Effects of altering the stop-signal position on SSRTT performance. Stopping was made more difficult by presenting an auditory ‘stop-signal' progressively closer to the execution of the response (a). SSRT, the latency to stop, was determined in sessions where the stop-signal was presented half way (50%) into the individualized go reaction time, generating values comparable to studies in other species (b). Stopping and going behaviors were dissociable as the effects of moving the stop-signal onset were specific to stopping behavior with other task measures unaffected by this manipulation including correct go trials (c), correct go reaction time (d), number of trials initiated (e), the latency to initiate a trial (f) and reward collection latencies (g). Data are mean±SEM, n=14. **p<0.01 and *p<0.05 for pairwise differences related to stop-signal position.