And in these involuntary knockings we have, therefore, an ample potential cause for the genesis of conscious states. But if the cerebrum is not completely or sufficiently rejuvenated when these knockings come, it will resist their untimely intrusion, will resist throwing off the oblivious state. The knocking must be repeated, continued and must perhaps become louder, more intense. Finally the cerebrum yields and throws off oblivion, perhaps sluggishly, reluctantly, at first, with a successive, instead of a simultaneous awakening of the various sensory powers.
And is this not the key to the genesis of both normal and abnormal conscious states? The normal conscious state is the product of complete voluntary sensation, when all sensory powers are working together, combined with activity of the cerebrum in a normal, rejuvenated condition, capable of properly and simultaneously combining, in chronological order and correct relationship, the re-cognitions of past experiences with the cognitions of present external relations.
The abnormal cognitions and conscious states are the defective product of imperfect sensations combined haphazard with re-cognitions of an exhausted or only partly active brain—a brain incapable of coordinating past and present relations; incapable of concentrating brain and nerve activity upon a multiplicity of simultaneous external relations and internal re-cognitions.
In the normal activity the sensory tracts are all simultaneously stimulated, guided and controlled by volition. In the abnormal activity the sensory tracts are partly or wholly controlled by the involuntary vital function and are inactive, except through accidental and generally excessive stimulation. The actual transmission of nervous energy impulses by sensory nerve fibers is always involuntary.
***Excerpt from Charles John Reed: The Law of Vital Infusion and the Phenomenon of Consciousness