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Boris Sidis, Ph.D., M.D.

Boston: R. Badger, 1909



Motor Consciousness and Sleep

THE condition of limitation of voluntary movements plays an important role in the induction of sleep states. This is due to the fact that motor consciousness not only forms the main body of our mental activity, but also that ideo-motor life is more subject to changes from slight stimulations than is our purely sensory life. Motor elements are highly plastic and modifiable; they enter readily into ever new combinations. From a biological standpoint one can realize the importance of the great modifiability displayed by sensori-motor and ideo-motor elements, since in the adaptation of the organism to its environment it is these elements that are mainly employed in reaction to stimuli of the external world. From the standpoint of adaptation a slight difference of sensory experience may give a widely different and highly complex motor reaction.

            Psychomotor processes form the most important and largest portion of mental life. With the exception of man, all the representatives of the animal kingdom, from the lowest to the highest forms, represent but different stages in the evolution of sensori-motor life. The great majority of mankind still leads a life closely allied to animal sensori-motor states. Instance the delight of children in their plays, and the all absorbing interest of college students in their baseball and football games. Even in the highest and most developed forms of mental activity motor ideas and representations are by far the most predominant. Without motor elements ideational life is arrested. It is these sensori-motor and ideo-motor elements that constitute the “stream, the flow, the current” of our mental life. Motor elements enter freely and easily into combinations with all other elements of mental life.

            This ease and high plasticity of ideo-motor elements is specially well brought out in hypnosis. Sensori-motor and ideo-motor suggestions are taken before purely sensory suggestions; paralysis, catalepsy, contracture, all kinds of motor and kinaesthetic illusions and hallucinations are easily induced even in the very light stages, while it is only in the deeper stages that changes of ideo-sensory elements can be brought about. The induction of purely ideo-sensory illusions, hallucinations or delusions, positive and negative, can only be effected in the very deep stages of hypnosis. The freedom in forming new combinations and associations makes the suggestion of motor ideas and representations highly, effective.

            Throughout the scale of animal life, from the lowest to the highest forms, intelligence is intimately related to the degree of development of the muscular system and to the delicacy of motor adjustments. Among the lower forms of life the Cephalopods are well equipped with powerful muscular arms capable of executing a great variety of vigorous movements. Now the Cephalopods also possess a more highly developed nervous system with a higher grade of mental functions than the rest of the Mollusca. The great activity of ants and bees is notorious and their instinctive psychic life is the richest among the Arthropoda. Note the great variety of motor adjustments of the beaver and also of the intelligence that goes along with it. Birds possessed of a high degree of activity and motor adaptability are also the most intelligent of their kind, such for instance as the different species of talking birds. Notice the activity and great agility of the fox and also the unusual cunning for which the animal is so celebrated in song and fable. The suppleness of the dog, his quick reactions to stimulations, the resources of his motor adjustments and the great extent of his modifiability under changing conditions are all well known and along with them goes a high degree of mental activity. Of all the Mammals the Quadrumana are the most active, the most imitative, and with the exception of man, they are also the most intelligent. When we come to man we cannot help admiring the high complexity and extreme delicacy of his motor adjustments. Most marvellous however is the human hand, that divine organ which gives shape and form to works of art, to all outward visible manifestations of civilization. The great artists and thinkers of antiquity held the human hand in great veneration. One of the great Greek philosophers did not even hesitate to declare that man's superiority over the brute was due to his hand. Finally in the wonderfully delicate motor adjustments of speech we find clearly illustrated the intimate relation between motor and psychic activities.

            Experiments prove the same truth of the importance of motor elements in our mental life. If a series of syllables or numbers is given to memorize, after one reading, five out of ten can be remembered, though with some difficulty; but if the syllables or numbers are written down at the same time, though not looked at during the writing, a far greater percentage such as six or seven syllables can be remembered. If the motor elements in a train of ideas are suppressed, the order of the series becomes confused and even totally destroyed, showing that the motor ideas are important links in trains of association of ideas. Motor elements form the nucleus of consciousness.

            Biologically regarded, voluntary activity, will, is the power of the organism to adjust itself to the conditions of the external environment. In its last psychological analysis voluntary activity, will, consists of ideo-motor elements, of various modes of adaptations. Will, consisting of kinaesthetic elements, constitutes the active subject of personality and individuality. If this be realized, then the vital importance of motor consciousness cannot be too highly overrated. Motor consciousness is at the very heart of personality. We are what we can accomplish. Extreme variability and adaptability of reactions to environment are the main characteristic traits of intelligence, will, personality.

            The readiness of psycho-motor elements and groups to enter into ever new combinations gives rise to the formation of a great wealth of associations which help to make the labile psycho-motor groups and systems easy of recall. In fact it may be said that the ease of recall is proportionate to the mass of associated kinaesthetic elements. The great modifiability and variability of systems of motor elements requisite in the adaptation of the organism to the varying conditions of life, to its environment, make the ever greater instability of motor elements an imperative necessity in the struggle for existence.

            Forming the predominant elements, both as to intensity and mass, of the most complex, relatively stable, though ceaselessly shifting groups and systems, constituting the highly developed organization of mental life, the motor elements, presentative and representative, are also the first to become involved in the process of dissociation. In the various forms of nervous and mental diseases, under different conditions of intoxication and auto-intoxication, in the traumas caused by shock, physical and psychic, the delicate movements of adjustment are the first to become affected; dissociations of systems of motor elements are first to occur.

            The instability of psycho-motor elements maybe brought in relation with the fact of the early affection of muscular and kinesthetic sensitivity and with the predominance of sensori-motor over purely sensory symptoms, so frequently occurring in the course of nervous diseases. With this may be correlated the significant fact referred to by Mosso that “all substances which slowly, destroy the organism must produce phenomena analogous to those of curari since the motor nerves. . . . have less vitality than the sensory.” It may also be observed in passing that cellular kinoplasm with the “kinocentrum,” the centrosome and its archoplasmic structures, possibly the most primitive organoids of the cell, similarly manifest a high degree of variability and instability.

