2. What is a hypnotic "trance" ?

2.3. What is Trance Logic?

Trance logic refers to a set of characteristics of mental functioning that are specifically found in 'deep trance' phenomena of hypnosis, as opposed to 'light trance,' which has not even reliable subjective correlates and cannot really be distinguished from simulation experimentally. These characteristics involve particularly an alteration in language processing. Words, in trance logic, are interpreted much more literally, communication being conveyed by focusing on words themselves rather than ideas. There is also an associated decrease in critical judgment of language being processed, and an increased tolerance for incongruity.

It is in some ways as if the subject were like a small child with very limited experience to use in interpreting ideas conveyed by the hypnotist. There also is a shift toward what psychoanalysts call 'primary process' thinking, or thinking in terms of images and symbols more than words; an increased availability of affect; and other characteristics that simulators do not consistently reproduce.

This consistent set of characteristics of deep trance has been one of the influences leading to several kinds of theories of what trance actually involves:

1. Partly because language skills are 'child-like,' and meaningful long forgotten childhood memories can apparently sometimes be vividly re-experienced (see the later section on the reliability of recall in hypnosis) the theory that trance generally represents some kind of psychological regression to an earlier developmental stage has long been popular in some circles.
2. Partly because the individual appears to become disconnected somehow with the usual context they use to evaluate ideas, a cognitive dissociation theory arose. (Also partly because of anomalies involving apparent multiple simultaneous 'intentions.')
3. Partly because the cues prompting the subject's behavior become more internal and progressively more obscure to an outside observer, trance has been viewed as 'contact with the unconscious mind.'
4. Largely because some of the characteristics of trance logic correlate well with some of those discovered to be specialized in many people in the non-dominant cerebral hemisphere, there is also a popular theory that deep trance involves a somehow selective use of one hemisphere of the brain, or in the most simplified version of this theory, a 'putting to sleep' somehow of the dominant (language specialized) hemisphere. Some brain scientists strongly disagree with this view, emphasizing the complex interdependence of the brain hemispheres even in typical hypnotic-type situations.