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Information producing responses in normal and retarded children
JOURNAL
OF
EXPERIMENTAL
CHILD
PSYCHOLOGY
Information in Normal
20,296-306
(1975)
Producing Responses and Retarded Children MARK E. COHEN’
Illinois Institute for Developmental Disabilities AND TAMAR
HELLER
Roosevelt University Normal and retarded children were given trials on several discriminations which varied in difficulty. On standard discrimination trials the retarded subjects did not differ from the MA control subjects in the number of errors made but both groups made more errors than the CA control group. On other trials if subjects were not sure which stimulus was correct they were allowed to press an information key which made the discrimination easier. The retarded subjects made significantly more informational key responses than either of the control groups. These results confirmed the findings of prior investigations dealing with outerdirectedness in an experimental situation which did not allow distractibility to be a significant factor.
Several discrimination learning studies have indicated that mentally retarded children are more likely to respond to external cues than are normal children of the same MA, and are less likely to attend to a stimulus dimension that would require a complex cognitive evaluation (Turnure & Zigler, 1964; Achenbach & Zigler, 1968; Turnure, 1970; Yando & Zigler, 1971). In a typical test situation, for example, the retarded child would be found to spend proportionately more time attending to the test giver in anticipation of a hint and proportionately less time attending to the primary task. These findings have been interpreted (Zigler, 1973) as supporting a motivational hypothesis of retardate problem solving strategies. According to this approach retardates tend to lack confidence in their own cognitive-evaluative capabilities as the result of their inordinate amount of past failure experiences. This is not the case for the normal child. Whereas the normal child receives problems commensurate with his MA, which are therefore appropriate problems, the retarded child 1 Now at the University of Wisconsin. Requests for reprints should be sent to M. E. Cohen, Waisman Center, 2605 Marsh Lane, University of Wisconsin, Madison, Wisconsin 53706. 296 Copyright All rights
0 1975 by Academic Press, Inc. of reproduction in any form reserved.
INFORMATION
PRODUCING
RESPONSES
297
receives problems commensurate with his CA. These problems are usually too difficult for the child. As the result of the increased amounts of failure experiences, retarded children are characterized by higher degrees of outerdirectedness even when tasks are simple and within their capabilities. The fact that retarded individuals frequently perform in discrimination situations below what would be predicted on the basis of their MA can now be attributed to this motivated outerdirectedness. Specifically, these individuals attend to other, external stimuli to a greater extent than normals. This inhibits learning of the primary cues and thus performance with respect to the primary, or test, task is adversly affected. Thus the motivational hypothesis can account for at least some differences between the performances of normal and retarded children in terms of a noncognitive mechanism. However, it is of importance to note the relationship between outerdirectedness and distractibility. Zigler contends that the retardate’s nonorientation toward primary tasks and stimuli is a manifestation of their outerdirectedness and develops from their experiential history. It may represent stimulus generalization from past situations where external stimuli provided effective cues to present situations where they may not. However, an alternate and equally plausible conception of this nonorientation is that it represents an inherent tendency to attend to salient environmental stimuli irrespective of any cue-reinforcement contingency. This distractibility can be considered to result from a cognitive deficit. Furthermore, supposed outerdirected behavior might simply be a special case of this form of distractibility where the environmental stimuli fortuitously contain relevant information. The confounding of outerdirectedness and distractibility is also a methodological problem. In prior studies the external stimuli had been presented prior to or concurrently with the presentation of the primary discriminative stimuli, at least during initial acquisition. As such it is not possible to logically distinguish between any effects due to motivated information searching behavior (outerdirectedness) and distractibility (as resulting from a cognitive deficit). The hypothesis that retarded children are more outerdirected than normals could be supported if it was demonstrated that retarded individuals are more likely to search out information in a situation in which distractibility cannot play a role. This was accomplished in the present study by making the presentation of additional information carrying stimuli contingent upon an overt volitional response by the subject. Specifically, the subject was first presented with a discrimination task and the subject could either make a choice response or an informational response. In the latter case additional information relevant to the dis-
