleep (Hathorn; 1974, 1975). The highest frequency of respiration is in waking, the lowest in quiet sleep with REM sleep frequency falling in the middle (Dittrichova, 1966). Skin Potential , There is an overall decrease in Skin Potential Response during sleep and an increase upon awakening. During REM, an increase in fluctuation about baseline occurs, usually in a negative direction and greater variability is present. The presence of skin potential re- sponses in active sleep during the newborn period is in Opposition to what is seen during adulthood. The change in distribution to the adult mode occurs during the first 2 months of life. There is a relationship between the development of spindle activity of the EEG and the shift to the adult mode of the skin potential response in quiet sleep. In- fants with spindles in quiet sleep EEG show more skin potential response in quiet sleep, whereas younger infants without spindles show more skin potential response in active sleep (Bell, 1970; Curzi-Dascalova &‘ Dreyfus-Brisac, 1976) (See Figure 1) (Appendix c). Intercorrelation Among Psychophysiolqgical Variables Prechtl, Weinmann, & Akiyama (1969), using serial correlation tech- niques, found that heart rate and respiration, which are centrally coupled in the brain stem, covary in normal newborns through sometimes not in apathetic and hyperexcitable babies. This is refuted by Baust 28 and Gagel (1977) who conclude that heart rate and respiration in new- borns are not yet regulated by a central pacemaker and hence are not of parallel cycles. They.explain that this is obscured by the use of arithmetic means, which may clarify Prechtl et al's original conclu- sions. The use of autocorrelational and power spectral analysis, how- ever, demonstrates differences in the variability within the two auto- nomic cycles. Respiratory median intervals are highly positively correlated with the voltages of the EEG and with the number of REMs and negatively correlated with EMG activity (Prechtl, Weinmann, & Akiyama, 1969). A correlational matrix yielded the following clusters of state concomitants: 1. EEG parameters, frequency of body movements in active sleep and maintenance of quiet sleep; 2. Duration of sleep states. Active sleep negatively corre- lated with quiet sleep and transitional states; 3. Phasic events of active sleep; frequency of REMs and EMG. (Paul, Brichacek & Dittrichova, 1978). The summary just cited provides evidence that a well defined sleep cycle exists from term on. Early in the first month of life, behavioral and physiological variables covary in occurrence in the mature or- ganism forming 40-60 minute sleep cycles. Moreover, the behavioral and physiological parameters of sleep develop predictably within the first 8-10 months of life. Within this normal range of development, however, exist broad individual differences which are relatively stable, at least through 6 months postnatal age. Consequently, the sleep polygram 29 allows for a peripherally derived view of the condition of central and autonomic functioning. Various factors can be gleaned from the study of these records, among them the activity level of the organism as in- ferred from amount of activity during sleep; the rhythmic component as gathered from the maturation of cycling activity using the index of rhythmicity; and state organization as understood from the duration of individual states or state maintenance and from the development of synchrony among state parameters. A These factors, though are some of the same elements which have been cited by students of individual differences or infant temperament. Two factor analytic studies of the NBAS, one yielding six factors (Osofsky & O'Connell, 1977) and one yeilding seven factors (Lester, Als, & Brazelton, 1978) concluded that state control constitutes a separate factor of the NBAS. Two of Thomas, Chess & Birch's tempera- ment factors are rhythmicity and activity level. The NBAS, though is not recommended for use past 30 days of age and the CIT is not standardized before 3 months. Consequently, correlations between the two scales have traditionally been for individual items only based on post-hoc examination of the results. Moreover, the number of compari-« sons which this procedure necessitates, inflates the probability of type 1 statistical errors thus reducing power (Brazelton, 1978). Estimations of sleep cycle rhythmicity and sleep state organization, may be correlated to themselves at different ages and should serve to minimize this error. The apparant overlap between concepts of the NBAS, infant temperament scales, and the index of rhymicity of the sleep polygram, also suggests possible comparisons. The purpose of this 30 study, then, was to compare performance on each of these individual measures: the sleep polygram, the NBAS, and a scale similar to the CIT. Summary: Procedure and Prediction: The Brazelton NBAS was performed on infants at 10-12 days of age. Stability of results has been shown to be better when infants are tested in the second week of life than when they are tested in the first (Sostek & Anders, 1977). This scale was then scored in accord- ance with predetermined factors (Lester, Als, & Brazelton, 1978). At four and six weeks, infants were brought to the laboratory where their sleep was monitored polygraphically and observationally by trained assistants. At six weeks of age, mothers were asked to fill out the MITS infant temperament scale which is based on the categories of Thomas, Chess & Birch (Bonem, 1978). The Hypotheses Are:' 1. There will be significant correlations between NBAS and state organization and sleep duration as measured by the sleep poly- gram. 2. Individual differences in infant sleep profile will be evident at 4 weeks of age and will remain stable through 6 weeks of age. E3. There will be significant correlations between NBAS factors and MITS temperament scales. CHAPTER III METHOD SUBJECTS Thirty-two women in their 7th to 9th month of pregnancy were re- cruited from local prenatal care agencies. They were visited by the experimenter at the agency and the study was described. If the subject was interested in participating, signed consent was obtained and ar- rangements were made for the subject to contact the experimenter imme- diately after the birth of the baby. In addition, 6 subjects were lo- cated through the birth announcements of a local newspaper. Mothers were telephoned and asked if they were interested in participating in a study of newborns. Appointments for testing were then made with in- terested mothers. When the experimenter visited mothers in their homes, the study was again described and signed consent was obtained. A total of 37 mothers completed at least one phase of the study. Of these, 20 eliminated themselves before the study was completed. Four were eliminated due to equipment failure and six were eliminated be- cause the infant failed to complete the study (e.g., because of fussiness or failure to fall asleep in the lab). Therefore, physiological data are available for only 7 infants at 4 weeks postnatal age. Of these, only 4 completed the full study through 6 weeks postnatal age. Ten subjects completed the two postnatal behavioral procedures; the Brazelton Neonatal Behavioral Assessment Scale (NBAS) at 10 days postnatal age; and the Michigan Infant Temperament Scale (MITS) at 6 weeks postnatal age. 31 DES fir H65 We: 32 Characteristics of the 10 families who completed the behavioral procedures were as follows. Five infants were male, 5 were female. The mean infant birth weight in grams was 3490.676 (range: 2688-4144). The mean birth length in centimeters was 53.3 (range: 52.1-55.1). Mothers had a mean of 14.8 years of education (range: 12-16) and fathers had a mean of 15.8 years of education (range: 10-20). Mothers mean age was 27.9 (range: 22-39) and fathers mean age was 30.4 (range: 23-41 years). Four mothers were primiparous, 6 were multiparous. The mean family income was between 310,000-313,000 (range: less than $4,000- greater than $30,000). None of the mothers reported any eating or sleep- ing problems with their infants. There were no significant difference in birth weight or birth length between those infants who did complete the study and those who did not. The mean weight at birth for those infants who did not complete the study was 3386.88 grams. The mean length at birth was 51.56 centimeters. DESIGN Each infant was tested on three separate occasions. During the first visit, an assessment of infant reflexive and behavioral performance was made. During the second and third visits, infant sleep profiles were obtained (see Table 1). PROCEDURE 1229121221: When each infant was 10 days of age, the experimenter visited the subject at home. The mother was asked to complete a questionnaire on the delivery of the infant. Infants were then evaluated by a certified examiner by means of the Brazelton Neonatal Behavioral Assessment 33 TABLE 1 RESEARCH PROTOCOL 10 Days Postnatal Laboratory Visits Week 4 Week 6 Neonatal Behavioral Physiological Recording - Physiological Assessment Scale Sleep Recording - Sleep Background Information Questionnaires MITS Infant Temperament Scale huma ms havi thrc inte WEE tr: 34 Scale (Brazelton, 1973), which is a behavioral scale for the newborn human infant. The NBAS assesses reflexive and motor behavior and.general physical state upon recovery from labor and delivery. Infants biobe- havioral state or dynamic levels of self-organization is followed throughout the examination as well as infant's responses to external and internal stimuli (Brazelton et al., 1973). Following the exam, arrangements were made for the infant to come to a laboratory on the Michigan State University campus in 18 days time. 28212115112: When the infant was 28 days of age, mothers brought their infants to the Developmental Psychobiology Laboratory. The testing procedure was explained. Then infant was dressed in diaper and tee-shirt to as- sure a constant body temperature and freedom of movement. The infant was placed on a dressing table in the experimental room. Here elec- trodes were attached. The experimenter first gently cleaned the recording sites on the infant's torso, and then taped (with sterile micropore tape) the Beckman Ag/AgCl biopotential electrodes in position, using Synapse Hypoallergenic electrode cream as the electrolytic medium. The electrocardiogram I (EKG) was recorded via two electrodes placed on the infant's chest, 2.5 cm above each nipple and a ground electrode 2.5 cm above the navel. The infant was then placed in a crib in the experimental chamber. The electrodes were then connected via a coupler cable to the Grass In- struments Polygraph amplification and writing system in the adjacent Instrumentation Laboratory. Mothers were then asked to feed their in- fants who were not already sleeping in order to help them fall asleep. DE?