I've been practicing self-hypnosis since I was a kid, and as an adult, hypnosis helped me overcome a five-year bout of writers' block, get rid of lifelong chronic back-pain, and painlessly kick an 18-year-old smoking habit. For all that, I know precious little of how hypnosis works — it just works (for me, at least).
Now the New Scientist reports that functional MRI scans of the brains of regular practitioners of hypnosis reveals physiological differences from those who are not susceptible to hypnosis.
But under hypnosis, Gruzelier found that the highly susceptible subjects showed significantly more brain activity in the anterior cingulate gyrus than the weakly susceptible subjects. This area of the brain has been shown to respond to errors and evaluate emotional outcomes.
The highly susceptible group also showed much greater brain activity on the left side of the prefrontal cortex than the weakly susceptible group. This is an area involved with higher level cognitive processing and behaviour.