298
COHEN
AND
HELLER
crimination was presented (the discriminative cues were made less similar). Since the information carrying stimuli cannot have distracting effects any differences in the rates of informational responding can be attributed to differences in the motivated behavior to search out external cues. If the outerdirectedness hypothesis is correct then retarded children should make more informational responses than either MA or CA controls even though the problems may not be more difficult for the retarded subjects. In this study difficulty was measured by performance on trials in which the subject had to respond without the option of additional information. METHOD
Subjects. A total of 30 white, middle class children served as the subjects. The sample consisted of a single group (N = 10) of noninstitutionalized retarded subjects and two groups (N = 10) of normal subjects matched to the retarded on either MA or CA. Groups are described in Table 1. The retarded subjects were obtained from several schools for the retarded located in the Chicago area, the MA controls came from a nursery school in Chicago, and the CA controls were obtained from a suburban school system. Apparatus. Subjects were seated in front of a 50 cm long X 32 cm high response panel. Centered 5 cm from the top of this panel was a 28 cm long X 15 cm high rear projection screen. Mounted below the screen were three, illuminable push button switches which served as response keys. Two 2 cm square choice keys (CK) were located 3 cm below the screen and 7 cm either to the right or left of center. Centered and 4 cm below the screen was a single 1.5 cm diam circular information key (IK). By means of appropriate curcuitry: (1) either the CKs, or the CKs and the IK could be illuminated by the experimenter, (2) a CK response by the subject immediately terminated all key illumination, and TABLE 1 MA, CA, AND SEX COMPOSITION OF EXPERIMENTAL GROUPS MA
CA
Sex
Group
Mean
SD
Mean
SD
M
F
Retarded MA control CA control
5.32a 5.756
.90 .86
12.OlP 4.56 11.07’
1.00 .21 .46
6 4 5
4 6 5
a Stanford-Binet. * Peabody Picture Vocabulary. c These means are not significantly different (U = 29.5)
INFORMATION
PRODUCING
299
RESPONSES
DISCRIMINATIONS
115
105
B
95
110
c
90
FIG. I. All six discriminations. KK trials subjects were shown shown discriminations B-F.
The numbers discriminations
D
85
refer to the number of dots in the array. On A-E and on non-IK trials subjects were
(3) CK or IK responses by the subject activated indicator lamps visible only to the experimenter. Six varieties of slides were projected onto the screen by means of a Kodak Carousel projector (see Fig. 1). Each slide contained two stimulus arrays, one on the left and one on the right such that each was directly above the corresponding CK. Each array was approximately 9 cm square. One variety of slide presented black versus a five dot pattern (F on Fig. 1) while the other varieties differed in the number of dots present: 100-100 (A), 105-95 (B), 1 lo-90 (C), 115-U (D), and 125-75 (E). Slides were rotated and/or reversed so that particular patterns could appear on the right or left and there was no consistent dot pattern. Procedure. For all experimental procedures, each child was removed from his classroom and brought to a private room within the same school. The child was told that he would be playing a series of games over the next few days and that if he did well he would receive some candy at the end of each daily session. (Subjects were rewarded regardless of performance.) Pretraining. The subject was told that he would be seeing a series of
300
COHEN
AND
HELLER
pictures and that he was to press the button (CK) below the picture which he thought was darker. Both CKs were illuminated while the IK was not. Subjects were then given trials on the F (black-5) discrimination. If a correct response was made the experimenter said “good” and if an incorrect response was made no feedback was given. Here and throughout training individual patterns occurred equally often on the right and left. This phase of pretraining was terminated following five successive responses to the black stimulus. After criterion was reached on the F discrimination, the subject was informed about the use of the IK which was now illuminated for the first time. The subject was told to press this button if he was unsure which picture was darker and that such a response would make it easier for him to choose. The subject was then given trials on the impossible A (100-100) discrimination. An IK response changed the stimulus array to the F pattern. If a subject made an IK response and then a choice response to black he was reinforced with “good.” If either an IK response was not made and the subject thus made a direct choice between the two 100 dot patterns, or if white was chosen after an IK response, then no feedback was given. Pretraining was terminated following either five successive IK responses or 20 IK responses, whichever occurred first. (The 20 response criterion