“ The fan ne: by 35 Lighting was uniformly dim and ambient noise included only that of an overhead fan and a nearby computer terminal. A trained assistant was seated inside the chamber and observed periods of waking, eye movement, facial movement, and body activity. These periods, as well as state changes, were indicated directly on the polygraph write out and served to indicate behavioral state of the in- fant. Observers typed behavioral codes on a computer terminal located next to the infant's crib. These were recorded directly on floppy disk by a L51 11/02 computer located in the adjacent experimental room. Simultaneously, an impulse was sent to the polygraph recorder on a sepa- rate channel. This enabled the experimenter to match up behavioral ob- servations with heart rate activity. The mother was then taken to a separate room by an assistant where she was asked to fill our several questionnaires, including the subject feedback record form (see Appendix A). The experimenter, operating the polygraph, checked to see that the infant's electrophysiological signals were being properly recorded. These signals were recorded both on the polygraph recording paper and on magnetic tape via an FM channel of Vetter 8-channel tape recorder. The magnetic tape was used for computer digitation of the heart period (HP) or interbeat interval. The infant was allowed to fall asleep in the crib. The experiment was completed when the infant entered the waking state or when the in- fant began to cry. The minimum recording time was 28 minutes. The maxi- mum recording time was 141 minutes; mean recording time was 67 minutes. When the session ended, electrodes were removed and the electrode sites were day 3:, r 36 were cleaned with alcohol pads. Arrangements were then made for the 45 day visit. When the infant was 45 days of age, mother and infant returned to the lab. At that time, the same procedure described above for the 28 dayvisit was repeated. In addition, mothers filled out the Michigan Infant Temperament Scale (MITS). OBSERVER RELIABILITY Observers were trained to judge the occurrence of state changes by observing eye movements as seen beneath closed lids, gross body activity, local body activity of one or more limbs, sucking activity, eye blinks, and facial movements. Mean percent agreement was 81.6% (range: 72%- 100%). A standardized state scoring system was used (Anders, Emde, & Parmelee, 1971). DATA REDUCTION THe raw EKG collected on magnetic tape via a Vetter FM tape recorder were computer-digitized. The heart period, or R-R (interbeat) interval of each heart beat was measured in milliseconds from the tape via a com- puter program. At this time, the experimenter entered into the record the instances of behavioral activity as recorded on the sleep polygram. These were then matched up with the written record of behavioral occur- rences as recorded on floppy disk. From these data the experimenter was able to determine when the infant had shifted state. The average heart rate (beats per minute) was computed from the digitized heart period. 37 Results of the Brazelton NBAS were summarized according to the fol- lowing seven clusters: 1. Reflexes; II. Habituation; III. Orientation; IV. Motor Performance; V. Range of States; VI. Regulation of States; VII. Autonomic Regulation (Lester, Als, & Brazelton, 1978). N§A§_ Data were scored according to the following 7-cluster scoring sys- tem for the Brazelton scale (Lester et al, 1978): 1. Habituation: state control maintenance in response to environmental intrusions such as light and sound. 2. Orientation: infant response to auditory and visual stimuli. Scores range from 1 to 9. "9" is an optimal score. 3. Motor performance: maintenance of good muscle tone and controlled motor behavior. Scores range from 1 to 9. "9" is an Optimal score. 4. Range of state: stability of infant behavioral state. Scores range from 1 to 6. An optimal score of "6" indicates a moderate range of state over the course of a 30 minute exam. 5. Regulation of state: state maintenance during an irritating pro- cedure. Scores range from 1 to 9. An optimal score of "9" indi- cates that infant's ability to maintain a quiet state. 6. Autonomic regulation: Integration of control mechanisms of skin color and nonelicited muscle reflexes. Scores range from 1 to 9 with an optimal score of "9" indicating moderate reactivity of autonomic responses. 7. Reflexes: signs of possible neurological damage. Scores range from 1 to 5 with an optimal score of “2". 38 Results of the MITS were summarized according to the following 10 categories: I. Activity level; II. Mood; III. Intensity of response; IV. Threshhold of response; V. Distractibility; VI. Rhythmicity; VII. Approach; VIII. Adaptibility; IX. Persistence 1; X. Persistence 2. Pearson Product-Moment correlation was done on the results of the NBAS and MITS summary scales. As so few subjects completed the six week sleep period, only data from the four week sleep period will be reported. Digitized interbeat intervals were the units of measurement. Data were divided into segments of two minutes prior to and two minutes following a state change. Two state changes were selected for each subject. Since all infants did not sleep through an entire sleep cycle, it was impoSsible to select one active sleep state and one quiet sleep state from each infant's record. Therefore, it was decided to select one ascending state change and one descending state change from each infant for analysis in order to verify that state changes could be reliably detected through behavioral obser- vation. An ascending state change was defined as a shift from a more quiet state to a more active state. Therefore, a shift from state one (quiet, NREM sleep) to state two (active, REM sleep) was defined as an ascending state change. A descending state change was defined as the reverse. A shift from state 3 (drowsy sleep) to state 1 (quiet NREM sleep) would then be defined as a descending shift. Data were then transformed into standard scores. Two-tailed T tests were performed to determine whether ascending sleep state shifts could be discriminated from descending sleep state shifts, thus illustrating that the observational determinations of sleep state shifts correspond with the physiological shifts. In addition, the 39 differential index, defined as the standard deviation of differences between successive R-R intervals, was computed as a measure of beat to beat, or short-term heart rate variability (Siassi, Hodgeman, Cabal & Hon, 1979). Additional significant tests were performed between as- cending and descending sleep state shifts using the differential index. This was done to determine whether sleep states could also be discrim- inated on the basis of short-term heart rate variability. Characteristics of four-week infant sleep state will be summarized. Unfortunately, the limited sample size of infants who successfully com- pleted the four week sleep polygram (7 subjects) precludes any meaning- ful comparison of the sleep polygram with the NBAS. A descriptive com- parison of sleep cycle characteristics was made between the four- and six-week polygrams for the four infants who completed the six week sleep polygram. CHAPTER IV RESULTS AND DISCUSSION Results are presented in two sections. The first section contains behavioral data. Descriptive statistics are reported for data from the Brazelton Neonatal Behavioral Assessment Scale (NBAS) performed at ten days infant postnatal age, and from the MITS temperament scale performed at 6 weeks of age. Pearson Product-Moment correlations were computed for the two measures to discover their relationship. It was hypothesized that certain personality traits are inborn, express themselves early in the neonatal period, and remain stable throughout early infancy. In order to determine if certain traits tapped by the Brazelton NBAS are consistent through the first weeks of life, the infants were tested first at 10 days of age, and then approxi- mately one month later. However, since most infants exhibit ceiling ef- fects on the NBAS by four weeks of age, it has not been deemed appro- priate to use the technique past thirty days of age (Brazelton, 1978). The MITS temperament scale was used for the second behavioral testing session as six weeks because most of its items could be applied to in- fants at that age. Certain items pertained only to locomotor infants, and mothers were advised to merely omit those items. Fortunately, several behavioral categories on the MITS seem to com- prise similar behavioral traits to those tapped by the BNAS. The BNAS . assessment of neonatal orientation or reactivity to stimuli, for example, can be compared to the MITS category of threshhold of response to stimu- lation. A score indicating high reactivity to stimuli on the BNAS seems 4O 41 intuitively related to low threshhold of response on the MITS. Secondly, the infant's ability to shut out intrusive stimuli at ten days, assessed by NBAS habitUation, should be related to the infant's ability to shut out distracting stimuli at six weeks of age, measured by the MITS cate- gory of "distractibility". Thirdly, the NBAS cluster of regulation of states could be related to MITS category of mood. It is conceivable that such items as infant cuddliness, consolability, and self-quieting ability at ten days of age might be related to general mood at a later time. Lastly, measures of early internal regulatory mechanisms, such as BNAS regulation of states and BNAS autonomic regulation, may tap the same mechanisms which regulate infant rhythmicity as measured by the MITS category "rhythmicity". These relationships are explored in the following section. The second section contains analysis of the physiological data ob- tained during four and six week infant sleep sessions. Average heart rate during sleep of total sleep sessions and of individual sleep states at four and six weeks are described. Researchers have shown that behav- ioral observation of infant sleep state transitions can be quite accu- rate when compared with physiological determination of sleep state transition (Fuller, Wenner & Blackburn, 1978). Evidence for effective observational identification of physiological sleep state transition as demonstrated in this study are presented. Means for pretransition and post-transitional heart periods were compared with t-tests. Heart rate variability for pretransitional periods and posttransitional periods were computed with the differential index. These indexes were then com- pared using the Wilcoxon Matched-Pairs Signed-Ranks test. 42 Behavioral Measures: NBAS 929.ULI§- The Brazelton NBAS 7-cluster summary scores are shown in Table 2. In general, scores range from 1 to 9 with 9 being the Optimal score. The MITS temperament scale scores are shown in Table 3. Scores range from O to 1: "1" indicates a high level Of the attribute, "0" indicates absence of the