This article looks at specific segments of the brain and the way in which hypnosis when applied affects the brain. The Dorsal Anterior Cingulate Cortex was identified as a key marker within the brain which altered within hypnosis.
Note the following extract:
"During hypnosis, the scientists found, a region of the brain called the dorsal anterior cingulate cortex became less active. Studies have found that that region helps people stay vigilant about their external environment. Spiegel noted that highly hypnotizable people are also more likely to lose themselves in a sunset or a movie. The activity in their dorsal anterior cingulate cortex may account for that behavior, too."
As a professional in the field of Clinical Hypnosis and Psychotherapy, I welcome studies such as this:
Douglas Clark Master of Hypnotherapy