Sunday, June 11, 2017

How scientists are trying to unlock the mysteries of hypnosis

Nevertheless, Patterson and research partner Jensen have made considerable strides by examining the neural underpinnings of a hypnotic trance. To study hypnosis, Jensen uses electroencephalography, or EEG, which measures electricity in the brain. Our individual neurons are constantly generating electrical pulses as they transmit information from the body to the brain and around the brain itself. Occasionally, large groups of neurons will coordinate these pulses into a sort of rhythmic pattern. Picture the brain as a giant football stadium, and the pulses are like the fans doing a wave. Using sensors attached to the skull, scientists can listen for broad electrical rhythms — called oscillations — caused by wide swaths of neurons working in concert.
Keep in mind, though, that the brain isn’t a single stadium, but rather 1.2 million interlocking stadiums at once. So the EEG may pick up many different interlocking elements, and to make matters more complicated, because the sensors are on the outside of your head, only the outer parts of the brain can be measured. That makes the stadium even harder to hear. “The Rolling Stones are in town, but you don’t have a ticket,” Patterson says. “So you are standing outside the stadium. It’s very loose. You don’t know what, exactly, you’re hearing, but you can tell if they are singing a ballad or a rock song.”
Amazingly, even with all these barriers, when scientists listen to multiple places in the brain, a neurological picture of hypnosis begins to emerge. During meditation, the “stadium chant” that many parts of your brain participate is measurably slower than in daily life; during hypnosis, the chant becomes even slower — about the only way to get the brain rhythms slower than those during hypnosis would be to fall into a coma.

In the human brain, alpha waves — electric waves that pulse 8 to 12 hertz, or 8 to 12 times per second — prevail when we are relaxed or closing our eyes. Theta — 4 to 8 hertz — commonly arise when we are drowsy or lost in thought, and delta waves — 0 to 4 hertz — happen when we are asleep or in a coma. Jensen’s work suggests that theta and alpha waves may be key to pain relief. When going about our daily activities, the brain generally uses the much faster beta and gamma waves (up to 100 pulses per second). This is especially true when we’re in pain, which usually goes hand in hand with anxiety and stress. Thus, if hypnosis can trigger slower brain waves, those waves may replace the faster patterns and thus replace the perception of pain.
The implications for helping the millions of people in chronic pain might be enormous. This idea led Jensen to a fascinating study. He looked at the brains of 20 patients before and after they experienced some relief from pain through both hypnosis and meditation. He found that people who naturally had high levels of theta waves — in other words, people with naturally relaxed, slower electrical activity — experienced a great deal of pain relief from hypnosis. Meanwhile, people with busy, overactive minds benefited the most from meditation, which slowed their buzzing brains down to a crawl.
“Meditation takes care of a problem that you have. Hypnosis builds on a skill,” Jensen says animatedly. “It’s capitalization or compensation. Are you capitalizing on a strength or are you compensating for a weakness? It looks like meditation is compensating for a weakness, and hypnosis capitalizes on a strength.” Imagine pain management as a skill, like running or weight lifting. According to Jensen, hypnosis is a little like taking an already strong sprinter to the gym and pushing her to a whole new level.

If Patterson and Jensen are right, their research could back up much of what scientists have suspected for many years: Hypnosis may be an exotic brain state that directly accesses expectation and perception — a little bit like turning off all the software in your computer and accessing its basic coding (although that is a huge simplification). And while a placebo says, “Take this amazing thing and it will make you feel better” and giving you a promise for the future, a hypnotic suggestion says, “Floating along this stream, you suddenly feel better,” which is a promise for right now. Which one is better? Which one taps into your expectation more effectively and permanently? That is a question that will take much more time and experimentation to unravel.


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