THE SEAT OF SLEEP.
These 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 _in_voluntary
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.