was added after the experiment began. Many subjects, but particularly CA control subjects, who knew how to use the IK continued to make choice responses in the presence of the A discrimination. It appeared as if these subjects believed that the task could not be as simple as the experimenters described it. After mastering the IK response in four trials or less they did not make this response continuously and were not able to reach the successive response criterion.) Training. Each subject was given 40 training trials immediately after pretraining was completed and 80 more 2 days later. Each block of 40 trials contained four each of ten different trial types presented in blocked random order. The trial types were defined in terms of the discriminative stimuli (5 levels) and the IK condition (2 levels). For five trial types the IK was unlit and inoperative and the subject had to make either the B, C, D, E, or F discriminations. On the remaining five trial types the IK was lit and operative. The subject was shown the patterns A, B, C, D, or E and the subject could either make a choice response or press the IK. With regard to these contingencies, the subject was told that when the middle button (IK) was unlit he must make a choice without help. However, when the middle button was lit he could press it if he was unsure which picture was darker and this would make it easier for him to choose. Each IK response made the discrimination one step easier (i.e., an IK
INFORMATION
PRODUCING
RESPONSES
301
response to A changed it to B, an IK response to B changed it to C, and so forth). On any particular IK trial the subject could press the IK as many times as were required to arrive at the F discrimination. For all subjects a choice response to the darker or more dense dot pattern was always reinforced with “good.” No feedback followed either a choice response to a lighter pattern, a choice response in the presence of the A ( 1OO- 100) array, or any I K response. RESULTS
Nonparametric tests were selected for analyzing the data as the result of strong tendencies towards heterogeneity of cell variances. Table 2 presents the means and standard deviations of all data which was analyzed. Though the assumption of homogeneity of variances was not rejected in all cases the tendencies were strong enough to warrant the use of the more conservative nonparametric procedures. It should be noted that the basis of the heterogeneity of variances cannot be unequivocally determined. The high correlations between cell means and cell standard deviations would seem to indicate that these differences were the result of floor effects. That is, for some groups and for some tasks subjects tended to make the minimum number of responses possible. Because of this scaling problem it is difficult to arrive at conclusions regarding the issue of differences in overall heterogeneity in normal and retarded populations. The general statistical procedure was to use the Kruskall-Wallis test to analyze for group effects across all levels. In the event of a significant result the Mann-Whitney test was used to make the three pair-wise group comparisons. Pretraining. Analysis of errors (E) to criterion on the F (black-S) discrimination and trials (T) to the IK response criterion did not reveal any significant group effects (HE = 2.49 and HT = 1.56). Training Errors. Of the 120 training trials, 60 were presented with the IK inoperative (non-IK). Twelve trials were given to each of the five discriminations ranging from B (105-95) through F (black-5). Mean errors for each discrimination are shown in Figure 2. Total errors for each subject on discriminations B through E were calculated and an analysis of these data revealed a significant group effect (H = 18.6, df= 2, p < .OOl). The pair-wise comparisons indicated that the CA control subjects made fewer errors than either the MA control subjects (V = 6. n = 112= 10, p < .OOl) or the retarded subjects (V = 0. nI = n2 = 10, p < .OOl). The difference in number of errors made between retarded and MA control subjects did not approach significance (V = 36).
Total IK responses
ap < .Ol. *p < .05. c Totaled across tasks. d Averaged across groups.
19.30 23.19
10.60
MC SD Md SD
Initial IK responses
9.67
44.90 43.91
22.50 15.81
6.16 5.97
4.13 3.42
12.00 9.40
9.50 8.73
M’ SD Md SD
5.90 3.75
25.30 17.66
4.83 3.80
1.95 1.95
4.20 2.89
33.90 39.15
Errors on non-IK trials
42.00 37.01
1.44
.lO .31
B
M’ SD Md SD
4.83 3.80
A
M SD
.90
RET
Trials to IK criterion
.20 .63
MA
M SD
0 0
CA
Group
TABLE STANDARD
Errors to F
variable
Dependent
AND
2
-
5.10 7.48
2.80 3.30
.70 1.02
C
task
4.63 8.40
1.63 2.32
1.06
ho
D
DEVIATIONS
Discrimination
Independent variable
MEANS
4.20 10.02
1.26 2.30
.13 .43
E
0 0
F
5129
319
5129
319
5129
319
319
319
kldf
.36
.7.5"
.30
.60
.62"
.62
.48
.84"
C
Cochran’s test of homogeneity
3
1
3
1
3
1
1
1
df
-SO
+.98
+.95b
+.99
+.96"
+.99
+.82
f.97
r
Correlation: Means and standard deviations
k
E c
u
ci
%!
H
INFORMATION
PRODUCING
303
RESPONSES
DISCRIMINATION
2. Mean number of errors made on non-N trials. Subjects were given 12 trials on each of the five discriminations. RET: retarded, MA: MA control, CA: CA control. FIG.
. .
