The duration of hypnotic sleep is exceedingly variable, but if left to himself the patient usually wakes spontaneously, without recollection of anything that has happened. If it be desirable to awaken him before the natural termination of the paroxysm, consciousness can be restored by almost any sudden and energetic appeal to the senses, such as an electric shock, a sudden illumination of the eye with vivid light, or a sharp puff of air upon the face.
According to Charcot,17 three principal types may be remarked among the hysterical subjects upon whom he experimented: (1) the cataleptic, (2) the lethargic, and (3) the somnambulic. Of these, the first may be developed primarily by any abrupt and powerful impression upon an organ of sense, as a bright light or a loud noise (gong). Fixing the eyes upon some object may produce the same result. Dumontpallier, for example, has reported the case of a young woman18 who accidentally hypnotized herself by gazing at her own image in the mirror before which she was dressing her hair. The cataleptic state may also be secondarily induced by merely opening the eyes of a patient in whom a condition of hypnotic lethargy has been previously developed. If only one eye is thus opened, the corresponding side of the body alone becomes cataleptic. Closing the eyes causes the disappearance of this symptom, with complete restoration of the purely lethargic state. During the cataleptic condition the several tendinous reflexes disappear, neuro-muscular hyperexcitability ceases; the skin becomes insensible, but the special senses, particularly those of sight and hearing, maintain a partial activity. In this state the senses may become avenues of suggestion for the production of muscular movements, but if left to themselves the limbs remain motionless.
17 Le Progrès médical, Feb. 18, 1882, p. 124.
18 Ibid., March 25, 1882, p. 223.
The lethargic state may be induced by simply closing the eyes of the patient or by causing him to fix his gaze upon some definite object. The paroxysm begins with a deep inspiration causing a peculiar laryngeal sound, followed by the appearance of a little foam on the lips. The eyelids are either wholly or partially closed, and are in a state of continual tremulous motion. The eyeballs are generally turned upward and inward. The muscles are completely relaxed. The tendinous reflexes are exaggerated; pressure over a muscle or upon a nerve arouses a peculiar contraction of synergic muscles and of groups of muscles which are supplied by the excited nerve-trunk. The facial muscles, however, do not thus become contractured: they merely contract during the application of the stimulus. If the lethargic patient be rendered cataleptic by opening the eyes, these contractions persist even after awaking, and they can only be dispelled by renewing the lethargic state before resorting to pressure upon the antagonistic muscles—a process by which the contractures peculiar to this species of lethargy may always be annulled. By the approach of a magnet to a contractured limb the phenomenon may be completely transferred to the corresponding muscles upon the opposite side of the body. If upon a limb of a lethargic patient who has been rendered cataleptic by opening the eyes an Esmarch's band be applied, pressure over the bloodless muscles excites no contracture until the band is removed. A contracture is then developed, and it may even be transferred to the opposite limb by the approach of a magnet. To this phenomenon has been applied the term latent contracture.
The extraordinary muscular excitability manifested by these hysterical hypnotics is further illustrated by an observation recorded by Dumontpallier.19 If one end of a caoutchouc tube one centimeter in diameter and five or six meters in length be applied over a muscle in the leg, and if the other end be in like manner connected with a watch, every movement of the second hand will be followed by a slight contraction in the muscle. The same result follows connection with the wire of a telephone, and if a microphone be introduced into the circuit the incidence of a ray of artificial light upon the instrument, or even its glancing reflection from the eye, will arouse a responsive muscular contraction. Charcot has sometimes observed muscular contractions upon the opposite side of the body when a mild galvanic current was applied to the parietal surface of the head. During the manifestation of muscular hyperexcitability there is complete analgesia, but the senses of sight and hearing seem to preserve some degree of activity. The patient, however, does not manifest any susceptibility to influence by suggestion.
19 Ibid., Jan. 14, 1882, p. 25.
The somnambulic state may be directly induced by fixed attention with the eyes, by feeble and monotonous excitation of the senses, and by various other methods of an analogous character. This forms the most common variety of the hypnotic condition. It may very easily supervene during either the lethargic or the cataleptic state as a consequence of pressure or gentle friction upon the top of the head. Thus, Heidenhain caused muscular paralysis by rubbing the scalp. Unilateral friction of the same surface produced paralysis of the opposite side of the body without notable affection of consciousness. The eye and the eyelids behave as in the lethargic state. The patient seems asleep, but there is less muscular relaxation than in hypnotic lethargy. There is no exaggeration of the tendinous reflexes, and muscular hyperexcitability is absent. But by lightly touching or breathing upon the surface of a limb its muscles may be thrown into a condition of rigidity which differs from the contracture of the lethargic state in the fact that it does not yield to excitation of the antagonistic muscles, though yielding readily to a sudden repetition of the same form of excitement by which it was originally produced. From the immobility of the cataleptic state it also differs by a greater degree of resistance to passive motion. Though analgesia may be perfectly developed in this state, there is generally an exalted condition of certain forms of cutaneous sensibility and of the muscular sense. Strange perversions of other special senses are sometimes remarked. Cohn20 discovered that a patient who was naturally color-blind “when unilaterally hypnotized was able to distinguish colors which were otherwise undistinguishable.” Conversely, when the cataleptic state is induced the eye becomes incapable of discerning colors. Spasm of accommodation is also present, and is one of the earliest demonstrable symptoms of the hypnotic condition.
20 Brain, vol. iii. p. 394.
These remarkable exaggerations and perversions of special sensibility have been the cause of much scepticism on the one hand regarding the verity of the phenomena of hypnotism, and of much credulity on the other, extending even to a belief in the existence of supernatural and miraculous gifts. But when the fact is once comprehended that in this capacity for uncommon feats of vision, hearing, touch, etc. we observe merely the exaggeration of a process which occurs in every act of attention, the miraculous semblance of the phenomena disappears. Attention implies an increase of activity in certain portions of the brain, with diminution of the function in the remainder of the organ. In the wild excitement of a cavalry charge the soldier feels not the sabre cut which will fill his consciousness with pain so soon as his attention is released from the fetters imposed by the more engrossing events of the combat. So in the somnambulic sleep those parts of the brain which remain awake perform their functions with a vigor that is enhanced by a concentration of cerebral energy in certain restricted portions of an organ that, by reason of its naturally excessive instability, had been previously fitted for the liberation of an inordinate amount of molecular motion. Hence the slightest suggestion of sense may suffice for the most extraordinary perception. Such persons see through their eyelids and hear at a surprising distance. The memory of past events, the recollection of long-forgotten words and thoughts, supplies in this state an abundance of materials out of which an exalted imagination may construct the most astonishing scenes. By this method of combination are produced those remarkable oratorical utterances which by the ignorant have been so widely attributed to the supervision of guiding spirits from another world. In this condition the essential characteristics of the mind of the so-called medium become the real guides of his mental processes. Hence the infinite variety and contrariety of the utterances of such declaimers.