Cardiac responses to auditory expectations during sleep reveal variations of hierarchical processing across arousal states

Embodied cognition proposes that visceral inputs play a fundamental role in variations of consciousness. However, the so far evidence showing that cardiac activity is modulated in response to the violations of auditory expectations come from pathological states of unconsciousness. Here, we will investigate this question during sleep by investigating cardiac responses to auditory deviants in a local-global paradigm - a modified version of the classic oddball. Bases on cerebral activity, this dataset has revealed that transition to sleep is accompanied by a preservation of low-level hierarchical predictions but a breakdown of high-level hierarchical predictions, confirming that this paradigm can be used to track variations in conscious processing across arousal states. We will here test whether cardiac responses to auditory deviants follow this pattern, and additionally, might reveal more subtle differences across sleep states. Preliminary results suggest that cardiac responses during light NREM sleep are accelerated after deviants regardless of the local vs. global contrast, while cardiac responses to deviants in REM sleep are accelerated in response to global, but not local, deviants. Together, these results suggest that cardiac responses to auditory deviants provides information above and beyond cerebral markers and shed new light on the potential of studying brain-heart interactions to unravel differences of conscious processing across conscious states.