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

Hypnosis actively reshapes brain networks and subjective experience, rather than simply inducing a passive, low-arousal state. Using EEG, respiratory monitoring, and first-person reports across resting, hypnotic induction, and ideomotor task conditions, the study found that light hypnosis involved early alpha suppression and increased theta activity in parieto-occipital regions. Deeper hypnosis increased frontoparietal theta connectivity while parasympathetic activation declined. During an ideomotor task, participants fell into two groups: Tremblers, who attempted movement despite feeling involuntary constraint, and Non-Tremblers, who refrained from acting due to perceived impossibility. Tremblers showed increased frontoparietal gamma and reduced delta connectivity, indicating heightened sensorimotor integration and executive monitoring under motor conflict. These findings support predictive coding accounts of agency disruption and highlight the value of neurophenomenological methods.

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 approach combining high-density EEG, respiratory and behavioral monitoring, and first-person reports across three conditions: baseline resting state, progressive hypnotic induction (Light and Deep states), and an ideomotor task comparing a hypnotically suggested arm catalepsy to a voluntary simulation. EEG results revealed that light hypnosis was associated with early parieto-occipital alpha suppression and increased theta-band activity. As hypnosis deepened, frontoparietal connectivity increased in the theta while parasympathetic activation declined, challenging the view of hypnosis as a passive, low-arousal state and instead pointing to active top-down reorganization of large-scale brain networks. During the ideomotor state, participants exhibited distinct patterns of behavioral responsiveness, classified as tremblers and non-tremblers, despite reporting comparable disruptions in the sense of agency. Phenomenological analyses corroborated these distinctions, revealing that Tremblers attempted to move despite experiencing the action as involuntary or constrained, whereas Non-Tremblers refrained from acting due to a perceived impossibility or an inability to initiate the motor command. EEG connectivity analysis in Tremblers showed an increased frontoparietal gamma activity and reduced delta connectivity, suggesting heightened sensorimotor integration and greater executive monitoring under motor conflict. Together, these findings demonstrate that hypnosis engages dynamic top-down processes that reconfigure both neural connectivity and subjective experience depending on suggestion-types. They support predictive coding accounts of agency disruption and underscore the value of neurophenomenological methods for advancing consciousness science and informing clinical applications.