What happens in the brain under hypnosis

Researchers identify neuronal changes in the trance state

Hypnosis causes concrete changes in our brain activity - where, researchers have now found out. © sb-borg / thinkstock
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Brain in a state of emergency: researchers have for the first time observed what happens in the brain in hypnosis. Her study shows that the trance state is revealed by three typical changes in brain activity. Knowing which regions in the brain are involved in successful hypnosis opens up new approaches to therapy. Above all, people who have been hypnotized so far could benefit from it.

Some people consider hypnosis to be lazy magic - wrongly, as medicine knows today. In fact, this method can be used to influence mental and physical processes that are otherwise difficult to control. Studies show that hypnosis helps patients with anxiety disorders, relieves chronic pain and can even improve sleep quality.

"Hypnosis is the oldest form of Western psychotherapy, " say scientists around Heidi Jiang at Northwestern University in Chicago. "It's an effective way to change the way we use our brains - and it's there to control our perception and our body." But although the method's medical potential is gaining more and more recognition, little is known about it. how it works on the physiological level. The research team has now closed this knowledge gap - and found out what happens in the brain under hypnosis.

Brain under observation

For their study, the researchers acquired 36 subjects who had proven to be particularly hypnotizable in aptitude tests, as well as 21 participants who were very difficult to put into a trance. "This control group is important. Because only then can we be sure that what we see is actually due to hypnosis, "the researchers explain.

Using functional magnetic resonance imaging (fMRI), the team observed the subjects' brain activity under four different conditions: while the subjects rested while remembering something and twice while being hypnotized. display

Changes in the trance state

In fact, Jiang and her colleagues were able to clearly identify certain brain regions that change in trance. For example, under hypnosis activity on the dorsal anterior cingulate gyrus decreases. This area belongs to the so-called salience network: It decides how strongly we react to certain stimuli and thus signals what is particularly relevant. "During hypnosis, you are so absorbed that you do not care about anything else, " explains co-author David Spiegel from Stanford University.

Second, the team observed an increased activity of the connection between part of the prefrontal cortex and the islet bark. According to the researchers, this helps the brain to process what happens in the body.

In this fMRI picture red areas indicate the areas active in Default Mode Network. Re Walter Reed's National Military Medical Center

The third change happens between the prefrontal cortex and the so-called default mode network, those regions that are active in idleness and are deactivated when solving tasks. The connection between these two areas becomes weaker in the hypnosis state.

The researchers believe that this indicates that their own actions and awareness are no longer linked. During hypnosis, this condition causes one to become unconsciously guided by others in one's actions. Interestingly, regular meditation also influences the links in the default mode network, as studies show.

Chance for hard-to-hypnotizable people?

In the future, these new findings could be of particular help to patients for whom hypnosis has not worked so far. "Now that we know which brain regions are involved in a trance state, we may be able to influence the effectiveness of hypnosis, " says Spiegel. The idea: a therapy that combines brain stimulation and hypnosis. "We are attracted by the approach to improve a person's hypnosis ability by specifically stimulating specific areas in their brains, " says Spiegel.

So far, according to the researchers, only about ten percent of the population are extremely hypnotizable, about half respond to medium to the method. The treatment devised by the team could potentially help people who had previously been difficult to treat with hypnosis, thus saving them, for example, strong pain medications. Before that becomes possible, but more research is needed, the team concludes. (Cerebral Cortex, 2016; doi: 10.1093 / cercor / bhw220)

(Stanford University Medical Center, 29.07.2016 - DAL)