Hypnosis has been practiced for hundreds of years, and has fascinated the public for nearly as long. Hypnosis involves a state of enhanced inner focus and can be a valuable tool for modulating pain, nausea, and other physical symptoms, decreasing anxiety, and influencing performance on cognitive task. Hypnosis is also frequently used to facilitate weight loss, improve confidence, and help break bad habits.
Who is Most Hypnotizable?
Milton H. Erikson said that most people could be hypnotized if the clinician was skillful enough. The current consensus is that about two-thirds of adults are hypnotizable, however, and that this trait is stable over time. A number of measures have been developed to assess hypnotizability, yet, these do not address the question of why one person may be more hypnotizable than another. Although many factors, including empathy, absorption, and expectation of benefit, have been postulated as predictive of hypnotizability, the evidence has been inconsistent.
Your Brain and Hypnosis
A study in the October 2012 issue of Archives of General Psychiatry has shed new light on what may differentiate those who do and do not respond well to hypnosis. The researchers hypothesized there would be greater functional communication between the executive and salience networks of the brain in people who are highly hypnotizable. Using structural and functional magnetic resonance imaging (fMRI), the team examined the brains of 24 participants as they rested in the scanner. Half of the participants were characterized as “high hypnotizable” and half as “low hypnotizable” based on their responses to the Hypnotic Induction Profile (HIP).
The executive-control network is involved in working memory, planning, decision-making, and paying attention. The salience network is involved in detecting, integrating, and filtering relevant information about our emotions as well as what is going on in the body. The salience network is thought to help us identify the most relevant internal and external stimuli, attend to these over less relevant stimuli, and thus generate the appropriate behavior in response.
What the team found was that those individuals who were considered highly hypnotizable had significantly greater functional connectivity between the dorsolateral prefrontal cortex (dlpc), and the left dlpc in particular (which is part of the executive control network), and the dorsal anterior cingulate cortex (part of the salience network). Interestingly, there were no significant differences between the two groups with regard to brain structure, despite differences in function.
Why is This Important?
The authors concluded that these findings support the assertion that those who are highly hypnotizable have better coordination between brain areas that integrate "attention, emotion, action, and intention." Hypnosis can be a powerful tool for managing pain, anxiety, and other symptoms. The results of this study give greater credence to offering this treatment to those who are likely to benefit from hypnotic interventions. Finally, the data help to dispel the myth that hypnosis involves mind control by another, and suggest instead that hypnosis involves enhanced control over one’s focus and attention.
This study does not tell us whether those characterized as “low hypnotizable” might not still benefit to some degree from hypnosis. Furthermore, the study was relatively small, which limits the generalizability of the findings. The data presented here describe differences in brain functioning at rest rather than during hypnotic trance. Yet, the findings seem important nonetheless. The team is currently examining whether there will be observable differences in functional connectivity between the two groups while participants are engaged in hypnosis.
For more information:
Hoeft, F., Gabrieli, J. D. E., Whitfield-Gabrieli, S., Haas, B. W., Bammer, R., Menon, V., & Spiegel, D. (2012). Functional Brain Basis of Hypnotizability. Archives of General Psychiatry, 69(10), 1064-1072.
Menon, V. & • Uddin, L. Q. (2010). Saliency, switching, attention and control: a network model of insula function. Brain Struct Funct. Available online: http://stanford.edu/group/scsnl/cgi-bin/drupal_scsnl/sites/all/publicati....
American Society of Clinical Hypnosis: www.ASCH.net