Hemispheric Differences on a Novel Task Requiring Attention

Abstract

16 students, 8 men and 8 women, ranged in age from 18 to 25 yr., served as subjects in an experiment, where 320 pairs of consonants and 320 pairs of lines were presented tachistoscopically to the left and to the right visual field. One pair, both for letters and for lines, constituted the nonsignal event and the remainder the signals. A high event rate and a low signal density were used. Subjects were instructed to press a key when a signal had been presented. Performance was scored according to nonparametric estimates of sensitivity and criterion. The main results were a clear-cut dissociation between the two measures, a greater sensitivity for the presentation in the right visual field, irrespective of the type of material, and different effects on detection and response bias for men and for women. The importance of these findings with respect to lateralization and information processing is discussed.