US scientists have been able to peer inside the brain to watch hypnosis in action. The research could settle a 200-year-old debate about whether hypnosis is a genuine psychological state or stage show gimmickry.
A high proportion of adults can be hypnotised, although there has always been an argument about the nature of the experience. David Spiegel, a psychiatrist at Stanford University, used positron emission tomography (PET) scans to watch changes in brain function in volunteers who were highly hypnotisable.
They were told to perceive colour, whether or not they were being shown colour. The areas of the brain used to register colour then fired up. Activity in the same area declined when the patients were told to see "grey" objects, even if they were being shown a coloured grid.
"When they believed they were looking at colour, the part of their brain that processes colour vision showed increased blood flow," he told the American Association for the Advancement of Science yesterday. "This is scientific evidence that something happens in the brain, that doesn't happen ordinarily, when people are hypnotised," Professor Spiegel said.
The study once again raises questions about a role for hypnosis in pain relief. "There are tremendous medical implications," he said. He and colleagues monitored brainwave patterns while applying electrical shocks to the wrists of volunteers.
Children could easily be hypnotised: the capacity often disappeared with maturity. Hypnosis had proved helpful in painful treatment that required catheters in the bladders of children who could not be given anaesthetics. The children were asked to focus on a visit to Disneyland. The treatment was less distressing, and over 20 minutes sooner.
"Hypnosis is a state of aroused attentive focal concentration with a relative suspension of peripheral awareness. It is a mental state that is something like looking through the telephoto lens of your camera, which you see with great detail, but you are less aware of the context," he said. "You can shift into the hypnotic state in a matter of seconds. It is not sleep, it is a form of highly focused attention," Prof Spiegel said.
He argued that every doctor should be taught simple techniques of hypnosis. It did not take control from the patient; instead it helped enhance self-control. "So you can teach people to manage their anxiety, how to manage their pain, and they are grateful for it."
