Sleep and Hypnosis A Journal of Clinical Neuroscience and Psychopathology Online Ahead of Print Copy

Hypnotic focused analgesia, comparable to chemical local anesthesia, has been widely documented in our Laboratory after hypnotic suggestions. This study is aimed at producing hypnotic local anesthesia suggesting that a hand does not belong to the body (body dysmorphism) without any direct suggestions of analgesia. Eight healthy, highly hypnotizable volunteers underwent a cold pressor test keeping left hand at 0 °C, a painful maneuver, being free to stop the test at any time. Such procedure was repeated after hypnotic induction with suggestion of dysmorphism. The highest pain reached at the first minute and at the end of the experiment, both in prehypnotic conditions and during dysmorphism, was subjectively quantified through a decimal visual scale. The objective measure of local anesthesia was based on time of tolerance and on reflex response to pain. During dysmorphism, pain perception was 92.5% lower at 1st minute and 87.5% lower at the end of the experiment (highest tolerable pain) than in prehypnotic conditions, and nullified in 5 subjects (62%). Tolerance to pain (minutes of voluntary immersion in icy water) increased by 315%. While in prehypnotic conditions pain produced a reflex increase in blood pressure, heart rate and resistance, no increase was found during dysmorphism. Hypnotic dysmorphism without any specific suggestion of analgesia reduced and often nullified subjective pain perception. Objective pain tolerance contextually raised, and the reflex stimulation of the sympathetic drive was prevented. Analgesia produced through hypnotic dysmorphism is therefore not a mere consequence of dissociation but a real physiological phenomenon.