The Mesmerized Mind


Scientists are unveiling how the brain works when hypnotized


Susan Gaidos

October 10th, 2009; Vol.176 #8

(p. 26)

THE MESMERIZED MINDIllustration by Lou Beach

Mention hypnosis, and the image that springs to mind is a caped magician swinging a pocket watch, seducing otherwise sensible people into barking like dogs.

But hypnosis is more than a stage show act. For years, psychologists have used it to help patients calm preflight jitters, get a good night’s sleep or chuck a cigarette habit. Hypnosis even has uses in mainstream medicine for reducing the side effects of cancer treatments and helping patients cope with pain. Some physicians routinely employ hypnosis as an adjunct to mainstream anesthesia to help block pain during surgery or childbirth.

Most recently, hypnosis has advanced from stage and clinic into the laboratory. It is now used as a research tool to temporarily create hallucinations, compulsions, delusions and certain types of seizures in the lab so that these phenomena can be investigated in detail.

Such studies may lead to more effective treatments for a number of psychiatric and neurological disorders, assert psychologists Peter W. Halligan and David Oakley in the June issue of Trends in Cognitive Sciences.

Other scientists, intrigued by the many practical uses of hypnosis, are striving to figure out how it works. Using the latest neuroimaging tools, these scientists are getting a look at what goes on in the hypnotized brain. The findings are mesmerizing.

When hypnotized people act on a hypnotic suggestion, they really do see, hear and feel differently, such research shows. When they’re told to see colors, for example, the color-processing parts of their brains light up—despite the absence of any real color in view. When they are told to envision color objects in black and white, these color-processing areas are less active. Other imaging studies show that hypnotically induced pain activates the same brain areas as “real” pain.

Still, questions remain, says Halligan, of Cardiff University in Wales, who has studied hypnosis for more than a decade. Scientists have yet to discover how hypnosis produces physiological changes. And some scientists question whether such changes are confined to hypnosis. Perhaps the patterns of brain activity seen during hypnosis can occur during everyday experiences when people are fully absorbed in an activity, some researchers say.

The real question, says Halligan, is whether hypnosis is a specific brain state that differs from any other.

“In other words, is there some sort of neural correlate, or biological marker, within the brain during a hypnotic trance?” he asks.


The answer so far, emerging from studies done during the past few years, is maybe. New research at the University of Geneva suggests that hypnosis alters neural activity by rerouting some of the usual connections between brain regions. Such neurological detours don’t happen when subjects merely imagine a scenario.

Changing your mind

Hypnosis got its start as a “miracle cure” in 1774 when physician Franz Mesmer found a way, using ethereal music played on a glass harmonica, to induce a hypnotic trance in patients suffering from various unexplained medical problems. Though eventually discredited as a healer, Mesmer demonstrated that the mind could be manipulated by suggestion to produce an effect in the body. So powerful is this effect that the practice was resurrected in the 19th century, before the discovery of ether, to block pain during major surgeries.

In this mysterious state of mind, the brain is “quiet,” focused and superattentive. People sometimes report feeling disconnected from their surroundings and lost in thought. During hypnosis, subjects are more open than usual to suggestions and have the ability to focus intensely on a specific thought, feeling or sensation.

Most adults, about two-thirds, are hypnotizable to some degree, though some people experience the effects of hypnosis more intensely than others do, says David Spiegel, a psychiatrist at Stanford University School of Medicine who uses hypnosis in his medical practice. Ten to 15 percent of adults are “highly hypnotizable,” he says, meaning they can experience dramatic changes in perception with hypnosis.

A person’s ability to become hypnotized is unrelated to intelligence, compliancy or gullibility, but may be linked to an ability to become deeply absorbed in activities such as reading, listening to music or daydreaming. People who find themselves engrossed in a best seller even while the television is blaring, or swept away by a movie and losing track of time, are likely to be quite hypnotizable.

