Asa Young

Presentation Title

Sync or swim: Cross-frequency coupling between brain and body rhythms is modulated by state stress

Abstract

The central and peripheral nervous systems are, emphatically, rhythmic. A spectrum of oscillations extending from the ultra-fast gamma band to the infra-slow peristaltic cycles reflect the varying timescales by which the organism processes information necessary for cognition and homeostasis. The present study assessed cross-frequency coupling, the mechanism whereby oscillators of different frequencies may communicate and integrate information vertically, between neuronal and physiological oscillators as a dynamic, state-dependent construct. Simultaneous EEG, electrocardiogram, respiratory effort, and electrogastrography were obtained from 23 healthy, neurotypical participants. Harmonic locking –the capacity of oscillators to align their instantaneous frequencies– and phase-amplitude coupling –whereby the amplitude of a high frequency oscillation varies according to the oscillatory phase of a low frequency oscillation–  were evaluated in resonant breathing, resting state, and arithmetic tasks. Our results indicate cross-frequency coupling between neuronal and physiological oscillations is modulated by state stress. Furthermore, there emerges a functional disassociation between enteric and cardiovascular systems: cardiovascular-brain coupling is linearly enhanced by state stress (resonant breathing < resting state < arithmetic); enteric-brain coupling is linearly suppressed (resonant breathing > resting state > arithmetic). The informational substrate between brain and body –what some scholars speculate underpins the embodiment of the cognitive agent within its somatic environment– is dynamic and multifaceted.