Investigating the Physiology of Controlled Decision-Making in Human Prefrontal Cortex
Through our interactions with the environment, we are constantly faced with decisions. In nearly every such situation, we must apply some degree of cognitive control to optimize our responses. For example, when approaching an intersection in which the traffic light turns yellow, we have to attend to relevant factors (velocity, distance to intersection, presence of cross-traffic or police), ignore irrelevant ones (radio, kids arguing in back seat), maintain the context of long-term goals (get to work on time, avoid traffic violations), and thus choose to hit the accelerator or brake. Our ability to efficiently evaluate environmental cues, parse the likelihood of various outcomes for a narrow range of responses, and choose the most profitable action is essential for successfully navigating our complex world. The prefrontal cortex (PFC), the most evolutionarily advanced region of the human brain, has developed specialized networks for making these decisions. We use a combination of single-unit and local field potential (LFP) recordings in human neurosurgical patients
Investigating Cortical and Basal Ganglia Networks Involved in Disorders of Mental Health
Patients with certain psychiatric disorders that are resistant to conventional treatment strategies may be candidates for surgical intervention. Studies over the past decade have shown extremely promising results for the surgical treatment of obsessive-compulsive disorder (OCD) and major depressive disorder (MDD), and many others are under investigation. The two types of surgical procedures currently available are stereotactic lesions and deep brain stimulation (DBS). By their stereotactic nature, both of these procedures target specific brain regions, putative nodes in a behavioral circuit whose function has gone awry. We use imaging analysis techniques such as diffusion tensor imaging (DTI), task-based and resting state functional MRI to study the structure of cortical and subcortical circuits in individuals with OCD, MDD, and other psychiatric conditions. We are interested in identifying structural or functional predictors of clinical response, as well as studying longitudinal changes over time.
Developing Novel Targets and Indications for Neuromodulation
The field of neuromodulation is undergoing a rapid expansion. Experimental studies and clinical trials are underway for a variety of neurological and psychiatric diseases. We collaborate closely with clinicians and scientists in the Departments of Psychiatry, Neurology, Neuroscience, Engineering, and others to develop new targets and indications for neuromodulation. Parallel investigations across species models and scale (synapses, cells, networks, behavior) allow information to flow back-and-forth between the lab and clinic, facilitating the advancement of our understanding of the system and how to therapeutically modulate it.