Evidence for hypnosis

17 Aug

Hypnosis is a fascinating subject. For years a debate has raged among psychologists over its reality. For many years the dominant view has been that hypnosis is not some special state of consciousness, but, actually, a social phenomenon where an individual simply conforms to the authority of the hypnotist because of prior beliefs about how a hypnotized person is supposed to behave.

Recently, however, the idea of hypnosis has an altered state of consciousness has re-emerged. This is because of studies showing physiological correlates of hypnosis. Here is the abstract of a recent paper published in the journal Cerebral Cortex:

“Hypnosis has proven clinical utility, yet changes in brain activity underlying the hypnotic state have not yet been fully identified. Previous research suggests that hypnosis is associated with decreased default mode network (DMN) activity and that high hypnotizability is associated with greater functional connectivity between the executive control network (ECN) and the salience network (SN). We used functional magnetic resonance imaging to investigate activity and functional connectivity among these three networks in hypnosis. We selected 57 of 545 healthy subjects with very high or low hypnotizability using two hypnotizability scales. All subjects underwent four conditions in the scanner: rest, memory retrieval, and two different hypnosis experiences guided by standard pre-recorded instructions in counterbalanced order. Seeds for the ECN, SN, and DMN were left and right dorsolateral prefrontal cortex, dorsal anterior cingulate cortex (dACC), and posterior cingulate cortex (PCC), respectively. During hypnosis there was reduced activity in the dACC, increased functional connectivity between the dorsolateral prefrontal cortex (DLPFC;ECN) and the insula in the SN, and reduced connectivity between the ECN (DLPFC) and the DMN (PCC). These changes in neural activity underlie the focused attention, enhanced somatic and emotional control, and lack of self-consciousness that characterizes hypnosis.”

(Hat tip to Brain Blogger)

2 Responses to “Evidence for hypnosis”

  1. Enrique Guerra-Pujol August 17, 2016 at 8:20 am #

    This might be of interest to you: http://slatestarcodex.com/2014/04/28/the-control-group-is-out-of-control/

    • jecgenovese August 18, 2016 at 10:17 am #

      Thanks. a very interesting piece, thank you for alerting me to it. I am very familiar with the Rosenthal teacher expectation study and I have read the original description (it was published as the book Pygmalion in The Classroom). The book was very popular in its time because of the implication that the simple, inexpensive, step of raising teacher expectation would dramatically increase student performance. It was not to be, there have been several good critiques of the Rosenthal study suggesting problems with the methodology. Subsequent research has suggested that expectation effects are real but not of the magnitude suggested in the study.

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