Deep Brain Stimulation for Parkinson's disease changes perception in the Rubber Hand Illusion

Area of Science:

• Neuroscience
• Human Perception
• Neurology

Background:

• Parkinson's disease (PD) impacts cortico-basal ganglia-thalamic circuits.
• Bodily awareness relies on multisensory integration, primarily in cortical networks.
• The role of subcortical connections in bodily awareness is largely unknown.

Purpose of the Study:

• To investigate the influence of subthalamic nucleus deep brain stimulation (STN-DBS) on multisensory integration for bodily awareness in Parkinson's disease patients.
• To compare the effects of STN-DBS on the Rubber Hand Illusion (RHI) in PD patients versus healthy controls.

Main Methods:

• Utilized the Rubber Hand Illusion (RHI) experiment.
• Compared 24 PD patients undergoing STN-DBS (both on and off stimulation) with 21 healthy volunteers.
• Assessed RHI susceptibility, proprioceptive judgments, and subsequent arm movements.

Main Results:

• PD patients, when not stimulated, showed weaker rejection of the asynchronous RHI compared to controls.
• STN-DBS increased RHI rejection in PD patients, though it remained lower than controls.
• PD patients off-stimulation misjudged hand position, perceiving it closer to the rubber hand.
• STN-DBS did not alter proprioception or movement execution influenced by the illusion.

Conclusions:

• The subthalamic nucleus (STN) and associated subcortical pathways play a significant role in multisensory integration underlying bodily awareness.
• Modulating cortico-subcortical circuitry impacts how the brain integrates sensory information to create a sense of body ownership.
• Findings contribute to understanding the neural basis of bodily awareness and the effects of deep brain stimulation in neurological disorders.