. 5 .Iuauu.‘ll..5115 15.111015.¢.r1ll.‘5 .15154005IKIJJ1'0..I110F’ 1'
1 «505.505.5405 .5015 b’lrunro .5. ...-7.5.1211 1w5. 11.550115 . . 1015 1. .. 410105~5151
. . l.5.....0v111.-1555 .15.... . 1 5 ... 5... 0 1 . . . .1 1..1 I
5 C O 5.50....501155m.0.11....15 510.15 .5.5 . ..1 05.. 915 5, 55559 55.“ 0.5. 0515515 55 .5 555.15..55155510.555.V51J55'555. 1.5.5.151“. 5“. . 0111. 10.55.13.555 10 .5 55. 0 51.1 .501 .... 1 . .1. . ..a1505r . 11. 5 r 5 ..
.5 5.1110 .5 1 .1v.\1......5151....1..1)555..5_ :11515. 5 5. 5... 35... 0 0,.1111.155.1..01..15010.1..1 050:1 .. .,11..5.00 51.1.1...
1.551.51. 5.1.1.1‘0‘55. 15,515 1. .12550 $57. 51.0 .0 .1. 1‘0 1 .. 4 1 1 .5. I0h5555
'1..I 5:0 5 5.! 100 1.5 .555 005.0510..v’r5.l..5 5 0000100105550. 5.5
5551 5. .1 . . 11.. . . . v . 9.. a
1 , ..0 1. 11....55‘ ... ...1.......0.5..5155110._5‘ . .5 5 0 .1
.. ..1 .5 1 10.0. I 11550..51\ . 1 55 50.001.5 “.0000 10.
. . 1 . 05 .. 5..
_ \5 1. 4 . . 0 51.555. .5 a 0'05...
_ 55 1. . . 1-5 ,0 a .0
15 11.5501 . . 1 .5105 5
1. . 0... 1 55 1 11 115. .01.|1.1 .1110 511! ‘
.0 . 550. .0 “1:11.105“..50.1. 1 1 011.0 05..I55l'01 0. 01¢ 05
1. 1 5 . In}! . 1 .5 5 50 51. 0.000 .1 fitn/ .5II04 O
. .1. 5 4 1 0 .1. 51 1. 1.0 \5. 5.1 ..0551'I5l 41I5I0 5
.4 O. 1 5 , . 53‘5w1.5150'.'100.¢ .\ 0 05 0 1 O '11.1‘.I/l’0 '0'.“
1 . 1. . . .0 . .1 . 11. . 5. .
1. 0 5\‘1 505 ...5 1 01 5. 11 . 155155.5.55.5550.0.11....51555‘1.505 . . 51050 101501;») 5 I01—1..5.D
0 41 . .. 1‘1 5 11.90 5 1.5 05 [.5 ,..1. . . 5 05.5 0511.55,. .5110 5’01155 I (1. ’05 O 5.4.
. .1 1 1 5. 00 . I5 0.5r 11. 5 5 1 5 000.1 ‘550 . . 1. 1.. 1 , . . I 1111. 5.0 5111(10.515/515(10.041501’00I5
...51 015 0 5 5 5 .5 1 . 1 .1 1555 .1. . 1. ._ 1 0 15 5.... 5 H . . 5’11 .555.I511551 500'0IIO 5115 00(551'1415 '1
15 1. .... 5 0. _ I :14. .5. 1.. .0 ..15 1 . 1.5.54 .. 5 ,5 .1 J .. ..5 . 11 .55 5 1 . [1’1 5.0.5/50 . /
.1 . 1 . 1 5 , 1 1 . . . .0 1 5 .01
. 5.00 1 11
. , . 01.. 1 1
. . J. 1 1 .5 .
. . 0. 1 55 .
. . . . . l 55.. 51 I5
. 1. . . . . . 0.5. 1 5 05515
. 10 5 0 I 015151 0.5
10 . . 15 115. .5 155551.-
. 0

  

  

.1..(1.1.5.5

 

       

 

        
          

     
     

 

         
    

                                          

 

 

 

 
 

 

 

 

 

. 1 .1 .0. 5 4
. 5.5 a 1. 1. 5 05K. 05r55051. 5 0 4r..
_. .. .. .. 1. 1. .I r 1111...... ,
. 1.1. 15.1 115 \h 1. 0'1. 5
0 5,.1 . . . . ”.../51.00.; 901 [#010155.“
. 51f . —...'.505.5, . . , 1-,,5I05 4 55 . If" x .055
. 55a. 1 . G505 . . A 0 .5500. 50.. 5 5 .00..“
1 50. 0 5 10 55. 5 , . .. . 11. '550I..(JI.5I.'11.1 51 .[Iloi‘
. 1 ....5. . .. . . 5115 5011 1. 01 1 1151!. 1
. 0. .1 5 1v
1 1 1. . 1
do 1.4. 1 1 11.1..
. .1 .1 1.. .5.
.1 1 11 5 .1 .5 J .
. .1 .1.01 1 .1\ 5 5 0 . .5 4..50150V5
0 . 5 11510 f '11 0 . 0 5.5.5 1. 51. .5. 1.91 0
1. 1 .5 4.. . 51. ..1.'O..1050511’1Ft
5 1 .1 5 1 .0.. 1. 5501.1. 1.155 .
0 1 5 .5 J 1 151 0
1 . 5 55.1151 1 01 55.
1 5 5. 5 0.. .1 1 1 1 5 5
. . ...5 .
“ 1. 1.15. 1 5‘05 . 155.
51 1 .5 l 1 5
. . I. 555.01 1 5 1
5 5 5 5‘51 1 5 5
50 . . 5
4 .5 1 1 . 1
. .1 5.. 1 ll. 5. '5.’ C
. 1 . 5r 5
1. 5 1 50 1 1. 5 5 .J.‘ . 1 I;
,0 4 551 .5. . 111 ..1. 5. . .....l... . 1.11.1. 5111.51/ . 05,01
‘ 5 5.5 5. 1 5 1 5 0 505 . v 5 5..1..50515. 50 ...00. 555105 00‘1J
” 10 5 1 5. 00 5 5 1.51 1 5 1 1 a 1 .5 . . 5.1.1.1.! 11 'v‘51.5“r05l5 5 0.1rf51100015..4 15 0
.51 . 1 1 . I... 01 1 1
O 5 55 55 5 5 0 O 1 r O 5 5 . 11 1 1 55 5'11 1 1 1!. I VI . 55. 5 0 '1’55ln 5 5.105! I‘V'nJiol. ’“
10 1 . 5 . 1 .. 4 1 1 . 1 ..1 0 , 11 I . .
r 1.1 5 551 . .5. . . 1 . 5 .105. . ... 1 1. .005. 0. 15» .f,/00.1....5rafiailt..155. 1.04 a
. 1 1 .1 1
o 1 . . 5. ..1 5 11..,. . . ..1... .5. 1511.511 5 .01....1/Ir 15.15 tt.I110.CI55151.101
5 ..1. 5 55. .5... 5. . O 151 55W...1555a .15r1I10 01.15I1111..I5Ir111.
. ,, . ...
a 5...... 15. 1, ..1 . 1 ... 1.. 1 1.1.11 0.5 1. .15515/ {EH-1,051 ..
5. 1 ..1 5 0.5 . 11.11 . .11. 0 5 1.0 15 . ..1! . I 1
1 1 . A. 5.5 5 .. 1 1 1 A 5 5 5 a. .5 . 5 00 . 055 55'. 5 1.5 .01’5 rd
‘1 1 5 . .5 1 5.1 5 11..r0 5 5. 1 . 0 .
1 1 11 . 55. r. . 5. . .15p 11. 1 1 .5 15.! ,
0 0 0 5 I 55 5 1 . I , 5 5 11 1 150 1 5..!
1 . . 1 .1 1 50 . 1 1 . .
. 1 1. .5 .1 ’5 5. .. 0 1 11!..1. 0 111 5
. 1 . 5 . 5.0 1 . 0 1 1 ...550/.. .I 1.05105...'
1 . 5 0 5 l 1 .1 5 .5.01 1 ..5 5 I0 vll’v
1 5 5 50 1 .5 .5 0 0111’. I545 1 0.45.
W .15. 1 . .5 5 l 1 5 . 0 1.. I. .1 1.1 1 ..0vu51. 0..
1 1 .. .1 .1 .1 1 4. . 41 11.5. .. 51. .011..5H.1050.01J
. 1.... .1 . , . . .. .rr...1. 11.1....512
5 1 5 5 5 1.. 5 ’ 5 .. .5 5 0 I551, [R 1’0
.1. I .1 . a... 5.011 1r. 1/. 17450 110.! 505.5 t1.r..
, .5 1 1 01 1 0 1 .1 1 .r 1 ,
5 . 5 1 0 1 5 5 I 5 I“ 5 r I 55. 5.0 5 LIA (l! I551'05 a!“
. ...1 .1, . .... .J... ....1 1.11.1513.
5 5.5”1. .5 .55 0f. 1. 155 .0 5.0 5 .00 5 . 0 5 50515.10 .1. I504 05201/(IIJ5F0IIOPQQ5 5 .1/5.r0 0555001
1 5 . 1.0 . .. n .. . 5 . 1 ... .5 I 1
1. 5.1. . L. .1, . . 51 155..5I.rp.11.1/ 5:0.5U'5. 505.1,...150, .1lard.orl.
. 5 . .1 5. . 5 1 5. 4 .1 .0 5.. 00, J. 55.55,.00011f400 5 1’15 0
I . .. 05 01451.. 0. 51.5..-.5151 I . r5l5'105.17.015.1. 5 s . l
J 1 . 5 0 .5 0 5 1 0 5. 051r 1'55.5 0 1 J 15(5
n. 1 1 5 1. . . 11 1r550. 1 1.... I5 . _ I..) (l5..51...01..
O. 1 o 1 ..1 . 1.141 11... .1... 5.. 0 ... . 5 111.05.555.11. 0.50 0.055
1 1 . . . 0 1 1 1 . 50 .
5 _ .5 .1 .5. 0 .1 500.. 01 0 5 15551.00 1 1.55. 5.15r11.lfl- 1 55.1
1 1 1 , ..1 1. 1. 0. 1 ...1. .1f.4l
. .5 5 .1 5 51. 50 111 . 5 5 .. 15/101 5 ’.I.’1I.Q
Q .0 0.15 11 1 1 . . 5 11.5.1111. .15 .(5.0l¢.0l'0-151'
1 5 1 O 5 1 141 5 5 0 5510‘5l'.'(. 5V'l"5 ’ 5'.
C 1 1 0 0 . 5 5000.1r (I. cor-55.0 5’1
_ 1 5 1 1 I5 .1 5 151101r. 1.515 1 5.1 000.), 5,01.
1 010 o . 5 5 t. 5 1 .5 5 5 10.03.01 5 .1 . 5.1
0. 5 I 5 1 1 1 1. 55 5 .90 I 55. 0 Al. 'I '055\ 1.0 0105‘.‘.'0/
. . 5. . 1. 0 5 . 1 15 0 1 01 551 4051/1 1. 51 01 5 1 1 1 1 5 . 1 . r 5 5. .15 5. I
1 5 O 1' .1
. . .115 0.... I .0 0, 1. .50.,. 1 .0I5f5/0. 00. 051.5.m.ll-.0’I\.5'r1ll520(114’ {111.1151'0015.‘
1 . . 150 1. .5 .. 1 . 41 . . 0 1
O .1 .15 5 .1 1 5 0 115 0 5 01 I50 0 1005.11. I ..1 1.5 r 1/01L1J0V1 u
I l 55 0 . .5 I . . 5 .
5 .. .
—‘1 5 ..
5 1 ..
C _ .. 15 .
‘0 .I 1 Q 0 1
1 5 . 1. 1
“5 I I o. 50
.1 55. 1
. , 5 .
q . .1
.1 .
A... 5 5 1 1.
.0 1 5
s 1 5
I 1 1.5 . O1 0 .
W . _ .5 51 O. 11 5 . 0 0
I 1 1 5 5 . . 1 1 . 51
1 1 1 V . 0 1 1 5 0
A 1 .5 5. I15 1 .1 . . .
5 5 5 ' O I! I
. I 1‘ '0
J 1/15 1 1 1 . 1 5 1/5 .0 1 .5
. . .. 1 . 1 . . 5 1 5 1
.. . , . .. . . . . 1
5 5 1 O 5
1 1 1 5 v 0 15 v 5 I. 6 1 11 .1 5
~ 1 1 5 1 . .5 05 1 . 1 I. 0 15
. 1. 1 . 5 5 .1 . 11. 5 .1 . 0
~ . 5. 551 0 551.1 0 15 5 .
0 1 1 1 1 1. 5
1 1 0 5’. 15.1 1 1 0 0
_ 1 1 l. 1 1
0 0 1 5 50 o 0 I 5 55 5
4 . 1 1 1 . 1 1 . 1
0‘ 1 5 5 1 #.I11 1 O1 5 0 . . C 1.
. . 1 . . 5 1 . 1 1 1 0 15 (151.: 0 _ 5.50.51. 1.15.0.l..“40005"11.’.1...fvvtvll.005105 0
1 1 . . 0 . . 1 1 .15 1 . 1
1 5 1 5 5 . 0f 11 . 1 1 0 1 0.11.5 5 5 1 .5. 5v )1. 0.5 5"!!00111l5.‘.1150r.00515
O 1 0 . 1 5. . .
0 . . . 1 0 1 0 5 .5 O V 1 1 010. I 5 J 4 ... 1 r 5505 1 05 . 011. 4' 1 1, ._ .. 0 1 .0 . '50 5'1 0
. 4 . . . . 1 .. . _. . 1- . . .1. .. 11.... .115..1I1.01...._55
P . . . 1 1. I o 1 5 . . 5 0 . . . 5 . .1 . 5 . 5.. 5. 1 11 1 1’1 5 . 10
1. . .5 .5 . I. . a .5 _ I 11 5 . 1. 1 111 . .. 50151010051511... 5“
. 4 . . 5 5 . 1 . 1 5 5 . 1 05. 1.. f . .. .0. 04
5 1 5 0 1 1 0 5 . 5 1 1 I 5 1 51 .5 5 . 0 I 5 055. I .I 1 L 5 50’051/51’1010. .
1 5 01 5 . .1 .0 . .1 1 , 5. 1 _51'... 51 5 ’10.5'5 . 1 I .11 1 D ( 51.}.1115.5lp1/.05("lf
. . 1 . 1 . . . 4 . 5. ... . . . .1 1 .. . r . . .155 . 1., .15. 5.5 15 1.. .501 5,. ..r1. 1 I14. , . 1 .
, . 1. 1' 1.0 11 .. 5 . I I 1 1
5 I .1 .. . . 1 r 1 0.; 5 1 5 5 15 . l1 . 5 1.05 5 I 011 .0 1 .05 I51. 5 1. .15 0 555101 5 I Q I1t'5 . I J'-
. 1 5 1 I .111 1 1 0
1 5

