Inhibition has been widely investigated in Tourette's syndrome (TS), but some inhibitory processes have received more attention than others. This study examined the relatively underresearched construct of cognitive inhibition in adults with TS and no comorbidities (TS-alone), using tasks thought to tap automatic (without conscious intent) and effortful (with deliberate intent) inhibitory processes. Method: Adult participants with TS-alone (n = 20) and healthy controls (n = 21) were compared on a retrieval-induced forgetting task thought to tap automatic cognitive inhibition and a directed forgetting task thought to tap effortful cognitive inhibition. Both tasks involved effortful memory as well as the key inhibitory effects. Results: Both the TS-alone and control groups showed typical inhibitory effects on both tasks, but the TS-alone group showed generally poorer effortful memory on both tasks. Conclusions: The findings appear to indicate intact cognitive inhibition in adults with TS-alone, with some evidence of impairment in effortful processing. This highlights the importance of using tasks related to different inhibitory processes to explore cognitive performance in TS-alone, and suggests that any inhibitory impairment associated with TS-alone is mild and relatively circumscribed.
