Vagal Flexibility Mediates the Association Between Resting Vagal Activity and Cognitive Performance Stability Across Varying Socioemotional Demands

Abstract

Vagal flexibility describes the ability to modulate cardiac vagal responses to fit a dynamic range of challenges. Extant theory on vagal function implies that vagal flexibility is a mediating mechanism through which resting vagal activity, a putative individual difference related to self-regulation, affects adaptive behavior and cognition. Nevertheless, little research has directly tested this hypothesis, thereby leaving fundamental mechanisms of vagal function and adaptability unclear. To this end, 47 healthy subjects completed a 5 min baseline followed by Stroop tasks combined with concurrent auditory distractors. There were four different Stroop task conditions that varied the social and emotional content of the auditory distractors. Electrocardiogram was continuously recorded to assess vagal responses to each condition as heart rate variability [root mean square of successive differences (RMSSDs)] reactivity. Vagal flexibility significantly mediated the association between resting vagal activity and stability of inhibition performance (Stroop interference) scores. In particular, higher resting RMSSD was related to higher standard deviation of RMSSD reactivity scores, reflecting greater differences in RMSSD reactivity between distractor conditions (i.e., greater vagal flexibility). Greater vagal flexibility was in turn related to more stability in Stroop interference across the same conditions. The mean of RMSSD reactivity scores across conditions was not significantly related to resting RMSSD or stability in Stroop performance, and mean RMSSD reactivity did not mediate relations between resting RMSSD and stability in Stroop performance. Overall, findings suggest that vagal flexibility may promote the effects of resting vagal activity on stabilizing cognitive inhibition in the face of environmental perturbations.

Physiological stress reactivity and recovery: Some laboratory results transfer to daily life

“…Overall, these assumptions about adaptive vmHRV underline how a general “higher vmHRV is better” is too simplistic when investigating vmHRV and that an interaction with the demands of the situation needs to be taken into account. Empirical evidence from laboratory studies supports the theory's predictions for vmHRV reactivity (e.g., Laborde et al, 2014 ; Park et al, 2014 ; Mosley et al, 2017 ; Spangler and McGinley, 2020 ).…”

Enhanced cardiac vagal tone in mental fatigue: Analysis of heart rate variability in Time-on-Task, recovery, and reactivity

“…We argue that by investigating the reactivity and recovery related changes in HRV we can identify more clearly the changes in vagal tone in an initial task performance phase and in a phase when individuals became fatigued. Such changes in vagal activity may provide insight into the flexibility of parasympathetic activation which was found to be essential to stabilizing performance in demanding cognitive tasks [ 33 ]. With other words, in addition to examining changes during Time-on-Task, the reactivity and recovery related changes in the vagal mediated HRV may indicate the sensitivity of the parasympathetic system to alterations in task demands.…”

The Association of Physical Activity and Stress-induced Neurocognitive Impairments in Inhibitory Control in Children

“… 40 Similarly, adapting parasympathetic activity to Stroop tasks that vary in socio-emotional demands has predicted greater stability in behavioral performance. 41 In a recent review, this vagal flexibility was discussed as an index of self-regulatory abilities, which are required to adapt cognitive processes, including inhibitory control, to varying environmental demands. 42 Physical activity seems to buffer physiological responses to stress that are linked with a withdrawal of parasympathetic activity.…”