The integrated brain-body field tracks the level of consciousness across the human sleep cycle

Abstract

The hypothesis that consciousness corresponds to integrated information predicts that measures of integration computed over the whole physiological system co-vary with the level of consciousness. Sleep provides an expert-scored axis from wakefulness through deep non-rapid-eye-movement sleep to rapid-eye-movement sleep. In 153 polysomnographic nights from a public cohort (78 subjects; two electroencephalographic channels plus eye-movement, muscle-tone and respiration channels), we computed two observables of the integrated totality per thirty-second epoch: a von Neumann-entropy measure of whole-system integration, and an information-theoretic balance measure distinguishing redundant from synergistic interactions among channels. Both tracked the stage axis within subjects and replicated across two independent nights; the balance measure shifted from redundancy in wakefulness to synergy in deep sleep, and the two observables co-varied beyond the stage confound. A first operationalization that appended body channels to the brain's covariance ruler significantly degraded tracking — a reader error, not absence of body contribution. Read with tissue-specific metrics, body signs moved with the axis in 82-100% of subjects and more than doubled stage-decoding accuracy, with a noise control showing the gain to be specific. Tracking and body contribution generalized to an alternative montage without respiration. Heterogeneous tissues thus cannot be read with a single covariance ruler; totality observables combined with tissue-specific readers operationalize integration at the whole-organism scale.