Corticostriatal Contributions to Parkinson's Disease Cognitive Impairment

This study examines how certain brain circuits (between the cortex and the striatum) contribute to thinking and memory problems in Parkinson's disease. It takes place during deep brain stimulation surgery, where researchers can record brain activity while patients are awake. **You may be eligible if:** - You have been diagnosed with Parkinson's disease - You are scheduled for deep brain stimulation (DBS) surgery at Vanderbilt University Medical Center under local anesthesia - Your surgical plan involves electrode placement near the caudate (a part of the brain involved in thinking) - You are 40 years of age or older - You speak English and can participate in short tests during the procedure **You may NOT be eligible if:** - You are under 40 years old - You have a movement disorder other than Parkinson's disease - You are unable to understand or follow directions during testing Talk to your doctor to see if this trial is right for you.