In the stop-signal task (Logan, 1994), participants had to periodically stop a prepotent categorization response in response to an auditory signal. In the first block of 48 trials, used to build the prepotent response, participants categorized 24 words (e.g., duck, gun) as referring to animals or nonanimals as quickly and accurately as possible. In four subsequent blocks (96 trials each), participants continued categorizing the words but had to withhold the response when they heard a signal (a 100-ms-long tone) during 25% of the trials. The signals occurred at one of three equally probable delays that were customized for each participant based on his or her average RT during the first no-signal block. The dependent measure was the stop-signal RT, the estimated time at which the stopping process finishes.
