Brain-body dynamics are asymmetric and stable across cognitive states

Abstract

The human body displays slow, correlated fluctuations in brain activity, autonomic physiology, and incidental behavior. These fluctuations are commonly linked to arousal and cognition, yet it remains unclear whether they reflect task-dependent reconfiguration of brain-body interactions or arise from a stable endogenous dynamic. Here, we used a multivariate dynamical systems approach to analyze simultaneously recorded neural activity, autonomic physiology, and behavior during rest and during attentive and distracted listening to spoken narratives. We found that narrative listening did not substantially alter the endogenous dynamics observed during rest. Instead, peripheral physiology and behavior predicted cortical activity more reliably than the reverse, revealing a pronounced directional asymmetry. In contrast, stimulus-driven physiological responses were primarily mediated by cortical processing rather than direct autonomic drive. Together, these findings indicate that slow brain-body dynamics are stable across cognitive states and provide a structured context through which narratives influence physiology.