Intracranial Recordings to Characterize Action Regulation Mechanisms

Humans can rapidly regulate actions according to evolving environmental demands, however, impairments of action regulation have been identified across a number of neurological disorders including Parkinson's Disease (PD). A key component of action regulation is action inhibition that occurs when stopping unwanted or inappropriate actions. There is mounting evidence that action inhibition also plays a critical part in selecting between competing alternative actions and switching to new actions in response to environmental changes. The investigators hypothesize that stop circuitry (involving frontal-subthalamic nucleus (STN) pathways) are involved in inhibiting unselected actions during action selection with competing alternatives (in the absence of overt stopping) and that switching motor plans also engages stopping circuitry (involving prefrontal-STN pathways) for cancelling the ongoing action, before changing to new one. The overall goal is to delineate the neural circuitry underlying a broad array of action regulation functions that involve inhibitory control, how these functions interrelate, and how they are implemented within brain networks. In this research, the investigator will take advantage of the unique opportunity provided by awake deep brain stimulation surgery to learn more about how the brain functions in a diseased state and how deep brain stimulation changes these networks to make movement more normal. The investigator will simultaneously assess cortical and subcortical electrophysiology in relation to clinical symptoms and behavioral measures and in response to deep brain stimulation in patients undergoing Deep Brain Stimulation (DBS) implantation surgery.