Inhibitory after-effects in the stop signal paradigm

The inhibition of responses to interfering stimuli in a trial results in longer reaction times in the following trial in which to-be-ignored stimuli become targets. This is due to the fact that the residual inhibition of the distracter must be overcome before the relevant response can be produced. Such negative priming effects are well-known inhibitory after-effects and the focus of intensive research. However, it seems reasonable to assume that the use of inhibitory processes leaves measurable after-effects in a variety of other tasks and situations. Therefore, the aim of the present study was to investigate whether the after-effects of inhibition could be obtained in a task measuring motor inhibition (i.e. the stop signal task). Our results indicate that inhibitory after-effects were present in the stop signal task whether or nor participants were successful in inhibiting their reactions. Moreover, inhibitory after-effects were greater when both trials consisted of the same primary task properties. Strategic effects might explain part of the results, but there is evidence that a specific inhibition of either the stimulus, or the response to that stimulus, or both plays a role in the constitution of the after-effects.