Role of cerebral hemispheric processing in the visual half-field stimulus-response compatibility effect.

Two experiments were conducted to test theories of the stimulus-response (S-R) compatibility effect. Stimuli presented above and below a fixation point in the left and right visual field signaled choice responses in the midsagittal plane. Even though the duration of stimulus presentation in Experiment 1 was sufficiently brief, such that the possibility of eye movements was precluded, a visual half-field S-R compatibility effect was still obtained. That such an effect is found when it can be adequately specified to which hemisphere stimulus information is presented suggests that an explanation in terms of cerebral laterality factors be considered. The second experiment employed arbitrary symbols to represent the spatial property of stimuli used in prior experiments, and a similar pattern of results was obtained. These results are discussed in terms of a functional view of cerebral organization.