Reduced action-related modulation of visual contrast perception in schizophrenia: Evidence from a 2-AFC paradigm

Investigating sensory attenuation within the visual pathway of individuals with schizophrenia is essential for understanding a core clinical feature of the disorder—impaired voluntary awareness. The present study employed a two-alternative forced-choice (2-AFC) paradigm to examine whether individuals with schizophrenia exhibit atypical action-related modulation of visual perception during voluntary actions compared with healthy controls. The results indicated no significant difference in perceived visual stimulus intensity between active control and passive reception conditions in the schizophrenia group. In contrast, healthy participants demonstrated a significantly reduced perception of stimulus intensity under active control relative to passive reception. Collectively, these findings suggest reduced action-related modulation of visual contrast perception in individuals with schizophrenia.