5
5
0
5
1
O
1
1
o
5

  

1 . . . . 4 ...0I' .II’5.(I(/550’00
. J 1 . . . 0. .1 1 o 1 1. . . 45.01.5f550

, . . ... .- 1 . . . . . .. 1.1 . . 1.1. _. ... 1.15 .1. .. . . .1 _. 1....r01._.. .0..11f 1.0.1.1I1..r101r.II/.l1
1 1 1 1 . v 1 5.. 5 5 .51 .1 501 5 11 10 1 1501 . 01.011 . 1 5150.01I500100 4' .05 .1 4/. 1051100 I51:1l.’05 f1 '0‘!
. .1 . . . . .01. 1.1. .I 5510. . 15.1. 1 0 0 .0O.0000000|00.511550111 5)- 015100550510000. 5 .5 P
. .0. 5. 1 5 , . .4 011. . .1 05.5. .011. 5. ‘0 05... 5001 ’5 .5. 1 1 . 111 51.51-. ._ a..04.011\ 55 .5 .

1 5 1.. 5 5 0 50 .51. u. 0 .1 1 .1. .011 ...5‘...‘~ 50 u 0.. I 0' 0 1 k. . 1 1
555.0 51.10.1111 1 . . 1

 

——-J-.
..m.“5¢<~¢0«-‘
‘ 0 ' .
0
Q .
.
V '__
5 5
..
1
5
0 O
I
1
.
I
I 0
0
- 0
' 0
.,
0
l
. I
. r
O
. .
C ‘Y
t .
-r
0"
’ I
z
, .
.
I .0
11'"
' U
1 (-
', 5'_1
'5
I 4
1
5’ 1
. . ,
-. 1
5
:0
1
1".
f ‘ 0
.I_ 1
r C
1
1 0.0‘
- l
'6 -f.
1,0 I' ’ ‘
' '0 '
5 _
1 5,
’ . 0
O
1
l
’ 1
'1‘1".'
0 l 1 ’
1, .0
. .
0 DD.
"/\
. I ..-
1 . 1
.150
, 5

0101 1.35

”‘0 0
1.1?

1‘5

, . .1 1 4. J 1 (11.111101.
111 I5 1 1 .1. 5 1555515500... 5’030I'155fl5d.01055..31 0 0.1.1.5hf1 0.0?J30.u‘d 515 501.0110, 00
.11 1 1 .11.....5..551.13...5550 50. m5 ..1 1.11 011. 05.5 1 5 10.. 1.111 1
5.51.3 . 2:1». 1.)...555.5.5. .5... .5 553..u5.15. ...1 ”01:. 5 ...V?!,555tl55‘dl‘551515mv111555\t1.51..555.55 . 55... 1.5.5 5 .055. 54.555155... 5.5.5.031 15 515.055.5515; J. 0 . 1151 .5, 4Vu510 .5101”. 011?”.51n5 .0155 fiefk515oklll5£1fi6§1~0£§so .510 ’Z‘?.
5 1 ‘0 3.. 01505,.‘1 '0 5. 115.15 5 055 555 . 05 . a“. 5.1.0 50.. vafi‘n- D151”. 10 Q
0 095.555 I 1 H 5 I H . .5 .5155 1 155.0. .0 5.551 D! 71.).5555ofll55fié15n5c55n11~i5a.»ru~1.0.3;0r~5€15 “flauna—{Jr‘fl 515.50‘J1‘gfiw5ika 0.030. 0~B.E¢5l.. .5555 F
5 J 55 0. I . . I ‘05; 4 1 H. .‘ g 5. .0005. 5. 1 1 . 1. 1 .51
. 1§5WKJ5W51 5111.511», .35.. 51. 24.1.1111.

 
 

 

 

 

“FEELS?!

 

ABSTRACT

HEINPOROERS FOR THE TWEEVE—MONTH-OLD
IN‘AN OPEBLNT MANIPULATIVE TASK

By
Suzanne P. Marshall

Selected auditory and visual reinforcers were compared
as to their effect upon responsiveness and color disormmi-
nation performance by 12-month-old infants in an operant
panel pressing task. The purpose was to find a reinforoer
which could maintain responding beyond the seven to 15 sinp
ute session typically employed with 12-month-olds. Seventy-
two infants (36 boys, 36 girls) were divided into eight
groups varying as a function of the color reinforced (blue
or green) and the reinforcer received. The types of rein-
forcement included: (1) a single auditory reinforcer: a
stranger's voice; (2) a single visual reinforoer: a red
light; (3) a compound auditory-visual reinforcer: a voice
and a red light combined; and (b) a variable reinforoer:
voice, red light, blinking lights, and chimes, presented
singly and in all possible two stimulus auditory-visual
combinations. In addition, a pilot group of 19 infants (10
boys, 9 girls) was run to determine what effect increasing
the probability of stimulus-response contiguity would have
on discrimination performance.

while the major analyses failed to find any differences
between the reinforoers, they did reveal: (1) a significant

Suzanne P. Marshall
decrease in responding and increase in discrimination
performance between the fourth and sixth minute of condi-
tioning, independent of any change in experimental manipula-
tions; (2) a significant effect of the color reinforced upon
discrimination performance; (3) a significant tendency to
respond more to one side than the other; and (1+) a suggestion
from the pilot data that stimulus—response contiguity may
improve discrimination learning by the 12-month-old. All
of these findings should be taken into account in designing
future studies with 12—month-olds.

 

Karl: E. Billing
Ellen A. Stronen
Committee Hubers

Date a/Z/j'a

REINFORCEBS FOR THE TWEEVE-MONTH-OLD
IN'AN OPEBANT MANIPULATIVE TASK

By‘,
Suzanne P.“ Marshall

A THESIS
Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of
MASTER OF.LR$3

Department of Psychology
1972

To Bruce

11

‘ACKNONLEDGMENTS

As the months of preparation, running, and evaluating
of the present study draw to a close, I welcome the oppor-
tunity to reflect back upon those times and to offer my
thanks to the many individuals whose unique contributions
have become so intimately entwined in this final work.