During hypnosis, the hypnotherapist tries to direct thoughts, feelings and behavior by instructing a person to concentrate on particular images or ideas. A typical session starts with some sort of induction procedure that helps the subject relax—say, counting down from 20 to one or mentally descending a set of stairs.

To produce a specific behavior or thought, the hypnotherapist will make suggestions targeted toward the goal. To reduce the pain of a medical procedure, for example, a hypnotherapist might invoke an image of pain being turned down like the volume on a radio.


YOUR BRAIN ON HYPNOSISView larger version | Studies show hypnosis reroutes brain signals. Hypnotized people who are told that their left hand is paralyzed show brain patterns (yellow) that differ from those who aren't hypnotized (red) and from those who aren't hypnotized but are told to pretend their left hand is paralyzed (green).Y. Cojan Et al./Neuron 2009

Over the years, rigorously controlled studies have shown that hypnosis can also control blood pressure and even make warts go away. But because very few studies have attempted to find out how it works, some scientists are still skeptical of its power.

Critics suggest hypnosis is nothing more than playacting, with subjects trying to please the hypnotist. That skepticism has driven some researchers to take a hard look at what happens in the brain during hypnosis. Over the past few years, scientists have begun gathering evidence that hypnosis can indeed measurably change how the brain works.

In 2005, scientists at Weill Medical College of Cornell University in New York City used functional MRI to show how hypnotic suggestions can override “automatic” processes in the brain. When shown the names of colors printed in different colors of ink—for example, the word red printed in blue—subjects were instructed to name the ink color while ignoring the word.

Though this task may sound easy, it’s often difficult for people who can read because the tendency is to automatically read the word instead of naming the color. When told under hypnosis that the words would appear as gibberish, highly hypnotizable subjects were able to perform the task faster, and with fewer errors, than subjects who were less hypnotizable and therefore less likely to respond to suggestion.

The fMRI results were also striking. Highly hypnotizable participants showed less activity in a brain area called the anterior cingulate cortex, which is active when people are trying to sort out conflicting information from different sources, such as contradictory word names and colors. The study was published in theProceedings of the National Academy of Sciences.

Going deeper

Scientists agree that there is a pattern or “orchestra” of brain activity during hypnosis. Halligan and his colleagues are working to figure out what this particular pattern might be, and which—if any—brain region serves as conductor. As part of a collaboration with psychiatrist Quinton Deeley of King’s College London, the researchers are looking at how patterns of brain activity in the induction phase—the countdown—prepare the brain for suggestions.

Preliminary findings suggest that hypnosis boosts activity in the brain’s prefrontal cortex—a region responsible for various executive functions such as decision making and regulating attention—while suppressing activity in other brain regions.


THE EYE-ROLL TESTSome researchers and hypnotists use a simple eye-roll test to get an idea of how hypnotizable people are. If more white, or sclera, shows when a person looks up (bottom), he or she is more likely to be susceptible to hypnosis.T. Dube, adapted from Powerlines/Istockphoto

Still, researchers are stumped to explain how these changes in brain patterns work to make hypnotized people feel and see things differently. Recent theories, discussed in the article in Trends by Halligan and Oakley, of University College London, propose that hypnotic suggestions may inhibit or disconnect certain mental processes from the brain’s executive control systems.

Until recently, such hypotheses had remained untested. But in the June 25 issue of Neuron, Yann Cojan of the University of Geneva and colleagues report a direct test.

The researchers put 18 subjects in a brain scanner, instructing them to push a button using one hand or the other. Each trial began with a cue indicating which hand to prepare for movement. After a brief interval, an image of a hand would turn green—signaling to press the button—or red, a command to inhibit any motion. Twelve subjects did half of the trials while hypnotized, with the suggestion that their left hand was “paralyzed,” and the other half in a normal, unhypnotized state. Six subjects did trials without hypnosis under instructions to pretend their left hand was paralyzed.

When volunteers used their right hands, the motor cortex linked up with brain regions that control body movement to carry out the task.

