Increased gamma oscillations evoked by physically salient distracters are associated with schizotypy.

Abstract

Over the last decade, there has been growing interest in aberrant salience as a precursor of positive symptoms in schizophrenia. The present study investigates the neurophysiology of attentional capture by salient stimuli in the visual modality. Evoked oscillatory activity in the gamma frequency range (40Hz) was assessed during visual processing of physically salient distracters and evaluated in relation to schizotypy and its positive, negative and disorganized dimension. The early evoked visual gamma-band response (GBR) was assessed for 24 healthy participants using EEG time-frequency analysis. Physical salience was constituted by colored stimuli diverting from an ongoing baseline condition. schizotypal personality traits were measured by the schizotypal personality questionnaire (SPQ; Raine in Schizophr Bull 17:555-564, 1991). The early evoked visual GBR was significantly pronounced in the physically salient distracter condition. GBR signal power was significantly correlated with positive schizotypal personality traits (r=0.588; p=0.024*). Our results indicate that the early evoked GBR in visual processing of physically salient distracters is associated with schizotypy. These findings refer to the phenomenology of aberrant salience by bridging the gap to neurophysiological research on early sensory selection and attentional capture in the schizophrenia spectrum.