Among these individuals the members of my committee Drs.

Mark Billing and Ellen Strommen deserve a special thanks.

Dr. Billing provided a large portion of the programming
equipment needed in the present study. Dr Strommen both long
before as well as when the present study was conceived spent
a great deal of her time listening and constructively evalua-
ting my ideas for infant research. I'd like especially to
thank my chairman Dr. Hiram Fitzgerald whose standards of
excellence in designing and evaluating one's research both
inspired my efforts and guided them in the present study.

In reflecting on the actual preparation and running
of the study a number of individuals come to mind. First
of all, I am grateful to my husband for the hours he spent
helping to build the apparatus and program the equipment.
Secondly, I'd like to thank my co-experimenters Beth latter
and Heidi Schwartz, NSP'undergraduate research assistants,
who each spent hours writing to prospective subjects and

111

helping to run.the study when it got underway. And finally
my thanks to the 1&8, 12-month-old infants who came to
participate in my task.

The present research was funded in part by NIMH He-

search Grant MH-18655 to Dr. Hiram Fitzgerald and by NSF-
UEP 61-8727.

iv

TABLE OF CONTENTS

LIST OF TABLE e e e e e e e e e e e e e e e e e e e e '11
1018 T OF FIGURES e e e e e e e e e e e e e e e e e e
INTRODUCTIONe e e e e e e e e e e e e e e e e e e e e

7111

Auditow reinforce” O O O O O O O O O O O O O O O 0
Visual reinforcers. . . . . . . . . . . . . . . . .
Compound auditory and visual reinforcers. . . . . .

variable reinforcers. . . . . . . . . . . . . . . .

a: \n «w' $' b) +4

Sex differences . . . . . . . . . . . . . . . . . .
Purpose and hypotheses. . . . . . . . . . . . . . . 10
METHOD. . . . . . . . . . . . . . . . . . . . . . . . 12
Subjects. . . . . . . . . . . . . . . . . . . . . . 12
Apparatus.....................12
Procedure . . . . . . . . . . . . . . . . . . . . . 15
RESULTS . . . . . . . . . . . . . . . . . . . . . . . 22
Total responding. . . . . . . . . . . . . . . . . . 22
Discrimination performance. . . . . . . . . . . . . 26

Relationship between total responding and
discrimination performance. . . . . . . . . . . . . 29

Length of time responding . . . . . . . . . . . . . 31
Poaltion preference 0 O O O O O O O O O O O O O O O 31
nonparametric tea t8 0 O O O O O O O O O O O O O O O 32

Stimulus-response contiguitye e e e e e e e e e e e 33

DISCUSSION............
Sex and reinforcement groups. .
Trials.............
Color . . . . . . . . . . . . .
Position preference . . . . . .
Stimulus-response contiguity. .

LIST. 01' REFERENCES. . . . . . . .

APPENDIX.............

vi

314
31}
39

#1

5:5

Tables

LIST OF TABLES

Page

Analysis of variance: Total Responses to
S+ and S in the Blue Positive Condition. . . #8

Analysis of variance: Total Responses to
and S‘ in the Green Positive Condition . . #9

Analysis of variance: Responses per Minute
in the Blue Positive Condition . . . . . . . 50

Analysis of variance: Responses per Minute
in the Green Positive Condition . . . . . . . 51

Analysis of variance: Discrimination Perfor-
mance in the Blue Positive Condition. . . . . 52

Analysis of variance: Discrimination Perfora
mance in the Blue Positive Voice and Red
Lightconditlonseeeeeeeeeeeeee 52

Analysis of variance: Discrimination Perfor-
mance as a Function of the Color Reinforced . 53

vii

Figures

1.
2A.

ZB.

3A.

330

53a

LIST OF FIGURES

Design of the experiment. . . . . . . . . . .

Total responses in blue positive, male and
female reinforcement groups. N - 5 per
001m 0 O 0 O O O O O O O O O O O I O O O 0

Total responses in green positive male and
female reinforcement groups. N a h per
0 01m 0 O O O O O O O O O O 0 O O 0 O O O 0

Average responses per minute for male and
female subjects across blue positive groups

Average responses per minute for male and
female subjects across green positive groups.

Discrimination ratios across trials in blue
positive groups. The line at 0 indicates
equal responding to the positive and negative
Stimuli O O O O O 0 O O O O O O O 0 O O 0 O 0

Average reinforcement group by sex discrimp
ination ratios in the blue positive condition.
The line at 0 indicates equal responding to
the positive and negative stimuli . . . . . .

Average reinforcement group by sex discrimi-
nation ratios in the green positive condition.
The line at 0 indicates equal responding to
the positive and negative stimuli . . . . . .

viii

Page
17

23

23

25

27

28

3O

30

INTRODUCTION

The purpose of the present study was to compare the
ability of selected auditory and visual reinforcers to sus-
tain the responsiveness of 12-month-olds in an operant mani-
pulative task. In order to stay within the time limits
imposed by the 12-month-old's attention span, such studies
have typically employed short sessions lasting on the order
of seven to 15 minutes (Hill, 1962, 1965; Lipsitt, 1963;.
Simmons, 196k; Simmons A Ldpsitt, 1961; Heisberg A Simmons,
1966). While simple discriminations have been trained in
these sessions (Hill, 1962, 1965; Lipsitt, 1963; Simmons,
196a; Simmons A Lipsitt, 1961; Weisberg a Simmons, 1966),
more demanding problems such as oddity discriminations gen-
erally have not been mastered (Hill, 1962; Lipsitt, 1963).

A methodological factor which may contribute to both the
necessity of short conditioning sessions and the difficulty

in training more complex problems is the type of reinforoer
which has been used. That is, the reinforcers commonly emp
ployed may not be powerful enough to maintain the 12-month-
old's interest beyond a 15-minute session or over the repeated
sessions required for more difficult problems. The character-
istics of reinforcing stimuli have been shown to have def-
inite effects on the level of responding by two-to-fiveamonth-

old infants (Caron, Caron, a Caldwell, 1971; Koch, 1968).
1

2
But the question remains as to which aspects of reinforcement
(e.g. modality and familiarity) are most important in main-
taining the attention of the 12-month-old.

A comparison of the effectiveness of reinforcers used
in past research is confounded by variations in the infants'
age and sex; the required response; and the manner of rain-
forcer presentation. A series of controlled investigations
is needed to compare reinforcers and to account for the
influence other experimental variables might have on the effec-
tiveness of such stimuli.

The present study was designed to compare selected
auditory and visual reinforcers presented to 12-month-olds
in an operant panel pressing task. The following review
illustrates the diversity of auditory and visual reinforcers
that have been used in infant research, and points to the
procedural and subject related variables that may have influ-
enced their effectiveness. (See Reese and Lipsitt's (1970)
review for a summary of other stimuli that have been used as
reinforcers in infant research.)

Auditor; reinforcers. Several studies have investigated
the infant's response to auditory social stimuli in the form
of the mother's or a stranger's voice. Friedlander (1968)
found that with increased experience with his Playtest appa-
ratus and increased chronological development , infants
ranging from 11-to 15-months-old came to prefer the more
novel disguised voice of their mothers over a stranger's

or their mothere' bright voices. Koch (1968) using repeated

3
presentations of the mother's face and voice or a stranger's
face and voice as a reinforcer for a conditioned orienting
response, found higher responding to the more novel stran-
ger as the number of sessions progressed. (Subjects were
two-to-five-month-olds and were tested in ten, 12-to 15-
minute sessions.) Rank (1968), Wahler (1967), and Weisberg
(1963) employed auditory social reinforcers in controlling
sucking, smiling, and vocalizing respectively.

Auditory stimuli such as 22.1.22 (Lipsitt, 1963; Simmons,
1969; Weisberg, 1963), buzzers (Lipsitt, 1963), 229. (Dor-
man, Watson, at Vietze, 1971; Watson, 1969), and 91.9.1.2 (Fried-
lander, 1968; Smith a. Smith, 1962) have also been used. '
Simmons (1961+) and Lipsitt (1963) found such reinforcers to
be effective in an cperant discrimination task with eight-
and 12-month-old infants. Friedlander's 13-month-old infant
preferred his mother's voice to Each. Smith and Smith (1962)
noted that infants as young as eight months showed a definite
interest in music but only one of 10 subjects from four to
22 months learned to touch a plate to activate tape recorded
songs. This failure may have resulted from their use of rela-
tively long (two-to three-minute) reinforcement periods which
limited the frequency of response-reinforcement pairings.
Using a 1000-Hz tone of medium intensity, Watson (1969) demon-
strated better operant control over visual fixations in 10-
and 1h-week-old girls than boys. (Fourteen-week-old boys
responded better to a visual reinforcer and 10-week-old boys
failed to learn.) Weisberg (1963), using contingent reinforce-

h
ment with a door chime, failed to condition vocalizations
in three-month-old infants.

21523; reinforcers. Various visual reinforcers such as
slides of geometric forms, schematic faces, checkerboards,
mothers' faces, and pictures of spinning clowns have been
given as reinforcers for such responses as headturning,
panel and lever pushing, nonnutritive sucking, and visual
fixations (e.g. Caron, 1967; Lipsitt, Pederson, a DeLucia,
1966; Rheingold, Stanley, & Cooley, 1962; Siqueland A DeLuoia,
1969; Watson, 1969). Lights, while not commonly used as rain-
forcers have been shown to elicit visual orienting (cchen,
1969; Levison & Levison, 1967) and have been.used by Fried-
lander (1961) as a reinforcer in a manipulative situation.

Compound auditogz 222.!l5221 reinforcers. Compound
auditory and visual reinforcers may prove superior to single
modality stimuli in sustaining the infant's attention over a
sufficient number of trials for the learning of complex
behaviors. Their effectiveness in simple tasks'has been
demonstrated by Rovee and Rovee (1969) in a conjugate rein-
forcement study. In their study, increased intensity of
kicking resulted in proportional increases in the movement
of a mobile eventually causing the parts of the mobile to
bang together producing both auditory and visual reinforce-
ment. Using a compound auditory and visual reinforcer,
Watson (1969) was successful in conditioning 10-week-old
girls but not boys to visually fixate one of two blank tars
gets. Rheingold, Stanley, and Doyle (196k) increased the

5
rates that two-to-five-year-olds touched a ball for a com-

pound sound and motion picture reinforcement. While the rein-
forcement was successful in maintaining the children's para
tioipation during the first session, the children lost in.
terest earlier in a second but otherwise identical session.

