Resting state functional connectivity in patients with chronic hallucinations

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Auditory verbal hallucinations (AVH) are a common and distressing symptom of schizophrenia.
• Existing research links AVH experience to activation in language-related brain areas like the right inferior frontal gyrus (rIFG) and left superior temporal gyrus (lSTG).
• However, the neural mechanisms predisposing individuals to AVH remain unclear.

Purpose of the Study:

• To investigate resting-state functional connectivity differences between patients with chronic AVH and healthy controls.
• To identify brain systems associated with the predisposition to experience AVH using the rIFG and lSTG as seed regions.

Main Methods:

• Resting-state functional MRI was used to compare connectivity patterns.
• 49 patients with chronic AVH and 49 matched controls were included.
• Connectivity was analyzed using the rIFG and lSTG as seed regions.

Main Results:

• Patients showed increased connectivity between the rIFG and the right parahippocampal gyrus.
• Reduced connectivity was observed between the rIFG and the right dorsolateral prefrontal cortex in patients.
• Patients exhibited decreased connectivity between the lSTG and the left frontal operculum, parietal opercular area, and left hippocampus.
• Reduced lSTG-hippocampus connectivity correlated negatively with hallucination severity.

Conclusions:

• Aberrant connectivity between language-related areas (rIFG, lSTG) and medial temporal lobe structures, crucial for memory retrieval, is associated with AVH.
• Decreased connectivity within language networks suggests impaired integration, potentially involving corollary discharge mechanisms.
• These findings highlight altered brain connectivity as a potential neural basis for the predisposition to AVH in schizophrenia.