attribute. In the case of the mood scale, "1" indicates general positive mood, "0" indicates general negative mood. A Pearson Product-Moment correlation was performed on the 7 NBAS clusters and the 10 MITS scales. Subjects included the 10 infants who completed both of these measures. Correlations among the scales are re- ported in Table 4. Several of the correlations are of interest and sug- gest some continuity of infant attributes and behavior from 10 days postnatal age to 6 weeks of age. Both infant autonomic regulation and infant state regulation at 10 days Of age are correlated to maternal re- port Of infant rhythmicity at 6 weeks Of age (r=.54, r2=.29, and r=.61, r2=.37, respectively; p < .05) Infants who were able to regulate their states better at 10 days were reported by their mothers as having more regular biological cycles at 6 weeks of age. This suggests that infants whose biological regulatory mechanisms are more mature at 10 days also are noted by their mothers as being more regular at 6 weeks. Autonomic regulation at 10 days also was negatively correlated with distractibility at 6 weeks (r=-.61, r2=.37; p < .05). Infant whose con- trol mechanisms for autonomic responses to stress are stronger at 10 days are reported as better able to shut out distracting stimuli at 6 weeks. Moreover, those infants who at 6 weeks were able to shut out distracting stimuli also tended tO shut out stimuli at 10 days. There was a BRAZELTON (NBAS) SUMMARY SCORES OF NEONATES. Reflexes Mean SD Range Habituation Mean 50 Range Orientation Mean SD Range Motor Performance Mean 50 Range Range of States Mean SD Range Regulation of State Mean SD Range Autonomic Regulation Mean 50 Range _ 43 . 1.895 1.883 0 - S .329 .767 - 7.3 HNN .100 .347 - 9 apex: 5.032 .681 4 - 6.6 3.475 .986 5.021 .527 .5 - 7.8 NH TABLE 2 N=20 44 TABLE 3 RESULTS OF THE MICHIGAN INFANT TEMPERAMENT SCALE.N=10 MEL" 5.0 Activity .501 .287 Mood .679 .109 Intensity .359 .220 Threshhold .710 .187 Distractibility .447 .227 Rhythmicity .619 .250 Approach .740 .228 Adaptibility .813 .148 Persistence - 1 .512 .332 Persistence - 2 .553 .312 45 TABLE 4 PEARSON PRODUCT-MOMENT CORRELATIONS BETWEEN 10 DAY NBAS FACTORS AND 6-WEEK MITS SCALES BNAS / MITS Activity Mood Intensity Threshhold Distractibility Reflexes .38 -.73f .62* -.75* .41 Habituation - .17 .03 .07 .37 -.4st Orientation .07 -.40 .27 -.49t .35 Motor Performance I .12 -.14 .18 .12 -.43 Range of States -.12 .19 -.O4 -.06 .04 Regulation of States .05 -.36 .04 -.19 .27 Autonomic Regulation .35 .12 .44 .21 -.61* Rhythmicity Approach Adaptibility P1 P2 Reflexes .52t -.79* -.53* .19 .11 Habituation -.41 -.06 .01 -.32 -.51t Orientation .12 -.36 -.23 .57* .60* Motor Performance -.10 .00 .07 .51t .37 Range of States -.25 -.22 -.14 -.12 -.21 Regulation Of States .61* -.24 -.09 .46t .42 Autonomic Regulation -.54* .19 -.26 .38 .43 * p < .05 t p < .10 46 nonsignificant negative correlation between habituation at 10 days and distractibility at 5 WEEKS (r=-.45, r2=.20; p < .10). Thus the child who easily habituated to irritating stimuli at 10 days tended to be less distractible at 6 weeks. This trend is in keeping with findings reported by Birns, Barter and Bridger (1969) who found stable responses to irri- tating procedures such as application of a cold disc pressor to the abdomen or removel of a pacifier. This trait, which was labeled sen- sitivity, remained stable from two to three days of age through one month, three months and four months of age. Vigor of response, on the other hand, was not a stable trait. Korner, Hutchinson, Koperski, Kraemer and Schneider (1981) express the belief that deviations of differences in central nervous system functioning, particularly in the area of differences in sensory thresh- hold levels and inhibitory regulatory mechanisms, are likely to be the most enduring individual traits. This is modestly borne out in the present study. The three most consistent areas of stability noted are in regulatory mechanisms, threshhold of response, and reactivity to stimulation. Habituation at ten days was related to persistence at 6 weeks (r=.. -.51, r2=.26; p < .06). The child who easily habitated at 10 days tended not to be very persistent at 6 weeks. However, there was a positive correlation between 10 day orientation to auditory and visual stimuli and 6 week persistence (r=.57, r2=.32 and .60 r2=.36; respectively p < .05). In other words, the neonates who were consistently able to follow a vis- ual stimulus and localize auditory stimuli, later were noted by mothers as being persistent infants. Orientation also tended to be related to threshhold (r=-.49, r2=.24; p < .10). Thus a high degree Of reactivity to animate and inanimate stimuli at 10 days of age was related to a low 47 threshhold of response, or high reactivity at 6 weeks Of age. Contrary to what was predicted, NBAS regulation Of state at 10 days of age was not significantly related to mood at 6 weeks, (r=.36, r2=.13, p < .15). However, it is not possible to state at this time that such a relationship does not exist, given the small number of infants who com-, pleted this phase of the study (N=10). Indeed the r2 value of .13 does suggest that a relationship does exist between the two variables. It is necessary to replicate this finding with a greater number of infants in order to determine whether or not there is a correlation between the ease with which an infant quiets himself and can be quieted by others dur- ing the first two weeks of life, and his general positive mood during the second month Of life and thereafter. Birns et al demonstrated a positive correlation between irritability measured at 2-3 days of age, and sooth- ability at 3 and 4 months of age (Birns et al, 1969). Therefore, the direction Of the correlation between infant consolability and self- quieting ability at 10 days and positive infant mood approximately one month later found in the present study is in keeping with previous findings. Summary gf_Behavioral Results Several interesting correlations and trends seem to suggest a certain amount of continuity between infant characteristics Observed by the exam- iner at 10 days of age and infant characteristics reported by mothers at 6 weeks of age. Although the trends are not statistically significant, this could be due to the small sample size (N=10). Each Of these trends accounted for 13% to 25% of the variance, as noted from the squared cor- relation coefficient (rz). Both autonomic regulation and state regula- tion at 10 days were correlates of infant rhythmicity at 6 weeks. Auto- nomic regulation at 10 days was correlated with distractibility at 6 wee and as tor tic ter TROY irr fir tii 48 weeks. Orientation at 10 days was a correlate of persistence at 6 weeks and tended to be correlated with threshold Of responsiveness at 6 weeks as well. Habituation at 10 days tended to be correlated with distract- ibility and persistence at 6 weeks. Of particular interest is the finding that certain autonomic regula- tory mechanisms present during the neonatal period, namely state regula- tion and autonomic regulation, were correlated with observable charac- teristics of biological regulation at 6 weeks. Thus the child who is more regular in his physiological functioning remains so through the first 6 weeks Of life. This lends support to the supposition that bio- logical rhythmicity is a stable property starting from very early in life. Additionally, response to stimuli also seems to be consistent in the period studied. Infants who are able to shut out distracting or irritating stimuli at 10 days seem to do so consistently throughout the first 6 weeks of life. On the other hand, infants who are highly reac- tive to stimuli (score high on the NBAS orientation scale) remain so through early infancy with low threshholds to stimulation at 6 weeks. Physiological Measures Characteristics of infant sleep: '4 weeks The average total sleep time in the laboratory at 4 weeks infant age was 67.43 minutes (range: 23-141 min.) (See Table 5). Of the 7 subjects reported, 5 completed at least one full sleep cycle Of 60 minutes with 1 subject completing 2 sleep cycles (sleep time = 141 minutes). Two subjects only slept through half a sleep cycle (sleep time 28 minutes and 31 minutes). Total Sleep Time in minutes Mean Range Percent Quiet Sleep Mean Range Percent Active Sleep Mean Range Longest Quiet Sleep in minutes Mean Range Longest Active Sleep in minutes Mean Range 49 TABLE 5 MEAN DURATION OF SLEEP 4 Weeks 67.43 28 - 141 54.46% 46.5% - 61.9% 19.89% 6.9% - 46.67% 28.43 17 - 47 10 2 - 32 6 Weeks 53.4 23 - 71 43.38% 35.2% - 57.7% 29.69% 10.5% - 54.6% 16.50 14 - 21 13.25 3 - 27 50 When total sleep time spent in quiet, NREM sleep was compared to total time spent in Active REM sleep, quiet sleep was predictably more pre- valent than active sleep. Infants spent an average of 54.36% of sleep time in quiet sleep (QS) (range: 46.55% to 61.90%) and an average of 19.89% of sleep time in active sleep (AS) (Range: 6.90% to 46.67%). To assess the length Of quiet and active sleep episodes, the longest quiet sleep episode and the longest active sleep episode were selected for each infant. The average longest QS episode, based on data from 7 subjects, was 28.43 minutes (range: 17 to 47 minutes). Two infants did not complete any AS episodes. Therefore, the average longest AS epi- sode, based on data from 5 subjects, was 10 minutes (range: 2 to 32 minutes). The direction of the quiet to active sleep ratio is in keep- ing with research previously cited, though the length Of the episodes of active sleep are a bit shorter and the lengths of the quiet sleep episodes are a bit longer than those cited by Dittrichova (Dittrichova, 1966). Dittrichova reported that duration of Q5 episodes are 13.8 min- utes at 2 weeks Of age and reach a mean length Of 22.2 minutes only at 20 weeks Of age. They further report that active sleep diminishes from 25.3 minutes per episode at 2 weeks a: 14.4 minutes at 20 weeks. The discrepancy between the results obtained in this study and those of Dittrichova may be due to the laboratory conditions. Following stress- ful conditions, Emde and his coworkers found changes in sleep cycle characteristics Of newborns. Following routine hospital circumcision, an increase in Quiet NREM sleep was noted in infants (Emde, Harmon, Metcalf, Koenig, and Wagonfeld, 1971). The laboratory experience did appear to be stressful tO the infants. Electrode attachment often 51 provoked irritable crying and many infants had to be soothed by their mothers for extended lengths Of time before falling asleep. Therefore, it is possible that these sleep sessions contain an inordinate amount of quiet sleep and are not typical of daytime sleep of the four week Old infant. The average heart rate for total sleep periods was 135.57 beats per minute (bpm) (Range: 125.10 bpm to 144.00 bpm) (See Table 6). The aver- age heart rate for state 1, quiet sleep was 128.88 bpm (range: 123.59tnxn to 136.30 bpm). The average heart rate for state 2, active sleep was 159.79 bpm (range: 122.33 bpm to 169 bpm). Four infants entered sleep in the adult mode with a prolonged state one NREM sleep segment (mean length 19.75 minutes). Three infants fell asleep with a brief segment of state 3 or Drowsy sleep (mean length 2 minutes) with rapid eye move- ments observed. This is the mode Often observed in laboratory study of infant sleep, but rarely seen in Older infants or adults. Characteristics of infant sleep: 6 weeks Five subjects completed the 6 week sleep session. Mean length of sleep time was 53.4 minutes (range 23 minutes to 71 mintues) (See Table 5). Of these, 3 completed one full sleep cycle. Two completed only A half of the sleep cycle (sleep time 23 and 38 minutes). Four subejcts completed one full quiet sleep episode and one full active sleep episode. When data from these 4 subjects are compared, re- sults indicate that mean percent time spend in quiet sleep was 43.38% (range: 35.2% to 57.7%), while mean percent time spent in active sleep was 26.69% (range: 10.53% to 54.69%). Thus the incidence of quiet sleep not only was still greater then the incidence of active sleep, but also 52 TABLE 6 MEAN HEART RATE DURING SLEEP SESSIONS IN BEATS PER MINUTES TOtal Sleep Period Mean Range Quiet Sleep Mean Range Active Sleep Mean Range . 