RET*
A
B
C
D
E
“{E-“E”
DISCRIMINATION
FIG. 3. Mean number of informational responses made to each discrimination :he first response on any IK trial was considered.
when only
304
COHEN
AND
HELLER
Information responses. Of the 60 trials in which the IK was operative, subjects received 12 trials to each of the discriminations ranging from A (100-100) through E (125-75). Initial IK responses are shown in Figure 3. This measure considered only the first response on any particular IK trial. Thus the maximum score for any discrimination was 12. Total IK responses are shown in Figure 4. This measure considered all IK responses made on a trial regardless of whether the response was first, second, third, fourth, or fifth in a sequence of IK responses. It will be recalled that after an IK response was made the subject could either make a choice response or press the IK again. Thus for the total IK response measure the maximum possible score on discrimination A was 12, B-24, C-36, D-48, and E-60. For example, 12 IK responses could be made to the B discrimination when it was the first discrimination on a trial, and 12 more responses could possibly be made if the subject had on every opportunity made an IK response to the A discrimination. Both initial (I) and total (T) IK responses were summed across discriminations B through E and the analyses of these data revealed a significant group effect (H, = 9.6 and HT = 10.0, df= 2, p < .Ol in both
11 10
RET*
9 8
2
CA’
1
0 A
B
C
D
E
“BE-“E”
DISCRIMINATION
FIG.
4. Mean
informational
number response
of informational responses made to each discrimination was any in a sequence of informational responses.
when
the
INFORMATION
PRODUCING
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305
cases). Pair-wise comparisons confirmed the directional hypothesis that retarded subjects would make more informational responses than either MA ( U1 = 25.0 and UT = 24.5, n, = nz = 10, p < .04 in both cases) or CA control subjects ( U1 = 13.0 and UT = 10.5, n, = n2 = 10, p < .005 in both cases). The two control groups did not differ in informational responding (U = 30 for both measures). DISCUSSION
The hypothesis that retarded children would be more outerdirected than normal children was supported. The retarded subjects pressed the IK significantly more often than the subjects of either of the control groups. Since the information-carrying stimuli could not function as distractors it is not possible to attribute these findings to differences in distractibility resulting perhaps from a cognitive deficit. The MA control and retarded subjects did not differ significantly in the number of errors made on trials in which they had to respond without the option of additional information (non-IK). Thus it cannot be argued that the retarded subjects pressed the IK more often merely because the discriminations were more difficult for them. However, in comparing the performances of CA control subjects with those of the MA control and retarded subjects it is possible to attribute some role to intellectual ability. The CA control subjects made significantly fewer errors than either of the other groups on non-IK trials. Therefore, the differences between the CA group and the other two groups on the IK measure could be at least partially attributed to a rational strategy to maximize correct responding. That is, the retarded and MA control subjects made more IK responses than the CA subjects possibly because the tasks were more difficult for them. The fact that levels of informational responding were generally low (at or below 50% of the maximum rate) suggests that the differences between the retarded group and the control group could not be a function of rigidity or response perseveration. This conclusion is also supported by the similarity of the inferential statistics from the analyses of initial and total IK responses. If retarded subjects made more IK responses as the result of such perseveration (pressing the IK successively) then the effect should have been greatly magnified in the total IK response measure. The data described in Figure 3 also suggests a developmental trend in the ability to recognize problem solving limitations. The CA control group made fewer IK responses on all solvable problems (B-E). However, in the case of the single unsolvable problem (A), the CA control subjects made substantially more IK responses than the MA control subjects and about the same number as the retarded subjects.
306
COHEN
AND
HELLER
The information response paradigm may be a particularly sensitive tool in investigating other motivational variables. This follows since it is possible to remove cognitive factors either by demonstrating no differences on non-IK trials or, if the assumptions of the statistical model are met, removing such effects through analysis of covariance. REFERENCES Achenbach, T., and Zigler, E. Cue-learning and problem-learning strategies in normal and retarded children. Child Development, 1968, 39, 827-848. Turnure, J. E. Reactions to physical and social distracters by moderately retarded, institutionalized children. Journal of Special Education, 1970, 4, 283-294. Turnure, J. E., and Zigler, E. Outer-directedness in the problem-solving of normal and retarded children. Journal of Abnormal and Social Psychology, 1964, 69, 427436. Yando, R. and Zigler, E. Outer-directedness in the problem-solving of institutionalized and noninstitutionalized normal and retarded children. Developmental Psychology, 1971, 4, 277-288. Zigler, E. Why retarded children do not perform up to the level of their ability. In R. M. Allen, A. D. Cortazzo, and R. P. Toisterer (Ed%), Theories of cognitive development: Implications for the mentally retarded. Coral Gables: University of Miami Press, 1973. RECEIVED:
July 12, 1974:
REVISED
November 20, 1974.