Variable reinforcers. In discussing the decreased
responding in their two-to-five-year-old children in the
second session, Hheingold et. al. (196%) suggested that
variation in reinforcement might have maintained responding
for a longer period of time. Research reported by Caron,
Caron, and Caldwell (1971); Koch (1968); Siqueland (1969);
and Siqueland and DeLucia (1969) speaks directly to this point.
Koch compared the effectiveness of a mother's face and voice;
a stranger's face and voice; and different noise making toys
as reinforcers for conditioned orienting in three groups
of two-to-five-month-old infants. As mentioned earlier,
infants reinforced by the stranger responded at higher rates
over the 10 sessions than those reinforced by the mother.
However, the group reinforced by different noise making toys
was the most resistant to satiation and therefore produced
the highest level of responding. Koch postulated that a
familiar repeatedly presented stimulus (the mother) will
lose its reinforcing value more quickly than will a novel
repeatedly presented stimulus (the stranger). Nevertheless,
the infant will in time, also become satiated with a novel
stimulus when it is repeatedly presented.

Siqueland and DeLucia (1969) conditioned high amplitude

6
nonnutritive sucking in two groups of 12-month-olds. The
groups differed in the amount of reinforcer redundancy.
Conditioning involved presentation of slides as reinforcers
over two consecutive four-minute sessions followed by two-
and three-minute periods of extinction respectively. A ”high-
redundancy" group saw four slides a total of four times
each over the two conditioning phases. A ”low-redundancy”
group saw eight slides, each presented twice. Slides were
changed every 30 seconds. The groups did not differ in respon-
siveness until the second conditioning phase at which time
the high-redundancy group responded at a higher level than
the low-redundancy group but also demonstrated a decline '
in the rate of responding. On the other hand, the response
rate for the low-redundancy group was stable. It appears
that if conditioning periods were lengthened, the response
level of the high-redundancy group may have continued to
decline to a level below that of the low-redundancy, stable
responding group. That is to say, satiation effects may not
be observable in the typical short session used with infant
subjects. But if longer sessions were needed for more complex
learning tasks, the less redundant reinforcers might prove to
be more effective than the repetitive reinforcers frequently
employed in infant research. Again it should be noted that
in Koch's (1968) study where the changing stimuli did bring
higher responsiveness, the infants were undergoing a series
of ten, 12-to 15-minute sessions and not one short session

as in the Siqueland and DeLucia study.

7
In 1969, Siqueland reported a study with fouremonth-

olds in which one group of infants was familiarized with
the reinforcing stimuli for two minutes prior to eight
minutes of conditioning. Results indicated attenuated cone
ditioned responding following familiarization. That is, the
group reinforced for‘high or low amplitude sucking following
familiarization, showed a lower rate of the required response
than those infants for whom the reinforcers were new. Sique-
land (1969) also reported studies with four-month-olds in
which novel auditory or visual reinforcements were intro-
duced following five or six minutes of training. Results
indicated an increase in conditioned responding by infants
reinforced by new stimuli compared with infants who received
no change in the type of reinforcer presented over trials.
Caron, Caron, and Caldwell (1971) carried out an exten-
sive investigation of the relative ability of reinforcers
varying in redundancy, pattern complexity, and color to
maintain an operantly conditioned head turning response in
three-and-one-half-month-old infants. Following a period
of varying reinforcers, all infants save the control sub-
jects, were exposed to one of several redundant reinforce-
ment conditions. Significant response decrements occurred
in those infants receiving simple or complex patterns
which either were purely repetitive or alternated only in
color. The extent of response decrement was attenuated when
reinforcing stimuli alternated in pattern or in both pattern

and color. Moreover, reinforcement by continuously changing

8

stimuli was superior to any stimuli in which repetition was
involved.

§g§ differences. The question of possible sex differences
in responsiveness to different reinforcers was raised by Wat-
son's (1969) study in which he conditioned 14-week-old in-
fants to visually fixate one of two blank targets. The
infant girls learned better with auditory reinforcement while
the boys learned better with visual reinforcement. Watson
suggested the possibility of an interaction of sex by modality
of reinforcement by the intensity of that reinforcement.
Accordingly, Dorman, Watson, and Vietze (1971) varied the
intensities of watson's stimuli adding a higher and lower-
intensity in each modality. Using a procedure similar to
Watson's, they found that only when the medium intensity
stimulus (Watson's) was the first to be presented were the
findings similar to those in the 1969 study. Lewis, Baumel,
and Groch (1971) compared the responsiveness of three-month-
olds to stimuli in the auditory and visual modalities. Their
findings were analogous to Watson's 1969 study in that girls
showed heart rate deceleration more to auditory than to
visual stimuli; although boys' decelerations did not signifi-
cantly differ for the two modalities.

Investigations of the relative attentiveness of infants
to novel and familiar stimuli have found sex differences
in habituation of attention and in the effects of stimuli
varying along a novelty continuum. (Novelty can be defined
as the extent of discrepancy from a standard familiarized

9

stimulus or as the degree of uncertainty within and between
the components of a stimulus.) If as Hagan (1967) ascertains,
learning is a function of both stimulus-response contiguity
and attentional involvement of the subject; and if sex dif-
ferences exist in the factors influencing this involvement,
then these differences must be considered in determining the
characteristics of an effective reinforcer. Cchen, Gelber,
and Lazar (1970); Kagan and Lewis (1965); and Pancrantz
and Cohen (1970) found greater incidence of habituation over
trials by males than by females in infants ranging from four
to 13 months. In particular, Kagan and Lewis found that 13-
month-old boys clearly habituated to a matrix of blinking
lights and to readings of a paragraph, while girls in both
cases were more likely to sustain attention across trials.
Caron and Caron (1969) in what appears to contradict the
above findings, found that three-and oneehalf-month-old
girls showed steeper decrements in visual fixations to checker-
board patterns than did males. These results were replicated
by Caron, Caron, and Caldwell (1971) in their study of
redundant and constantly changing reinforcers which is de-
scribed above.

thall and Hagan (1970) and Meyers and Cantor (1967)
found differential responsiveness in heart rate deceleration
to novel and familiar stimuli only in their’male sub-
jects (fours and six-months-old respectively). Studies in
which the extent of novelty has been varied (Hagan A Lewis,
1965; McCall A Hagan, 1967; Weizmann, Cchen, A Pratt, 1971)
have in general found that infant girls respond preferentially

10
to the more novel stimuli. In the Hagan and Lewis study,
six-month-old girls preferred jazz music (as determined by
heart rate deceleration) whereas boys preferred an intermit-
tent tone. Paragraphs with low meaning, high inflection (i.e.
the condition of maximum uncertainty) were more preferred by
13-month-old girls than boys. Weizmann et al.'s (1971)
eight-week-old girls responded more reliably to a novel
mobile when in a novel bassinet; whereas the eight-week—old
boys responded to the novel mobile more reliably when in
a familiar bassinet. McCall and Hagan (1967) familiarized
infants from their third to fourth month with a standard
stimulus and then at four months presented three graded dis-
crepancies from it. Hagnitude of cardiac deceleration was
an increasing function of discrepancy for girls but not for
boys.

Pumose and hmotheses. The purpose of the present
study was to compare selected auditory and visual reinforcers
in terms of their ability to maintain responding by 12-month-
old infants in an operant manipulative task. All subjects
participated in a color discrimination task. Groups varied
as a function of the discriminative stimulus rewarded and
the reinforcer which was given. The following questions were
considered:

(a) Would a single auditory or visual stimulus or a
combination of these be more effective in maintaining a high
level of responding across trials? Although the present study
chose an auditory and a visual stimulus, the primary interest

11

was in the particular stimuli and not in the modalities
they represented. The same reasoning applied to the social
versus nonsocial nature of the reinforcers (i.e. the con-
cern was with the stimuli themselves not the class of stimuli
represented).

(b) Would the decrease in redundancy facilitated by a
series of different reinforcers, serve to sustain interest
and thereby maintain responding more than a single reinforccer?

(c) Would the differential responsiveness of boys and
girls to novelty and modality of a stimulus array interact
with the reinforcing stimuli in determining the most effective
reinforcer?

It was hypothesized that the ability of the reinforcer
to maintain a high response level across trials would increase
with the number of different stimuli presented within a sin-
gle and across a number of trials. Although sex differences
may emerge both in the extent of sustained responding and
as a result of the effects of reinforcers varying in sen-
sory modalities and degree of familiarity, past findings
are not clear enough to predict with confidence the direc-

tion such differences would take.

METHOD

Subjects. Ninety-one 12-month-old infants (#6 boys, 45
girls with a mean age of 11.9 months and a range of 11.“ to
12.6 months) were solicited by mail, newspaper ads, and
notices to married students at Michigan State University.
names for those solicited by mail were obtained from news-
paper birth announcements. Each family whose name was obtained
from the newspaper received a letter explaining the general
purpose of the experiment with a postcard to be returned if
they were interested. Families were then called, all questions
answered, and appointments made. An effort was made to‘have
each infant come to the laboratory at a time when the mother
felt he would be most alert and rested. Infants were randomly
assigned to the various reinforcement groups within one phase
of the study at a time with the restriction that the sexes
be as equally balanced as possible across all conditions. The
91 subjects were those remaining from a total of 1&8 after
pilot work was complete and subjects eliminated for failure
to meet performance criteria (see explanation below). Five
other subjects were eliminated to make the experimental
groups more equal in size.

Apparatus. The infant's responses were made to a three
panel apparatus with a 2h X 15% inch front surface. The

apparatus was made of wood and painted flat black. Its front
12

13
face sloped 30° from the vertical away from the infant. Each
6 x u inch panel was composed of four pieces of plexiglas
(clear, white, and two frosted from top to bottom) with a
1% inch diameter hole in the center of the white piece
through which blue or green stimulus lights could be seen.
The panels and discriminative stimulus lights were the same
in the first two phases of the study. During the third phase
which was essentially pilot in nature, a new set of lights
was used and a hole was out in the top layer of the plexi-
glas directly above the stimulus lights. This gave an additional
dimension to the panels which it was hOped would draw the
subjects' attention to the discriminative stimuli and increase
the likelihood of stimulus—response contiguity.1 In all phases
of the study, six small circles were found equally spaced
around the larger‘hole and 5/8 inch from it. Through these
six spaces neon blinking reinforcer lights could be seen.
Each panel was above a microswitch that was triggered when
the infant depressed the panel. The apparatus was wired such
that a response to the positive stimulus could not be recorded
while a response was being made to the negative panel and
vice versa.

