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

Hypnotic induction and ideomotor suggestions reorganize brain connectivity and subjective experience in distinct ways. Using EEG, cardiorespiratory monitoring, and first-person reports, the study tracked changes across resting baseline, hypnotic induction, and an ideomotor challenge (suggested arm rigidity versus voluntary simulation). Induction produced gradual parieto-occipital alpha suppression, increased theta activity, enhanced frontoparietal theta connectivity, and reduced parasympathetic cardiac modulation, indicating active top-down network reorganization. During the ideomotor challenge, participants fell into two behavioral groups—tremblers and non-tremblers—despite both reporting disrupted agency. Tremblers showed increased frontoparietal gamma and reduced delta connectivity, consistent with enhanced sensorimotor prediction error signaling under motor conflict. The findings support predictive coding and dissociation accounts of agency disruption.

Study at a glance

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.