Schizotypal traits do not influence behavioral asymmetries for language processing in the non-clinical population

Abstract

People with schizophrenia show atypical patterns of lateralization, including reduced structural and functional asymmetries in language-related brain regions. Given conceptualization of a continuum of schizotypal traits, people with normal but high levels of schizotypal traits may also exhibit atypical language lateralization. The present study was thus designed to examine language lateralization in the general population as a function of self-rated schizotypal traits. Ninety participants (M=31, F=59) completed a lateralized lexical decision task and measures assessing handedness and schizotypy (O-LIFE; Mason, Claridge, & Jackson, 1995). Results indicated that lateralized lexical decision performance was not affected by schizotypy: people with both high and low O-LIFE scores showed a similar right visual field (i.e., left hemisphere) advantage. Hierarchical regression confirmed that when participant gender and handedness were controlled, levels of schizotypal traits did not predict lateralization. Such findings indicate that the reduced language lateralization observed in people with schizophrenia is not evident, even to a lesser degree, in healthy people with high levels of schizotypal traits. These data thus indicate a degree of discontinuity between schizophrenia and schizotypy. Structural and functional imaging investigation is needed to further investigate these suggestive behavioral findings.