Bilateral writing ability, cerebral organization, and hand posture

Among a group of 12 persons selected for the ability to write with ease with either hand, none were found to write using a hooked hand posture with either the right or left hand. Tests of verbal and manipulospatial ability indicated a normal balance of these two types of abilities, usually associated with the left and right hemispheres. Findings are discussed in terms of implications for cerebral organization and hand position in writing.     

Testing different interpretations for the mistaken belief that rays exit the eyes during vision

Research has shown that children and adults believe that emissions from the eye occur during the act of vision. Such beliefs are similar to ancient extramission theories of perception. In Study 1, the authors tested the idea that extramission beliefs might stem from people's thinking about what might occur during vision as opposed to what is necessary for seeing. Training participants to think about what is necessary for vision, however, had no effect on extramission responses. The results of Study 2 indicated that emphasizing the idea of visual input led to a decline in extramission responses and supported the hypothesis that extramission notions stem from the outer-oriented phenomenology of vision.     

A theory of work softening

Observed features of the yield drop in work softening support the view that the structure in a slip band is heterogeneous in a metal such as aluminium or copper. The centre of the band is almost empty of dislocations. These are concentrated round its boundary, particularly as walls of edge dipoles at its ends. It is argued that work hardening is due to the prevention of the passage of these dislocations by a forest of obstacles with small activation volumes and energies. Thermal energy enables them to cut through their obstacles and so to penetrate further into their walls, thereby reducing their back stress and enabling the Frank-Read sources, within the bands, to become active at lower applied stresses. The yield drop is explained as due to an overshooting, resulting from this thermally activated cutting, of the stress to operate the sources.     

Evidence and a computational explanation of cultural differences in facial expression recognition

Facial expressions are crucial to human social communication, but the extent to which they are innate and universal versus learned and culture dependent is a subject of debate. Two studies explored the effect of culture and learning on facial expression understanding. In Experiment 1, Japanese and U.S. participants interpreted facial expressions of emotion. Each group was better than the other at classifying facial expressions posed by members of the same culture. In Experiment 2, this reciprocal in-group advantage was reproduced by a neurocomputational model trained in either a Japanese cultural context or an American cultural context. The model demonstrates how each of us, interacting with others in a particular cultural context, learns to recognize a culture-specific facial expression dialect.     

Help seeking in aggressive and nonaggressive boys as a function of social or mechanical mediation of assistance

The behavior of preadolescent and adolescent boys, rated as aggressive and nonaggressive, was examined to test predictions from Bandura and Walters' social-learning theory and from Weiss and Miller's punishment model of audience-observation effects. The subjects were given a bogus motor task, actually insoluble, with help available on each trial. For half the subjects, help was given through the mediation of a social agent; for the rest, help was on a nonsocial, mechanically mediated basis. The groups for whom help was socially mediated made fewer help-seeking responses and decreased the number of such responses over successive trial blocks. The predictions from Bandura and Walters' theory were not supported, since neither age nor degree of aggressiveness had an effect on help-seeking responses. The results were, however, consistent with the punishment model of audience effects.The preparation of this report was supported by U.S. Public Health Service, Maternal and Child Health Service Project No. 916, and by Grant HD-03110 from the National Institute of Child Health and Human Development. Appreciation is expressed to Miss Sydney Silverstein, who served as experimenter; to Mr. James Blank and Mr. William Blecker of the Iowa City Public School System; and to Dr. Jane E. Anderson, Dr. Dee W. Norton, Dr. A. L. Benton, and Dr. David A. Parton of the University of Iowa.