ABNORMAL LATERALITY IN SCHIZOPHRENICS AND THEIR PARENTS

Previous studies found that schizophrenics do not show the normal righ t ear-left hemisphere perceptual advantage on language-related dichoti c tests of lateralized cerebral function. We report evidence of a simi lar abnormality in non-schizophrenic parents of schizophrenic patients . Perceptual asymmetry was first measured with a dichotic word test wh ich had previously yielded differences between schizophrenics and cont rols. The parents (n=18) demonstrated a lower right ear advantage (REA ) than controls (n=10) (p=0.05), but performed similarly to their schi zophrenic offspring (n=10). The same subjects were given two additiona l tests. Neutral words were paired with words of a positive emotional valence in one test, and with words of a negative emotional valence in the other. On these two tests, the parents were more similar to the c ontrols than to their offspring with the schizophrenics demonstrating a lower REA than their parents (p=0.005) on the negative test. These r esults suggest that schizophrenics and their parents have similar abno rmalities in hemispheric activation at baseline only, but when listeni ng to words with negative emotional valence, only the schizophrenics d emonstrate a further decrease in left hemispheric activation.