Abstract:

Cognitive control refers to two critical processes: signal monitoring and inhibitory control. Before executing inhibitory control, the individual first monitors the signal of conflict or warning. However, whether the reward influences signal monitoring or inhibitory control remains poorly understood. In addition, some literature employed pretask reward cueing to study the effect of reward, but the role of pretask reward cueing on cognitive control was influenced by response strategies rather than stimulus processing.
To address the above issues, the present study designed three novel variants of the classical stop signal task that combined the reward with certain stimuli or stimulus features and held stimulus-processing demands constant while varying attention demands. For experiment 1, participants tried to cancel responses on trials that were interrupted by the infrequent triangle but not to slow the initiation of the response. The results indicated that the SSRTs could be further accelerated if successful response inhibition were rewarded. Experiment 2 involved separation of signal monitoring from the stop signal task. Participants responded by pressing the left or right button when the trials were interrupted by the infrequent triangle. The results showed that participants could monitor a signal faster when the signal was associated with reward and conflicted with current behavior tendencies. Accordingly, we considered that the individual could more quickly activate behavior in correspondence with the signal and control the conflict because the signal monitoring was enhanced by reward, which indicated that the process needs more attention. Experiment 3 is the same as the second experiment, except that when trials were interrupted by an inverse triangle, participants made a dual button press. We found that the reaction time of the reward-related signal was shorter than that of the reward-unrelated signal in Go trials, even though the processing of the stop signal depletes the attention resource. These findings indicate that the reward-related signal captures more attention and enhances signal monitoring.
In summary, these findings show that the reward-related signal captures more attention than bias for the enhancement of signal monitoring, thereby leading to more efficient stimulus processing and improving cognitive control.

Key words: reward, cognitive control, signal monitoring, stop signal task