Deficits and Temporal Dynamics of Inhibitory Control over Voluntary and Involuntary Actions in Tourette Syndrome

Grant Type
Grant Year
Institution Location
Institution Organization Name
University of Virginia Medical Center
Investigators Name
Wylie, Scott, PhD

The spectrum of tic disorders, including chronic Tic Disorder (TD) and Tourette syndrome (TS), has been linked to abnormalities in frontal-basal ganglia circuits. These circuits are critically involved in the activation and inhibition of actions, thus contributing to the brain’s network that enables cognitive control over behavior. A disruption in inhibitory control is often proposed as a potential underlying mechanism that is responsible for the unwanted motor and vocal tics, the hallmark features of TS. The objective of the proposed behavioral experiments is to provide new insight into the nature of inhibitory control deficits associated with TS spectrum disorders. A first aim focuses on the effects of tic-spectrum disorder on susceptibility to impulsive reactions and the proficiency of suppressing these action impulses. Because patients can sometimes suppress their motor and vocal tics for short time periods, a second aim considers the impact of tic-spectrum disorders on “proactive control” over impulsive reactions. A third aim considers differences in the ability to suppress impulsive behavior versus suppress deliberately initiated behavior. Finally, a fourth aim considers how inhibitory control over manual and vocal actions may be differentially impacted in tic-spectrum disorder. In summary, our four aims address novel and complementary issues that further specify the nature and role of inhibitory control dysfunction as a potential mechanism for tic symptoms. A greater understanding of the effects of TD and TS on inhibitory control functions may provide novel measures for future treatment studies and lay the groundwork for future studies that combine behavioral and imaging techniques to further elucidate the neural mechanisms of cognitive control dysfunction in tic spectrum disorders. Scott A. Wylie, Ph.D. , Wery van den Wildenberg, Ph.D., Daniel Claassen, M.D. University of Virginia Medical Center, Charlottesville, VA. Award: $52,985 Commentary: This study will investigate the idea that people with Tourette syndrome are unable to suppress impulsive or unwanted actions. In this study individuals diagnosed with Tourette syndrome or a related tic-spectrum disorder will perform a series of tasks that measure the ability to inhibit impulsive actions as well as the ability to stop vocal and manual actions. This work aims to provide new insights on how Tourette syndrome impacts the brain system that is involved in suppressing and controlling actions. Tourette Association of America Inc. – Research Grant Award 2010-2011