4 Weeks 135.57 125.1 a 144.0 128.88 123.5 - 136.3 135.79 122.3 - 169.0 6 Weeks 140.59 134.9 - 150.0 125.75 123.9 - 154.4 147.04 124.2 -146.7 53 was more in keeping with data reported elsewhere regarding neonatal sleep. Mean length of the longest quiet sleep episode was 16.5 minutes, (range: 14-21 minutes). Mean length of the longest active sleep episode was 13.25 minutes (range: 3-27 minutes). This too is clear to Dittrichova's report of duration Of sleep states within the sleep cycle. One possibility is that the second laboratory sleep visit was not as upsetting to the infants as the first laboratory visit. A second possibility is that the second laboratory visit was not as upsetting to the mothers as was the first visit. Once the mothers had been intro- duced to the laboratory proceedings, they may have felt more comfortable bringing their infants back for the second visit. This, in turn, may have had a calming effect on the infants. Therefore, the infants might not be expected to be as stressed during the second visit as they were during the first. The average heart rate for total sleep periods was 140.59 bpm (range: 134.97 to 150 bpm) (See Table 6). This is higher than the average heart rate of 135 bpm at 4 weeks. Harper, HOppenbrouwers, Sterman, McGinty and Hodgeman (9976) found that heart rate tends to in- crease at 30 days of age and does not decrease again until 3 months postnatal age. The current results would tend to support the findings of increased heart rate after the fourth week of life. The average heart rate for state 1, quiet sleep was 125.75 bpm (range: 123.93 bpm to 154.4 bpm). The average heart rate for state 2 active sleep was 147.04 bpm (range: 124.2 to 146.71 bpm). Two infants entered sleep in the adult mode, with prolonged initial state 1 Q5 epochs. Three infants entered sleep in the immature mode with brief, 1 to 2 minutes REM eipsodes. 54 Determination gf_Sleep_State Transitions In order to ascertain whether or not behavioral Observation is a reliable method of detecting sleep state transitions, heart period, (in- terbeat interval) segments were selected from the 4 week sleep polygram for the 2 minutes immediately preceding and 2 minutes immediately succeed- ing the Observation of a transition from one sleep state to another. It would have been preferable to have selected one active sleep episode and one quiet sleep episode for each subject. However, the limited number of subjects who completed the procedure made it inadvisable to elim- inage still more subjects on the basis of this criterion. Therefore, it was decided to select one ascending state change and one descending state change from each subject. An ascending state change was defined as a change from a more quiet to a more active state. These included shifts from state 1 OS to state 2 AS; from state 2 AS to state 3 Drowsy state; and from state 3 Drowsy sleep to state 4 awake. A descending state change was defined as a change from a more active to a more quiet state. These included shifts from state 4 awake to state 3 drowsy; from state drowsy to state 2 AS; and from state 2 AS to state 1 Q8. Since interest was in seeing change from before the transition to after the transition, and not within the period preceding or succeeding the change, all scores were transformed into standard 2 scores. This made it possible to group seg- ments as follows: (1) all ascending pre-shift segments; (2) all descend- ing pre-shift segments; (3) all ascending post-shift segments; and (4) all descending post-shift segments. As can be seen in Figures 2 and 3, Observers did reliably detect sleep state transitions. The correlation between pre-transition and post transition means for ascending sleep state V’ZDN.‘ P1231) .7500 .6767 .6333 .5300 .4567 .3833 .3100 .2367 .1633 .0900 55 -.6489 “.5067 'o3640 '.2222 -.0800 O '07200 “05778 -04356 -0293} '01511 POST MEANS Figure 2. 07200 .6767 .5300 .3100 .2567 .1633 .0303 Pre- and Post-Transition Means For Ascending Sleep States (n‘lfl‘l fWD‘ .8900 .6349 .5967 .3789 .2511 .1233 -0059‘ -01322 ‘o2500 56 -.7156 -.4467 -.1778 .0911 .3600 .Q-c--.----§----.coo-QQCOCQc---§----Q----.----§. O. Q ........ .0....... 9.0....00 Q........ Q........ Q..00.... 9.0.0.... O....0..0..0000.0.. 9 00000000 900000000 9 00000.00 O.....0.. 9......00 9 0....... 900...... Q.......0......00.. O i O . OCOC—QQCCQQOQOCQc---.----.----Q----Q----.----§. -.8530 -.5811 '.3122 -.0433 .2256 POST MEANS Figure 3. Pre- and Post-Transition Means For Descending Sleep .890 .634 0536 .373 O I.) ll H “.03“ '0132 '0230 States 57 transitions is -.996 (p < .001). Results of a t-test indicate that the two means are significantly different (t = 4.80; p < .003). The correlation between pre-transition and post-transition means for descending sleep state transitions is -.995( p < .0001). However, a t-test does not indicate a significant difference between the means (t=.99). It is possible that the small number of subjects is responsible for the lack of significance. On the other hand, the large negative correlation between pre-transition mean Heart Period and post-transition mean Heart Period strongly suggests that there is a reliable difference between the two minutes before and the two minutes after the point wherein an Observer noted a change in infant sleep state. Therefore, the data does suggest that Observational methods Of sleep state transition detection are highly related to physio- logical methods Of sleep state transition detection. An additional demonstration Of reliable behavioral Observation of sleep state transition can be seen by graphing heart rate for the two minutes before and two minutes after transitions. Figures 4 to 7 depict heart rate accelerations. Heart rate is shown in milliseconds between beats. A small beat-to-beat interval indicates a rapid heart rate whereas a large interbeat interval indicates a slower heart rate. Figure 4 demon- strates an ascending shift from a quiet sleep state to an active sleep state. Figure 5 depicts a transition from a low variability quiet sleep state to a high variability drowsy sleep state. Figure 6 shows heart rate acceleration during a transition from a quiet sleep state to an awake state. Figure 7 further demonstrates a heart rate acceleration from a drowsy sleep state to an awake state. Heart rate changes during descend- ing sleep states are portrayed in figures 8 to 11. Figure 8 demonstrates 58 .00 46.00 00.00 1120.00 150.00 200.00 230.00 HEHRTBERTS Figure 4. Ascending Transition from State I OS to State 2 AS 59' .00 40.00 30.00 100.00 100.00 200.00 210.00 HEHRTBEHTS Figure 5. Ascending Transition from State 1 OS to State 3 Drowsy Sleep. 1 450.00 L 400.00 360.00 c;OO.OO 60 .00 40.00 00.00 120.00 100.00 200.00 200.00 HEHRTBEHTS Figure 6. Ascending Transition From State I OS to State 4 Awake 460.00 J 1 450.00 61 cssO.OO Figure 7. fii I I j I I .00 40.00 00.00 120.00 160.00 200.00 240.00 HEHRTBEHTS Ascending, Transition from State 3 Drowsy to State 4 Awake 800 . 0t 1 syLmi ‘ gyoxm 8 4m igomn 62. amoxm .00 JLOO Figure 8. I a04m 200 1 0 100.00 200.00 200.00 HEHRTBEHTS Descending Transition from State 2 A5 to State 1 Q5 63 J ago 200.00 1 240.00 c300.00 .00 40.00 00.00 120.00 100.00 200.00 200.00 HEHRTBEHTS Figure 9. Descending Transition from State 3 Drowsy to State 1 Q5 64 .00 40.00 00.00 00.0 100.00 200.00 200.00 1 O HERRTBEHTS Figurejo DescendingTransition from State ‘1 Awake to State 1 Q5 65 1 T f .00 40.00 80.00 20.0 1 0 100.00 200.00 200.00 HEHRTBEHTS Figure l]. Descending Transition from State 4 Awake to State 3 Drowsy Sleep 66 a shift from an active sleep state to a quiet sleep state. In figure 9, the transition from a drowsy sleep state to a quiet sleep state is seen by a sharp increase in heart rate followed by a gradual decline. The transition from an awake state to a quiet sleep state in figure 10 in depicted by a steady increase in heart rate, whereas the transition from awake to drowsy sleep in figure 11 demonstrates a sharp decline in heart rate. The marked change in heart rate pattern following the detection Of a sleep state transition as seen in these graphsillustrates that a physiological change most likely occurred at the point at which an Ob- server noted a behavioral change in the infant's sleep. Thus, it seems a justifiable conclusion that sleep state changes can be reliably de- tected by trained observers. Differential Index A method for determining beat-tO-beat heart rate variability is computation of the differential index (DI), defined as the standard de- viation of differences between successive R-R intervals (Yeh, Forsythe & vHon, 1973; Siassi, Hodgman, Cabal & Hon, 1979). Table 7 contains the differential indexes for each Of the two-minute periods preceeding and. succeeding the observed state change. According to results of the Wilcoxon Matched-PairsSigned-Ranks test, the differential indexes of the pre-transition Heart Period are not significantly different from the differential indexes of the post-transition Heart Periods. This is similar to the findings Of Siassi et al., (1979). In a comparison Of the sleep Of premature and full term infants, Siassi and his coworkers found that whereas the differential index did significantly discriminate Pre Transition Mean- 50 Post- Transition Mean SD 67 TABLE 7 DIFFERENTIAL INDEXES FOR ASCENDING STATE CHANGES Pre Transition Post Transition 3375.07 2490.37 1339.65 2314.29 2259.51 1690.73 2525.09 1261.29 3358.90 1675.15 1321.04 1873.04 205.81 1398.80 DIFFERENTIAL INDEXES FOR DESCENDING