A speaker, 3 inches in diameter, was located below each

 

1Several investigators (Jeffrey A Cchen, 1965; Murphy A
Killer, 1959; Ramey a Goulet, 1971) have demonstrated that
children ranging in age from hi months to 11 years have con,
siderable difficulty solving discrimination problems when the
discriminative stimuli and locus of response are spatially
separated. The present pilot work was an attempt to determine
the applicability of these findings to 12-month-olds.

1h»
panel. A small red light protruding approximately i inch
from the front surface of the box, was found centered above
each panel. The speakers and red lights provided the auditory
and single light reinforcers (see below). The use of three
speakers, three red lights, and three sets of blinking lights
was to maximize the probability that the infant would asso-
ciate the reinforcement with a given discriminative stimulus
and not with the entire experimental situation (Friedlander,
1966).

Presentation and timing of the stimulus lights and
reinforcers and counting of the subject's responses to each
panel was controlled from the experimenter's unit located
in an adjoining room. A tape recorder used in playing a female
stranger's voice saying "that's good; you're doing fine",
and chimes from the Sound of Music, was placed with the
experimenter's unit.

Testing for all infants with the exception of a few
pilot subjects took place in a 6% x 5% x 55 foot sound-
attenuated room with an ambient noise level of 30 db. The
only sound other than that coming from the apparatus, the
infant, or his parent was. produced by a fan in the ceiling
above the test box. This sound was 30 db above the ambient
level. The room was dimly lit so that the discriminative
stimuli and reinforcing lights would be maximally visible.
The lighting was not however so dim as to possibly upset
the infant.

15

Procedure. A period of five to 10 minutes was set aside
at the beginning of each session to talk to the parent and
to enable the parent and the infant to become comfortable
in the situation in the absence of the experimenter. At
the beginning of this time the parent was given a further
explanation of the study; asked to sign a permission form;
and asked not to interact with the infant during the actual
experiment unless it was necessary to comfort him. (Host
subjects were accompanied by their mothers although several
fathers stayed with the infants during the session.) The
parent was informed that the experimenter would be able to
hear what was happenning and would terminate the session.
should the infant become upset during testing. It was ex-
plained to the parent that after he and the infant were alone
in the situation for a few minutes and when the infant seemed
at ease, the experimenter would turn on the stimulus lights.
The parent was instructed to direct the infant's attention
to the lights and to demonstrate by pushing each of the two
outer panels twice. Following the demonstration, the lights
would be turned off momentarily. This was to signify to the
parent that from that point on, he was to refrain from
directing the infant in any way. During the study the parent
positioned'himself in a location which would be to the rear
of the infant whenever“he was playing with the apparatus.
The parent sat either on the floor or on a chair whichever
was preferred. The parent was however encouraged to sit on

the floor‘because in this position the infant was less likely

16
to want to climb on his parent's lap which would be several
feet from the experimental apparatus. During pilot work an
attempt was made to have infants remain seated in front of
the apparatus, but the protests which ensued led to a change
in procedure which would allow the infant to move freely
around the sound-attenuated room.

The experimental design is summarized in Figure 1.

The first two phases of the study were alike with the excep-
tion of the stimulus which was rewarded. Subjects in the
first phase were reinforced for responding to the blue light
while those in the second phase were reinforced for the green
light. Within each positive stimulus group, subjects were
divided into four additional groups varying only with regard
to the kind of reinforcement received. Eachblue positive
reinforcement group was composed of 10 infants (five girls,
five boys) and each green positive group had eight infants
(four girls, four boys). The four reinforcement groups were
as follows:

Group I (single auditory reinforcer) subjects were
rewarded by a three—second tape recording of a cheery female
stranger's voice saying, ”that's good; you're doing fine".

Group II (single visual reinforcer) subjects saw three
seconds of a red light presented above the positive stimulus.

Group III (compound auditory-visual reinforcer) subjects
saw three seconds of the light and heard the voice simul-
taneously.

Group IV'(low redundancy, variable reinforcer) subjects

1?

 

 

 

 

 

 

 

 

 

 

 

 

Group SI’ SubjectsI Reinforcement eriods (Same for all)
- 5 male 3 sec. voice Baseline:
I Blue 5 female of stranger two, 15 sec.periods
~two, 5 sec.timeouts
h male
Green # female: Conditioning:
+eix, 60 sec.periods
5 male 3 sec. red six, 5 sec.timeouts
II Blue 5 female light
- Extinction:
a male two, 60 sec.periods
Green a female two, 5 sec.timeouts
5 male 3 sec. voice Reconditioning:
III glue 5 femalenplus red ix, 60 sec.pbriods
light ix, 5 sec.timeouts
h male
Green it female Final Extinction:
four, 60 sec.periods
£1 5 male 3 sec. presen- three, 5 sec.timeouts
IV us 5 female tations, 1 stim-
ulus for 30 sec.
4 male voice; red light;

Green

4 femaleqvoice A red;

blinking lights;
voice A blinking;
chimes; chimes A
red; chimes A

 

 

 

 

blinking
Pilo 5 male Same as Group IV
Flat ue 5 female)
Pilo male Same as Group IV
Hole ue female

 

 

 

Total: 91 subjects

18 minutes, 30 see.
with lights; 1 minute
35 sec. timeout

 

Fig. 1. Design of the experiment.

18
received eight different reinforcers: stranger's voice; red
light; voice plus red light; blinking lights; blinking
lights plus voice; chimes; chimes plus red light; and chimes
plus blinking lights. The order of these stimuli was rams
domly determined within blocks of eight with the stipulation
that the same stimulus could never be the last in one block
and the first in the next. The order of presentation of
the three randomized eight stimulus blocks was also rans
domized across subjects. All reinforced responses in a
given 30 second period received the same reinforcer.

The general experimental paradigm was the same for all
groups: 30 second baselinez; six minutes conditioning; two
‘minutes extinction; six minutes reconditioning; and four
minutes final extinction. In all phases the stimulus lights
were turned off after every minute for a five second timeout.
After each 30 second interval, the experimenter recorded the
cumulative responses to each panel and to the positive and
negative stimuli and changed the reinforcing stimulus for
Group IV. After each minute the experimenter also changed
the position of the stimulus lights according to a predeter-
mined random pcsition sequence. Each subject received one
of six orders of stimulus light presentation with each light
appearing half the time on the right and left sides. (It

 

2One subject in each green positive group received one
minute of baseline. A prtest performed on the total responses
of these versus the remaining green positive subjects did not
reveal a significant difference (p_= .879, $2,: 30).

19
should be noted that the center panel was never'used in the
present study.) During the baseline period the lights were
on but no reinforcement was given. Following the first 15
seconds of the baseline, the position of the colored stimu-
lus lights changed. Baseline data was originally deemed
necessary to determine the existence of color or position
preference as well as the operant level of responding. It
was however too short to be used for anything but color
preference testing. (Some subjects did not respond at all
during this time; but color preference could only be tested
prior to reinforcement of responding.) Position preference
was determined with data from the entire session. A longer
baseline used in pilot work was shortened because it ap-
peared to extinguish the subjects' interest in the apparatus.
Subjects received continuous reinforcement throughout all
conditioning periods. However, the apparatus was set up
such that responses occurring during a reinforcement were
recorded on the counters but did not lead to another rein-
forcement. Subjects therefore frequently responded more than
once for each reinforcement. During extinction the stimulus
lights remained on (except during timeouts) and changed as
required at the end of one minute periods. No reinforcement
was given during extinction except at the end of the first
extinction period in order to regain the subject's attention
to the box prior to the reconditioning phase. Reconditioning
and final extinction followed the same format as original
conditioning and extinction . If during the first conditioning
period the subject stopped responding for*more than three

20
minutes or if any time after first extinction reaponding
ceased for greater than two minutes, the session ended.
Also, if at any time during the session the infant refused
to continue (e.g. by crying) the session was terminated.
Subjects had to remain in the study at least through the
first extinction period in order for their data to be
considered.

The third phase of the study was run.primarily to col-
lect pilot data concerning the importance of stimulus-
response contiguity in the discrimination performance of
12-month-olds. As noted previously, evidence gathered with
older children (e.g. Jeffrey A Cchen, 196%) indicated that
discrimination was severely retarded when the discriminative
stimuli and the required response were not spatially contiguous.
The question was therefore raised as to whether 12-month-olds
could discriminate better if they pressed the panel directly
at the stimulus light. It was noted during the first two
phases that the infants were particularly attracted to any
part of the box that protruded or indented from the remaining
portions. It was hoped that if the panel were indented only
at the light itself, this might prompt responding at the
discriminative stimuli. Therefore, a hole was made in the
top piece of the plexiglas panels directly over the stimulus
lights. Five male and four female subjects were run in
the blue positive, variable reinforcement condition with
the indented panels. Abomparison group of five males and five
females had a flat panel and was also run under the blue

21
positive, variable condition. However, the two groups
were not completely comparable because the first had a 30
second and the second a one minute baseline. Nevertheless,

the data was worth considering for information applicable

to possible future research.

RESULTS

To determine the effects of the reinforcement condi-
tions on total responding as well as their effects on dis-
crimination, two basic measures of each subject's performance
were used in the analysis: total number of responses and
discrimination ratios, 8+ — S' . The former measure con-

8... + 8‘
sisted of merely counting the responses made to each stimulus
during each minute of testing. The latter measure examined
the relative number of responses to the positive (3+) and
negative (8') stimuli during each minute and thus limited
the effect of large individual differences in the amount of
responding. The possible discrimination ratios range from
-1 indicating that the subject responded only to the
negative stimulus, through 0 representing equal responding
to both stimuli, to +1 indicating responding only to the
positive stimulus.

‘22§§;,responding. No differences were found in the
total number of responses made by subjects in each of the
four reinforcement groups in either the blue or green
positive stimulus conditions (Figures 2A A 2B).,A three
factor mixed design with repeated measures on one factor
(Reinforcementu X Sexz x S+S‘2) performed within each pos—
itive stimulus condition (blue and green) yielded a significant

22

23

 

 

 

 

 

3 female I!

to

z

a .

c.

m

I“

e:

-l

e:

p—

a

h ,

‘ voice ml voice It vstisllle
light light '

REINFORCEMENT GROUPS

Fig. 2A. Total responses in blue positive, male and female
reinforcement groups. ll - 5 per column.

female I

 
  
 

assrowsss

 

 

 

 

.l
<
1..
c
.—
voice red voice 8 variable
light light
REINFORCEMENT GROUPS

Fig. 2B. Total responses in green positive, male and female
reinforcement groups. R :- 11» per column.