OF
EXPERIMENTAL
CHILD
PSYCHOLOGY
Information in Normal
20,296-306
(1975)
Producing Responses and Retarded Children MARK E. COHEN’
Illinois Institute for Developmental Disabilities AND TAMAR
HELLER
Roosevelt University Normal and retarded children were given trials on several discriminations which varied in difficulty. On standard discrimination trials the retarded subjects did not differ from the MA control subjects in the number of errors made but both groups made more errors than the CA control group. On other trials if subjects were not sure which stimulus was correct they were allowed to press an information key which made the discrimination easier. The retarded subjects made significantly more informational key responses than either of the control groups. These results confirmed the findings of prior investigations dealing with outerdirectedness in an experimental situation which did not allow distractibility to be a significant factor.
Several discrimination learning studies have indicated that mentally retarded children are more likely to respond to external cues than are normal children of the same MA, and are less likely to attend to a stimulus dimension that would require a complex cognitive evaluation (Turnure & Zigler, 1964; Achenbach & Zigler, 1968; Turnure, 1970; Yando & Zigler, 1971). In a typical test situation, for example, the retarded child would be found to spend proportionately more time attending to the test giver in anticipation of a hint and proportionately less time attending to the primary task. These findings have been interpreted (Zigler, 1973) as supporting a motivational hypothesis of retardate problem solving strategies. According to this approach retardates tend to lack confidence in their own cognitive-evaluative capabilities as the result of their inordinate amount of past failure experiences. This is not the case for the normal child. Whereas the normal child receives problems commensurate with his MA, which are therefore appropriate problems, the retarded child 1 Now at the University of Wisconsin. Requests for reprints should be sent to M. E. Cohen, Waisman Center, 2605 Marsh Lane, University of Wisconsin, Madison, Wisconsin 53706. 296 Copyright All rights
0 1975 by Academic Press, Inc. of reproduction in any form reserved.
INFORMATION
PRODUCING
RESPONSES
297
receives problems commensurate with his CA. These problems are usually too difficult for the child. As the result of the increased amounts of failure experiences, retarded children are characterized by higher degrees of outerdirectedness even when tasks are simple and within their capabilities. The fact that retarded individuals frequently perform in discrimination situations below what would be predicted on the basis of their MA can now be attributed to this motivated outerdirectedness. Specifically, these individuals attend to other, external stimuli to a greater extent than normals. This inhibits learning of the primary cues and thus performance with respect to the primary, or test, task is adversly affected. Thus the motivational hypothesis can account for at least some differences between the performances of normal and retarded children in terms of a noncognitive mechanism. However, it is of importance to note the relationship between outerdirectedness and distractibility. Zigler contends that the retardate’s nonorientation toward primary tasks and stimuli is a manifestation of their outerdirectedness and develops from their experiential history. It may represent stimulus generalization from past situations where external stimuli provided effective cues to present situations where they may not. However, an alternate and equally plausible conception of this nonorientation is that it represents an inherent tendency to attend to salient environmental stimuli irrespective of any cue-reinforcement contingency. This distractibility can be considered to result from a cognitive deficit. Furthermore, supposed outerdirected behavior might simply be a special case of this form of distractibility where the environmental stimuli fortuitously contain relevant information. The confounding of outerdirectedness and distractibility is also a methodological problem. In prior studies the external stimuli had been presented prior to or concurrently with the presentation of the primary discriminative stimuli, at least during initial acquisition. As such it is not possible to logically distinguish between any effects due to motivated information searching behavior (outerdirectedness) and distractibility (as resulting from a cognitive deficit). The hypothesis that retarded children are more outerdirected than normals could be supported if it was demonstrated that retarded individuals are more likely to search out information in a situation in which distractibility cannot play a role. This was accomplished in the present study by making the presentation of additional information carrying stimuli contingent upon an overt volitional response by the subject. Specifically, the subject was first presented with a discrimination task and the subject could either make a choice response or an informational response. In the latter case additional information relevant to the dis-
