Studies on Hypnosis

Hypnosis is a state of heightened suggestibility, in which certain individuals can experience imagined situations that seem real. There is great interest in hypnosis several therapists use to treat mental illnesses with it. Some Psychology PhD programmes tend to offer courses in hypnosis. Scientists who explore whether hypnosis is a unique state of altered consciousness tend to put the claims about it through several tests.

Hypnotic Behaviour

Hypnotic Induction is the process by which a person (a researcher or a hypnotist) leads another, the subject, into a state of hypnosis. A hypnotist may request the subject to sit down and gaze at an object on the wall, or something like a pendant in his hand. He then may suggest that the subject's eyes are getting heavy. The goal of this test is to relax the subject while increasing their concentration.

Contrary to popular belief, a person can't be hypnotised against their will. Even when people want to be hypnotized, they differ in susceptibility to hypnotic suggestions. Hypnotic susceptibility scales contain a standard series of pass/fail suggestions being read to a subject after hypnotic induction. The subject's score is based on the number of passes. Some subjects tend to be completely non-responsive; some pass all while the rest fall in between.

Does hypnosis alter one's behaviour and psychological function? Some claim it does.

Involuntary Control

Hypnotised individuals subjectively experience their actions as involuntary ones; they believe they're controlled by a mysterious force rather than their conscious control.

If behaviour seems to be involuntary under hypnosis, can it be used to perform harmful acts? According to Martin Orne and Fredrick Evans, hypnotised subjects were able to be made to dip their hands briefly in a solution of foaming liquid, which as made to believe was acid, and throw on another person's face.

This might be an example of the power of hypnosis in getting people to act against their will. However, in another controlled group that Orne and Fredrick tested on, the subjects were asked to simply pretend to be hypnotised. These subjects were just as likely as the earlier group to dip their hands in the solution and throw it at another.

In another experiment, researchers induced hundreds of adults to keep giving what they believed to be hundreds of  painful electric shocks to an innocent man with a heart condition, while he begged them to stop. None of the subjects were hypnotised; they were simply following the researchers' orders. This shows that contrary to popular beliefs, hypnosis does not involve a unique power to get people to behave against their will. A legitimate authority figure can induce people to commit out of character, dangerous acts with or without being hypnotised.

Amazing Feats

Have you seen or heard of stage hypnotists who gets an audience member to perform an amazing physical feat such as the 'human plank'? The subject, usually a male, is hypnotised and lies  outstretched between two chairs. He is told that his body is rigid and then, amazingly, another person stands on his legs and chest.

Similarly, psychology can have striking effects. Consider the classic experiment which involved 13 people allergic to the toxic leaves of a certain tree. Five of the test subjects were hypnotised while being blindfolded and were told that a leaf from a harmless tree they weren't allergic to was touching one of their arms, when, in fact, it was toxic. But four of five hypnotised subjects had no allergic reaction. For the next  step, the other arm of the hypnotised subjects were rubbed with a leaf from a harmless tree and he or she was falsely informed of the leaf being toxic. All five of them reacted to the harmless leaf with an allergic reaction.

Should the human plank, as well as the unusual responses of the allergic subjects, be attributed to the unique powers of hypnosis? Here is why a healthy dose of critical thinking may be of importance.

Pain Tolerance

Scottish surgeon James Esdaile performed more than 300 major operations in the mid-1800s using  hypnosis as the sole anaesthetic. According to experiments, an increase in pain tolerance, which wasn't due to the Placebo Effect, was confirmed.

For patients who experience chronic pain, hypnosis can produce relief lasting for months, or even years. Brain imaging research has revealed that hypnosis modifies a person's neural activity in areas that process painful stimuli, but non-hypnotic techniques such as mental imagery and performing distracting cognitive tasks also alter neural functioning and reduce pain.

We do not know exactly how hypnosis produces painkilling effects. It may influence the release of endorphins, decrease a patient's fear of pain, distract patients of their pain, or somehow help them in separating the pain from the conscious experience.