Distinct Brain Systems Support Afferent and Efferent Autonomic Activity
Jungwon Min1, Gengshuo Liu1, Martin J Dahl2
1University of Southern California, Los Angeles, CA, US.
Social Cognitive and Affective Neuroscience
|July 30, 2026
Summary
This study reveals how brain activity relates to heart rate variability (HRV), suggesting a feedback loop. Aging impacts this brain-autonomic coordination system.
Area of Science:
- Neuroscience
- Autonomic Nervous System Research
- Cardiovascular Physiology
Background:
- Brain correlates of autonomic activity are known, but their afferent (receiving) or efferent (sending) nature is unclear.
- The interplay of emotion, aging, and brain-autonomic coordination requires further investigation.
Purpose of the Study:
- To investigate the afferent and efferent brain mechanisms underlying heart rate variability (HRV).
- To explore how emotion and aging influence brain-autonomic coordination.
Main Methods:
- Utilized time-varying heart rate variability (HRV) and blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) data.
- Analyzed data from younger and older adult cohorts during rest and emotion regulation tasks.
- Employed Granger causality analysis to determine information flow between brain regions.
Main Results:
- Insular and cingulate cortex activity negatively correlated with HRV during emotion regulation.
- Afferent regions (posterior insula, postcentral gyrus, frontal pole) showed increased BOLD activity with decreased HRV.
- Efferent regions (anterior insula, cingulate) showed increased BOLD activity with increased HRV.
- Afferent brain activity Granger-predicted efferent activity, suggesting a unidirectional feedback loop.
- Aging altered the brain-autonomic system, with greater overlap between afferent and efferent regions in older adults.
Conclusions:
- A feedback loop exists where HRV influences brain activity in specific regions, which in turn modulates HRV.
- Brain-autonomic coordination differs between younger and older adults, with aging potentially altering this feedback system.
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