24
difference in total responding to the positive and negative
stimuli (Blue: 3 = 6.154, g; a 1/32, p < .025; Green: _F_‘ a 8.2,
g; = 1/2“, p<.01) (All analysis of variance tables yielding
significant results may be found in the Appendix.)

In order to examine the change in total responding per
minute (i.e. trial) a three factor mixed design with repeated
measures on one factor (Reinforcementu X Sexz X Trials) was
performed separately within the blue and green positive
conditions. Only the six minutes of the first conditioning
and the two minutes of the first extinction were examined
because of the small number of subjects completing the
remaining portions of the study. Results within the blue-
positive condition indicated a significant trials effect
(3: ... 9.32, g; a flash, p <.001). A Neuman Kuels (Winer, 1962)
performed on this effect revealed a significant difference
(p < .01) between trials one through four and six through
eight. It should be noted that trial six which is part of
conditioning was significantly different from trials one
through four of conditioning but not from trials seven and
eight which composed extinction (see Figure 3A). That is,
responding decreased prior to the implementation of the
extinction phase. Results within the green positive con-
dition also revealed a trials effect (3 a 9.155, g; =- 7/168,
2 <.001). In addition a Reinforcement _x_ Sex ; Trials inter-
action was also found (g = 2.35, d; :3 21/168, 24. .005).

A Neuman Keuls performed on the trials effect found trials
seven and eight (i.e. extinction) to be significantly

25

d

a "10.8 _
female .4-

guns

w

d

AVERAGE RESPONSE

       

.m'234551t7 a,

conditioning extinction
MINUTES (TRIALS)

Fig. 3A. Average responses per minute for male and
female subjects across blue positive groups.

26
different (p < .01) from trials one through four but not
from trials five and six; trial five was significantly dif-
ferent from trials one and two; six was also different from
one. Note that here again, responding in the last trials of
conditioning did not significantly differ from responding
during extinction (see Figure BB).

In a three factorial design (Reinforcementu X Sex2 x
Color Reinforcedz), no difference was found in total
responding as a function of the color which was rewarded.

Discrimination performance. Discrimination ratios were
used in a three factor mixed analysis (Reinforcementu X Sex2
x Trialss) performed separately for the blue and green posi-
tive stimulus conditions. Within the blue condition a sig-
nificant trials effect was found (3 a 2.2, _d_§ = 7/221-5, p<.05)
as well as trends toward Reinforcement 5 Trials; Reinforce-
ment 5,8ex; and Reinforcement 5,8ex §_Tria1s interactions
(3 a 1.51, df = 21/22”, p < .07; g a 2.146, g; =- 3/32, 2 < .09;
‘g = 1.56, g; = 21/22”, 2,: .05; respectively). A Neuman Keuls
performed on the significant trials effect yielded a signifi-
cant difference (p.<:.05) between trials four’and five (see
Figure h). It should again be noted that this difference lies
within the conditioning trials. As seen in the figure, dis-
crimination during trial five was better than in trial four.
No significant differences or trends were found in the com-
parable analysis for the green positive subjects. It should
also be noted that no significant differences were found in

discrimination performance between reinforcement groups

2?

male. .—
female 1"

IyUTE

S/M

d

AVERAGE RESPONSE

 

12 3 4 5 e‘p'l a_

conditioning fiewtinction
MINUTES (TRIALS)

Fig. 33. Average responses per minute for male and
female subjects across green positive groups.

SUM 5”-S‘

ACROSS BLUE POSITIVE GROUPS

S*+ S‘

28

18‘

16

14

12

1O

 

 

 

    

      

'4 1 2 3 4 5 AL 7 a.
conditioning extinction
MINUTES (TRIALS)

Fig. It. Discrimination ratios across trials in
blue positive groups. fine line at 0 indicates

egual responding to the positive and negative

s ilul .

29
(see Figures 5A a 53). while the figures suggest possible
differences, the results of any post hoc testing should be
viewed sceptically. A two by two analysis Reinforcement“ 1
Sara) performed within the blue positive voice and red light
groups did yield a significant Reinforcement ; Sex inter-
action (3: - 10.16, g; - 1/16, p «(.01).

Average discrimination ratios across the first eight
minutes (first conditioning and first extinction) were cal-
culated for each subject. these ratios were then employed
in a three factorial analysis {Reinforcement}, x Sexz 2:

Color Beinforcedz) to determine the relative effects of

the two positive stimuli on discrimination performance. A
significant color effect and Reinforcement ; Sex 5 Color
interaction were found (3 - 5.90, if . 1/56, p< .025;

g - 2.79. d; - 3/56, p< .05, respectively). is illustrated
(Figures SA 0. SB), performance was superior in the blue
positive condition.

M anon-h ...—between 222;. W m W
W. Spearman rank order correlations were performed
with each subject's total responses and average discrimination
ratio within each positive stimulus condition. the purpose
of this analysis was to find the degree of the linear rela—
tionship between amount of responding and discrimination per-
formance. Correlations of .019 within the blue positive and
.26 within the green positive both demonstrated the lack of
a significant relationship between these two measures. a

high degree of responding by subjects within a given

30

fifti—

 

 

 

AVERAGE GROUP

   

voice Ted voice & vstiallle
I inn! light
REINFORCEMENT GROOPS

Fig. 5A. Average reinforcement greup by sex discrim-
ination ratios in the blue positive condition. The
line at 0 indicates equal responding to the positive
and negative stimuli.

 
  

,§+S‘
.a N

 

 

a
a
o
a:
co
3
g .0 1
I;
<
. voice gall Items 8 variable
hght huh! '

REINFORCEMENT GROUPS

Fig. 53. Average reinforcement group by sex discrim-
ination ratios in the green positive condition. file
line at 0 indicates equal responding totthe positive
and negative stimuli.

31

reinforcement group is not therefore a good predictor of
high discrimination performance. One of the more extreme
examples within the present data is the performance of males
in the blue positive red light reinforcement group. In this
case, total responses were the second highest of all blue
positive groups but the average discrimination ratio was
only -.06. That is, while male subjects responded well, they
actually chose the negative more often than the positive
stimulus (Figures 2A a 5A).

my; 2; _t_i_m_e_ respmdig. Since the purpose of the
study was to find reinforcers which would maintain responding,
a two factorial Reinforcement“ x Sexz) analysis of the length
of time subjects continued to respond was performed within
each positive stimulus condition. lo significant differences
between reinforcement groups were found in either analysis.
On the average, subjects continued to respond for 10.7
minutes. This does not include time in the baseline period
or the time following the last response during which subjects
continued to remain under the experimental conditions.

Position preference. In order to determine the existence
of position preference as an error factor in the present
study, each subject's total response data was converted into
the absolute value of the ratio t - ft . the resulting
values could fall between 0 and 1 indio:ting responding
equally to both sides and responding to only one side respec-
tively. A two factorial (Reinforcementj, X sexz) analysis
within each positive stimulus condition found no significant

32

differences in the amount of position preference in the
various reinforcement groups. However, failure to find a
difference here does not mean that responding was not highly
influenced by position preference but merely that no dif-
ferences were found as a function of the reinforcement groups.
A t test was performed within each positive stimulus condi-
tion to determine if the mean ratio was significantly greater
than a ratio of 0 which would be predicted if no position
preference existed. The _t_ within both positive stimulus groups
was highly significant indicating the strong prevalence of
responding more to one side than the other (Blue: 3 - 9.77,
91 - 39. 2 < .0005, one-tailed; Green: 1 - 9.66, g; . 31,
p_ < .0005, one-tailed).

W 29.2.29.- Krushal-Uallis one way analyses
of variance (Siegel, 1956) performed on portions of the data
yielded results similar to those found above using parametric
analysis of variance designs. hat is, no significant dif-
ferences were found in total responses in each group-by-sex
cell in both blue and green positive conditions; nor were
there any differences in group-by-sex cells using average
discrimination ratios for each subject. The presence of
great individual differences between subjects suggested the
possible use of the median test (Siegel, 1956) to see if
those subjects who discriminated better responded. differently
as a function of the reinforcement group. This test requires
that no more than 201 of the cells have an 1195.5. his assump-
tion could not be met in blue and green reinforcement group

33
comparisons. While it could be met in both blue and green

sex comparisons, the results were not significant.
Stiglus—rgsponse contiggitz. A _t_ test was performed
on the pilot data collected to determine the effect of
increasing the probability of contiguity between the discrim-
inative stimuli and the infant's response. A one—tailed test
of the data using average discrimination ratios in the in-
dented versus flat panel groups found a trend at the .06
level (1; =3 1.69, g; - 17, g(.06).

DISCUSSION

lhe main findings may be readily summarized. First, in

the major analyses there were no significant effects of sex
or reinforcement groups on length of participation, total
responses, or discrimination performance in either the blue
or green positive condition. Second, infants showed a sig-
nificant change in both their rate of responding (blue and
green conditions) and discrimination performance (blue only)
between the fourth and sixth minute of conditioning indepen-
dent of any major changes in the experimental conditions.
And'finally, while more responding to the positive than to
the negative stimulus was found, performance (a) was signifi-
cantly influenced by the color of the positive stimulus;
(b) had to overcome strong tendencies to respond more to one
side; and (c) could possibly have been enhanced by an appara—
tus in which the probability of stimulus-response contiguity
was improved.

93; ad, W gm. the intent of the present
investigation was to find reinforcing stimuli which could
maintain the interest of 12-month-clds in an operant, manipu-
lative task longer than the typical seven to 15 minute
session. Past studies (Caron, Caron, a Caldwell, 1971; Koch,
1968) had demonstrated the effectiveness of changing reinforcers
but unfortunately most of the previous work had been done

31.

35
with two- to five-month olds. In general, these young infants

are more accepting than 12-nonth-olds of the restrictions an
experimenter might impose on their activities. Nevertheless,
while the restless character of the 12-month-old makes exper-
imentation more difficult, it also provides an excellent prep-
aration for testing the power of the reinforcing stimuli to
maintain interest in the task. This is particularly true in
the framework of a free operant study where the subject can
change the rate of responding and in this way inform the
experimenter of the effectiveness of his stimuli. Such effec-
tiveness may also be measured in terms of the length of time
the subjects respond, the amount of responding, and the qual-
ity of responding in terms of the experimental contingencies.
In all these measures (responses per minute, time, total
responses, and discrimination ratios) the reinforcing con-
ditions in the present study brought statistically equivalent
results. After a few minutes of responding, subjects pre-
ferred to examine the experimental room, climb on the chair,
and turn to their parents for stimulation. mring pilot work
subjects were at first seated in a car seat, and in a later
modification merely restricted to a playpen. Both situations
brought such strong protests that the final design was adopted
in which subjects were allowed relative freedom within the
confines of the 6% X 5% x 5} foot sound-attenuated room.

