Midline frontal cortex low-frequency activity drives subthalamic nucleus oscillations during conflict

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Computational Neuroscience

Background:

• Decision-making under conflict requires time and involves specific brain regions.
• The medial prefrontal cortex and subthalamic nucleus (STN) are implicated in conflict monitoring and decision-making.
• Elevated low-frequency activity (<10 Hz) in these areas correlates with response time during conflict.

Purpose of the Study:

• To investigate the functional interaction between the medial prefrontal cortex and STN during conflict processing.
• To determine if functional coupling between these areas increases during high-conflict decision-making.
• To explore the role of theta-delta band coherence in cortico-subthalamic communication.

Main Methods:

• Recorded deep-brain stimulation (DBS) activity from STN electrodes in Parkinson's disease patients during a sensory integration task.
• Manipulated stimulus conflict by varying coherent dot motion and introducing opposing dot motion.
• Simultaneously recorded midline frontal electroencephalography (EEG) to assess cortico-subthalamic coherence.

Main Results:

• Increased STN theta-delta activity was observed specifically during high-conflict trials.
• Theta-delta band coherence between frontal cortex and STN increased significantly during high-conflict conditions.
• Granger causality analysis indicated that frontal cortical activity preceded STN activity, suggesting directional influence.

Conclusions:

• Established a cortico-subthalamic circuit involving the medial prefrontal cortex and STN for successful conflict-based decision-making.
• Demonstrated frequency-specific communication (theta-delta band) between these regions during conflict.
• Provided evidence for the hypothesis that the brain utilizes specific frequency channels for conveying behavioral information.