Event-related potential correlates of suspicious thoughts in individuals with schizotypal personality features

Abstract

Suspiciousness is a common feature of schizophrenia. However, suspicious thoughts are also commonly experienced by the general population. This study aimed to examine the underlying neural mechanism of suspicious thoughts in individuals with and without schizotypal personality disorder (SPD)-proneness, using an event-related potential (ERP) paradigm. Electroencephalography (EEG) was recorded when the “feeling of being seen through” was evoked in the participants. The findings showed a prominent positive deflection of the difference wave within the time window 250–400 ms after stimuli presentation in both SPD-prone and non-SPD-prone groups. Furthermore, the P3 amplitude was significantly reduced in the SPD-prone group compared to the non-SPD-prone group. The current density analysis also indicated hypoactivity in both frontal and temporal regions in the SPD-prone group, suggesting that the frontotemporal cortical network may play a role in the onset of suspicious thoughts. The P3 of difference wave was inversely correlated with the cognitive-perception factor and the suspiciousness/paranoid ideation trait, which provided preliminary electrophysiological evidence for the association of suspiciousness with SPD features.

Keywords:

• Schizotypal personality
• Suspicious thoughts
• Event-related potentials

Acknowledgments

This study was supported by the Project-Oriented Hundred Talents Programme (O7CX031003), the Research Initiation Fund (O9CX083008), the Knowledge Innovation Project of the Chinese Academy of Sciences (KSCX2-YW-R-131), the National Basic Research Programme (973 Programme No. 2007CB512302/5), the National Nature Science Foundation of China (NSFC 30900441), and the Outstanding Young Investigator Award from the National Science Foundation China (81088001) to Raymond Chan.