Neural Noise as a Marker of Schizotypal Traits: EEG Patterns from Visual Noise Processing

Perceptual processing occurs under conditions of both external noise and internally generated neural noise, understood here as neural noise within cortical systems. Within the psychosis continuum framework, schizotypal traits provide a useful model for examining whether individual differences in neural noise are related to perceptual performance in non-clinical populations. The present study investigates whether resting-state neural noise, indexed by the aperiodic (1/f-like) component of the EEG power spectrum, was associated with schizotypal traits and perceptual accuracy in a visual motion discrimination task. Twenty-eight healthy participants completed a two-interval forced-choice motion coherence task with systematically varied dot numerosity, alongside pre-task and post-task resting-state EEG recordings. Schizotypy was assessed using a multidimensional self-report questionnaire (O-LIFE), and neural noise was quantified using aperiodic exponent and offset parameters derived from resting-state EEG. Correlational analyses revealed no statistically significant associations between resting-state neural noise, schizotypy, and overall perceptual accuracy. However, mixed-effects modelling showed that the relationship between dot numerosity and perceptual accuracy was moderated by the aperiodic exponent, whereas the corresponding interaction with aperiodic offset was not statistically significant. In addition, both aperiodic parameters showed strong pre–post stability across the experimental session, indicating that they reflect relatively stable characteristics of resting-state cortical activity. These findings suggest that aperiodic neural activity may not function as a simple standalone marker of schizotypy or perceptual performance in non-clinical samples but may be relevant in a more context-dependent manner. Larger studies are needed to clarify its role in perception and psychosis-related vulnerability.