STATE CHANGES 2447.69 636.61 191.69 783.63 4129.17 7699.74 1274.31 3185.50 2878.55 1766.61 1128.25 344.86 2010.81 1842.50 TABLE 8 MEAN DIFFERENTIAL INDEXES Ascending Descending 2055.009 2072.925 1167.296 1263.229 1814.811 2322.78 416.426 2559.96 68 between the premature and the full term infants, it did not discriminate between quiet and active sleep. Therefore, it appears as though short- term heart rate variability does not significantly differ between quiet and active sleep states, and is not a good means of discriminating be- tween the two. 69 Summary 9: Physiological Results Analysis of four and six week infant sleep sessions resulted in greater percentages of quiet sleep than active sleep. At four weeks infants spent an average Of 54.63% Of their sleep time in quiet sleep, while only spending 19.89% of the time in active sleep. The remaining time was spent either in drowsy or indeterminate sleep or in quiet awake state. While it was predicted that infants would spend more time in quiet than in active sleep, it was also predicted that the gap be- tween precent quiet sleep and percent active sleep would be much smaller. Whereas at birth, infants spend as much time in active sleep as they do in quiet sleep, it is not until 8 months that they have been demonstrated to spend twice as much time in quiet sleep as they do in active sleep (Stern et al, 1969). It was hypothesized that the discrepancy between Stern's findings and the findings of the current study may be due to the stressful nature of the laboratory visit. Stress in early infancy has been shown to result in increased quiet sleep (Emde et al, 1971). Mean length of longest quiet sleep episode at 4 weeks was 28.43 minutes and at 6 weeks was 16.50 minutes. Mean length of longest active sleep episode at 4 weeks was 10 minutes and at 6 weeks was 13.25 minutes. These figures too differ from those presented by Stern et al, who found duration of 05 episodes to be only 13.8 minutes at 2 weeks of age and duration Of AS episodes to be 25.3 minutes at two weeks. Data from 6 week sleep sessions in the current study are more similar to Stern's results than are the results of the four week sleep sessions. Stress is seen as the significant factor in inflating duration Of quiet sleep epi- sodes in the current study. 70 Average heart rate was 135 bpm at 4 weeks and 140 bpm at 6 weeks. This replicates findings Of Harper et al (1967) who found that heart rate tends to decrease between 21 and 30 days postnatal age, after which it begins to increase. Not until three months of age does heart rate begin to decrease again. Reporting on infants aged 30 days, Harper and his coworkers also found mean quiet sleep heart rate to be 128 bpm and mean active sleep heart rate to be 134.5 bpm. The current findings are very similar, with a mean QS heart rate of 128.88 bpm and a mean AS heart rate Of 135.79 bpm at 4 weeks. Little beat-tO-beat variability was found among Harper's subjects at four weeks of age compared to the considerable variability found at one week of age. This too is similar to the findings of the current study, in that variability, measured by the differential index, failed to discriminate between quiet and active sleep. Lastly, sleep state transitions were found to be reliably detected by trained observers who used presence or absence of rapid eye movement, gross and local body movement, eye blinks, facial smiles and grimaces, and non-nutritive sucking in determining point of transition from state to state. High negative correlations between means for the two minutes immediately before and the two minutes immediately after the Observed sleep state transition verify that observational methods of transition detection are highly related by physiological methods. This relation- ship has been reported by others, and serves as a justification for re- lying on non-polygraphic means Of sleep state transition detection UUders, 1978; Fuller, Wenner & Blackburn, 1978). CHAPTER V SUMMARY AND CONCLUSIONS Summary'gf’Results Researchers have found correlates between early infant behavior be- ginning at two days Of age and behavior later in the first year Of life. Infant physiological rhythmicity is an identifiable trait at three months of age and is believed to be somewhat stable from early infancy through adulthood (Thomas et al, 1968). Such factors as activity level, sooth- ability, and reactivity to stimuli have been demonstrated as stable from early in the newborn period (2 days) until the end Of the first quarter of the first year Of life. The present study sought to confirm the stability of the rhythmicity trait from approximately the beginning to the end of the newborn period (10 days to 6 weeks). An effort was made to obtain a more direct physiological index of rhythmicity, the sleep polygram, in addition to such behavioral measures as the neonatal be- havioral exams and temperament questionnaires. Ten infants were followed from birth through 6 weeks of age. In- fants were first tested in the home at 10 days of age with the NBAS and than brought to a laboratory at 4 and 6 weeks of age for physiological sleep recordings. At 6 weeks, mothers also filled out questionnaires re- garding the infant's temperament. A comparison Of examiner behavioral Observation at 10 days and mater- nal report Of temperament at 6 weeks (N=10) revealed some interesting consistency. Measures of physiological regulatory processes at 10 days were correlated to mothers' perceptions of infant rhythmicity at 6 weeks. 71 72 One can conceive Of temperamental rhythmicity as an index Of biological regularity, as items tap the regularity Of infants' biological function- ing (e.g., "Infant has no regular time for napping each day". See Ap- pendix 8). Therefore it is interesting that both the measures of auto- nomic regulation and the measure of state regulation at 10 days corre- lated to temperamental rhythmicity at 6 weeks of age. Thus infants who were better able to regulate their states and autonomic processes at 10 days were judged to be highly regular, or rhythmic, by their mothers at 6 weeks of age. This is evidence for an early appearance autonomic regulation as a stable temperament trait at least from the period of 10 days to 6 weeks Of life. In confirmation of previously cited studies, (Birns et al, 1969; Korner et al, 1973, 1981), responsitivity to stimuli was stable during the period of study. Good orientation to animate and inanimate stimuli at 10 days was related to high reactivity to stimuli at 6 weeks of age (low threshhold of response). Moreover, the ability to shut out unde- sirable stimuli was stable over this period. Infants who were unable to habituate to irritable stimuli at 10 days were considered distractible by their mothers at 6 weeks Of age. In other words, these children were consistently vulnerable to impinging stimuli. In summation, reac- tivity to stimuli and biological regularity both appear to be stable traits from 10 days of age through 6 weeks of age. This study provides evidence for trait consistency in infants from 10 days of age to 6 weeks Of age in several categories Of behavior. Bio- logical rhythmicity, or regularity, was found to be stable during the 73 period of study. Moreover, infants responsivity to stimuli was also stable. Infants who were unable to shut out impinging stimuli early in the first month of life were also distractible in the second month of life. On the other hand, infants who were able to orient to stimtfli at 10 days were also highly responsive to stimuli at 6 weeks. One might hypothesize, however, that these results are due to sampling error. Ten subjects completed the BNAS exam at 10 days of age but did not com- plete the 6 week phase of the study including the MITS temperament scale. Consequently, they were not included in the analysis. One might conclude that only those babies who were able to control their response to stress and to shut out the disturbing conditions present in the laboratory were tested with the MITS scales. This would indeed bias the results in favor Of greater consistency as only those subjects who were consistently regular and undistractible would have completed the study. However, there is no indication that this selective sampling occurred. A comparison of the BNAS results for those infants who did complete the entire study and those who did not does not reveal any significant differences between the two groups on any of the seven BNAS clusters. This finding serves to increase confidence in the results supporting the trait consistency hypothesis. With regard to the rhythmicity of the sleep cycle, the limited num- ber of subjects who successfully completed a full sleep cycle at 4 weeks (N=5) precluded any meaningful analysis of rhythmicity. Moreover, of these 5 infants, only 2 completed full sleep cycles at 6 weeks. There- fore, no comparison could be made between infants with rhythmic or 74 arhythmic sleep at 4 and 6 weeks of age. However, analysis of sleep state composition revealed some interesting descrepancies from previous research. Data from 4 week infant sleep revealed greater percentages of quiet sleep than had been expected (Stern et al, 1969). A ratio Of 2.7:1 quiet: active sleep was Obtained, whereas others have reported that not until 8 months infant age is the incidence of quiet sleep twice the in- cidence of active sleep in infants. It was speculated that the increased quiet sleep was a response to the stress Of the laboratory situation. Quiet sleep is more restful than active sleep, as indicated by the fact that infants are less responsive to stimulation during quiet sleep than during active sleep (Emde et al, 1971). For those infants who completed 6 week sleep polygrams, the ratio of quiet to active sleep was closer to the predicted relationship (1.5:1). It was hypothesized that mothers may have found the second visit less stressful than the first. This may have had a calming effect on the infants who then might have found the second visit less stressful as well. An alternate hypothesis may be that those infants who were most up- set at the 4 week visit were not brought back by their mothers for the‘ 6 week visit. This, in fact, seems to be the case. Of the 7 babies who completed the four week session, the two who were most upset by the electrodes and the strange situation did not return for the 6 week ses- sion. A third did return but was too fussy at 6 weeks to be tested. Therefore, only the babies who were calm during both Of the two sleep sessions are represented in the 6 week sleep data. This selective 75 sampling may account for the decreased stress effect in the 6 week sleep data. The mode in which infants fell asleep was more adult-like than had been found previously. Typically, laboratory study of infants under 12 weeks of age reveals a brief initial REM period at the onset Of sleep (Bernstein et al, 1973). However, of 7 4-week