Schizotypy and patterns of lateral asymmetry on hemisphere-specific language tasks.

Following the notion that abnormalities of hemispheric asymmetry may underlie schizophrenia, patterns of cognitive hemispheric asymmetries, as assessed by left and right hemisphere language tasks, were examined in relation to schizotypal symptoms. Ninety right-handed undergraduates completed the Oxford-Liverpool Inventory of Feelings and Experiences questionnaire (O-LIFE; Mason, O., Claridge, G., Jackson, M., 1995. New scales for the assessment of schizotypy. Personality and Individual Differences, Vol. 53, pp. 727-730), which measures different aspects of schizotypy symptomatology. Low scores on right, but not left, hemisphere language tasks were significant predictors of high scores on positive schizotypal symptomatology scales (Unusual Experiences and the STA) over and above the contributions of the left hemisphere language tasks and demographic variables. Low scores on both left and right hemisphere language tasks were significant predictors of high scores on the Cognitive Disorganisation factor, over and above the contributions of tasks related to the contralateral hemisphere and demographic variables. Neither the right nor the left hemisphere language tasks resulted in a significantly good degree of prediction of introvertive anhedonia (an index of negative schizotypal symptomatology) or impulsive non-conformity. The findings provide partial support for some current theories of hemispheric differences in schizophrenia and schizotypy.