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

Area of Science:

• Neuroscience
• Psychiatry

Background:

• Auditory verbal hallucinations (AVH) are a core symptom of schizophrenia.
• Understanding the neural underpinnings of AVH is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the distinct and shared brain activation patterns during a hallucination capture task and an avatar-based task for auditory verbal hallucinations (AVH).
• To explore the neural mechanisms underlying AVH and their potential relevance for therapeutic interventions.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan twenty participants with schizophrenia and persistent AVHs.
• Participants underwent two tasks: a hallucination capture task and an avatar task exposing them to a representation of their most distressing AVH.
• Region of interest (ROI) analyses focused on the left inferior frontal gyrus (language), amygdala (emotion), and dorsomedial prefrontal cortex (social cognition).

Main Results:

• The hallucination capture task elicited significant activation in the left inferior frontal gyrus.
• The avatar task demonstrated significant activation in the left amygdala and left dorsomedial prefrontal cortex.
• Conjunction and disjunction analyses confirmed distinct activation patterns between the two tasks.

Conclusions:

• Exposure to an avatar representing distressing AVH specifically activates brain regions associated with emotional processing and social cognition.
• The avatar task shows promise for investigating the neural mechanisms relevant to dialogical therapies for AVH.