old infants in this study, 4 entered sleep with a prolonged state 1 NREM sleep period, and only 3 entered sleep with a brief period Of REM sleep. Of the 5 6-week old infants stUdies, only 2 entered sleep in the adult mode of initial quiet sleep and 3 infants did reveal initial periods of Rapid Eye Move- ment. It is possible though, that of those infants reported to have entered sleep in state 1 NREM sleep, initial REM periods were unrecorded. Several Of the infants fell asleep while nursing and were then placed in the crib for recording purposes. Therefore, it is impossible to state conclusively that a higher percentage of infants entered sleep in state 1 NREM sleep than has been previously reported. Of particular interest was the relationship between behavioral Ob- servations of state changes and physiological determination of state changes. The negative correlation between heart periodicity before and after observed state changes were highly significant, demonstrating the overlap between observable and physiological state changes. CONCLUSIONS LIMITATIONS Several aspects of the present study limit the generalizability of the findings. Firstly, the procedure adopted in this study proved to be 76 highly stressful to the subjects. Infants were brought to an unfamiliar laboratory and subjected to some disturbing procedures. Electrode at- tachment was unpleasant for the infants. This was predicted, however it was assumed that once the infants were soothed by their mothers, that they would then sleep undisturbed for a period Of one to three hours. This was not the case. Contrary to predictions, many of the infants did not habituate to the sensation of the electrodes. Furthermore, those who did adjust to the circumstances, did not do so permanently. Several infants were successfully soothed into a sleep state, only to resume fussing during the brief periods of wakefullness which are part of the normal sleep cycle. At that time, data collection ceased. Therefore, sleep was unduly interrupted. This may very well have affected the nature of the sleep data. In the future, it would be advisable to take precautions to prevent this course of events. Secondly, there was a large attrition rate in this study. Only 26% of those subjects who began the study completed it in its entirety. This too may be the result Of the stressful nature of the experiment. Very possibly, the description of the laboratory visit caused some mothers to cancel their participation. Others dropped out after bring- ing the infant in for one lab visit, thus not completing the second lab visit. This may have affected the results Obtained during the lab sleep visits since the cancellation pattern may not have been random. Those infants who were more fussy at an earlier stage Of the study may not have been brought back by their mothers at a later stage. Finally, due to the large attrition rate, the final sample size was small. Although there is no reason to assume that those who remained in 77 the study were different from those who dropped out, a replication Of these findings with a larger sample of infants would further substan- tiate the results. IMPLICATIONS In order to alleviate some of the difficulties encountered in this study, certain procedural changes may be in order. Two possible altera- tions are discussed below. One alternative to the laboratory setting is the Observation Of in- fants in the natural setting of the home. The finding of high correla- tions between observed and physiological sleep state transition is shared by other researchers. Fuller, Wenner and Blackburn (1978) found an 83% concordance between observational and physiological detection of REM sleep, and 60% concordance between polygraphic and Observational detec- tion of NREM sleep. In keeping with this finding, others have begun using home recordings Of infant sleep with a time-lapse video procedure. This allows the experimenter to "Observe" the infant in his own mileu, the home, for prolonged periods of nighttime sleep with minimal intru- sion on either infant or parents. Moreover, since tapes are viewed fol- lowing the procedure, at the experimenter's leisure, it eliminates the problem of Observer tedium and consequent diminished Observer reliability (Anders, 1978). The findings of the current study support this technique. It seem increasingly appropriate to conduct sleep research in the home in addition to the laboratory. There is a high likelihood that data Ob- tained in the home will be more representative than sleep data obtained in the artificial setting Of the lab. Moreover, using this technique, it is feasible to collect data from nighttime sleep in addition to daytime 78 sleep. Hence home observation Of sleep seems to be a promising avenue Of research. For future study of infant sleep in the laboratory, some provisions should be made to enable infants to adapt to the strange situation. One possibility would be to perform two sleep sessions in one day. During a morning sleep session, infants would be allowed to adjust to the sen- sation of the electrodes on their skin and the strangeness Of the labora- tory setting, but no data would be collected. Once the infant had ad- justed to the sensation of the electrodes and to other aspects of the experimental setting, an afternoon sleep session would be recorded, thereby providing data which would not reflect the stressful nature Of laboratory sleep. Use of these two methods of sleep research may serve to answer several Of the questions which could not be addressed in the present study. It is left to future research to explore the relationship be- tween behaviorally observable manifestations of biological rhythmicity and autonomic regulation and physiological manifestations as measured by the sleep cycle characteristics Of neonates. However, evidence from the two behavioral measures used in this study, the BNAS and the MITS temperament scales does suggest taht there is a certain amount of trait consistency present from very early infancy on. The discovery of the extent to which these traits persist throughout the child's life must be left to future long-term longitudinal study. REFERENCES Anders, T.F. Night-waking in infants during the first year of life. Pediatrics, 1979, 63, 6, 860-864. Anders, T.F. Home-recorded sleep in 2- and 9- month old infants. Journal of the American Academy 9f Child Psychiatry, 1978, 11, 3, 421-432. Adamson, L., Als, H., Tronick, E., & Brazelton, T.B. A priori profiles for the Brazelton Neonatal Assessment. Unpublished Manuscript, 1975. Anders, T.F. The infant sleep profile. Neuropaediatrie, 1974, 5, 4, 425-442. Anders, T., Emde, R. & Parmelee, A. Eds. A_Manual‘gfi Standardized Terminology Techniques and Criteria for Scoring gf_$tates 9f Sleep and Wakefullness in Newborn Infants. UCLA Brain Information Serv1ce, MINDS NeuroTOgicaT-Information Netework, 1971. Anders, T.F., Zangen, M. RIPVAN: Sleep state scoring in human infants. Psychophysiology, 1972, 2, 6, 653-654. Anders, T.F. & Hoffman, E. The sleep polygram. A potentially useful tool for clinical assessment in human infants. American Journal gj_Mental Deficiency, 1973, Z], 5, 506-514. Anders, T.F. & Roffwarg, H.P. The relationship between maternal and neonatal sleep. Neuropaediatrie, 1973a, 4, 1, 64-75. Anders, T.F. & Roffwarg, H.P. The effects Of selective interruption and deprivation of sleep in the human newborn. 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Thorne, P.R., Engel, B.T., & Holmblad, J.B. An analysis of the error in- herent in estimating heart rate from cardiotachometer records. Psychophysiology. 1976, 15, 3, 269-272. APPENDICES APPENDIX A 88 Michigan State University, Department of Psychology Parent-Infant Project Letter to Parents: Dear Parent: I am.conducting a study of infants during the first three months of life. The purpose of the study is to see how different infants develop in relation to their respective environments. Parent expectations and attitudes toward their infant are an important part of the infant's environment. Therefore, I will be asking you a number of questions about your feelings as an expectant parent, and your expectations concerning your infant before the infant is born. I also will be interested in any changes that you anticipate in your lifestyle as a result of the birth of your infant. In addition, after delivery I will ask you to fill out several forms concerning your baby's routine behaviors. I will contact you at least three times after the baby is born. I will ask you to contact me once the baby is born. When she or he is 10 days old, one of our research team members will visit your home to observe and interact with your baby. The researcher will conduct an examination of your infant which includes behavioral tasks such as noting whether your baby can follow'an Object with his or her eyes, reset to noises, or respond appropriately to movement of objects across the visual field. In addition, a variety of neurological tasks are part of the examination and these are used to test your baby's reflexes. You will be given a diary and asked to note in it your baby's daily routines such as feeding, sleeping and waking. At most recording these behaviors in the diary should take approximately 15 minutes osch day. One cnpy of the diary will be kept by you and one copy will be kept by the research team. As indicated on the research protocol several sessions will take place in your home and several at Michigsn State University. During the university sessions, I will be recording a variety of your bsby's physiological reactions while your baby is sleeping. Sensors are placed on your baby's chest, hand, diaphram, cheek and temples to record heart rate, sweat gland activity, respiration, facial muscle activity and eye movement during sleep. This part of the study is designed to see how infant sleep behavior changes during the first three months of life. Your baby would complete one whole sleep period in the laboratory for this part of the experiment, or approximately a three hour period for most infants. While your baby is sleeping you will be asked to complete the questionnaires listed on the research protocol. Your participation and that of your infant in this research project will be completely anonymous. You will each be assigned code numbers and your names will not be attached to any of the information which we receive from you. Confidentiality and anonymity will be assured in all records kept as a result of your participation in this project. The general group results of the study will be available to you if you choose to receive them, individual records will not be available. ’89 If at any time you. should choose to withdraw from the study, of course, you are free to do so and any records which have been collected from you or your infant will be destroyed, unless you would grant permission for them to be used. we hope that you will consider participating in this study. If you have any questions concerning this study please feel free to call me for additional information. I can be contacted at 353-3933 nearly any time during the day. If you need to contact me at night, please call 332-3811. Cordially, 'v ‘.')