No evidence for theta power as a marker of hypnotic state in highly hypnotizable subjects

Hiltunen, Seppo; Karevaara, Maria; Virta, Maarit; Makkonen, Tommi; Kallio, Sakari; Paavilainen, Petri

doi:10.1016/j.heliyon.2021.e06871

Cited by 10 publications

(14 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Variables include scores of the change in the state of consciousness (∆SoC); EEG theta, alpha and gamma PSD, which are modulated during relaxation and hypnosis [ 9 , 46 ]; EEG Multidimensional Recurrence Plot (mRP); and DET and ENT, which have been found different between highs and lows during relaxation [ 44 , 45 ].…”

Section: Participants and Study Designmentioning

confidence: 99%

Is Hypnotic Induction Necessary to Experience Hypnosis and Responsible for Changes in Brain Activity?

et al. 2023

View full text Add to dashboard Cite

The relevance of formal hypnotic induction to the experience of trance and its neural correlates is not clear, in that hypnotizability, beliefs and expectation of hypnosis may play a major role. The aim of the study was assessing the EEG brain activity of participants with high (highs) or low hypnotizability scores (lows), aware of their hypnotizability level and informed that the session will include simple relaxation, formal hypnotic induction and neutral hypnosis. A total of 16 highs and 15 lows (according to the Stanford Hypnotic Susceptibility Scale, form A) were enrolled. Their EEGs were recorded during consecutive conditions of open/closed-eyes relaxation, hypnotic induction, neutral hypnosis and post hypnosis not interrupted by interviews. The studied variables were theta, alpha and gamma power spectral density (PSD), and the Determinism (DET) and Entropy (ENT) of the EEG signal Multidimensional Recurrence Plot (mRP). Highs reported significantly greater changes in their state of consciousness than lows across the session. The theta, alpha and gamma PSD did not exhibit condition-related changes in both groups. The Alpha PSD was larger in highs than in lows on midline sites, and the different sides/regions’ theta and gamma PSD were observed in the two groups independently from conditions. ENT showed no correlation with hypnotizability, while DET positively correlated with hypnotizability during hypnosis. In conclusion, the relevance of formal hypnotic induction to the experience of trance may be scarce in highs, as they are aware of their hypnotizability scores and expecting hypnosis. Cognitive processing varies throughout the session depending on the hypnotizability level.

show abstract

Section: Participants and Study Designmentioning

confidence: 99%

Is Hypnotic Induction Necessary to Experience Hypnosis and Responsible for Changes in Brain Activity?

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Hypnosis is a state of consciousness that can be self‐induced or promoted through various procedures (“induction”) enacted by other persons (Elkins et al, 2015). It is described as different from the ordinary state of consciousness (Pekala et al, 2006) and cannot be defined independently from self‐reports, although many cortical correlates have been observed by imaging (Landry et al, 2017; Wolf et al, 2022) and EEG studies (Baghdadi & Nasrabadi, 2012; Hiltunen et al, 2021; Rho et al, 2021; Yargholi & Nasrabadi, 2015). Neutral hypnosis (NH) is a state following hypnotic induction without specific suggestions, that is, requests to imagine perception, memory, and behavior different from the actual ones (for instance, analgesia, hallucination, movement) and to experience them as real and involuntary.…”

Section: Introductionmentioning

confidence: 99%

Modulation of the heartbeat evoked cortical potential by hypnotizability and hypnosis

et al. 2023

View full text Add to dashboard Cite

Hypnotizability is a psychophysiological trait measured by scales and associated with several differences, including interoceptive accuracy and the morpho‐functional characteristics of interoception‐related brain regions. The aim of the study was to assess whether the amplitude of the heartbeat evoked cortical potential (HEP), a correlate of interoceptive accuracy, differs in participants with low (lows) and high (highs) hypnotizability scores (assessed by the Stanford Hypnotic Susceptibility Scale, Form A) before and after the induction of hypnosis. ECG and EEG were monitored in 16 highs and 15 lows during an experimental session, including open eyes baseline (B), closed eyes relaxation (R), hypnotic induction (IND), neutral hypnosis (NH), and post session baseline (Post). No significant difference was observed between groups and conditions in autonomic variables. The HEP amplitude was lower in highs than in lows at the right parietal site, likely due to hypnotizability related differences in the functional connection between the right insula and parietal cortex. It increased in highs and decreased in lows across the session, possibly due to the highs' preeminently internally directed attention and to the lows' possible disengagement from the task. Since interoception is involved in several cognitive‐emotional functions, its hypnotizability related differences may contribute to the variability of experience and behavior in daily life.

show abstract

“…Hypnosis is a state of consciousness which can be self-induced or promoted through various procedures ("induction") enacted by other persons (Elkins et al, 2015). It is described as different from the ordinary state of consciousness (Pekala et al, 2006) and cannot be defined independently from self-reports, although many cortical correlates have been observed by imaging (Landry et al, 2017;Wolf et al, 2022) and EEG studies (Baghdadi & Nasrabadi, 2012;Hiltunen et al, 2021;Rho et al, 2021;Yargholi & Nasrabadi, 2015). Neutral hypnosis (NH) is a state following hypnotic induction without specific suggestions, i.e., requests to imagine perception, memory and behavior different from the actual ones (for instance, analgesia, hallucination, movement) and to experience them as real and involuntary.…”

Section: Introductionmentioning

confidence: 99%

Modulation of the heartbeat evoked cortical potential by hypnotizability and hypnosis.

Callara

Fontanelli

Belcari

et al. 2023

Preprint

View full text Add to dashboard Cite

Hypnotizability is a psychophysiological trait measured by scales and associated with several differences including interoceptive accuracy and the morpho-functional characteristics of interoception-related brain regions. The aim of the study was to assess whether the amplitude of the heartbeat evoked cortical potential (HEP), a correlate of interoceptive accuracy, differs in participants with low (lows) and high (highs) hypnotizability scores (assessed by the Stanford Hypnotic Susceptibility Scale, form A) before and after the induction of hypnosis. ECG and EEG were monitored in 16 highs and 15 lows during an experimental session including open eyes baseline (B), closed eyes relaxation (R), hypnotic induction (IND), neutral hypnosis (NH), post session baseline (Post). No significant difference was observed between groups and conditions in autonomic variables. The HEP amplitude was lower in highs than in lows at the right parietal site, likely due to hypnotizability-related differences in the functional connection between the right insula and parietal cortex. It increased in highs and decreased in lows across the session, possibly due to the highs’ preeminently internally directed attention and to the lows’ possible disengagement from the task. Since interoception is involved in several cognitive-emotional functions, its hypnotizability-related differences may contribute to the variability of experience and behavior in daily life.

show abstract

No evidence for theta power as a marker of hypnotic state in highly hypnotizable subjects

Cited by 10 publications

References 56 publications

Is Hypnotic Induction Necessary to Experience Hypnosis and Responsible for Changes in Brain Activity?

Is Hypnotic Induction Necessary to Experience Hypnosis and Responsible for Changes in Brain Activity?

Modulation of the heartbeat evoked cortical potential by hypnotizability and hypnosis

Modulation of the heartbeat evoked cortical potential by hypnotizability and hypnosis.

Contact Info

Product

Resources

About