Dimensions of Problem Behavior in institutionalized retardates

A factor analysis of teacher ratings of 55 items of deviant behavior in a sample of 252 institutionalized retardates resulted in the emergence of three interpretable factors. Two factors clearly represented the broad-band dimensions of conduct disorder and anxiety-withdrawal, while the third reflected psychotic behavior. Only conduct disorder was related to age, sex, trace, or intellectual level.     

Rehearsal capacity and dimensional independence in retardates

Retardate use of retention strategies and the independence of color and form retention were compared with predictions of the Attention-Retention theory of retardate discrimination learning. Lists of two-choice discrimination problems were increased in length from one to capacity, which was defined through criterion retention across a 20-sec interval. It was demonstrated that (a) capacity and rate of adjustment of retentional strategy were directly related to intelligence, (b) at capacity limits the retention of problems in one dimension interfered with retention in a second dimension, and (c) results consistent with a capacity allocation strategy were obtained. The results were interpreted as reflecting short-term memory capacity constraints on the use of rehearsal.     

Visual backward masking in retardates and normals

Educable adolescent male retardates were compared with normal males of equal CA and equal MA on a visual backward masking task. Significantly shorter interstimulus intervals were required to induce a masking effect in the equal-CA group than in the retarded and equal-MA groups, who did not differ from each other. Speed of visual processing is a function of MA. It is related to CA in normals. and to IQ when retardates are compared with equal-CA normals.     

Receptive training of adjectival inflections in mental retardates

A generalized discrimination of /er/ and /est/ suffixes as labels for stimuli exemplifying comparative or superlative relationships was established in three institutionalized retardates through differential reinforcement. The subjects were first taught correct pointing in response to opposite adjectives (e.g., "big-small") presented as labels for simple visual stimuli, and then taught each of the comparatives, or each of the superlatives possible for those opposites (e.g., "big-bigger" and "small-smaller", or "big-biggest" and "small-smallest"). As training proceeded, novel combinations of the training stimuli were presented as unreinforced probes to display any developing generalization of the training. As training of comparative discrimination proceeded, correct pointing response to comparative probes was high, but correct response to superlative probes was low. When training of superlative discriminations replaced training of comparatives, correct response to superlative probes increased, and correct response to comparative probes remained high.     

Differential reinforcement of reaction times in developmental retardates.

The effects of differential reinforcement on reaction times to two intensities of reaction signal were investigated in 36 developmental retardates. One group was reinforced for reaction times to the higher intensity signal; a second group was reinforced for reaction times to the lower intensity signal; a third group received no reinforcement. Reaction time decreased as signal intensity increased and decreased over sessions as a function of reinforcement. Likewise, reinforcement either exaggerated or reversed differences in reaction times to each signal depending on the particular reinforcement contingency. Results were discussed in terms of attentional and motivational explanations of effects of signal intensity on reaction times of retardates.     

Demonstration versus instructions in concept attainment by mental retardates

Training through observed silent demonstrations was compared with providing equivalent information by verbal instructions, using adult mental retardates of three age and ability levels. At all levels, demonstration surpassed instructions in promoting concept attainment and transfer. During imitation testing, all groups received feedbeck (‘right’ or ‘wrong’) about their responses. Dispensing candy rewards for correct answers did not affect performance.     

Anchoring and relational judgments by young children and retardates

In five experiments using as dimensions brightness, texture, facial happiness, height, and weight, young children (ages 3.4 to 5.3 years) rendered bipolar judgments of stimuli intermediate in value between alternately given extreme anchors. Consistent relational shifts away from the anchors were found for all dimensions judged, and these effects proved virtually independent of children’s ages, the sequential orders of stimulus and anchor presentation, or the provision of overt visual memory props. Evidence of relational judgment within the narrower range of the test stimuli alone was also found. Essentially similar relational judgments were replicated with a sample of severe adult mental retardates.