Scientific Reports
September 22, 2023
Victor Oswald, Audrey Vanhaudenhuyse, Jitka Annen et al.
24 citations
Self-induced cognitive trance (SICT) is a voluntary non-ordinary state of consciousness involving narrowed awareness, hyper-focused immersion, and altered perception. This study examined autonomic nervous system changes during SICT by measuring heart rate variability and respiration rate variability in 25 proficient participants across three conditions: resting state, SICT, and a mental imagery task. During SICT, participants showed increased heart rate, decreased high-frequency heart rate variability, and specific increases in respiratory amplitude, phase ratio, and respiration rate variability compared to control conditions. These findings suggest SICT is associated with reduced parasympathetic activity, indicating a hyperarousal state of the autonomic nervous system.
Current Opinion in Behavioral Sciences
May 9, 2024
Olivia Gosseries, Nolwenn Marie, Yannick Lafon et al.
16 citations
Trance states, found across cultures from shamanic rituals to contemporary practices, are increasingly studied by researchers and clinicians. This review describes their common phenomenological features, such as altered awareness and perception. Using advanced neuroscientific techniques, it reports on the neural mechanisms underlying these states, including changes in brain connectivity and dynamics. The review also examines clinical applications, suggesting that trance states may be useful in therapeutic settings. By connecting subjective experience, brain function, and practical use, it advances understanding of trance and its potential benefits.
Int J Clin Health Psychol
January 1, 2025
Victor Oswald, Karim Jerbi, Corine Sombrun et al.
4 citations
People vary widely in their experiences during non-ordinary states of consciousness, and this variation is linked to measurable differences in the autonomic nervous system. The study shows that subjective experiences—such as changes in perception, emotion, or sense of self—correspond with distinct patterns of physiological responses, like heart rate or skin conductance. These findings suggest that the body's nervous system plays a key role in shaping how individuals experience altered states, highlighting a direct connection between inner, subjective phenomena and physiological processes.
arXiv (Cornell University)
September 23, 2025
Victor Oswald, Karim Jerbi, Corine Sombrun et al.
A self-induced, substance-free trance state called Auto-Induced Cognitive Trance (AICT) engages frontal regions, the posterior cingulate cortex, and the left parietal cortex, brain areas linked to rich subjective experiences. Analysis of EEG recordings from 27 trained participants showed that the aperiodic component of the power spectrum, entropy, and complexity measures distinguished AICT from rest, with the aperiodic component being the strongest discriminator. Baseline neural activity in frontal and parietal regions predicted how much brain activity changed when entering the trance. These results suggest that self-induced trance states alter neural functioning in ways that may explain their intense and unique subjective qualities.