Corollary Discharge Hypothesis of Auditory Verbal Hallucinations in Schizophrenia – A combined DTI and EEG Study

The corollary discharge theory posits AVHs as a neurobiologically-grounded misattribution of self-generated sounds to perceived sounds. Yet, the mechanism of this process remains unclear. This preliminary study utilized transcranial magnetic stimulation (TMS) to stimulate Broca’s area, electroencephalogram (EEG) to measure gamma oscillatory activity synchronicity between language circuit regions, and diffusion-tensor imaging (DTI) techniques to quantify white matter tract structural integrity in schizophrenia-diagnosed patients with AVHs and a non-patient healthy comparison group, aiming to experimentally demonstrate the between-group difference of corollary discharge process and to establish relationships between corollary discharge dysfunction, frontoparietal circuit microstructural integrity, and AVHs symptom severity. There was a difference in gamma-band synchronicity between the two groups, which was positively correlated with AVHs symptom severity. However, there was no association among white matter integrity, altered functional synchronicity, and AVHs symptoms. This preliminary study supported the corollary discharge hypothesis by manipulating Broca’s area neural activity to demonstrate different frontoparietal synchronicity patterns between groups and establish an association between frontoparietal synchronicity and AVHs symptom severity, providing a new experimental framework for future large-scale studies on corollary discharge hypothesis.