When the experiment was designed it was thought that
“variable reinforcement" composed of four basic stimuli,
presented singly and in all possible two stimulus auditory-

36
visual arrays, would have the equivalent effect of Siqueland
and DeLucia's (1969) eight stimulus "low-redundancy“ rein-
forcement. That is, it would maintain a stable rather than
a declining response rate characteristic of their four stimu-
lus "high-redundancy” group. It is possible, however, that
the new combinations of stimuli in the present study were
seen by the infants as repetitions of old stimuli. If this
were the case then the “variable reinforcement” would have
an effect similar to Siqueland and DeLucia's high-redundancy
group. This similarity did in fact occur. If the variable
group did not lack redundancy then it is logical that dif-
ferential effects of reinforcement groups did not occur in
this dimension. Hypotheses dealing with the relative effects
of the novelty of the reinforcer would also be affected by
this interpretation. Specifically, differences based on the
preference of females for novelty could not occur if the
stimuli were not sufficiently variable.

Although the study was primarily concerned with specific
reinforcers, the fact that both visual and auditory modalities
were represented permitted investigation of sex differences
in responsiveness to the two modalities. It was acknowledged
that any results that could arise would be confounded by
such factors as the social nature of the voice and the addi-
tional tactual modality inherent in the red light reinforcer.
In addition to investigating the effects of the reinforcer's
modality, the recording of each subject's responses per

minute allowed for a crude measure of sex differences in

37
habituation to the task. Previous studies had found more

orienting and better learning by three-month-old females
under auditory and males under visual reinforcement (Lewis,
Baumel, a Groch, 1971; Watson, 1969). Such results had

been tempered by a failure to replicate except when medium
intensities were used (Dorman, Watson, a Vietze, 1971). work
relating to the question of habituation has usually been
done with very young infants, however; one study which did
test 13-month-olds (Kagan and Lewis, 1965) found greater
habituation in their male subjects.

In the major analyses of the present study, all sig-
nificant results involving sex took place in three way inter-
actions (Blue, discrimination ratios: Reinforcement _x_ Sex ;
Trial, 2 - .05; Green, responses per minute: Reinforcement ;
Sex 5 Trial, 2 <.005; Discrimination ratios: Reinforcement
5 Sex 5 Color Reinforced, p < .05). Graphical representations
and a survey of the data itself indicated that the effects
were due either to particular subjects whose responses grossly
deviated from the others in their group (Green responses per
minute) or to so many differences across trials, sex, reinforce-
ment, and color reinforced cells that as a whole no consistent
pattern of relationships could be found.

with regard to habituation, graphical representation
of the data (Figure 3A) indicated approximately equal patterns
of responding per minute by males and females in the blue
positive condition. In the green positive condition (Figure 33)
females showed a more consistent decrease in response rate
although no significant Sex 5 Trials interaction occurred.

38
The general findings at least as they appear graphically,
are contrary to those of Kagan and Lewis (1965). The findings
with the green positive subjects are however congruent with
Caron, Caron, and Caldwell's (1971) data with three- and
one-half-month-old infants. In the latter study, habituation
was determined by a response rate measure; while in the
former cardiac deceleration and visual fixation were used.
The discrepant results of these two studies may be a function
of the different measures employed. Conclusions based upon
such measures are likely to vary when general phenomena
such as habituation are considered.

The difficulties in interpretation of the three way inter-
actions and interest in possible sex by modality interactions
in the voice and red light groups prompted the post hoc two
factorial analysis in the blue positive condition. Ellie sig-
nificant Reinforcement _x_ Sex interaction reflected the failure
of the males in the red light condition and females in
the voice condition to discriminate between the positive and
negative stimuli. In contrast to these findings, males on
the average earned ratios of .23 and females earned ratios of
.29 in the voice and red light groups respectively (see Figure
5A). These results contradict the previous findings of
greater attentiveness and superior performance by three-
month-old females under auditory and males under visual rein-
forcement (Lewis, Raumel, a Groch, 1971; Watson, 1969).
Nevertheless, they serve to emphasize the warning of Dorman,
Hatscn, and Vietze (1971) that the nature of sex by modality
interactions is a function of the intensity of the particular

39
stimuli and the context of stimulation in which they occur.

It is also likely that the differences in the task itself
(i.e. visual fixation versus panel pressing) and the age of
the subjects (three versus 12 months) confounds any predictions
from one study to the next. In contrast to the above results
using discrimination ratios, if one compares total responses
under the voice and red light reinforcement groups in the
blue positive condition (see Figure 2A) then the results
comply at least graphically with those expected from previous
research. That is, females respond more (although not signif-
icantly more) in the auditory and males in the visual rein-
forcement groups.

_T_r_i_a_l_§_. The finding of a significant decrease in response
rate during the conditioning session is not completely with-
out precedent in the literature of manipulative responding
by the 12-month-old. In a study of the effects of conjugate
reinforcement on panel pushing by 12—month-olds, Lipsitt,
Pederson, and DeLucia (1966) found a significant difference
in the rate of responding between the first and the fourth
but not between the first and fifth minute of conditioning.
In the present study in the blue positive condition (see
Figure 3A) responding increased gradually during the first
three to four minutes of conditioning and then decreased
rather abruptly resulting in a significant difference between
the the fourth and sixth minute of conditioning. The sixth
minute was not significantly different from the rates in
minutes seven and eight which composed extinction. This is

1&0
similar to the Lipsitt et al. data in that it appears that
extinction had begun around the fifth minute of the study
independent of a change in experimental contingencies. mte
of responding in the green positive condition began at a
higher level than in the blue and decreased as the study pro-
gressed (see Figure BB). For female subjects this decrease
was a gradual one but for males occasional rises in response
rate interrupted the decline. Here again a change around the
fifth minute is evident, responding per ainute being signif-
icantly less than in minutes one and two but not differing
from minutes seven and eight of extinction.

The writer knows of no other free cperant manipulative
discrimination study with 12-month-olds in which conditioning
was carried beyond four minutes. There is thus no comparison
available for the significant rise in discrimination per-
formance from minute four to five in the blue positive group.
Perhaps the decrease in responding per se at this time facili-
tated recognition of the experimental contingencies but the
rapid onset of extinction prevented maintaining this level
of performance across succeeding trials.

m. The current finding of a significant difference
in discrimination performance in the blue and green positive
groups is somewhat analogous to the superior discrimination
ratios of red versus blue groups in Simmons' (196“) study.
Simmons found an initial preference for red in her baseline
data to which she attributed differential performance in
the two groups in the remaining phases of the study. In the

#1
present study analysis of the 30 second baseline data yielded
no such preferences. The mean responding to the blue and green
stimuli in the blue positive baseline was 3.87 and b.25 re-
sponses and in the green positive baseline was “.5 and h.b
responses reapectively. Original preferences do not therefore
seem to account for the significantly better discrimination
under the blue positive versus the green positive condition.
Studies by Chase (1937) and Spears (1966) have shown that
blue and green can be discriminated and at least in Spears'
data with four-month-oldsg there is no evidence of a signif-
icant preference between them. Brightness differences could
have influenced the results since this variable was not
rigidly controlled. An attempt was made to keep the lights
as equivalent as possible as judged by the adult eye within
the grave limitations of the present apparatus. As noted by
Simmons (196a), this brightness dimension may be of crucial
importance in regulating the discrimination performance of
12-month-01ds.

Position preference. Position preference as defined in
the present study means that the subject had tendencies to
respond more to one side than the other. Whether this was a
function of hand preferences that the subject brought with
him to the study or a tendency to continue responding to the
previously reinforced side is not determined. Analyses by
Simmons (196h) of baseline data in a similar study did not
find preferential responding. Weisberg and Simmons (1966)
using a modified Wisconsin General Test Apparatus did however

b2 .

find definite tendencies to respond to the previously rein-
forced side. Analyses in the present study concerned all
the responses the subject made and thus included both ini-
tial and task produced biases. The significant results of
position preference testing serve to emphasize the necessity
of developing techniques to eliminate such biases in an operant
task. Weisberg and Simmons (1966) found it necessary to spend
20 to 40 trials, or approximately one session, to eliminate
the perseverative tendencies. An initial session of this sort
in which such tendencies were weakened might improve subse-
quent performance. Modification of the task so as to require
only one panel (successive rather than simultaneous discrimi-
nation) would also eliminate such biases. If either of these
measures were taken, subjects perhaps could learn simple
as well as more complex discriminations more quickly before
they habituated to the task.

Stimulus-response contiguity. when the apparatus used
in the present study was designed, contiguity of stimulus
and response was facilitated by placement of the discrimin-
ative stimuli in the center of the manipulanda. During the
course of the investigation it became apparent that infants
frequently were pushing the panels without regard to the
stimuli. For example in the red light group, an infant
could be touching the red light which protruded above the
panel while pushing on the panel with the base of the hand.
The infant could in this manner keep the light on while igno-
ring the discriminative stimulus. Personal communication

#3
with Dr. Lipsitt (1971) who used a similar apparatus,
brought out the point that in his apparatus the stimulus light
was somewhat indented from the remainder of the panel. In
the present study the panel was flat. An observation_fre-
quently made during the major portion of the study was that
infants liked to feel any portion of the box which showed
three-dimensional contour (e.g. a screw). Perhaps by in-
denting the stimuli (i.e. cutting a hole in the top layer
of plexiglas) the infants, because they were attracted to
contour, would be more likely to press the panel directly
on top of the discriminative stimulus. In this way the prOb-
ability of stimulus-response contiguity would be improved.
However, it would not be assured because the infants could
still press the panel at any other location and the response
would be rewarded. With this limitation, the trend at the
.06 level for a significant 2,1ndicating a difference in
performance between subjects with the original and modified
panels is very encouraging. The results are congruent with
studies concerning older children (Jeffrey a Cchen, 196k;
Haney & Goulet, 1971). Discrimination was better for the
group with the modified panels.

LIST OF REFERENCE

LIST 01" REFERENCES

Caron, B. P. Visual reinforcement in young infants. gm
of merimental Child Psychology, 1967, j, #89- 511.

Caron, B. P. s Caron, a. J. Degree of stimulus complexity
and habituation of visual fixation in infants. PM
Science, 1969, _13, 78-79.

Caron, R. 3., Caron, a. J., a Caldwell, R. C. satiation of
visual reinforcement in young infants. W
Ps cholo , 1971, i, 279-289.

