A team of researchers from the Stanford University School of Medicine has identified key areas of the human brain that, under stimulation, could make a person more susceptible to hypnosis. Clinical Hypnosis represents a valuable tool to physicians, and is gaining respectability as an alternative treatment option for dealing with chronic pain, addiction, and anxiety or trauma.
"Hypnosis is the oldest Western form of psychotherapy, but it's been tarred with the brush of dangling watches and purple capes," states David Spiegel MD, professor and associate chair of psychiatry and behavioral sciences at Stanford University. "In fact, it's a very powerful means of changing the way we use our minds to control perception and our bodies."
Previous studies that involved scanning the brain of an individual under the influence of hypnosis have focused on the altered state's control over, for example, a patient's ability to feel pain, or how it affects their vision, and overall perception. The new study aimed to identify the regions of the brain that behave and communicate differently as a result of the hypnotic state itself, rather than its effect on other brain functions.
In order to detect the hallmarks of hypnosis, the team used functional magnetic resonance imaging, which essentially works by tracking the flow of blood to analyze localized brain activity. The researchers observed the brain activity of 57 patients as they were subjected to the altered state. The group was composed of 36 individuals who, out of an original pool of 545 participants, scored very highly on tests designed to determine a person's hypnotizability (yes it is a word, we checked), and a further 21 who scored on the low end of the spectrum.
By including individuals who are by and large unaffected by hypnosis, the researchers were better able to identify the brain functions synonymous with the altered state in patients who are considered to be highly susceptible. To help isolate a pattern, the subjects were scanned while in a state of rest, when asked to recall a memory, and over the course of two separate hypnosis sessions.
Three distinct patterns were isolated in the brains of individuals susceptible to hypnosis while being subjected to the treatment. First, the team noted a reduction in activity in the dorsal anterior cingulate, which forms part of the brain's salience network.
Elsewhere, there was an increase in connections between the dorsolateral prefrontal cortex and the insula – two parts of the brain that help us to understand what is happening inside our bodies. The third alteration in brain activity took the form of a reduction in connections between the dorsolateral prefrontal cortex and the default mode network. The researchers suggest that the lack of connection lead to a disassociation between a person's actions and their awareness of said actions as prompted by their physician.
The team believes that by stimulating the aforementioned regions of the brain during a clinical hypnosis session, that even those toward the bottom of the hypnotizability scale could be rendered susceptible to the treatment. If the effectiveness of hypnotic treatment could be supplemented in such a way, hypnosis could reduce the number of patients turning to side effect ridden pharmaceuticals for pain and anxiety relief.