Somnambulism
(Latin, somnus, sleep, and ambulare, to walk.) The condition in which walking, talking, and actions of a more complicated character are performed during sleep, without the agent's consciousness or after recollection. The somnambulist may have his eyes closed, and ears deaf to auditory impressions or sense impressions, without waking in him any gleam of consciousness. This may have some effect in rousing new trains of association. and suggesting a new line of action. It is suggested that the sleep-walker may see only a mental picture of what he is doing that is, a dream-and not the objective reality, and certain experimental tests have proved that this occurs in some cases at least. Somnambulism admits of many varying degrees. Its mildest form is typified in the inarticulate murmurings or vague gestures of a dreaming child, while in the most extreme cases where all the senses are active, and the actions apparently as purposive as in the normal waking state, it borders on the condition of spontaneous hypnotism. Indeed its affinity with hypnosis was early recognised, when the hypnotic subjects of the magnetists were designated somnambules. It is remarkable that somnambulists may walk in dangerous paths with perfect safety, but if they are suddenly awakened they are liable to fall. Spontaneous somnambulism generally indicates some morbid tendency of the nervous system, since, as a rule, only in some abnormal state could the dream ideas exercise so exciting an influence on the brain as to rouse to activity centres normally controlling voluntary movements.