Neuroimaging resolution of the altered state hypothesis

Area of Science:

• Neuroscience
• Psychology

Background:

• A central debate in hypnosis research concerns the existence of a unique hypnotic state and its causal link to suggestibility.
• Brain imaging studies have been employed to investigate altered states of consciousness during hypnosis, but findings remain inconclusive.

Purpose of the Study:

• To critically evaluate neuroimaging evidence regarding the relationship between hypnotic states, brain activity, and suggestibility.
• To address the confounding factors in previous study designs that hinder the resolution of the hypnosis controversy.

Main Methods:

• Analysis of neuroimaging studies examining brain activity during hypnosis and suggestion.
• Distinguishing between studies that confound hypnotic induction with suggestion and those that do not.

Main Results:

• Many neuroimaging studies confound hypnotic induction with suggestion, limiting their ability to resolve the debate.
• Studies without this confound show that hypnotic inductions alter brain activity, but these changes are not necessary for hypnotic suggestion effects or their neural correlates.

Conclusions:

• Current neuroimaging data do not definitively establish a causal link between brain activity changes from hypnotic induction and those from other suggestions.
• It remains uncertain whether observed brain activation changes during hypnosis reflect a unique state or more common cognitive processes.