Ernest Hilgard, who developed the "neodissociation" theory of hypnotism, hypothesized that hypnosis causes the subjects to divide their consciousness voluntarily. One part responds to the hypnotist while the other retains awareness of reality. Hilgard made subjects take an ice water bath. None mentioned the water being cold or feeling pain. Hilgard then asked the subjects to lift their index finger if they felt pain and 70% of the subjects lifted their index finger. This showed that, even though the subjects were listening to the suggestive hypnotist, they still sensed the water's temperature.
Contemporary hypnotism uses a variety of suggestion forms including direct verbal suggestions, "indirect" verbal suggestions such as requests or insinuations, metaphors and other rhetorical figures of speech, and non-verbal suggestion in the form of mental imagery, voice tonality, and physical manipulation. A distinction is commonly made between suggestions delivered "permissively" and those delivered in a more "authoritarian" manner. Harvard hypnotherapist Deirdre Barrett writes that most modern research suggestions are designed to bring about immediate responses, whereas hypnotherapeutic suggestions are usually post-hypnotic ones that are intended to trigger responses affecting behaviour for periods ranging from days to a lifetime in duration. The hypnotherapeutic ones are often repeated in multiple sessions before they achieve peak effectiveness.
A 2006 declassified 1966 document obtained by the US Freedom of Information Act archive shows that hypnosis was investigated for military applications. The full paper explores the potentials of operational uses. The overall conclusion of the study was that there was no evidence that hypnosis could be used for military applications, and no clear evidence whether "hypnosis" is a definable phenomenon outside ordinary suggestion, motivation, and subject expectancy. According to the document:
Azam's enthusiasm for hypnotism influenced Ambroise-Auguste Liébeault, a country doctor. Hippolyte Bernheim discovered Liébeault's enormously popular group hypnotherapy clinic and subsequently became an influential hypnotist. The study of hypnotism subsequently revolved around the fierce debate between Bernheim and Jean-Martin Charcot, the two most influential figures in late 19th-century hypnotism.
Controversy surrounds the use of hypnotherapy to retrieve memories, especially those from early childhood or (supposed) past-lives. The American Medical Association and the American Psychological Association caution against recovered-memory therapy in cases of alleged childhood trauma, stating that "it is impossible, without corroborative evidence, to distinguish a true memory from a false one." Past life regression, meanwhile, is often viewed with skepticism.
Hypnotic music became an important part in the development of a ‘physiological psychology’ that regarded the hypnotic state as an ‘automatic’ phenomenon that links to physical reflex. In their experiments with sound hypnosis, Jean-Martin Charcot used gongs and tuning forks, and Ivan Pavlov used bells. The intention behind their experiments was to prove that physiological response to sound could be automatic, bypassing the conscious mind.
“My hypnotherapy business is humming along. Within less than a year of graduating, I am doing between 8 and 15 sessions per week now! I love my work and give thanks to God every day for the opportunity to help others. I wouldn’t be where I am today, having these successful outcomes, if it were not for the thorough training I received at the Hypnotherapy Academy. My confidence is strong and unwavering. It still amazes me how easily this all came together and continues to do so! And my thanks to Susan for the sessions I received while at the Academy, they worked wonders for me in so many ways.”
“I never expected how much transformation is possible with this work. This hypnotherapy training went far beyond my expectations. The incredible amount of wonderfully presented material and deep wisdom touched my heart on a very deep level. The combination of hypnosis and very profound and effective methods of processing is incredible. To see the profound changes in my classmates and myself is such a gift, I feel deep gratitude for that. To imagine how much positive change will occur in other people due to this work moves my heart.”
"I feel now I am ready to express an experience that has transformed my life and in the process the lives of lots of people! To begin with, I could not have imagined that I would no longer feel my (formerly) chronic backache. I have learned to relax the muscles and actually pass on the healing thoughts and energy to the pain areas. The changes in my life are nothing short of a miracle. Healing my personal relationships has been the highlight....