The Problem of Sleep74
Everybody knows that sleep does not set in instantaneously, that it is a gradual process. Similarly one does not awake all of a sudden; certain time is required before one gradually becomes active and, so to speak, completely throws off the fetters of sleep. Hypnosis is sleep which develops very slowly, i.e., it is at first confined to a very small and restricted area and then begins to spread farther and farther until it finally descends from the cerebral hemispheres to the subcortex, leaving untouched only the centres of respiration, of the heart-beat, etc., though somewhat weakening these too. As for clinical sleep, the clinical concept of the centre of sleep is well known to clinicians; it is based on the fact that after an infection of the brain, the so-called encephalitis, which is accompanied by somnolence, considerable changes take place in the hypothalamus.