How Does Hypnosis Work in the Brain?

Brain imaging shows that hypnosis changes how a few specific networks behave, in people who respond strongly to it, while they are hypnotized. It does not show the brain switching off, and it does not yet explain how those changes turn into relief from pain or anxiety. The clearest single picture comes from a Stanford study published in 2016.

What did the Stanford study find?

According to Stanford Medicine’s report on the study, the team screened 545 healthy volunteers and selected 36 who were consistently highly hypnotizable and 21 at the extreme low end. All 57 were scanned with functional MRI at rest, while recalling a memory, and during two hypnosis sessions. Three changes appeared, and each one was seen only in the highly hypnotizable group and only during hypnosis.

1. Less activity in the dorsal anterior cingulate. This area is part of the brain’s salience network, which helps decide what deserves attention. The study’s senior author, psychiatrist David Spiegel, described the effect this way: “In hypnosis, you’re so absorbed that you’re not worrying about anything else.”

2. Stronger connection between the dorsolateral prefrontal cortex and the insula. Spiegel described this as a brain-body connection that helps the brain process and control what is going on in the body.

3. Weaker connection between the dorsolateral prefrontal cortex and the default mode network. The default mode network includes the medial prefrontal and posterior cingulate cortex. Spiegel said this likely reflects a disconnect between someone’s actions and their awareness of those actions: when you are really engaged in something, he said, “you just do it.”

Read together, the three findings fit the experience Spiegel describes: absorbed attention, a brain more engaged with what the body is doing, and less self-conscious commentary.

Why does the comparison group matter?

Because it rules out the setting as the explanation. The low-hypnotizable volunteers lay in the same scanner and heard the same instructions, yet their brains did not show the three hallmarks. That design is what lets researchers tie the changes to hypnosis itself rather than to lying still and relaxing.

It also points to the practical question of why people differ so much. Spiegel’s team raised the possibility of one day stimulating specific brain areas to change how hypnotizable a person is, but the report is clear that more research would be needed before anything like that could be used as treatment.

What do other methods add?

The Stanford work is one study using one method. A 2024 review of the cognitive neuroscience of hypnosis brings together research using functional MRI, PET and EEG, and frames the findings around three large networks: the default mode network, the salience network and the executive control network.

The review links changes in executive control during hypnosis to an altered sense of agency, the feeling that a movement or experience is happening by itself rather than being done on purpose. It reads the connectivity findings as consistent with two theories, dissociated control and cold control, which explain hypnotic responses through changes in how the brain monitors its own intentions. Other studies in the review found that suggestions given during hypnosis can change activity in brain regions involved in the sensory and emotional sides of an experience.

What does the brain research not show?

It does not show that hypnosis treats any condition. A 2025 review of pediatric clinical hypnosis makes the point directly: mechanistic findings such as altered connectivity or neurotransmitter changes “do not automatically translate into consistent clinical benefit.” Whether hypnosis helps with irritable bowel syndrome or labor pain is a question for clinical trials, not for scans.

It also does not give you a personal test. These are findings from groups chosen at the extremes of hypnotizability; of the 545 people Stanford screened, 488 were not selected for scanning. Group results like these are not a bedside test of whether a particular person is hypnotized.

What it means if you are considering hypnosis

The imaging gives a reasonable answer to the question “is anything really happening?” In highly responsive people, yes: hypnosis leaves measurable traces in brain activity. How much that matters for you depends on two things the scans cannot settle, namely how responsive you are and what the clinical evidence says about your specific problem.

This article is general information, not medical or psychological advice; talk with a licensed clinician about your own situation.