Once the person is in the trance state, and is in a safe seated position, you can use the power of suggestion on your hypnotized subject. For example, you can tell them that when you count to three that they will open their eyes but that they will not remember their name. Then count to three and tell them to open their eyes. When their eyes are open, ask them to tell you their name. They will be amazed that they can't remember their own name.
Olness thinks there must be something about the intense mental imagery that comes with a hypnotic state. One little boy she worked with told her he was imagining that he was touching the sun. Whether such visions activate different parts of the brain than those associated with rational thought is less clear. As Olness says, “We’re a long way from specifics on that.”
The earliest definition of hypnosis was given by Braid[contradictory], who coined the term "hypnotism" as an abbreviation for "neuro-hypnotism", or nervous sleep, which he contrasted with normal sleep, and defined as: "a peculiar condition of the nervous system, induced by a fixed and abstracted attention of the mental and visual eye, on one object, not of an exciting nature."
In Trance on Trial, a 1989 text directed at the legal profession, legal scholar Alan W. Scheflin and psychologist Jerrold Lee Shapiro observed that the "deeper" the hypnotism, the more likely a particular characteristic is to appear, and the greater extent to which it is manifested. Scheflin and Shapiro identified 20 separate characteristics that hypnotized subjects might display: "dissociation"; "detachment"; "suggestibility", "ideosensory activity"; "catalepsy"; "ideomotor responsiveness"; "age regression"; "revivification"; "hypermnesia"; "[automatic or suggested] amnesia"; "posthypnotic responses"; "hypnotic analgesia and anesthesia"; "glove anesthesia"; "somnambulism"; "automatic writing"; "time distortion"; "release of inhibitions"; "change in capacity for volitional activity"; "trance logic"; and "effortless imagination".
It is used for a wide variety of applications, and studies into its efficacy are often of poor quality which makes it difficult to determine efficacy. Several recent meta-analyses and systematic reviews of the literature on various conditions have concluded that the efficacy of hypnotherapy is "not verified", that there is no evidence or insufficient evidence for efficacy.