Control in memory for movement cues by mentally retarded children

The study was designed to determine the desirability of providing external prompts (1) to use a mnemonic to enhance accuracy of recall and (2) to use response 'priming' in memory for spatial location by mentally retarded persons. Two groups of 40 mentally retarded boys and girls and two groups of 40 MA-matched nonretarded children were compared for accuracy in the recall of movement on an arm-positioning task. No differences were found between mentally retarded subjects and MA-matched subjects treated under the same conditions. However, all groups were unable to make spontaneous control adjustments to accommodate the covert manipulations made just prior to recall. By providing response primes, appropriate performance adjustments were made by all groups, resulting in a significant improvement in accuracy of recall. These findings serve to reaffirm earlier reports showing remarkable similarity between the mentally retarded and MA-matched nonretarded subjects.     

Effects of a paradoxical intervention on a child's anxiety about sleep- and sports-related performance

A paradoxical instruction was used to treat a 10-yr.-old boy's complaint of crying when unable to sleep and the daytime equivalent of fearing the public display of crying when failing at sports performances. The instruction resolved both the sleep disturbance and the public crying. The results suggest that, like adults, children may experience anxiety about sleep difficulties and that paradoxical intention may have promise for the treatment of some children's insomnia.     

Cognitive styles: illusory phenomena

The relationship between cognitive style and illusion magnitude was examined using the assimilation and contrast Delboeuf distortions. As in previous research, field dependence correlated positively with assimilation; however, a significant negative correlation with contrast was also found, suggesting that, while field dependence may involve the illusory integration of the stimulus field, field independence may involve its equally illusory differentiation.     

Handling time and choice in pigeons

According to optimal foraging theory, animals should prefer food items with the highest ratios of energy intake to handling time. When single items have negligible handling times, one large item should be preferred to a collection of small ones of equivalent total weight. However, when pigeons were offered such a choice on equal concurrent variable-interval schedules in a shuttlebox, they preferred the side offering many small items per reinforcement to that offering one or a few relatively large items. This preference was still evident on concurrent fixed-cumulative-duration schedules in which choosing the alternative with longer handling time substantially lowered the rate of food intake.     

Temporal proximity and reinforcement sensitivity in multiple schedules

Distributions of reinforcers between two components of multiple variable-interval schedules were varied over a number of conditions. Sensitivity to reinforcement, measured by the exponent of the power function relating ratios of responses in the two components to ratios of reinforcers obtained in the components, did not differ between conditions with 15-s or 60-s component durations. The failure to demonstrate the “short-component effect,” where sensitivity is high for short components, was consistent with reanalysis of previous data. With 60-s components, sensitivity to reinforcement decreased systematically with time since component alternation, and was higher in the first 15-s subinterval of the 60-s component than for the component whose total duration was 15 s. Varying component duration and sampling behavior at different times since component transition may not be equivalent ways of examining the effects of average temporal distance between components.     

Induction of depressive affect after prolonged exposure to a mildly depressed individual

Scores on the Beck Depression Inventory (BDI) were periodically obtained from the roommates of college students who exhibited a persistent mild depression over a 3-month period. For comparative purposes, BDI scores were also obtained from roommates of individuals who were transiently depressed and from subjects with nondepressed roommates. In comparison with control subjects, the roommates of persistently depressed persons displayed a progressive increase in BDI score over the course of the study.