My lab studies how populations of neurons implement decision making and motor control. We record and manipulate the activity of hundreds or thousands of neurons in mouse cortex, then use sophisticated analyses to understand how these areas compute variables that the animal needs in order to behave. With calcium imaging, we can identify each neuron's cell type, layer, or projection pattern, and use this information to better understand inter-area communication and the organization of computation within cortex. With optogenetics, we can close the causal loop to determine if the activity is necessary or the roles of cell types in computation. Finally, with pharmacological manipulations, we can begin to understand how psychiatric drugs drive their behavioral effects.