Temporal integration, hemispheric specialisation and psychological illness

Abstract

Schizophrenic subjects were found to differ from normal control subjects, and from older depressed subjects and their normal controls on the basis of a temporal integration (left hemisphere) task. The temporal integration task was shown to produce reliable right ear advantages for normal subjects, whereas schizophrenics showed a trend toward a left ear advantage. The older depressed subjects (all female) and their controls showed no ear advantage or any evidence to differentiate between them. The contrasting evidence for schizophrenics, which shows that they have difficulty processing temporal information, is consistent with previous findings that implicate dysfunction of the left "language" hemisphere in this illness. It is particularly consistent with previous findings which show schizophrenics have specific difficulties in integrating verbal information and that they are also different from normals and non-psychotic patients in the way they respond to changes in presentation rate and to right sensory field stimuli.