Poor Stop-Signal Task Performance: Mechanisms Revealed through Event-Related Brain Potentials

Abstract

The stop-signal task has been used extensively in order to test abilities of inhibition as well as cognitive functioning. In previous experiments, a relatively large number of participants had to be excluded from analysis because of poor performance on the task. In this experiment, we examined the differences between adequate and poor performers on a stop-signal task embedded in an emotional lexical decision task. The personality and behavioral data of the poor stop-signal task performers did not differ from the adequate performers, but the P3 and error-related negativity (ERN) ERPs provided evidence that the poor stop-signal performers attended to the lexical decision portion of the task rather than the stop-signal. However, poor stop-signal task performers did not fail to process the stop signal. These results suggest that the selection of the task in which the stop signal is embedded is crucial.