The dynamic role of the left dlPFC in Neurovisceral Integration:
Differential effects of Theta Burst Stimulation on vagally-mediated
Heart Rate Variability and cognitive-affective processing
Abstract
Adapting to the ever-changing demands of the environment requires a
complex interplay between cognitive-affective, neuronal, and autonomic
processes. Vagally-mediated heart rate variability (vmHRV) is positively
associated with both cognitive-affective functioning and prefrontal
cortex (PFC) activity. Accordingly, the Neurovisceral Integration Model
has posited a shared role of the PFC in the regulation of
cognitive-affective processes and autonomic nervous system (ANS)
activity. While there are numerous correlational findings in this
regard, no study so far has investigated whether the manipulation of PFC
activity induces changes in vmHRV and cognitive-affective processing in
an inter-dependent manner. In this study, we examined the effects of
continuous (cTBS) and intermittent theta-burst stimulation (iTBS) over
the left dorsolateral PFC (dlPFC) on vmHRV and cognitive-affective
processing within an emotional stop-signal task (ESST) in 66
participants. Our results revealed that both resting vmHRV and
reactivity, at least partly, predicted cognitive-affective processing.
Furthermore, we found a dampening effect of cTBS on resting vmHRV, as
well as an enhancing effect of iTBS on ESST performance. Our results
show no direct association between vmHRV changes and ESST performance
alterations following stimulation. We interpret our results in the light
of a hierarchical model of neurovisceral integration, suggesting a
dynamical situation-dependent recruitment of higher-order cortical areas
like the dlPFC in the regulation of the ANS. In conclusion, our results
highlight the complex interplay between PFC activity, autonomic
regulation, and cognitive-affective processing, emphasizing the need for
further research to understand the causal dynamics of the underlying
neural mechanisms.