Tourette's syndrome (TS): inhibitory performance in adults with uncomplicated TS

Tourette's syndrome (TS) is a neurodevelopmental disorder linked with frontostriatal dysfunction. Previous work has shown some evidence of mild performance deficits on a range of different tasks that involve inhibitory processes. The present study evaluated this in adult participants with uncomplicated TS. Interference control was measured using the Stroop and flanker tasks and a Stroop-flanker task that combined the inhibitory demands of both. Motor inhibition was measured using a letter continuous performance test (CPT) task and word CPT tasks that manipulated the inhibitory demands using compatible and incompatible words. The TS group was found to be slower than the control group on most measures, but showed differential slowing under conditions with enhanced inhibitory demands on the combined Stroop-flanker and the incompatible CPT tasks. The findings suggest that TS-alone is linked to mild impairments in aspects of inhibitory function, and that these can be detected by relatively powerful inhibitory manipulations. A range of different types of inhibitory tasks may be sensitive to TS-alone, and this may depend on both the type of inhibition and the strength of the inhibitory manipulation.