Activation of left medial temporal gyrus and adjacent brain areas during affective theory of mind processing correlates with trait-schizotypy in a nonclinical population

International audienceAbstract Schizophrenia, a severe psychiatric disorder, is associated with abnormal brain activation during theory of mind (ToM) processing. Researchers recently suggested that there is a continuum running from subclinical schizotypal personality traits to fully expressed schizophrenia symptoms. Nevertheless, it remains unclear whether schizotypal personality traits in a nonclinical population are associated with atypical brain activation during ToM tasks. Our aim was to investigate correlations between fMRI brain activation during affective and cognitive ToM tasks and scores on the Schizotypal Personality Questionnaire (SPQ) and Basic Empathy Scale (BES) in 39 healthy individuals. The total SPQ score positively correlated with brain activation during affective ToM processing in clusters extending from the left medial temporal gyrus (MTG), lingual gyrus and fusiform gyrus to the parahippocampal gyrus (BA 19). During affective ToM processing, the right inferior occipital gyrus, the right MTG, precuneus and posterior cingulate cortex negatively correlated with the emotional disconnection subscore and the total score of self-reported empathy. These posterior brain regions are known to be involved in memory and language, as well as in creative reasoning, in nonclinical individuals. Our findings highlight changes in brain processing associated to trait-schizotypy in nonclinical individuals during affective but not cognitive ToM processing