Parkinson's Disease (PD) and Tourette's Syndrome (TS) have both been linked
to disorders of the dopamine system. In collaboration with Tammy Hershey
and Kevin Black, we are conducting combined cognitive and pharmacological
neuroimaging of PD and TS patients to examine brain activation abnormalities
related to dopamine dysfunction. Patients are scanned on and off L-DOPA
while performing difficult cognitive control tasks (e.g., N-back, go-nogo).
Results suggests that L-DOPA normalizes brain activation abnormalities in
patients and that these changes are related to behavioral performance (Hershey
et al., submitted).