The Mezzich MMPI regression formula revisited

In a sample of depressed psychiatric inpatients, the Mezzich regression formula, based on five MMPI scales, correlated moderately with clinicians' judgments and yielded few false negative diagnoses in identifying patients with unipolar Major Depressive Disorder, but was less effective in eliminating false positives.     

Behavior analytic studies of creativity: A critical review

Studies that treat creativity as operant behavior were critically reviewed. Of the twenty studies, most met minimal requirements for methodological adequacy; all provided at least some evidence for increased creative responding. Major difficulties involved potential confounds between instructions and contingencies, lack of an independent record of the training interaction, lack of social validation data, and very limited evidence for generalization. Several issues were discussed: problems in the behavioral definition of creativity, objections to the use of contingent reinforcement, and the need for empirical analysis of the creative process.     

Word length and age influences on forward and backward immediate serial recall

The present research is aimed at understanding the processes involved in short-term memory and how they interact with age. Specifically, word length effects were examined under forward serial recall, backward serial recall, and item recognition tasks, with performance being interpreted within an item-order theoretical framework. The interaction of age, word length, and direction of recall was examined in two experiments, the first of which confirmed that the word length was present with forward recall and absent with backward recall. In addition, age effects were stronger in backward recall than in forward recall. In the second experiment, an item-order trade-off methodology was utilized with backward recall. When order memory was required, there was no word length effect and strong age effects. When memory was tested via an item recognition test, there was a reverse word length effect and no age effect. While word length effects can be interpreted within the item-order framework, age effects cannot.     

Book reviews

Blackman, D.E., & Lejeune, H. (Eds.) (1990). Behaviour analysis in theory and practice: Contributions and controversies. Hove: Lawrence Erlbaum Associates Ltd, pp. x + 317. ISBN 0-86377-144-0. £29.95.

Davis, J.L., & eichenbaum, H. (Eds.). (1991). Olfaction: A model system for computational neuroscience. Cambridge, MA: MIT Press. Pp. 319. ISBN 0-262-04124-3. £49.50 (hardback).     

Perceptions of depth elicited by occluded and shearing motions of random dots

A computer-controlled display of random dots was used to study perceptions of depth. In this display, a field of stationary random dots surrounded a rectangular area in which random dots moved with uniform velocity in a single direction. The boundaries of this rectangle did not move. When dot motion was perpendicular to the longer boundary of the rectangle (occluded motion), the rectangle seemed to be behind the stationary background surround. Motion parallel to the longer boundary of the rectangle (shearing motion) made it appear in front of the surround. The relative lengths of the sides of the rectangle determined which effect predominated. Thus, for motion perpendicular to the long axis of the rectangle the occlusion predominated and naive subjects reported that the central area seemed farther away than the surround. For shearing motion parallel to the long axis, the subjects reported that the rectangle was closer than the surround and the strength of both effects also depended on the length-to-width ratio of the rectangle. If there was occluded motion along the long axis, as the length-to-width ratio increased so did the likelihood that subjects would report seeing the rectangle behind the surround. Conversely, with shearing motion along the long axis, increasing the length-to-width ratio increased the likelihood that the rectangle would appear unambiguously in front of the surround. Some subjects integrated the two cues with the resulting perception being a rotating cylinder. The occlusion effect was stronger than the shearing effect.(ABSTRACT TRUNCATED AT 250 WORDS)