Differential hemispheric mediation of nonverbal visual stimuli.

Studies employing schematic faces of three features explored the role of the left hemisphere as an analytic processor in difficult discriminations and the role of the right hemisphere in easy gestalt matches. In a discrimination task, the successively presented members of a stimulus pair differed in all three features. When both stimuli went to the same visual field there was a Visual Field X Judgments interaction; judgments same were processed faster in the left visual field. When a test stimulus differing on all three features from a previously memorized target face was matched to the latter, both judgments same and different were made faster for stimuli in the left visual field. However, when the test stimulus and the memory items differed on only one feature the right field proved superior for both judgments same and different.