Lateralization of auditory steady state response (ASSR) deficits in first-episode schizophrenia – Effects of attention and associations with auditory hallucination severity

Psychotic disorders, characterized by perceptual abnormalities and cognitive decline, affect millions of people. Auditory hallucinations (AH), or the perception of non-existent sounds, are particularly taxing. While AH is often viewed as a perceptual disorder, patient distress is more closely related to cognitive factors. Research suggests that dysfunctional attentional control of auditory systems may contribute to AH development, and auditory cognitive control may be a key factor in the link between AH and functional decline. This study used magnetoencephalography (MEG) to investigate attentional control of ASSR in first-episode psychosis (FEP) within left and right primary auditory cortex (A1) at initial clinical contact and 4-12 months later. We investigated the relationships among ASSR deficits and attention-mediated sensory gain in 40 FEP and 40 matched healthy comparison subjects (HC). We measured ASSR to click trains with attention directed toward or away from the auditory stimulus at both timepoints. Results indicated that FEP patients showed reduced attentional modulation of ASSR, particularly in the right A1, and increased ASSR during passive listening in left A1, correlating with AH severity. ASSR measurements were reliable, with persistent group differences despite symptom reduction. These findings highlight the role of selective attention deficits in psychosis and suggest ASSR as a potential biomarker for temporal lobe dysfunction. Early identification of ASSR deficits could enable targeted treatments for individuals at highest risk of developing a chronic disorder.