There is growing amounts of research being done on how hypnosis affects the brain. For example, when patients were hypnotized to experience a paralyzed limb, experimenters found that…
“…brain areas normally associated with the intentional inhibition of movement are not active in people with hysterical paralysis nor hypnotized volunteers, suggesting that it really is the case that they cannot, rather than will not, move.”
Some individuals are more hypnotizable than others; research seems to suggest that those with a bigger anterior corpus callosum, which is a part of the brain thought to help focus attention, has show to associate with higher hypnotizability.
Neuropsychologist Peter Halligan at Cardiff University, UK, believes it may one day be possible to create “virtual patients” through hypnosis in order to help study some of the stranger neurological conditions seen in individuals. Some conditions researchers believe can be duplicated in healthy people through the power of hypnosis include:
- Hysterical blindness (the person cannot see but has no perceptible damage to their eyes or brain)
- Hysterical paralysis (an inability to move a part of the body despite having no physical injury – the same limb may move while the person is asleep)
- Prosopagnosia (an inability to recognise faces despite having good sight)
- Alien limb syndrome (the feeling that an arm or leg is acting of its own accord)
- Visual neglect (total lack of awareness of half of the visual field)
- Capgras syndrome (a delusional belief that a loved one has been replaced by an imposter).
NewScientist.com reports on Halligan:
“Oakley [another researcher who works with Halligan] and Halligan are convinced their virtual patients are experiencing some of the same brain changes as people with genuine disorders. Halligan tells how they once induced a case of visual neglect in a volunteer by suggesting that the left side of his visual field would cease to exist. They then asked him to copy a picture with a dozen objects scattered on the page. Most hypnotized people given this instruction would copy only the objects on the right hand side of the page, as most people with visual neglect do. But this volunteer drew the right-hand side of every object on the page. ‘That’s not something you would intuitively expect,’ says Halligan, ‘but it is also seen in real patients.'”
I personally have been studying hypnosis and practicing it on myself for the past five years. It was one of the first things to get me interested in the mind and what influenced me to pursue a degree in psychology. If you would like to read some of my writings on hypnosis I recommend: Hypnosis: The Nature Of Suggestion and Hypnosis Explained (Debunking The Myths). These articles mention some of the science on hypnosis but mostly focus on a pragmatic analysis.