In a hypnotic state an individual tends to see, feel, smell, and otherwise perceive in accordance with the hypnotist's suggestions, even though these suggestions may be in apparent contradiction to the actual stimuli present in the environment. The effects of hypnosis are not limited to sensory change; even the subject's memory and awareness of self may be altered by suggestion, and the effects of the suggestions may be extended (posthypnotically) into the subject's subsequent waking activity. It could be said that hypnotic suggestion is explicitly intended to make use of the placebo effect. For example, in 1994, Irving Kirsch characterised hypnosis as a "nondeceptive placebo", i.e., a method that openly makes use of suggestion and employs methods to amplify its effects. 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 hypnotised subjects might display: "dissociation"; "detachment"; "suggestibility", "ideosensory activity"; "catalepsy"; "ideomotor responsiveness"; "age regression"; "revivification"; "hyperamnesia"; "[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". Neuroimaging accounts of hypnosis have reported an extensive variety of brain patterns instead of a common signature. This may be explained by the fact that different suggestions engage different brain areas. Various reports link hypnosis to structural and functional changes in regions of the central executive network (CEN) and salience network (SN). The earliest definition of hypnosis was given by Braid, 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." Braid elaborated upon this brief definition in a later work, "Hypnotic Therapeutics":  Therefore, Braid defined hypnotism as a state of mental concentration that often leads to a form of progressive relaxation, termed "nervous sleep".