Facilitative and suppressive effects of punishment on the reaction time in humans under various conditions

Summary

The effects of brief shock as the punishing stimulus during a simple or choice reaction time task (SRT or CRT) and the change in skin resistance during a key-pressing response were investigated under various conditions. A slowing of the SRT and CRT occurred similarly during the shock phase under both the response-contingent and response-independent shock conditions. After the elimination of shock, the suppressive effect of contingent shock was still observed but an effect for independent shock disappeared at once (experiment 1). A facilitation of a punished response could be demonstrated under the discriminative punishment condition in which the unpunished response was available, although the CRT for the punished response showed an eventual slowdown as punishment trials progressed. By contrast, the unpunished response showed a slowdown of the CRT throughout the punishment period. Consequently, both the CRTs for the punished and the unpunished responses indicated similarly high values in the late stage of punishment. The removal of shock brought about a completely different trend for both types of responses; a suppression of the punished response was maintained but the CRT for the unpunished response recovered to the baseline level immediately (experiment 2). These results were explained by two distinct effects of punishment: a nonspecific emotionalizing effect arising from the punishment situation itself and a specific reaction to the punished response stemming from response-shock contingencies. The former effect could be easily affected by giving a pseudo-instruction in advance (experiments 3 and 4). Changes in skin resistance were mainly dependent upon the response-shock contingencies, but they did not parallel changes in the CRT for the punished response. The autonomic response rose and diminished prior to changes in overt behavior.