on the next trial. Trials continue to vary until the individual is able to inhibit (stop) his or her key press responses on approximately 50% of trials. Stop RT is computed by subtracting the average stop-signal delay at which the individual is able to inhibit the go response 50% of the time from the average go RT. Each administration of the stop task consisted of four blocks of 64 trials (256 total trials). Completion of all 256 trials with brief breaks between the blocks takes approximately 10 min.
