Читать книгу A monograph on sleep and dream: their physiology and psychology - Edward W. Cox - Страница 8
CHAPTER IV.
THE SEAT OF SLEEP.
ОглавлениеThese facts point to the conclusion that the partial paralysis to which the senses are subjected in sleep does not occur at the points of communication with the external world, but somewhere between the extremity of the sense-nerves and the brain, or at the point of communication between the brain and the Conscious Self. There can be little doubt that impressions are made upon the nerves in sleep as when we are awake. There is some evidence that the impressions so made are conveyed by the afferent nerve to the ganglion at the base of the brain hemispheres. The experiments of Professor Ferrier have proved this ganglion to be the centre upon which the sense-nerves converge; that to this centre those impressions are conveyed and thence are transmitted to the brain hemispheres, or at this point the hemispheres of the intelligence receive notice of their presence.
In Sleep the brain is unable to convey its commands to the body. The nerves do not obey. Something that operates between the brain and the nerves and which was active in the waking state is inactive in sleep. What is that something? It is the Will. The Will has ceased to act and thus the body has ceased to be controlled by the mind. This is the process by which the needful rest of the body is brought about.
Here the question comes, in what part of the mechanism does the change occur that thus causes the suspension of the power of the Will and the partial severance of the Conscious Self from its normal control of the body? How does sleep accomplish so great a revolution? If the whole mental mechanism were inactive in sleep this question would be answered easily. We should say, “the entire of the brain is sleeping and therefore the whole mechanism is at rest. The motive forces that move and direct the machine in its waking state have ceased for a time from their work and the structure stands still.”
But that is not the condition. All the forces have not ceased from their work. The vital force continues in full activity, keeping the machinery in motion and performing the work of nutrition, reparation and growth. The mind is not at rest; the phenomena of dream directly contradict such a conclusion. The whole mental mechanism is certainly not at rest. A part of it is very busy. The hemispheres of the brain are not sleeping—or sleeping but partially. They are enacting dreams. They are in truth working with infinitely greater speed and power when we are asleep than when we are awake!
If, then, the brain hemispheres are waking above and the body is sleeping below, the communication between them must be severed by sleep at some part of the mechanism below the brain hemispheres (which are the mechanism of the Intelligence) and the point where the brain branches into the nerve system—which is the mechanism by whose action the vital force forms and sustains the organic structure.
That point is obviously the point at which the Will exercises its power of control over the body. Thus does this inquiry into the Psychology of Sleep and Dream promise to throw light upon that mysterious part of the mechanism of man. Professor Ferrier has proved that the Will is exercised through the brain hemispheres, which are the organs of the Intelligence. In the waking and normal condition of the structure the Will commands and controls the body. In sleep and other abnormal conditions the Will ceases to command the body. Between the brain hemispheres and the nerves that move the body something seems to be interposed which either paralyses the Will or ceases to transmit its commands. What is that something? Anatomically we find two ganglia, one being the centre upon which the nerves of the senses converge. We know, also, that in sleep the senses cease to transmit their impressions, or do so but dimly. The conclusion is, that the seat of sleep is in this ganglion. Because that is slumbering, the commands of the Will cannot be conveyed from the brain to the body, nor can the messages sent by the senses from the body be conveyed to the brain.
It is a moot point if the entire of the mechanism of the brain, or parts of it only, and, if so, what parts, fall into the condition of sleep. But, however that may be, there can be little doubt, from the facts stated above, that the ganglion at the base of the brain hemispheres is the seat of sleep. It is certain that the entire of the two brain hemispheres does not always sleep or dream could not be. Whether the ganglion that interposes between the cerebral centre and the body, and whence streams the nerve system, succumbs to sleep we have no certain knowledge. The presumption is that it does not, for the nerves whose office is to sustain the functions of the vital organs do not sleep. Why they need not the rest that is required by other parts of the mechanism we do not know. Rest appears to be necessary for that portion of the mechanism only that is subject to voluntary action. Where the Will controls, the repose of sleep is required for all structure subjected to it. Why?
Does the nerve system that moves the mechanism of the body sleep? The bonds that link brain and body are relaxed. The Will has ceased to control either of them. The material form is at rest. But it rests only because the power of the controlling Will is paralysed. All involuntary actions continue and with the more regularity and efficiency because they are not subjected to the disturbing influences of the Will.
And what is this potent Will?
The Will is merely the expression of the Conscious Self—the power which the Conscious Self exercises over the material mechanism of the body and through the body upon the material world without.