Decoding hypnotic consciousness: neural and experiential insights into induced and ideomotor suggestions.

Abstract

Hypnotic induction and ideomotor suggestions provide a powerful framework for investigating the remarkable capacity of verbal influence to reshape conscious experience, cognition, and motor control. We employed a multimodal, neurophenomenological approach combining high-density electroencephalography, cardiorespiratory, and behavioral monitoring, as well as first-person reports across three conditions: a resting-state baseline, a hypnotic induction, and an ideomotor challenge involving either a suggested arm rigidity with attempted movement or a voluntary wakeful simulation used as a behavioral control condition. Electroencephalography (EEG) analyses revealed that hypnosis induction-related changes unfolded gradually, beginning with parieto-occipital alpha suppression and increased theta activity, followed by enhanced frontoparietal theta connectivity and reduced parasympathetic cardiac modulation. These results confirm and extend prior findings, showing that hypnotic induction suggestions involve an active, high-arousal, top-down reorganization of large-scale brain networks. During ideomotor challenge, participants displayed distinct behavioral patterns, classified as tremblers and non-tremblers, despite reporting comparable disruptions in agency. Phenomenological reports clarified these differences: tremblers attempted movement despite experiencing the action as involuntary or constrained, while non-tremblers refrained from acting due to a felt impossibility or an inhibited motor command. EEG connectivity in tremblers specifically showed increased frontoparietal gamma and reduced delta connectivity, consistent with enhanced sensorimotor prediction error signaling under motor conflict, relative to voluntary simulation. Together, these findings demonstrate that hypnosis dynamically reconfigures neural connectivity and subjective experience depending on suggestion type. They further support predictive coding and dissociation-based accounts of agency disruption and underscore the value of neurophysiological and neurophenomenological methods for advancing consciousness science and informing clinical applications.