Distinct neural mechanisms underlying hallucination experience and exposure to its externalised virtual...

This study aimed to investigate the shared and distinct activation patterns between a hallucination capture task and a task consisting of exposure to an avatar representing the participants' most distressful auditory verbal hallucination (AVH) (Avatar task).Methods: Twenty participants with schizophrenia and persistent AVHs were recruited. During an fMRI session, they performed the Avatar task and the hallucination capture task. Whole-brain analyses were performed for each task. The potentially shared and distinct activations between tasks were examined using a region of interest (ROI) approach. To avoid inflating the number of brain regions tested, we selected as ROIs brain regions involved in language (left inferior frontal gyrus), emotional processing (amygdala) and social cognition (dorsomedial prefrontal cortex).

We found that participants with AVHs exhibited significant activation in the left inferior frontal gyrus during the hallucination capture task. In contrast, they showed significant activation in the left amygdala and the left dorsomedial prefrontal cortex during the Avatar task. Conjunction and disjunction analyses produced similar results.

The exposure to the AVH avatar specifically activated regions involved in emotional processing and social cognition, suggesting that the Avatar task is relevant for exploring the neural mechanisms involved in dialogical therapies for AVH.