Scientists use high-tech brain stimulation to make people more hypnotizable

The depth to which a person can be hypnotized – known as hypnotizability – appears to be a stable trait that changes little throughout adulthood, much like personality and IQ. But now, for the first time, Stanford Medicine researchers have demonstrated a way to temporarily augment hypnotization, potentially allowing more people to access the benefits of hypnosis-based therapy.

In the new study, published January 4 in Natural mental healthResearchers found that less than two minutes of electrical stimulation targeting a specific area of ​​the brain could increase participants’ hypnotizability for about an hour.

“We know that hypnosis is an effective treatment for many different symptoms and disorders, especially pain,” said Afik Faerman, Ph.D., a postdoctoral researcher in psychiatry and lead author of the study. “But we also know that not everyone benefits from hypnosis equally.”

Focused attention

About two-thirds of adults are at least somewhat hypnotizable, and 15 percent are considered highly hypnotizable, meaning they score 9 or 10 on a standard 10-point measure of hypnotizability.

“Hypnosis is a state of highly focused attention, and higher hypnotizability improves your chances of being more successful with techniques using hypnosis,” said David Spiegel, MD, professor of psychiatry and behavioral sciences and author principal of the study.

Spiegel, the Jack, Lulu and Sam Willson Professor of Medicine, has spent decades studying hypnotherapy and using it to help patients control pain, reduce stress, quit smoking and much more. Several years ago, Spiegel led a team that used brain imaging to uncover the neurobiological basis of this practice.

They found that highly hypnotizable people had stronger functional connectivity between the left dorsolateral prefrontal cortex, which is involved in information processing and decision-making; and the dorsal anterior cingulate cortex, involved in stimulus detection.

“It made sense that people who naturally coordinate activities between these two regions could focus more,” Spiegel said. “That’s because you coordinate what you’re focusing on with the system that’s distracting you.”

Change a stable trait

With this knowledge, Spiegel teamed up with Nolan Williams, MD, associate professor of psychiatry and behavioral sciences, who pioneered non-invasive neurostimulation techniques to treat conditions such as depression, obsessive-compulsive disorder, and suicidal ideation .

The hope was that neurostimulation could modify even a stable trait like hypnotizability.

In the new study, researchers recruited 80 participants with fibromyalgia, a chronic pain condition that can be treated with hypnotherapy. They excluded those who were already highly hypnotizable.

Half of the participants received transcranial magnetic stimulation, in which paddles applied to the scalp deliver electrical impulses to the brain. Specifically, they received two 46-second applications that delivered 800 electrical pulses to a specific location in the left dorsolateral prefrontal cortex. The exact locations depended on the unique structure and activity of each person’s brain.

“A novel aspect of this trial is that we used the person’s own brain networks, based on brain imaging, to target the right location,” said Williams, also lead author of the study.

The other half of the participants received a sham treatment with the same look and feel, but without electrical stimulation.

Hypnotizability was assessed by clinicians immediately before and after treatments, without either patients or clinicians knowing who belonged to which group.

The researchers found that participants who received the neurostimulation had a statistically significant increase in their hypnotizability, scoring about one point higher. The sham group suffered no effects.

When participants were reassessed an hour later, the effect had worn off and there was no longer a statistically significant difference between the two groups.

“We were pleasantly surprised that with 92 seconds of stimulation we could change a stable trait of the brain that people had been trying to change for 100 years,” Williams said. “We finally cracked the code on how to do this.”

The researchers plan to test whether different dosages of neurostimulation could improve hypnotizability even further.

“It’s unusual that you can change hypnotizability,” Spiegel said. A study of Stanford University students, begun in the 1950s, for example, found that this trait remained relatively constant when students were tested 25 years later, as constant as IQ over that period. . Recent research from Spiegel’s lab also suggests that hypnotizability may have a genetic basis.

Bigger Implications

Clinically, a transient increase in hypnotizability might be enough to allow more people with chronic pain to choose hypnosis as an alternative to long-term opioid use. Spiegel will follow up with study participants to see how they perform in hypnotherapy.

The new findings could have implications beyond hypnosis. Faerman noted that neurostimulation could temporarily alter other stable traits or improve people’s response to other forms of psychotherapy.

“As a clinical psychologist, my personal vision is that in the future, patients will come in, they will participate in a quick, non-invasive brain stimulation session, and then they will go see their psychologist,” he said. “Their benefit from treatment could be much higher.”