298
COHEN
AND
HELLER
crimination was presented (the discriminative cues were made less similar). Since the information carrying stimuli cannot have distracting effects any differences in the rates of informational responding can be attributed to differences in the motivated behavior to search out external cues. If the outerdirectedness hypothesis is correct then retarded children should make more informational responses than either MA or CA controls even though the problems may not be more difficult for the retarded subjects. In this study difficulty was measured by performance on trials in which the subject had to respond without the option of additional information. METHOD
Subjects. A total of 30 white, middle class children served as the subjects. The sample consisted of a single group (N = 10) of noninstitutionalized retarded subjects and two groups (N = 10) of normal subjects matched to the retarded on either MA or CA. Groups are described in Table 1. The retarded subjects were obtained from several schools for the retarded located in the Chicago area, the MA controls came from a nursery school in Chicago, and the CA controls were obtained from a suburban school system. Apparatus. Subjects were seated in front of a 50 cm long X 32 cm high response panel. Centered 5 cm from the top of this panel was a 28 cm long X 15 cm high rear projection screen. Mounted below the screen were three, illuminable push button switches which served as response keys. Two 2 cm square choice keys (CK) were located 3 cm below the screen and 7 cm either to the right or left of center. Centered and 4 cm below the screen was a single 1.5 cm diam circular information key (IK). By means of appropriate curcuitry: (1) either the CKs, or the CKs and the IK could be illuminated by the experimenter, (2) a CK response by the subject immediately terminated all key illumination, and TABLE 1 MA, CA, AND SEX COMPOSITION OF EXPERIMENTAL GROUPS MA
CA
Sex
Group
Mean
SD
Mean
SD
M
F
Retarded MA control CA control
5.32a 5.756
.90 .86
12.OlP 4.56 11.07’
1.00 .21 .46
6 4 5
4 6 5
a Stanford-Binet. * Peabody Picture Vocabulary. c These means are not significantly different (U = 29.5)
INFORMATION
PRODUCING
299
RESPONSES
DISCRIMINATIONS
115
105
B
95
110
c
90
FIG. I. All six discriminations. KK trials subjects were shown shown discriminations B-F.
The numbers discriminations
D
85
refer to the number of dots in the array. On A-E and on non-IK trials subjects were
(3) CK or IK responses by the subject activated indicator lamps visible only to the experimenter. Six varieties of slides were projected onto the screen by means of a Kodak Carousel projector (see Fig. 1). Each slide contained two stimulus arrays, one on the left and one on the right such that each was directly above the corresponding CK. Each array was approximately 9 cm square. One variety of slide presented black versus a five dot pattern (F on Fig. 1) while the other varieties differed in the number of dots present: 100-100 (A), 105-95 (B), 1 lo-90 (C), 115-U (D), and 125-75 (E). Slides were rotated and/or reversed so that particular patterns could appear on the right or left and there was no consistent dot pattern. Procedure. For all experimental procedures, each child was removed from his classroom and brought to a private room within the same school. The child was told that he would be playing a series of games over the next few days and that if he did well he would receive some candy at the end of each daily session. (Subjects were rewarded regardless of performance.) Pretraining. The subject was told that he would be seeing a series of
300
COHEN
AND
HELLER
pictures and that he was to press the button (CK) below the picture which he thought was darker. Both CKs were illuminated while the IK was not. Subjects were then given trials on the F (black-5) discrimination. If a correct response was made the experimenter said “good” and if an incorrect response was made no feedback was given. Here and throughout training individual patterns occurred equally often on the right and left. This phase of pretraining was terminated following five successive responses to the black stimulus. After criterion was reached on the F discrimination, the subject was informed about the use of the IK which was now illuminated for the first time. The subject was told to press this button if he was unsure which picture was darker and that such a response would make it easier for him to choose. The subject was then given trials on the impossible A (100-100) discrimination. An IK response changed the stimulus array to the F pattern. If a subject made an IK response and then a choice response to black he was reinforced with “good.” If either an IK response was not made and the subject thus made a direct choice between the two 100 dot patterns, or if white was chosen after an IK response, then no feedback was given. Pretraining was terminated following either five successive IK responses or 20 IK responses, whichever occurred first. (The 20 response criterion was added after the experiment began. Many