Application of the Premack principle to the behavioral control of extremely inactive schizrophrenics

The four most inactive schizophrenic patients were selected by an observational technique from a ward of severely ill chronic patients. Of the four, two patients repeatedly refused to accept any dispensable rewards. Applying Premack's principle of reinforcement, consistent work behavior was shaped and maintained, using sitting as the reinforcer. The results indicate that the strict application of Premack's principle may have considerable therapeutic potential for those patients who, by refusing all tangible rewards, fail to respond to a reinforcement regime.     

Color aftereffects contingent on perceptual organization

The present experiment demonstrated that (a) cognitive organizational factors influence an orientation-contingent color (McCollugh) aftereffect, and (b) adaptation to colored gratings affected the perceptual organization of a reversible figure. Following adaptation to colored gratings, color aftereffects were reported in only one of two organizations of a reversible figure, and the colors conformed to the subjective contours of the test pattern rather than exclusively to the regions defined by horizontal and vertical pattern elements. In addition, an organization of the reversible figure that segregated vertical and horizontal pattern elements was dominant subsequent to adaptation.     

A probabilistic model for validation of behavioral hierarchies

A probabilistic model for the validation of behavioral hierarchies is presented. Estimation is by means of iterative convergence to maximum likelihood estimates, and two approaches to assessing the fit of the model to sample data are discussed. The relation of this general probabilistic model to other more restricted models which have been presented previously is explored and three cases of the general model are applied to exemplary data.     

Event knowledge,elaborative propensity,and the development of learning proficiency

An experimental test was made of two hypotheses formulated to account for age differences across adolescence in the learning of arbitrary associations. One hypothesis ascribes such differences to two factors: the propensity to elaborate coherent relationships among initially disparate items, and accessibility to event knowledge that can form the bases of such relationships. The other hypothesis assumes that propensity remains constant across age, and that development stems entirely from increases in the accessibility of relevant event knowledge. These hypotheses are evaluated with reference to the performance of 11- and 17-year-olds in learning relationships among paired nouns. The results discredited both hypotheses, instigating the formulation of a revised conception of the relationship between knowledge and propensity as developmental determinants.     

What you don't know can hurt you: The effects of performance criteria ambiguity on sex differences in self-confidence1

Previous investigators have suggested that women display lower self-confidence than men across almost all achievement situations. The empirical validity of this suggestion is assessed in an experiment testing the hypothesis that performance evaluation guidelines moderate sex difference in self-confidence. Undergraduates read the guidelines by which their performance on an impending test would be evaluated. Guidelines were: ambiguous (A); clear—specifying the dimensions of performance to be examined, but not providing any examples of others' performance against which subjects' work would be compared (C); or clear with performance examples (CE). Subjects then completed the test and estimated how will they had done. Results showed the predicted pattern in conditions A and C: While women underestimated their actual performan?e much more than men when guidelines were ambiguous, they did not do so when guidelines were clear. Further, the rise in self-confidence for women from conditions A to C was greater than that for men. Also as predicted, both sexes' self-confidence and performance were higher in condition C than in condition A. Finally, although condition CE was expected to depress only women's self-confidence and performance, both sexes showed this effect. It is concluded that sex differences in self-confidence are moderated by situation variables and that programs designed to reduce such differences might be improved by a greater focus upon women's response to clearly specifiable factors in achievement settings.     

THE IMPACT OF AUDITION ON THE DEVELOPMENT OF VISUAL ATTENTION

Interactions between audition and vision were investigated in two experiments In the first experiment, school-age hearing children, deaf children with cochlear implants, and deaf children without implants participated in a task in which they were to respond to some visual signals and not others This task did not involve sound at all Deaf children without implants performed much more poorly than hearing children Deaf children with cochlear implants performed considerably better than deaf children without implants The second experiment employed a longitudinal design and showed that the rate of development in visual selective attention was faster for deaf children with cochlear implants than deaf children without implants Moreover, the gams were rapid–occurring within 2 years post-implant surgery The results suggest that a history of experience with sounds matters in the development of visual attention The results are discussed in terms of multimodal developmental processes