But fMRI scans showed changes in several brain areas when hypnotic paralysis prevented subjects from responding to the “go” signal with their left hands. Under hypnosis, neurons in the brain’s motor cortex fired up as usual to prepare for the task. But when instructed to use the left, or “paralyzed” hand, the motor cortex failed to send signals to motor execution regions. Instead, it directed its signals to another brain region, the precuneus.

The precuneus is a sort of center for self-consciousness. If you’ve ever pictured yourself falling flat on your face in the middle of an important event, that’s your precuneus working overtime. Its function is to help retrieve memories and images of yourself from the brain’s archives and help to visualize movements.

By rerouting motor signals to the precuneus, hypnosis appeared to decouple the typical relationship between brain areas that generate the signals for hand movement and the areas that carry out such movements. Subjects who were not hypnotized and were asked to fake paralysis showed no such disconnect between these regions.

Because the precuneus is involved in mental imagery and self-awareness, Cojan says, hypnosis appeared to enhance the brain’s self-monitoring processes to allow images generated by suggestion—“your hand is heavy and cannot move”—to guide behavior.

By linking to the precuneus, “the motor cortex is connected to the idea that it cannot move the left hand,” Cojan says. “So even if you try to move, it will neglect to send signals to the motor execution areas.”

Because the motor cortex fired up as usual to prepare for the task, the findings suggest that mental images created through hypnotic suggestions work by redirecting normal brain functions rather than actively suppressing them, he adds.

Generating piece of mind

Using insights gleaned from the brain scans of subjects paralyzed under hypnosis, Cojan conducted a follow-up study to see whether something like hypnosis happens in the brains of patients during hysterical paralysis. In such instances, patients become paralyzed even though the condition can’t be traced to any physical or neurological brain damage.

An fMRI study of patients with hysterical hand paralysis did not find the heightened precuneus activity that is seen in hypnosis, Cojan’s group reported in the September NeuroImage.

Previously, it had been suggested that hysterical paralysis was “a kind of self-hypnosis,” Cojan says. “Our findings show that’s not the case.”

Halligan points to the recent paralysis studies as examples of how hypnosis can be used to further studies on the nature of hypnosis and to provide insights on a variety of real-life syndromes and disorders.

In 2000, he and Oakley began looking at ways to use hypnosis to simulate psychosomatic conditions, such as hysterical paralysis or hysterical blindness, in the lab. By creating virtual patients through hypnosis, scientists might be able to better understand the basis for such disorders by comparing patients’ brains with hypnotized brains, the researchers reckoned.

Deeley, who treats psychiatric patients at his private practice in London, says using hypnosis also allows him to track brain processes involved in other kinds of disorders that would not ordinarily be possible to study with brain imaging.

In an ongoing series of experiments, he and his colleagues are using hypnosis to study conditions in which patients sense a “lack of control” over their movements or behavior. Such perceptual experiences may be reported by people who experience nonepileptic seizures or who suffer delusions caused by schizophrenia.

By making some targeted suggestions—“Your left hand is now shaking at your side” or “Your right leg is twitching”—the scientists can model a particular symptom in a consistent and controlled way, Deeley says.

“You can’t have somebody having a full-blown seizure within an MRI scanner,” he says. “It’s not safe because they’re moving fast, and you wouldn’t get any useful information. But if you actually restrict an involuntary movement to a particular limb or a hand, it is possible to create a partial model of these involuntary movements.”

Another advantage of hypnosis is that it allows researchers to untangle the many components that make up a complex disorder, such as schizophrenia. In such cases, patients may feel not only that they’re losing control, but also that their actions or behavior are guided by an outside force or agent, such as the CIA.

Scientists then have the problem of sorting out whether a change in brain activity is associated with the physical experience of a movement or whether it is tied to the delusional beliefs behind the movement.

“In such cases, you’ve got two processes going on associated with complex change in brain activity, and you just can’t unpack them in terms of working out what’s associated with what,” Deeley says.

Experimental manipulations using hypnosis could provide a window into a wide range of disorders, he says, and could help explain other types of altered states, such as meditation.