Chase, w. P. Color vision in infants. Journal of gperimengglI
Psychology, 1937, g, 203-222.

Cohen, L. B. Observing responses, visual preferences, and
habituation to visual stimuli in infants. on g;

E_xperimental Child Ps cholo , 1969, 1, hi - .

Cohen, I.. B., Gelber, I. B. & Lazar, n. A. Infant habituation
and generalization to repeated visual stimulation. Unpub-
lished manuscript, 1970. Referenced in Jeffrey, V. E. 0.
Cohen, 1.. B. Habituation in the human infant. In B. Reese
(ld.) ces in child development and behavior. Vol 6,

New tor : c eifc Press, .

Dorman, I.., watson, J. S., a Vietze, P. Cperant conditioning
of visual fixation in infants under three intensities
of auditory and visual reinforcement. Paper presented at
the meeting of the Society for Research in Child Develop-
ment, Minneapolis, 1971.

Priedlander, B. Z. Automated measurement of differential
operant performance in human infants. American Psychologist,
1961 . 12. 350. —"""""'"

Priedlander, B. Z. Three manipulanda for the study of human

infants' operant play. Jou g; the W 52511323
2; Mvior, 1966, 2, (+7.55.

Priedlander, B. Z. The effect of speaker identity, voice
inflection, vocabulary, and message redundancy on infants'
selection of vocal reinforcers. Jou 91 W

Child Psychology, 1968, g, M3-“ .

u.

“5

Bill, S. D. Chronological age at which children solve three
prgblemg v ing in complexity, Perceptual an__p_d Motor m,
19 2. l... 2 -

Bill, S. D. The performance of young children in three dis-
firimination learning tasks. Child Develppment, 1965, 1g,
25- 35o

Jeffrey, W. E. 5. Cohen, L. B. Effect of spatial separation
of stimulus, response and reinforcement on selective

learning in children. Journal p_f_ gperimental szchoiogz,
1961;, 6 , 577—580.

Kagan, J. The growth of the "face“ schema: Theoretical sig-
nificance and methodological issues. In J. Bellmuth (Bd.)
Exce tional infant Vol.1 Rom infant. New Iork: Bruner/
EzeE, Eon-T5377

Kagan, J. a Lewis, M. Studies of attention in the human
infant. Merrili Palmer garterlz, 1965, ii, 95-127.

Koch, J. Conditioned orienting reactions to persons and
{1111 g 1111 2-5-month—old infants. Human Deveiopmgpt, 1968,
-’ -9 .

Levison, C. a Levison, B. Operant conditioning of head
turning for visual reinforcenent in three-month—old infants.

Pszchonomio Science, 1967, _8_, 529-530.

Lewis 14., Baumel, 151., a. Grooh, A. Infants' attentional
distribution across two modalities. Paper presented at
the meetings of the Eastern Psychological Association,
New Iork, April, 1971.

Lipsitt, L. P. Learning in the first year of life. In L. P.
Lipsitt a C. C. Spiker (Eds.) Advances in child deve o ent
and behavior. Voll. Mew Iork: m1: mm, 937.11.»...

Lipsitt, L. P. Personal communication, 1971.

Lipsitt, L. P. Pederson, L. J. A DeLucia, C. Conjugate
reinforcement of operant responding in infants. Pszppo-

nomic Science, 1966, 5, 67-6

McCall, R. B. a Iagan, J. Stimulus-schema discrepancy and

attention in the infant. fig; 2; W Child
Ps cholo , 1967, j, 381- .

McCall, B. B. A Kagan, J. Individual differences in the
infant's distribution. of attention to stimulus discrepancy.

Lezeiopmentgi Pslchoiogz, 1970, a, 90-98.

46

Meyers, W. J. a Cantor, G. N. Observing and cardiac responses
of human infants to visual stimuli. Journal at gpepimental
Child Ps cholo , 1967, 1, 16-25.

Murphy, J. V. e Miller, B. E. Spatial contiguity of cue,
reward, and response in discrimination learninfiain children.

Journal 3; Elperimental Ps cholo , 1959, 5_8_, 5-489.

Pancrantz, C. N. 8: Cohen, L. B. Recovery of habituation

in infants. Journal 2; Experimental Child Pszchoiogz
1970, 2, 208-21?"- . ’

Bauey, C. T. 8: Goulet, L. R. Effects of spatial separation
of stimulus, response, and reward in discrimination
learning by children. Child Melopment, 1971, 9;, 978-982.

m, L. An investigation of two different response contin-
gencies on sucking in three to four month-old infants
using auditory reinforcements. Unpublished M.A. Brown
University, 1968. Cited in Reese, R. W. a Lipsitt, L. P.

or mental ohiid pslchologz. New York: Academic Press,

Reese, R. W. a Lipsitt, L. P. erimental ghiigi W.
New York: Academic Press, 19 .

Rheingold, R. L., Stanley, w. C., a Cooley, J. A. A method
for studying exploratory behavior in infants. Science,
1962, 1 6, 105u-1055.

meingold, R. L., Stanley, w. C., a Doyle, G. A. Visual and
auditory reinforcement of a manipulatory response in the

young child. Jou 2g erimental Qiild Ps cho o
196“, 1;, 316-52599;- L_ ...—... .1.—LEI.

Rovee, C. K. a Rovee, D. T. Conjugate reinforcement of
infant exploratory behavior. Jou pg gpepipental
Child Ps cholo , 1969, §_, 33- .

Siegel S. Nonpafietpic satiatics fo thp WIDE].
spiehoes. ew o : cGraw- 1:00., .

Simmons, M. H. Operant discrimination learn in human
infants. Chiid Development, 196“. 1.5.9 737-7 .

Simmons, M. w. a Lipsitt, L. P. An operant discrimination

apparatus for infants. ournal 9_1_'_ pp; gperimenpgi gin“
2!. _J—m or: 1961: is £37175?

Siqueland, R. R. The development of instrumental exploratory
behavior during the first year of human life. Paper presented
at the meetings of the Society for Research in Child Develop-
ment, Santa Monica, March, 1969.

“7

Siqueland, E. R. a DeLucia, C. A. Visual reinforcement of
neflutfigive sucking in human infants. Science, 1969, 165,

Smith R. U. A: Smith W. M. Peppeption and motigp. Phila-
dlephia: Sanders, 1962.

Spears, W. C. Visual preference in the four month-old infant.
Pszohonomio Science, 1966, 3, 237-238.

wahler, R. G. Infant social attachments: A reinforcement
theory interpretation and investigation. th d ngpigppgpp,
1967, 8, 1079-1088.

Watson, J. S. Operant conditioning of visual fixation in
infants under visual and auditory reinforcement. 22:21.22-
mental Ps cholo , 1969, 1, 508-516.

Weisberg, P. Social and nonsocial conditioning of infant
vocalizations. Child Develo ment, 1963, 33, 377-388.

Weisberg, P. a Simone, M. W. A modified WGTA for infants
in their second year of life. Journal 2; Pslchoiogz, 1966,
_619 99'10ne

Weizmann, P., Cohen, L. B., a Pratt, R. J. Novelty, familiarity,
and the development of infant attention. Melopmentai
Ps cholo , 1971, g, Tile-151+.

Winer B. J. Statistical nci es in e er ment desi .
. 3% MA

New York: McCraw-HHI o., 962'.

APPENDIX

#8
TABLEI
Analysis of Variance:
Total Responses to S+ and S' in the Blue Positive Condition

 

 

 

Source ,9; fig ‘g
Reinforcement (R) 3 602.18
Sex (8) 1 8.85
3.x 8 3 928.58
Error Between 32 1803.15
3*3’ (n) 1 2101.25 6.1:!"
R X D 3 180.98
S X D 1 6.05
R.X S X D 3 171.98
Error Within 32 326.b9

 

 

 

 

*2<.025

“9

TABLE 2
Analysis of Variance:
Total Responses to 8+ and S" in the Green Positive Condition

 

 

 

Source 511 _Mg 2 .-
Reinforcement (R) 3 1907.83
Sex. (S) 1 ($.52
R x S 3 “58.81
Error Between 24 1579.79
3+5“ (D) 1 3291.89 8.20*
a x D 3 “50.93
S x D 1 .76
a x s x D 3 “53.89
Error Within 2h 1401.68

 

 

 

 

*p_<.o1

50

TABLE 3
Analysis of Variance:
Responses per Minute in the Blue Positive Condition

 

 

 

Source 513: Lag g
Reinforcement (R) 3 59.96
Sex (8) 1 .11
n x s 3 97.12
Error Between 32 158.08
Trials (T) 7 #20. 51 9.321.
R X T 21 62.215
8 X T 7 10.38
a x s x a: 21 31.63
Error Within 22h 15.19

 

 

 

 

*p<.001

51

TABLE 4
Analysis of Variance:
Responses per Minute in the Green Positive Condition

 

 

 

 

 

 

 

Source 9;. [pg ‘3

Reinforcement (R) 3 175.66

Sex (S) 1 11.39

R.X S 3 66.90

Error Between 29 197.10

Trials (T) 7 391.38 9.h5**
B X T 21 142.11

s x T 7 65.09 _
B X S X T 21 97.26 2.35"
Error Within 168 41.92

*p<.005

"p < . 001

52

TABLES
Analysis of variance:
Discrimination Performance in the Blue Positive Condition

 

 

 

 

 

 

 

Source g3, flé [g
Reinforcement (R) 3 .05
Sex (S) 1 .09
R X 8 3 .96 2.96.
Error Between 32 .39
Trials ('1') 7 .99 2.204...
R X T 21 .68 1.519
s x 'r 7 .39 .
RXSX T 21 .70 1.56'
Error Within 229 .95
55223?

TABLE 6

Analysis of variance:
Discrimination Performance in the Blue Positive
Voice and Red Light Conditions

 

 

 

Source 9;, pg, ‘2
Reinforcement (R) 1 . 01
Sex (S) 1 .09
2.x S 1 .39 10.169
Error 16 .03

 

 

 

 

*p<.01

53

TABLE 7
Analysis of Variance:
Discrimination Performance as a Function of the Color Reinforced

 

 

 

 

 

 

 

Source if _ng I
Reinforcement (R) 3 .01
Sex (S) 1 .05
Color Reinforced (C) 1 .29 5.90“
B X S 3 .06
R X C 3 e03
8 X C 1 .01
R X S X C 3 .19 2.798
Error 56 .05
’2<.05

"22.025

 

“'17111111:11[@Wm'“