Robotically-induced hallucination triggers subtle changes in brain network transitions.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Presence hallucination (PH) is a symptom in Parkinson's disease, often linked to severe illness, psychosis, and cognitive decline.
• PH can occur in healthy individuals and has been experimentally induced using robotics and sensorimotor stimulation during fMRI.
• Previous neuroimaging studies showed altered activity in specific brain regions but lacked a direct link to PH intensity.

Purpose of the Study:

• To investigate the neural mechanisms underlying experimentally induced presence hallucinations (PH) in healthy individuals.
• To explore dynamic functional connectivity patterns associated with PH.
• To identify specific disruptions in brain network interactions during PH.

Main Methods:

• Utilized advanced dynamic functional connectivity analysis on fMRI data acquired during robot-induced PH.
• Decomposed fMRI data into time-varying co-activation patterns.
• Analyzed pattern occupancies, durations, and transition probabilities across conditions.

Main Results:

• Induced PH significantly and selectively increased transition probabilities towards a specific brain pattern involving the posterior superior temporal sulcus, angular gyrus, and prefrontal cortex.
• This dynamic change was specific to PH induction and not observed in control conditions or other robot-induced sensations.
• Findings identified a distinct disruption in brain network dynamics during PH.

Conclusions:

• The study elucidates the neural mechanisms of PH in healthy individuals through dynamic functional connectivity.
• A specific disruption in brain network interaction dynamics is identified as a hallmark of PH.
• These findings extend understanding of network dysfunctions in hallucinations from psychotic patients to induced hallucinations in healthy individuals.