The neuroscience of suggestion and hypnosis are helping us to understand mysterious disorders where people are blind or paralysed with no apparent medical explanation, and may be useful in investigating altered states from diverse cultures – according to an engaging discussion in the monthly JNNP podcast.
The JNNP is the slightly catchier name for The Journal of Neurology, Neurosurgery, and Psychiatry and let me ‘fess up and say the interview is with a colleague of mine, psychiatrist Quinton Deeley, who discusses our recent article on how cognitive neuroscience is providing tantalising evidence for an old theory on how hypnosis and hysteria might be linked.
Neurologist Jean-Martin Charcot believed that there may be a connection because he could simulate almost any aspect of hysteria through suggestion in susceptible individuals. Hysteria is now typically diagnosed as conversion disorder and its a condition where people appear to have neurological problems despite their nervous system seeming to be in perfect working order.
It turns out that the idea of hypnosis is a bit of a smokescreen because it depends much more on the person listening to the suggestions, than the person making the suggestions.
We now know that we all have a certain capacity to allow other people to suggest changes to our mental state. This differs between people and the ability is normally distributed, like many psychological traits, and we know its partly genetic and there’s evidence its linked to differences in brain structure.
Contrary to the popular myth, if you are experiences the effects of suggestion, your mind isn’t ‘under control’ and it’s much like watching a film. You can choose to turn away at any point but you don’t decide to be scared or amused by the movie – it just happens. Highly suggestible people can allow suggestions of paralysis, amnesia or even hallucinations.
I wrote more about the neuroscience of suggestion in an article for The Guardian but as happens with almost any piece about this area, it got given a daft headline and a ridiculous picture of someone swinging a watch. However, it remains a good place to start if you want an introduction to the science, rather than the myths.
Our recent research looked at neuroscience studies on both ‘hysteria’ and hypnosis and found there is intriguing evidence that both may involve the frontal cortex inhibiting other brain functions. For example, in cases of both ‘hysterical paralysis’ and suggested paralysis you can often see the motor areas of the brain being deactivated as the frontal cortex ramps up its activity when the person tries to move.
Quinton has a long-standing interest in anthropology and another line of this work is to look at whether this has links with ritual trance states or altered states of consciousness that happen in cultures across the world where people feel that they are making involuntary movements or feel they are not in control of their actions – even when drugs are not being used.
The discussion on the podcast touches on all these areas, and you can download the whole thing with the other half on multiple sclerosis and Vitamin D, or grab the mp3 with just the bit on suggestion, hysteria and altered states.
Link to March JNNP podcast page.
mp3 of just the suggestion, hysteria and altered states discussion.
Link to full scientific paper.
Link to Guardian article on the neuroscience of suggestion and hypnosis.