Heart Rate Variability Covaries with Amygdala Functional Connectivity During Voluntary Emotion Regulation
The Neurovisceral Integration Model posits that shared neural networks support the effective regulation of emotions and heart rate, with heart rate variability (HRV) serving as an objective, peripheral index of prefrontal inhibitory control. Prior neuroimaging studies have predominantly examined both HRV and associated neural functional connectivity at rest, as opposed to contexts that require active emotion regulation. The present study sought to extend upon previous resting-state functional connectivity findings, examining HRV and corresponding amygdala functional connectivity during a cognitive reappraisal task. Seventy adults (52 old and 18 young adults, 18-84 years, 51% male) received instructions to cognitively reappraise negative and neutral affective images during functional MRI scanning. HRV measures were derived from a finger pulse signal throughout the scan. During the task, young adults exhibited a significant inverse association between HRV and amygdala-medial prefrontal cortex (mPFC) functional connectivity, in which higher HRV was correlated with weaker amygdala-mPFC coupling, whereas old adults displayed a slight positive, albeit non-significant correlation. Furthermore, voxelwise whole-brain functional connectivity analyses showed that higher HRV was linked to weaker right amygdala-posterior cingulate cortex connectivity across old and young adults, and in old adults, higher HRV positively correlated with stronger right amygdala - right ventrolateral prefrontal cortex connectivity. Collectively, these findings highlight the importance of assessing HRV and neural functional connectivity during active regulatory contexts to further identify neural concomitants of HRV and adaptive emotion regulation.