Tonic and phasic cardiac vagal activity predict cognitive-affective processing in an emotional stop-signal task

Abstract

Both the Neurovisceral Integration Model and the Vagal Tank Theory propose cardiac vagal activity (CVA) as proxy for self-regulatory or processing resources required for attentional and top-down control as key mechanisms in executive functioning or emotion-regulation. These resources have, according to the Dual Competition Model, limited capacity and are prioritized for processing the most salient of different competing stimuli. As such, emotional and especially negative or threatening stimuli attract these self-regulatory/processing resources, and may thus interfere with ongoing cognitive processes if not integrated adaptively. Here, we investigated whether tonic and phasic CVA represent self-regulatory/processing resources and thus predict response inhibition in an emotional stop-signal task as a measure of cognitive-affective integration. Thereby, we examined not only the independent effects of tonic and phasic CVA, but whether and how the interaction of both variables predicts response inhibition. We assumed that the effects of CVA on response inhibition would be more pronounced in negatively-valenced trials compared to positive or neutral ones. Our results show that CVA significantly predicted response inhibition, with higher tonic CVA predicting faster, and larger phasic withdrawal CVA predicting slower stop-signal reaction times. The interactive effects of tonic and phasic CVA revealed that high tonic CVA levels prevented the negative effects of CVA withdrawal on response inhibition. Contrary to our assumption, we did not find differential effects of tonic and phasic CVA on trials with different valences. Our results support the notion of CVA as index for self-regulatory/processing resources. However, further research is needed to investigate how CVA is related to specific neural processes of cognitive-affective processing.