Why some doctors are reassessing hypnosis

I find these results of imaging the brain during the process of hypnosis interesting:

Changes in brain activity begin with induction, says Mathieu Landry, a neuroscientist at the University of Quebec at Trois-Rivieres and the author of a widely cited review of brain-imaging research related to hypnosis. He points in particular to increased activity in hypnotised people in the central executive network (CEN), a collection of brain circuits known to be involved in regulating attention and focus. There also seems to be greater communication between parts of the CEN and the insula, which helps to monitor and interpret signals coming from the body.

The insula is part of the brain’s “salience network”, so named because it brings attention to important changes in the environment. It is involved in processing threats and making people feel scared or uneasy when appropriate—perceptions common with pain and phobias. Dr Spiegel thinks the increased communication between the CEN and the insula might suggest that hypnotherapy allows the CEN to exert more control over unpleasant emotions.

Elsewhere in the salience network, hypnosis affects activity in the anterior cingulate cortex,  a collar-shaped structure underneath the prefrontal cortex, which, among other things, helps direct a person’s attention, and which is crucial to the processing of pain, as well as of anticipation. There is some evidence that hypnosis also alters connections from the prefrontal cortex to a third brain area, the amygdala, which helps govern emotional responses. All these changes may relate to hypnosis’s ability to reduce anxiety and fear in the face of things—such as IBS, say—that cause pain.