The valence strength of unpleasant emotion modulates brain processing of behavioral inhibitory control: neural correlates.

As an ability critical for adaptive social living, behavioral inhibitory control (BIC) is known to be influenced substantially by unpleasant emotion. Nevertheless, how unpleasant emotion of diverse strength influences this control, and the spatiotemporal dynamics underlying this influence, remain undetermined. For this purpose, Event-related potentials (ERPs) were recorded for standard stimulus which required no BIC, and for deviant stimuli that required controlling habitual responses, during highly unpleasant (HU), mildly unpleasant (MU) and Neutral blocks. The results showed delayed response latencies for deviant compared to standard stimuli, irrespective of emotionality. Moreover, there were significant main effects of stimulus type, and significant stimulus type and block interaction effects on the averaged amplitudes of the 230-310 ms and 330-430 ms intervals. In the deviant-standard difference waves which directly index BIC-relevant processing, these interactions were manifested by increased negative potentials as a function of the strength of unpleasant emotion across N2 and P3 components. In addition, these influences are specific to unpleasant emotion, as pleasant emotion of diverse strength produced a similar impact in the control experiment. Therefore, unpleasant emotion of diverse strength is different in impact on brain processing of behavioral inhibitory control. This impact is evident not only in early monitoring of response conflicts, but also in late processing of response inhibition.