This commentary discusses divergent findings in 2 articles published in this issue of Neuropsychology. The studies used negative priming (NP) to probe the associations between basal ganglia function and cognition in Parkinson's disease (PD) and tested different predictions about NP in PD. Different NP tasks were used, and although the subject samples appeared to have similar clinical features, results were quite different. This commentary, written jointly by the authors of the 2 studies (J. V. Filoteo, L. M. Rilling, & D. L. Strayer, 2002; S. A. Wylie & J. C. Stout, 2002), describes a process by which their disparate results may be used to facilitate the design of new studies that may determine how specific features of NP tasks lead to different findings in PD. The results are a more systematic account of how task features, such as specific response demands, interact with the response selection processes that are implemented by the basal ganglia.