People in a hypnotic trance often remember things less accurately than when fully awake, a panel of scientists concludes, raising doubts about the use of the technique in legal proceedings.
"Contrary to what is generally believed by the public," the panel writes in the Journal of the American Medical Association, "recollections obtained during hypnosis . . . actually appear to be less reliable than nonhypnotic recall."
As a result, hypnosis should be used only during criminal investigation and not for courtroom testimony.
The eight-member panel, chaired by Dr. Martin T. Orne, was set up late last year to study the use of hypnosis on "witnesses and victims of crimes."
Hypnosis leads people to have more memories than they would otherwise have, but many of these memories are inaccurate, the panel writes. In addition, the view that the mind is like a videotape recorder -- able to play things back accurately -- is not supported by scientific evidence or memory theory.
And because people become more open to suggestion in a trance, the psychiatrist or psychologist performing the hypnosis must avoid "leading questions." The witness should be allowed to recall what happened without being asked specific questions, the panel suggests.
The scientists also warn that while hypnosis is useful for psychotherapy, "witnesses and victims . . . are not selected for their mental health" and may become disturbed as a result of hypnosis.