Abstract
AIMS: The value of assessing basic symptoms in clinical-high-risk for psychosis (CHR) is becoming increasingly apparent. Greater recognition of subjective experience in neuroscience and psychiatry has renewed research interest in electrophysiological biomarkers of basic symptoms. This study aims to investigate whether cognitive basic symptoms (COGDIS), which capture a subset of basic symptoms, are associated with P3b attenuation and the modulation of brain connectivity in a large sample of CHR. METHODS: Data from the North American Prodromal Longitudinal Study- 3 (NAPLS-3) comprised 440 male and female CHR individuals who completed both the COGDIS items of the schizophrenia proneness instrument as well as a two-tone auditory oddball task. P3b amplitude was measured at the central (Cz) as well as left (P3) and right (P4) parietal electrodes. Brain connectivity was calculated across 300 ms windows before (-300 ms to 0 ms) and after (100 ms to 400 ms) onset of target stimuli. Brain connectivity modulation was calculated as the difference between pre-stimulus and post-stimulus windows. RESULTS: Multiple linear regression analysis indicated that COGDIS was associated with reduced P3b amplitude at the P4 electrode. This effect was not associated with the severity of positive or negative symptoms. No differences in connectivity strength or modulation were found between the groups. CONCLUSIONS: In a large sample of CHR/UHR individuals, cognitive basic symptoms criteria was associated with reduced P3b amplitude at the P4 electrode, approximating the right temporo-parietal area. Parietal P3b attenuation may reflect greater preoccupation towards sensory data, which could play a role in cognitive basic symptom pathogenesis.