“We are what we repeatedly do”. Throughout our life we need to decide which actions to take, determine when and how to execute the planned actions, and specify what actions to reinforce, so as to obtain pleasure and avoid pain. The basal ganglia, a group of subcortical nuclei, play crucial roles in action selection, execution/control, and reinforcement/evaluation. Dysfunctions of these processes have been exemplified in many neurological disorders, including Parkinson’s disease, Huntington’s disease, obsessive-compulsive disorder, and drug addiction. Our lab aims to understand the mechanisms by which basal ganglia circuits select, execute and reinforce actions. We employ a synergistic combination of experiments and theory to address these three distinct but related questions.

(1) Action selection: How does the brain govern the selection of desired action and inhibition of competing actions? What are the neural bases underlying the action selection/decision making under motivational conflicting conditions (such as cost-benefit conflict and risky decision)?

(2) Action execution: How does the brain modulate the movement kinematics (such as vigor)? How does the brain control movement initiation and represent action sequences? What are the neural bases underlying the graded control and coordination of continuous movements? (see Deng & Xiao et al., Cell, 2021)

(3) Action reinforcement: How does the basal ganglia-dopamine system reinforce the “good” actions and discourage the “bad” actions? How is the basal ganglia system modulated by the monoamines during the learning process? (see Xiao et al., Cell, 2020)