Response inhibition is disrupted by interoceptive processing at cardiac systole.

The present study investigated how cardiac signals influence response inhibition at both behavioral and electrophysiological levels by using participants' electrocardiogram signals to control the occurrence of events in a stop-signal task, in which the go cue was unpredictably followed by a stop signal requiring the cancellation of the prepotent response. We observed prolonged stop-signal reaction times, reduced stop-signal P3 amplitudes, and higher heartbeat evoked potential amplitudes when the stop signal was presented at cardiac systole, compared to presentation randomly within the cardiac cycle. These effects were independent of the emotional attribute of the stop signal (i.e., emotional facial expression change or non-emotional color change). Our results suggest that coupling stop signals to peripheral autonomic cardiac signals has an impeding effect on response inhibition, probably via shifting attention from exteroception to interoception. Our findings help clarify the precise impact of interoceptive signals on inhibitory control.