ix SCIENTIFIC HYPNOSIS AND THE OCCULT 359
Since the time of Braid we may distinguish three types of theory to explain hypnosis the pathological, the physiological and the psychological. The principal representative of the first line was Charcot, who taught that hypnosis is essentially a symptom of a morbid condition of hysteria or hystero-epilepsy. Professor McDougall says that ' this doctrine, which, owing to the great repute enjoyed by Charcot, has done much to retard the application of hypnotism, is now completely discarded \
The physiological theory attached special importance to the fixation of the eyes, or to the other forms of long-continued and monotonous, or violent, sensory stimulation in the induction of hypnosis. They induced a peculiar condition of the nervous system resulting in the temporary abolition of the cerebral functions and the consequent reduction of the subject to machine-like unconscious automatism. The leading exponent of this view was R. Heidenhain, Professor of Physiology of Breslau, whose experimental investigations played a large part in convincing the scientific world of the genuineness of the leading symptoms of hypnosis. The theory now has little support.
Pavlov, however, regarding hypnosis in the light of conditioned reflexes and inhibitions, said : ' We can regard " suggestion " as the most simple form of a typical conditioned reflex in man. The command of the hypnotist . . . concentrates the excitation in the cortex of the subject ... in some definite narrow region, at the same time intensifying . . . the inhibition in the rest of the cortex and so abolishing all competing effects of contemporary stimuli and of traces left by previously received ones. This accounts for the large and practically insurmountable influence of suggestion as a stimulus during hypnosis as well as shortly after it' I74