Association between symptoms of psychosis and reduced functional connectivity of auditory cortex

We have previously reported altered functional asymmetry of the primary auditory cortex (Heschl's gyrus) of patients with schizophrenia (SZ) and their relatives during auditory processing. In this study, we investigated whether schizophrenia patients have altered intrinsic functional organization of Heschl's gyrus (HG) during rest. Using functional magnetic resonance imaging (fMRI), we measured functional connectivity between bilateral HG and the whole brain in 24 SZ patients, 22 unaffected first-degree relatives and 24 matched healthy controls. SZ patients and relatives showed altered functional asymmetry in HG and altered connectivity between temporal and limbic areas in the auditory network during resting-state in comparison with healthy controls. These changes in functional connectivity correlated with predisposition towards hallucinations in patients and relatives and with acute positive symptoms in patients. The results are in line with the results from task-related and symptom-mapping studies that investigated the neural correlates of positive symptoms, and suggest that individual psychopathology is associated with aberrant intrinsic organization of auditory regions in schizophrenia. This might be evidence that reduced hemispheric lateralization and reduced functional connectivity of the auditory network are trait markers of schizophrenia.