Halligan agrees, noting that hypnosis could be used to simulate various disorders commonly associated with brain injury, such as visual impairment. In a recent study, he used hypnotic suggestions to replicate conditions described by injured soldiers who are still capable of detecting motion in certain visual fields but are unable to make out any distinguishing features of the moving object.

“That’s not to say that the same psychological consequences of pathology seen in patients are somehow replicated in hypnosis,” Halligan says. “But using hypnosis to simulate a specific condition for imaging may tell us which brain systems are involved.” This information may then feed back into the development of new treatments and rehabilitation tools, he says.

Such advancements, however, hinge on learning more about the underlying processes involved in hypnosis itself. Current efforts may help scientists differentiate between the brain structures that play a role in hypnosis and those that are involved in the tasks subjects are asked to perform.

“These are still early days,” Halligan says, noting that it has yet to be seen how well hypnotically simulated disorders will actually match the conditions they’re intended to mimic. Still, he says, hypnosis provides a  way to “test and probe.”

Best of all, no pocket watches are involved.

Susan Gaidos is a freelance science writer based in Maine.

  • This is absolute crap. Laboratory research in hypnosis has been going on since the 1940s, at least, and the finding is that there is no "trance," nothing unique about hypnotic responding. "Hypnosis" is the name of a script that the subject knows, he or she is supposed to act as though the "hypnotist" has taken over their mind. Nothing happens in hypnosis that can't happen in a a normal waking state. This kind of fake-science has no place on this web site, I count on you to weed this junk out.

    1. Medium Buddy

    2. Sep. 26, 2009 at 2:31pm

    3. I think the research discussed here is PROVING that there IS something "unique" about hypnotic responding. Did you read the article, or is your comment a knee-jerk reaction to the word "hypnosis"?

    4. ButMadNNW

    5. Sep. 27, 2009 at 2:04pm

    6. MB; People with excessively strong opinions like yourself are known to be easily and deeply hypnotizable. You are feeling veerrry sleepy, and even stupider ...

    7. Brian Hall

    8. Sep. 27, 2009 at 7:33pm

    9. No, hypnosis is not a fake. My husband studied for some time with Kreskin, and learned self-hypnosis. Then one day we went to sit in the audience of one of Kreskin's shows. The place was quite hot, so Kreskin casually mentioned that we would all feel cooler in one minute. We did feel cooler, it seemed, but my husband, who was very susceptible to that particular hypnotist (but very far back in a very big audience) got cold, goosebumps, and the shivers. I had to take him out of the auditorium to get him warm. And he also had all his teeth crowned (10 or 12 of them) without anesthesia, through self hpnosis. If Medium Bud were right, that would be impossible. I am afraid to lose control and be hypnotized, but I stopped perspiring when Kreskin said I should.Kreskin was very famous for what he did, back in the 50's to 70's. I don't know what happened to him after that.I think the technologies being used are extremely interesting, and the results of the scans are tangible evidence of brain activities. Linda J

    10. Linda Johnson

    11. Sep. 27, 2009 at 9:59pm

    12. This article says Critics suggest hypnosis is nothing more than playacting, with subjects trying to please the hypnotist. But "critics" don't say this, this is the mainstream social-psychological view of hypnotic responding, first advanced by Ted Sarbin in the 1950s and elaborated with a very strong research program by the late Nick Spanos, Bill Coe, and others. Spanos' "simulating subject" paradigm demonstrated that there is no difference of any sort between a person who is hypnotized and a person who is faking it. Any amazing feat that can be performed by a hypnotized person is done exactly the same way by a person who is instructed to pretend they are hypnotized. Scientists agree that there is a pattern or “orchestra” of brain activity during hypnosis. --Compared to what? Compared to having unsusceptible subjects fake being hypnotized? I seriously doubt it. Six subjects did trials without hypnosis under instructions to pretend their left hand was paralyzed -- that is not the equivalent condition. The six subjects should have been told to pretend they were hypnotized and should have received the hypnosis induction, after screening to ensure they were not susceptible.The studies described here make a naive assumption about mind and brain, as if brain imagining is more real or accurate than observing behavior. Showing that some area of the brain is active does not say that the individual is "really" in a weird trance, it is entirely likely, and an equally persuasive perspective, that they are enacting a cognitive strategy that happens to activate those neurons.There has been rigorous research into hypnosis for many decades, and a lot of progress has been made. To ignore all that and pretend that the mechanics of brain functioning somehow "explain" things better than a psychological model is regressive and unproductive. You want to believe there is a magical trance state that makes people do things they can't ordinarily do, fine, go ahead and be gullible. The scientific research does not support that viewpoint, and this normally-reliable web site should not, either.

