[Assessment of experimentally-induced pain effects and their elimination by hypnosis using pupillometry studies]

Hypnotherapeutical technique were often used for control of pain. However, an objective examination of this phenomenon was seldom carried out. The aim of the study was the psychophysiological objectivation of the effect of experimental induced pain and the elimination of pain by means of hypnosis. 22 healthy volunteers (11 female and 11 male) aged between 22 and 35 years participated in the study. In the 1st phase of the experiment static pupillometry was carried out before randomized presentation of a light stimulus (143 lux, 0.3 sec) and of a pain stimulus (coldness-spray, -50 degrees C, 0.5 sec) respectively. Afterwards the dynamic pupillary measurement was done. Additionally the Fourier analyses of pupillary oscillations reflecting central nervous activation during the static measurement (25,6 sec) was calculated. In the 2nd phase the subjects were investigated by means of the same techniques during hypnosis with specific suggestions for elimination of pain. Under light condition as well as after induction of pain an autonomic deactivation could be observed during hypnosis. Furthermore under pain condition a central deactivation could also be found, reflecting the depth of the hypnosis and the reduced perception of pain.