Seminar: 5/24 - Adam Aron
12:00 to 1:30 PM at:
Department of Psychology
The Cognitive Neuroscience of Response Inhibition
The ability to stop ongoing behavior is critical to adaptive behavior, and deficits in response inhibition are observed in a number of neuropsychiatric disorders. In my talk I will outline a program of research that has characterized the neural system responsible for inhibiting ongoing responses. This research has combined a number of methods, including lesion analysis, functional MRI, psychopharmacology and diffusion tensor imaging, to examine how the brain inhibits responses in the stop-signal paradigm. Our lesion studies have shown that the right inferior prefrontal cortex is critical for the ability to inhibit an already-initiated response. Using fMRI, we have confirmed this result, and also found that the subthalamic nucleus (part of the basal ganglia) is involved in stopping. Further, we have found that activity in both of these regions predicts the speed with which individuals are able to stop. Using diffusion tensor imaging, we have found that these regions are directly connected. I then outline results showing that stopping ability is impaired in Attention Deficit Hyperactivity Disorder, which is ameliorated by stimulant medication. Based on these and related results, I will outline a functional anatomical model of response initiation and inhibition, and demonstrate its relevance to neuropsychiatric disorders.