/ C L.>"_’7‘.11 Esther Dienstag Department of Psychology Michigan State University 90 Department of Psychology, Michigan State University Parent-Infant Project Dear Expectant Mother, You can use this postcard to informhme of the birth of your infant. I will collect the other materials enclosed in this packet during the scheduled 10 day home visit. I would greatly appreciate your completing these forms prior to the birth of your baby. Upon receipt of the enclosed postcard infbrndhg me of the birth of your baby, I will telephone you in order to schedule a visit to your home when your baby is 10 days of age. Thank you, éi77b7ie/Z [33:3253¢?é;- Esther Dienstag' "F Department of Psychology 91 Department of Psychology Developmental Psychobiology Lab. Michigan State University Infant Learning Unit I(we) would like to participate in the study soon to be conducted in the Infant Learning Unit. Please call mc(us) to provide additional information and to schedule an appointment. (Please print) Name Phone Child's Name Child's Birth Date Most convenient time for my(our) participation: (Check as many as apply) M T W Th F S Morning: Afternoon: Evening: FIRST CLASS Pm" No. 94! [on Lou-om. Inch ”suns REPLY IIIL no Pastas: MECESSADY w IAILED IN THE UNIYEO states Department of Psychology Michigan State University East Lansing. Michigan 48824 Illlllllllllllllllllllll 11-3763-HEF 92 Michigan State University, Department of Psychology Developmental Psychobiology Laboratory Parent-Infant Project 1. Informed Consent Statement I have freely consented to take part in a study of parent-infant behavior being conducted by Esther Dienstag and Cathleen McGreal under the supervision of Professor Hiram Fitzgerald all of the Department of Psychology, Michigan State University. The study has been explained to me and I understand the explanation that has been given and what my participation will involve. I understand that I am free to discontinue my participation in the study at any time without penalty. ‘I understand that the results of the study will be treated in strict confidence”and that I”and’my'infant will remain anonymous. Within these restrictions, results of the study will be made available to me at my request. I understand that my participation in the study does not guarantee any beneficial results to me or to my infant. I understand that in the unlikely event of physical injury resulting from research procedures, Michigan State University, its agents, and employees will assume that responsibility as required by law. Emergency medical treatment for injuries or illness is available where the injury or illness is incurred in the course of an experiment. I have been advised that I should look toward my own health insurance program for payment of said medical expenses. I undersrand that, at my request, I can receive additional explanation of the study after my participation is completed, but that proceedures used to assure confidentialty prevents the release of individual results. Signed: Date: 93 LOCKKD FILE Developmental Psychobiology Laboratory Subject Cnfiq Subject feedback Record Participant: Name: Address: .(please indicate a mailing address that viii cover your movements for the next 12 mnnrhs). If you change addresses during the next 12 months, please let us know so that we can update our files. Phone Number: Number of Children: Do you wish to receive summaries of research reports that will be deveiopod from the results of this study? Yes No ' 94 Risk/benefit Ratio: Risks involved in thses studies are minimal. The methods used to obtain data are in standard use throughout the field and involve minimal discomfort to the subject. Electrolytic mediums may produce slight reddening of the skin. However, the actual electrolyte is hypoallergenic. Moreover, subjects routinely are asked if they have allergies prior to their participation, (or if their infant has any allergies). When rashing does occur, it generally subsides within 15-30 minutes after the skin has been cleaned. We believe the benefits of the research outweigh the resks. The potential information concerning factors which regulate adult-infant interaction seem far more important than any slight discomfort the subject may experience during this experiment. 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Physical Aspects (mother) 1. Normal Delivery: Yer , No 2. Timing: gestational age at birth weeks 3. Labor: a. False Labor - how soon before true labor? How long did it last? b. Was it necessary to stimulate labor? Yes , No c. On admission: 1. Stage at which admitted: Early ; Midpoint ; Late 2. How much dilated in centimeters d. Duration of Labor: Very short (below 6 hours)_____5 Short (6-12 hrs.) ; Average (12-15 hrs) ; Moderately long (IS-18 hrs.) ; Prolonged (over 18 hrs) . 4. Complications while in hospital: Yes ; No If yes, state nature of complication briefly. 5. Anesthetics: ' Yes NO . a. If yes, what type . When was it administered . 3. Physical Aspects (infant) 1. Birth weight grams 2. APGAR: 1 minute 5 minutes C. First Response to Infant: (Check one) Welcoming 2. Accepting . Ambivalent . Negative [— O _________} 4 5. Rejecting 99 D. Mood and Emotional State While in Hospital: Euphoric Contented Anxious or fearful Deptressed temporarily (for a day or a few days) Continuously depressed 100 BACKROUND INFORMATION SHEET: The information requested in this form will be used to report the general characteristics of the-infants used in our research. Only group results will be published, and theridentity of individual infants remains anonymous. All information provided on this form will be kept strictly confidential. ; Subject Number Date of Test Time of Day A.M. P.H. (circle) Experimentars Backround Information on Infant Date of Birth. Sex: Male Female (circle) Month Day Year b Place of Birth, ‘ City or Town State (or Country, if foreign) Height at Birth lb. oz. Length at Birth inches. Due Data Is your infant breast fed bottle fed some combination, with bottle feeding 752 502 252 Has your infant had any prolonged or general illness since birth? If so, please briefly describe. Any special problems with ( ) colic, ( ) rashes, ( ) feeding, ( ) sleeping. If so, please briefly describe the problems. Is there anything else special about your infant that you think it would be important for us to know about for this research project? 101 BACKROUND INFORMATION SHEET on INFANT - 2 Today's Schedule and Trip to the Laboratogz When was your infant last fed? When was your infant's last nap? Any break from the infant's routine (other than coming to the laboratory)? If so, please describe. How long did it take you to get to the laboratory? In your judgement, was your infant either (a) unusually irritable or excitable today, or (b) unusually quiet today? ‘ M? 133”!" '2 £1 102 Subject Number Backround Information on Parents and Family, Education: Circle the last level of schooling complete, and list any degrees. secondary college post-graduate degree mother: 8 9 10 ll 12 13 14 15 16 17 18 19 20 or more father: 8 9 10 11 12 13 14 15 16 17 18 19 20 or more Occupation: mother Age: mother father father Please list the age, and sex of other children in the family: Years married: Have you ever had any experience with children before: yes N0 Please explain Did you participate in any prenatal training classes? yes No Approximately what is your present annual family income? (circle) 1. Under $4,000 2. $4,001 - $7,000 3. $7,001 - $10,000 4. $10,001 - $13,000 5. $13,001 a $16,000 6. $16,001 - $20,000 7. $20,001 - $30,000 8. over $30,000 103 l :2... 2.. .22.». . ....... .2 2...... .....o.........:. . = .. .n .. 2 . .2 2...... 2.3.3.... . :2... 3.. .2... .o 2:33 . .. o. . .5... 8.8 s... .o 2.3.... . 3 .. .. .n. 2....» . =2... 3.. 8.5.6.2....» . :2... .3... 2.2.2 . .. .. .2 2.32.... . .. 2 a .. 52.. 9...... .. 2...... . .2 2.2.2.2.. .e a..._ . .n .n .v .u o. 2 233.3230 . .3 2.3626... 3.2.2.0 . 3 .v. 32.3.30 .. .. .2 5.2.2.. . .. .2 2.5.... 3...... . .. .2 2...... .22.... . 3... 2 22...... . 3.3 3 >839... a .2...» 22...... 5:23...“ . .. .v. 22...... 22...... 3:256. . S... .. .3... 2.5.... 5.2.5.... . 3 .v. 22...... 225...... 3:23.... . 2.... .. .3... .33.... 8.82.2... . .n .u .3 3...... 2 2.2.2.... 8:99.... . .n .u. s... 2 2.5.8.. 23...... . .o .u. 2.... 3 2.2.88... 2.33.: . 3.2 2... o. 2.2.8.03 3.3.3.: . . 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Infant often plays with his/her food. Please read and try to answer all items. If a question is completely inappropriate, then you may omit it (be sure to skip the space on the question- naire). If your child has outgrown an activity or behavior mentioned in an item, answer the item according to how he/she used to act. That is, if your child drinks only from a cup, answer items regarding breast and bottle-feeding from your memory of his/her feeding habits. we have worked very hard to make all items equally applicable to infants of botl sexes and to those who have been breast or bottle-fed. Please do the best you can in answering as accurately as possible. All information on this questionnaire is confidential, and will only be handled by the research staff, with no names attached. today's date at the top of this page. contact one of the examiners. Please be sure to put If you have any questions, please REHEMBER, AKSUER ALL QUESTIONS. 105 1. Baby is irritable or cranky after sleep. 2. There is a great deal of fussing and crying with any illness. 3. When waiting to be fed, baby is generally still. 4. Responses to diapering and dressing are usually intense with much laughing or crying. 5. When lights are turned on in the room, infant is usually not awakened. 6. Child does lots of squirming or kicking while being diapered or dressed. 7. Stops eating if hears noise such as bell, radio, etc. 8. During play the infant is usually very active and vocal. 9. When playing with one toy, the infant is easily distracted by another. 10. Child kicks, splashes or wiggles throughout bath. 11. Child usually fusses during diapering and dressing. 12. There is no clearly evident pattern in the time for child's bowel move- ment, it varies from day to day. 13. Child's initial reaction to most foods, solids, liquids or vitamins, is to accept them without much fussing. 14. Child is usually willing to be held and cuddled by strangers. 15. Infant generally appears happy upon waking up. 16. If playing with one toy, the infant does not usually become distracted by others. 17. Infant's times for liquid feeding are unpredictable--vary more than 1 hour. 18. Child's reaction to bath, whether she likes or dislikes it, is mild and not very excited. 