    13. Medium Buddy

    14. Sep. 27, 2009 at 10:25pm

    15. Medium Buddy said, "You want to believe there is a magical trance state that makes people do things they can't ordinarily do, fine, go ahead and be gullible." Firstly, you're the only person who's used the word "magical"; for every study you can point to trying to debunk hypnosis, there's another that supports it. There is now a lot of science supporting the efficacy of hypnosis. And who says trance has to be something "mystical, mysterious, unusual"? The school of thought I and others I know subscribe to says that trance is part of the natural continuum of human consciousness, something we all experience multiple times a day.Secondly, where did anyone in the article or in the comments say that hypnosis makes people do things they can't ordinarily do? It's long been known and proven that hypnosis CAN'T make anyone do anything they can't or wouldn't ordinarily do.I take it, MB, that you haven't heard about any of the recent studies showing that hypnosis is related to the REM stage of sleep (the same eye movement is often seen in hypnotized subjects). For instance, the article talks about paralysis/catalepsy in hypnosis; this same physical phenomenon is experienced when we dream during REM, presumably because it could be quite dangerous to physically act out our dreams.Really, I'm not going to waste my time trying to convince you of anything in a comment chain on a website; you're obviously dead set against believing in the efficacy of hypnosis. Me, I don't "believe" in hypnosis - I *know* that it works. I've experienced the changes it's helped me make in my life, from decreased stress and skill improvement to overcoming a self-harm issue and weight loss. I've seen a friend recover from a lifelong phobia, and my mother decrease her need for pain medication. So many people I know have experienced positive changes in their lives thanks to hypnosis. If that makes us all "gullible," well, at least we're enjoying healthier, less stressed lives in our gullibility. ;-)Hypnosis is one of the most powerful tools we humans have at our disposal to create real change in our lives and behaviors. Deny yourself that if you wish. Be well.

    16. ButMadNNW

    17. Sep. 29, 2009 at 12:46am

    18. Hypnosis is nothing more than a context where one person says he is going to "hypnotize" another and the other believes it will happen. It doesn't work if the second person doesn't know what "hypnosis" is, if they don't know what is expected of them in the role of hypnotized person. You might enjoy thinking that hypnosis "works," that it somehow helps you overcome pain or whatever, but there is nothing in the room but you and the hypnotist -- real, imagined, or implied. No person is changing your brain state, all that happens is that you behave in the way you think a hypnotized person is supposed to behave. You might use a distraction strategy to minimize your awareness of pain, well you could do that without any hypnotic induction, anybody can do that. Anybody can lose weight, anybody can relax, you don't need to claim "hypnosis did it." If you like to think that hypnosis is some special brain-state that gives you unusual powers then go for it, man. Your statement about not believing, but knowing, shows that this is a religious topic for you, and I'm not going to convince you of anything here. Remember Wittgenstein saying, “If there were a verb meaning "to believe falsely," it would not have any significant first person, present indicative.” You must "know" because you can't believe and risk being wrong. But this is a science blog, I understand the articles are popularized for a nonacademic audience but the site editors have some responsibility to present real science, not silly woo asserting that brainwaves prove hypnosis is real and promising to unlock the mysteries of the brain.Social influence is a profound phenomenon. The self is socially constructed and very complex. It should not be a surprise that someone can do surprising things when influenced by a person who has been described to them as having special powers. You don't need a special construct called "hypnosis" to make it interesting, it is already interesting.I keep Science News in my RSS aggregator and often encounter interesting reports here. Occasionally there are lapses. This was one.

