Deep Brain Stimulation of the Subthalamic Nucleus Does Not Affect the Decrease of Decision Threshold during the...

Area of Science:

• Neuroscience
• Cognitive Science
• Decision Science

Background:

• Decision-making involves integrating evidence over time until a threshold is met.
• The subthalamic nucleus (STN) is hypothesized to control the decision threshold.
• Evidence suggests decision thresholds can decrease within a trial to aid difficult choices.

Purpose of the Study:

• To investigate if the STN mediates the within-trial decrease of the decision threshold.
• To determine if deep brain stimulation (DBS) of the STN affects this decision threshold modulation.

Main Methods:

• Assessed 13 Parkinson's disease patients with STN DBS, 11 age-matched controls, and 12 young healthy controls.
• Participants completed decision tasks with evidence presented at discrete time points.
• Decision thresholds were estimated, and performance (accuracy, reaction time) was analyzed with and without STN DBS.

Main Results:

• The slope of the decision threshold varied widely but was not influenced by STN DBS status (on/off).
• No significant differences in decision threshold slope were found between patients and controls.
• Accuracy and reaction time did not differ between STN DBS on/off conditions or compared to controls.

Conclusions:

• The STN does not seem critical for modulating within-trial decision threshold decreases in the absence of reward, decision conflict, or time pressure.
• The findings suggest the STN's role in decision threshold control is context-specific, not universally applied during all choice processes.