19. Infant's time of waking is not consistent from day to day (times vary more than half an hour). 20. When child is with one person, she/he will easily go to another person. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 106 During diapering and dressing, child's expressions are mild—-little smiling or fussing. The infant shows discomfort with changes of place and situation even after continued exposure. Child is generally happy when left alone in a room: will occupy herself. Child is a heavy sleeper° it takes a loud noise to wake him/her. Baby reacts to an undesired food in a mild way. Child notices and reacts to small amounts of urine in diaper. When crying from getting a shot, infant can easily be calmed by milk, pacifier, etc. If bath is given in new place, infant readily accepts change. Infant is active or playful on a fairly regular schedule. Child protested when put into bath for the first time. During feeding, the child will continue to suck even if there is much activity around him/her. If left on the floor, infant will usually move to another area. Before going to sleep, child is often fussy. Infant's general reaction to familiar people is intense--crying or laughing. ' Child can be left on couch or chair for period of time without moving very much. Baby usually does not accept company (visitors). Child liked his/her first tub bath. During diapering and dressing, child is generally pleasant and smiling. During milk feedings, child is not easily distracted and continues to suck undisturbed. Child does not seem to mind changes in amounts, kinds, or tastes of solid foods. 46. 47. 48. 49. 50. 51. 52. S3. 54. 55. 56. 57. 58. 59. 60. 107 . Baby often consumes close to the same amount of food during a feeding. Infant's general reaction to familiar people is mild-frown or smile. Child generally indicates that he/she has soiled. . Infant's play involves much movement and exploration. Infant is easily distracted during breast or bottle-feeding. Infant does not like to be bathed by different people. Infant does not adjust easily to efforts at changing feeding schedule. While playing with one toy, child can easily be distracted by another. Child will rarely allow strangers to hold or cuddle him. Child protested considerably to first bath. When going to sleep, infant is usually happy. While playing, the infant is easily distracted by everyday occurances like the ringing phone or doorbell. Infant reacts to slight temperature changes (in room or outside). when given a food which he does not want, he reacts in a strong manner --response is intense or powerful. Infant exhibits regular, easily identifiable actions around meal time. Infant falls asleep at about the same time most nights--within half an hour. I when lying in crib, infant moves around a great deal. Does not readily accept changes in types or characteristics of foods. Child continues to object to grooming procedures (combing, washing, nail cutting, etc.) even after experiencing them several times. Sudden appearances of strangers will cause crying and/or a turning away. 61. 62. 63. —-—.—— 64. 65.‘ 66. 67. 68. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 108 When in carriage or stroller, baby is usually quiet and still. Infant's general reaction to familiar people is friendly with laughing and smiling. Changes in lighting will not stop the baby's crying. Whether he likes or dislikes bathing, the infant's reaction is usually intense or energetic. when being washed or dressed, baby is generally pleasant, smiling etc. Infant initially accepts new foods. When infant is full, he/she simply turns head away and lets food drool out of mouth. If left on the floor, child rarely moves from spot. Diapers must be heavily soiled before infant reacts. Baby often wakes during naps. When playing, baby will respond to hearing his/her name called. Child is a light sleeper. It takes only the slightest noise to wake him/her. Infant shows a mild reaction to light or sound with little or no crying. Child has a loud response to a wet or soiled diaper. Child initially does not accept most new procedures; usually cries, fusses or does not cooperate.‘ Infant takes nap at approximately the same time each day-~within a half hour. Infant is generally fussy during play. After receiving a shot, it is difficult to stop baby's crying. In playpen or on floor, infant is active: gets into things, pulls at objects, or puts nearby objects in mouth. when the lights are turned on in his/her room, child is easily awakened. 109 81. When infant cries because of hunger, she will usually stop for at least a minute if she is picked up, given a pacifier, etc. 82. Does not follow a regular nightly sleeping pattern. 83. If there is any activity around him, child stops sucking during feeding. 84. Infant can be fed at same time each day. 85. When she is hungry. almost nothing can make infant stop crying. 86. Infant notices and reacts to slightly soiled diapers. 87. When there are interruptions in solid or milk feedings; the child generally remains happy. 88. Diapers are usually very wet before baby shows any reaction. 89. Even after several trials, infant continues to reject most new foods. 90. The baby will eat his meals at varying times during the week. 91. Baby drinks a predictable amount of milk: (if bottle—fed, varies less than 2 ounces; if breast fed, time sucking does not greatly vary). 92. Infant usually lies still while being diapered or dressed. 93. Child cheerfully tries new foods whether he/she ultimately likes them. 94. Initial reaction to strangers is relatively mild such as a frown or smile. 95, Child generally takes milk around the same time of day: does not vary more than 1 hour. 96. Child still exhibits strong reactions even after repeated contacts with bright light or loud sound. 97. Infant does not become easily accustomed to changes in caretakers~-baby— sitters, grandparents, etc. 98. Whether liking or disliking a food, baby's response to it is dramatic. 99. Infant initially accepts any new procedure. 100. Infant generally cries when solid or milk feedings are interrupted. 101. 102. 103. 104. 105. 106. 107. 108. 109. 110. 111. 112. 113. 114. 115. 116. 117. 118. 119. 120. 110 In her stroller, infant is usually quite active or noisy. Child makes himself at home most anywhere; appears comfortable in new situations. It is difficult to predict infant's activity or play time. Child resists going to different persons. When brought to the doctor for a well baby check-up, child is usually fussy. Baby adjusts easily to different care-takers. When left lying in crib, infant usually lies quite still. Infant's reaction to animals is intense with much laughing or crying. While playing child does not notice or react to his/her name being called. Baby readily accepts bathing by a new or different person on the first or second time. When diaper is wet or soiled, child makes no fuss or whimpers slightly. Infant cannot be left for very-long on ebuch or bed because he might wiggle off. Child wakes up from napping at approximately the same time every day (within half an hour). After 1-2 tries baby adjusts easily to changes in feeding schedule. The infant initially tolerates or enjoys new places and situations. When left alone for more than 5 minutes, child generally fusses or cries. Baby shows little reaction to bright lights or loud noises. Child usually indicates that diaper is wet. Child initially reacts to strangers with much laughing or crying. Infant will readily accept bathing by a different person or in a different place. 126. 127. 128. 129. 130. 131. 132. 133. 134. 135. 136. 137. 138. 139. 140. 111 Child seldom seems to notice or react to differences in the taste, consistency, or temperature of foods. Changes in sound (voices, TV, radio) will not stop baby's crying. Child usually rejects new foods. Infant takes 3 or more days to adjust to changes in daily schedule. . At the doctor's for a well baby check-up infant is uSually friendly and smiling. Baby smiles, gurgles, or plays with new people. Child seemed to dislike his/her first car ride. Infant does not readily tolerate or enjoy new places and situations. Child has low tolerance for pain. Baby lies fairly still while he/she sleeps. Child seldom or never indicates that diaper is wet. Infant has no regular time pattern for napping each day (varies more than 1/2 hour). While playing, infant generally does more quiet observing than active exploring. When engaged in play, baby is usually actively moving and making sounds. Child seemed to enjoy his first car ride. Child seldom or never indicates that he/she has soiled (b.m.). Child will usually lie and wa t h - . period of time (30 seconds or C a hanging mobile for Just a short less). If an object is out of reach inf ' several minutes. ’ ant continues to reach for it for Baby does not persist i n attem ts a ' . Gives up easily. p t turning over, crawllng, or walking When given a toy, the infant plays with it for many minutes 141. 142. 143. 144. 145. 146. 147. 148. 149. 150. 151. 152. 153. 154. 155. 156. 157. 159. 160. 112 Baby usually fusses during bath. Baby persists in attempts to crawl or walk until a few steps are taken. When seeing a new animal, child's initial reaction is one of interest and attraction. When being washed or dressed, infant generally cries or fusses. If child wants a toy that is in the other side of the room, he will crawl until she reaches it; or, if unable to crawl, child will continue to show an interest in it for quite a while. Infant cannot occupy himself in crib or playpen for more than a few minutes. The infant often continues playing no matter what goes on around him. Infant does not notice or react to changes in voice quality or level. When napping, baby almost always sleeps through without waking. Infant usually stops trying for a toy out of reach in less than 1 minut: When trying to turn over or crawl, child tries for a minute or two, then gives up. Child is not very active during play. We displays few movements and makes few sounds. When given a food, he/she does not like, infant protests briefly but soon takes it anyway. Infant plays with one toy for only about 1-2 minutes. Diapering is often a battle. Even after first 2 weeks of bath, child continued to protest. Child will not crawl across room to another toys nearer to him/her. toy if there are other Baby shows little reaction to animals (dogs, cats, etc.). Infant explores very little; needs help to find play objects. In a crib or play pen, infant can amuse him/herself for quite a while. 113 161. Infant usually plays quietly and calmly. 162. For at least 3-5 minutes, child will lie and watch a hanging mobile. 163. Infant is usually cheerful during play; laughing, smiling, etc. 164. If fussy during grooming procedures (nail cutting, hair brushing, etc), baby is not easily distracted. 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