subjects, but particularly CA control subjects, who knew how to use the IK continued to make choice responses in the presence of the A discrimination. It appeared as if these subjects believed that the task could not be as simple as the experimenters described it. After mastering the IK response in four trials or less they did not make this response continuously and were not able to reach the successive response criterion.) Training. Each subject was given 40 training trials immediately after pretraining was completed and 80 more 2 days later. Each block of 40 trials contained four each of ten different trial types presented in blocked random order. The trial types were defined in terms of the discriminative stimuli (5 levels) and the IK condition (2 levels). For five trial types the IK was unlit and inoperative and the subject had to make either the B, C, D, E, or F discriminations. On the remaining five trial types the IK was lit and operative. The subject was shown the patterns A, B, C, D, or E and the subject could either make a choice response or press the IK. With regard to these contingencies, the subject was told that when the middle button (IK) was unlit he must make a choice without help. However, when the middle button was lit he could press it if he was unsure which picture was darker and this would make it easier for him to choose. Each IK response made the discrimination one step easier (i.e., an IK
INFORMATION
PRODUCING
RESPONSES
301
response to A changed it to B, an IK response to B changed it to C, and so forth). On any particular IK trial the subject could press the IK as many times as were required to arrive at the F discrimination. For all subjects a choice response to the darker or more dense dot pattern was always reinforced with “good.” No feedback followed either a choice response to a lighter pattern, a choice response in the presence of the A ( 1OO- 100) array, or any I K response. RESULTS
Nonparametric tests were selected for analyzing the data as the result of strong tendencies towards heterogeneity of cell variances. Table 2 presents the means and standard deviations of all data which was analyzed. Though the assumption of homogeneity of variances was not rejected in all cases the tendencies were strong enough to warrant the use of the more conservative nonparametric procedures. It should be noted that the basis of the heterogeneity of variances cannot be unequivocally determined. The high correlations between cell means and cell standard deviations would seem to indicate that these differences were the result of floor effects. That is, for some groups and for some tasks subjects tended to make the minimum number of responses possible. Because of this scaling problem it is difficult to arrive at conclusions regarding the issue of differences in overall heterogeneity in normal and retarded populations. The general statistical procedure was to use the Kruskall-Wallis test to analyze for group effects across all levels. In the event of a significant result the Mann-Whitney test was used to make the three pair-wise group comparisons. Pretraining. Analysis of errors (E) to criterion on the F (black-S) discrimination and trials (T) to the IK response criterion did not reveal any significant group effects (HE = 2.49 and HT = 1.56). Training Errors. Of the 120 training trials, 60 were presented with the IK inoperative (non-IK). Twelve trials were given to each of the five discriminations ranging from B (105-95) through F (black-5). Mean errors for each discrimination are shown in Figure 2. Total errors for each subject on discriminations B through E were calculated and an analysis of these data revealed a significant group effect (H = 18.6, df= 2, p < .OOl). The pair-wise comparisons indicated that the CA control subjects made fewer errors than either the MA control subjects (V = 6. n = 112= 10, p < .OOl) or the retarded subjects (V = 0. nI = n2 = 10, p < .OOl). The difference in number of errors made between retarded and MA control subjects did not approach significance (V = 36).
Total IK responses
ap < .Ol. *p < .05. c Totaled across tasks. d Averaged across groups.
19.30 23.19
10.60
MC SD Md SD
Initial IK responses
9.67
44.90 43.91
22.50 15.81
6.16 5.97
4.13 3.42
12.00 9.40
9.50 8.73
M’ SD Md SD
5.90 3.75
25.30 17.66
4.83 3.80
1.95 1.95
4.20 2.89
33.90 39.15
Errors on non-IK trials
42.00 37.01
1.44
.lO .31
B
M’ SD Md SD
4.83 3.80
A
M SD
.90
RET
Trials to IK criterion
.20 .63
MA
M SD
0 0
CA
Group
TABLE STANDARD
Errors to F
variable
Dependent
AND
2
-
5.10 7.48
2.80 3.30
.70 1.02
C
task
4.63 8.40
1.63 2.32
1.06
ho
D
DEVIATIONS
Discrimination
Independent variable
MEANS
4.20 10.02
1.26 2.30
.13 .43
E
0 0
F
5129
319
5129
319
5129
319
319
319
kldf
.36
.7.5"
.30
.60
.62"
.62
.48
.84"
C
Cochran’s test of homogeneity
3
1
3
1
3
1
1
1
df
-SO
+.98
+.95b
+.99
+.96"
+.99
+.82
f.97
r
Correlation: Means and standard deviations
k
E c
u
ci
%!
H
INFORMATION
PRODUCING
303
RESPONSES
DISCRIMINATION
2. Mean number of errors made on non-N trials. Subjects were given 12 trials on each of the five discriminations. RET: retarded, MA: MA control, CA: CA control. FIG.
. .
