Psychological and Psychodynamic Aspects of Disturbances in the Sleep Mechanism

Disturbances in sleep consisting of insomnia or hypersomnia (somnolence) can be divided into two main categories: those associated with lesions of the central nervous system and those of psychogenic origin. Normal sleep is essentially a biologic function governed chiefly by the hypothalamus. The fact that man is able to fall asleep in a conscious or unconscious attempt to escape certain emotional difficulties, or to keep awake in emergency situations or under deep emotional strain, would indicate that the higher cortical centers also play an important rôle in the regulation of sleep through their influence upon the hypothalamus. Men like Caesar, Napoleon, Freud and others were able to sleep or keep awake at will.

It is well to bear in mind that cortical activity does not cease during sleep. Discoveries have been synthesized in sleep and dreams. Otto Loewi, who discovered the action of acetylcholine on the transmission of nerve impulses, dreamed about it, woke up and recorded his ideas. Kekulé, who advanced the structural formula of the benzene ring, wrote, 'I was sitting and writing but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed off. Again the atoms were gamboling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by repeated visions of the kind, could now distinguish larger structures of manifold conformation: long rows, sometimes more closely fitted together; all twining and twisting in snakelike fashion. What was that? One of the snakes had seized hold of its own tail and the form whirled mockingly before my eyes. As if by a flash of lightning, I