Jump up ^ Braid, J. (1844/1855), "Magic, Mesmerism, Hypnotism, etc., etc. Historically and Physiologically Considered", The Medical Times, Vol.11, No.272, (7 December 1844), pp.203-204, No.273, (14 December 1844), p.224-227, No.275, (28 December 1844), pp.270-273, No.276, (4 January 1845), pp.296-299, No.277, (11 January 1845), pp.318-320, No.281, (8 February 1845), pp.399-400, and No.283, (22 February 1845), pp.439-441: at p.203.
But for the comparison between PHA and functional amnesia to be most meaningful, we need to know that they share underlying processes. One way to test this is to identify the brain activity patterns associated with PHA. In a groundbreaking study published in Neuron, neuroscientist Avi Mendelsohn and colleagues at the Weizmann Institute in Israel did just that using functional magnetic resonance imaging (fMRI). They carefully selected 25 people to participate in their experiment. Although all were susceptible to hypnosis, earlier testing had shown that half could respond to a PHA suggestion (labelled “the PHA group”) and half could not (the “non-PHA group”). In the Study session of their experiment, participants watched a 45-minute movie. One week later, in the Test session, participants returned to the laboratory and were hypnotized while they lay within the fMRI scanner. During hypnosis, people in both the PHA and non-PHA groups received a suggestion to forget the movie until they heard a specific cancellation cue.
Hypnosis is not a psychotherapeutic treatment or a form of psychotherapy, but rather a tool or procedure that helps facilitate various types of therapies and medical or psychological treatments. Only trained health care providers certified in clinical hypnosis can decide, with their patient, if hypnosis should be used along with other treatments. As with psychotherapy, the length of hypnosis treatment varies, depending on the complexity of the problem.