RET*
A
B
C
D
E
“{E-“E”
DISCRIMINATION
FIG. 3. Mean number of informational responses made to each discrimination :he first response on any IK trial was considered.
when only
304
COHEN
AND
HELLER
Information responses. Of the 60 trials in which the IK was operative, subjects received 12 trials to each of the discriminations ranging from A (100-100) through E (125-75). Initial IK responses are shown in Figure 3. This measure considered only the first response on any particular IK trial. Thus the maximum score for any discrimination was 12. Total IK responses are shown in Figure 4. This measure considered all IK responses made on a trial regardless of whether the response was first, second, third, fourth, or fifth in a sequence of IK responses. It will be recalled that after an IK response was made the subject could either make a choice response or press the IK again. Thus for the total IK response measure the maximum possible score on discrimination A was 12, B-24, C-36, D-48, and E-60. For example, 12 IK responses could be made to the B discrimination when it was the first discrimination on a trial, and 12 more responses could possibly be made if the subject had on every opportunity made an IK response to the A discrimination. Both initial (I) and total (T) IK responses were summed across discriminations B through E and the analyses of these data revealed a significant group effect (H, = 9.6 and HT = 10.0, df= 2, p < .Ol in both
11 10
RET*
9 8
2
CA’
1
0 A
B
C
D
E
“BE-“E”
DISCRIMINATION
FIG.
4. Mean
informational
number response
of informational responses made to each discrimination was any in a sequence of informational responses.
when
the
INFORMATION
PRODUCING
RESPONSES
305
cases). Pair-wise comparisons confirmed the directional hypothesis that retarded subjects would make more informational responses than either MA ( U1 = 25.0 and UT = 24.5, n, = nz = 10, p < .04 in both cases) or CA control subjects ( U1 = 13.0 and UT = 10.5, n, = n2 = 10, p < .005 in both cases). The two control groups did not differ in informational responding (U = 30 for both measures). DISCUSSION
The hypothesis that retarded children would be more outerdirected than normal children was supported. The retarded subjects pressed the IK significantly more often than the subjects of either of the control groups. Since the information-carrying stimuli could not function as distractors it is not possible to attribute these findings to differences in distractibility resulting perhaps from a cognitive deficit. The MA control and retarded subjects did not differ significantly in the number of errors made on trials in which they had to respond without the option of additional information (non-IK). Thus it cannot be argued that the retarded subjects pressed the IK more often merely because the discriminations were more difficult for them. However, in comparing the performances of CA control subjects with those of the MA control and retarded subjects it is possible to attribute some role to intellectual ability. The CA control subjects made significantly fewer errors than either of the other groups on non-IK trials. Therefore, the differences between the CA group and the other two groups on the IK measure could be at least partially attributed to a rational strategy to maximize correct responding. That is, the retarded and MA control subjects made more IK responses than the CA subjects possibly because the tasks were more difficult for them. The fact that levels of informational responding were generally low (at or below 50% of the maximum rate) suggests that the differences between the retarded group and the control group could not be a function of rigidity or response perseveration. This conclusion is also supported by the similarity of the inferential statistics from the analyses of initial and total IK responses. If retarded subjects made more IK responses as the result of such perseveration (pressing the IK successively) then the effect should have been greatly magnified in the total IK response measure. The data described in Figure 3 also suggests a developmental trend in the ability to recognize problem solving limitations. The CA control group made fewer IK responses on all solvable problems (B-E). However, in the case of the single unsolvable problem (A), the CA control subjects made substantially more IK responses than the MA control subjects and about the same number as the retarded subjects.
306
COHEN
AND
HELLER
The information response paradigm may be a particularly sensitive tool in investigating other motivational variables. This follows since it is possible to remove cognitive factors either by demonstrating no differences on non-IK trials or, if the assumptions of the statistical model are met, removing such effects through analysis of covariance. REFERENCES Achenbach, T., and Zigler, E. Cue-learning and problem-learning strategies in normal and retarded children. Child Development, 1968, 39, 827-848. Turnure, J. E. Reactions to physical and social distracters by moderately retarded, institutionalized children. Journal of Special Education, 1970, 4, 283-294. Turnure, J. E., and Zigler, E. Outer-directedness in the problem-solving of normal and retarded children. Journal of Abnormal and Social Psychology, 1964, 69, 427436. Yando, R. and Zigler, E. Outer-directedness in the problem-solving of institutionalized and noninstitutionalized normal and retarded children. Developmental Psychology, 1971, 4, 277-288. Zigler, E. Why retarded children do not perform up to the level of their ability. In R. M. Allen, A. D. Cortazzo, and R. P. Toisterer (Ed%), Theories of cognitive development: Implications for the mentally retarded. Coral Gables: University of Miami Press, 1973. RECEIVED:
July 12, 1974:
REVISED
November 20, 1974.