Decreased Broca-left supplementary motor area connectivity underlying auditory verbal hallucination: A resting-state NIRS study

BACKGROUND: Despite decades of research, the underlying mechanism of auditory verbal hallucinations (AVH), a core symptom of schizophrenia, remain unclear. Previous studies have tried to capture the neural activity during AVH episodes, whereas trait features of AVH have been less investigated. To address this gap, we employed functional Near-Infrared Spectroscopy (fNIRS) to investigate the neuroimaging patterns in healthy controls (HCs), patients with schizophrenia with a history of AVH (AVHh+) and those without a history of AVH history (AVHh-). We hypothesized that significant differences of functional connectivity (FC) changes would be observed in AVHh+. METHOD: We recruited 23 AVHh+, 16 AVHh-, and 17 matched HCs. Participants underwent an 8-minute resting-state fNIRS scanning. Data processing and analysis were conducted by the NirSpark software (HuiChuang, China) package and R Studio. RESULT: Compared to the AVHh-, the AVHh+ showed significantly lower FC between the Broca's area and the left supplementary motor area (SMA). CONCLUSION: The hypoconnectivity of Broca-left SMA circuit might serve as a trait-like marker of vulnerability to AVH.