    19. Medium Buddy

    20. Sep. 29, 2009 at 9:05am

    21. MB, you're the one who keeps mentioning "special powers." I've said nothing of the sort. We both know neither of us is going to convince the other. I'm not even trying to convince you.Be well.

    22. ButMadNNW

    23. Sep. 30, 2009 at 11:42pm

    24. I am a trained, certified hypnotist and have been presenting and practicing in this field for about 18 years. It not only works, but is profoundly simple to use. I also have a degree in psychology and have been studying cognitive neuroscience as part of my reserarch for the last ten years. There are special techniques to use with people like medium buddy who have doubts. When you turn their logic inward and create a paradox, they collapse and go into trance. I've had university psychology professors leave my presentations and return to apologize as they were on intellectual overload, seeing events demonstrated that were outside their knowlege belief system. They just could not handle that they had been wrong in what they taught for many years. Thomas Kuhns was correct in his paradigm shift theories...!!I've worked with several people who were very intellectual, (some were MDs)and had one or more of their children killed in an accident. The event caused such a loop in their logic that they were in total denial of the reality of the event 10-15 years later, even though they were still able to be fully functional in their work environment. I found similar patterns in studying people with delusional thinking. Hypnosis is an excellent tool to remove the splintering event and heal the wound.The big problem is the model promoted for the brain is totally wrong. Rather than functioning as a computer with memories being stored somewhere in the synapses like a computer hard drive, the brain functions a a radio transmitter and receiver, interacting with fields surrounding the body. This is easy to demonstrate and prove, even in a scientific setting. Karl Pribram at Stanford was correct in his theory of holographic memory storage.Brain scans are like photographing a speaker to see what music is playing. They are very limited in their use to understand psychological processing.If you want to read some excellent research on hypnosis, read about its use with animals. Pavlov used hypnosis in working with dogs during his research in classical condiitioning.

    25. Psi Guy

    26. Oct. 1, 2009 at 9:33am

    27. Buddy said....."This is absolute crap. Laboratory research in hypnosis has been going on since the 1940s, at least, and the finding is that there is no "trance," nothing unique about hypnotic responding. "Hypnosis" is the name of a script that the subject knows, he or she is supposed to act as though the "hypnotist" has taken over their mind. Nothing happens in hypnosis that can't happen in a a normal waking state. This kind of fake-science has no place on this web site, I count on you to weed this junk out." The "shock" one experiences after an auto accident or a soldier sometimes experiences in battle situations is also a form of hypnosis. There are many, many induction techniques, some work better with specific personality traits in the subject. A simple technique which works quite well is to have two people talking to a subject at the same time. This causes logical confusion and induces trance.One thing you are correct on buddy is that hypnosis is a horizontal surrendering of a person's personal control or authority to another person. People like yourself who claim to not be hypnotizable are also usually closed to intimacy in relationships as they are afraid to be vulnerable, a precurser to experiencing the feeling of "Love." When they do enter a relationship, it is usually a control one where they can feel safe and keep their partner in an emotional consciousness state. Opposites do attract!

    28. Psi Guy

    29. Oct. 1, 2009 at 10:02am

    30. Buddy can rail all he or she wants, but hypnosis does work. I teach HypnoBirthing and 70% of the women who take our course are able to birth without anesthesia or analgesia, and most report being pretty comfortable and enjoying the experience.

    31. Kathleen Dolce

    32. Oct. 9, 2009 at 6:47pm

    33. This is an incredible article that has left me pondering about faith. We have all heard about if you have faith, it will happen, you will heal, you will succeed, you will not be afraid. We are constantly filled with self doubt which challenges our faith. Hypnosis seems to relieve you of that self doubt and enables your true ability to be who you want to be. The possiblilities are staggering.

    34. Swany

    35. Nov. 4, 2009 at 3:16pm