            Motor elements may be regarded as the labile constituents of consciousness;—they become easily and frequently dissociated and dropped into the subconscious; but for that very reason they are also very easily reproduced or regenerated. In this respect motor elements follow the general biological law of organic regeneration: Organs that are easily and frequently lost in the struggle for existence are also easily regenerated, as for instance, the legs and claws of Crustacea or the tentacles of the starfish and the octopus. Dissociated systems of motor elements often become regenerated and under pathological conditions, when synthesis is impossible, they may recur with great persistence giving rise to the most uncontrollable types of insistent ideas and impulses and to various forms of so-called “psychic epilepsy,” especially of the motor type, closely mimicking typical organic epilepsy. Such dissociated, subconscious systems, like rudimentary, aborted organs, the appendix, for instance, may often prove very injurious to the organism. The recurrence of such subconscious, submerged, dissociated systems has its parallel in the biological phenomena of reversion or atavism.

            The fact that psycho-motor elements enter easily into combinations and form extensive associative systems, makes them easy of recall and hence persistent in memory. From an educational standpoint one realizes the importance of this fact. Children learn things best not by abstract notions, not by looking at objects and hearing of things, but by acting out whatever is taught them. Motor consciousness is more vital than sensory. In the training of the mentally defective the best method followed is that of motor instruction,—to get at the meaning of things by means of action, even if it be automatic at first. As a matter of fact even the normal and well balanced mind gets at the meaning of things by handling them, by having the attributes and qualities of the objects and processes to be learned acted out. Acting forms the greater part of man’s life.

            Forming as motor consciousness does the very heart of mental activity, we can well realize the paramount importance of the condition of limitation of voluntary movements. By limiting the motor activity of the organism we impoverish its mental processes and lower the heart-beat of mental life. The active nucleus of psycho-motor reactions becomes passive, the organism becomes disabled in its response to the stimulations of the external environment, the thresholds rise and the organism is no longer in relation with the external world. When motor activity with its concomitant motor-consciousness becomes lowered, restricted, and fades away, the organism becomes necessarily passive and passes into sleep.

            Thus monotony and limitation of voluntary movements work in one direction,—they tend to raise the thresholds of psychomotor reactions, they cooperate in the induction of sleep. These conditions are usually brought about naturally in the course of the daily or nightly life activity of the individual organism, or the conditions may be produced artificially. In both cases the result is the same,—the organism falls asleep. In the life of higher animals the two cases may often combine. When the individual has fagged out his life interests in his active relations with his surroundings, when the stimuli have become monotonous to him and his activity with its correlative motor consciousness has become limited and lowered, he makes artificial arrangements for the intensification of the conditions of monotony and limitation of voluntary activity. He seeks for a dark nook, closes his eyes to exclude as much as possible all extraneous disturbing stimulations and tries to lie down quietly and comfortably, restricts his voluntary movements, breaks his connection with the external world and goes to sleep. The organism falls into sleep, when the thresholds rise, wakes and rises when the thresholds fall.

            Looked at from a purely physiological standpoint and expressed in terms of energy, of the “cell-energy,” sleep maybe regarded as the onset of fatigue, as the onset of exhaustion of the levels of dynamic energy in response to external stimuli. The law of stimulus-exhaustion comes here into play as we have indicated in our discussion of cell-energy. Each particular stimulus has its maximum amount of energy which can be drawn upon, under ordinary conditions of daily life. As the special stimulus approaches its limit, it works under greater and greater difficulties, draws less and less energy and finally ceases to awaken any response,—the threshold is raised to its maximum and the organism, as far as that special stimulus is concerned, is no longer awake,—the organism is asleep. In the course of its daily activity the same takes place in regard to most of the objects, to most or to all of the stimuli that constitute the external world of the organism. The stimuli of the external world have drawn all that was permitted to them on their bank accounts, so to say, and the account for the time being is closed. Nothing more is permitted to go out. No stimulus of ordinary life is permitted to draw over and above a certain amount. There must always be ready capital for unusual situations, for emergencies. When the stimuli have drawn their due and the organism is left with its reserve energy,—liberation of energy with its accompanying waking states ceases. The organism is no longer awake to the stimuli and is asleep.

            As in the waking states the katabolic processes predominate, so in sleep the reverse processes, the anabolic, take the upper hand. The organism begins to recuperate its losses and fills up the accounts drawn upon by the stimuli of the external environment, when in active relation with them. With the increase of the income of energy the raised thresholds begin to fall until a point is reached when the stimuli once more overstep the lowered thresholds and once more gain access to the stores of life-energy,—the organism awakes and enters into active relations with the external environment.

            Regarded then from various standpoints, sleep is a rise of moments-thresholds under conditions of monotony and limitation of voluntary movements. In this respect sleep strongly contrasts with hypnosis. In hypnosis the individual is specially accessible to any kind of suggestions coming from the external world, the psycho-motor reactions are greatly lightened and are released by the suggestion or external stimulus with great facility, far greater than in the waking state. This great facility is often expressed by the statement that in hypnosis the inhibitions are removed. What specially characterizes hypnosis is the fact of fall of thresholds present in individuals, with a predisposition to states of dissociation; in sleep, on the contrary we have found from our study, the general characteristic is the rise of psycho-motor thresholds. In passing from the waking state into the subwaking hypnoidal state the individual may either pass into hypnosis with its dissociated states and lowered psycho-motor thresholds or may go into sleep with raised psycho-motor thresholds. The process of redistribution of thresholds takes place in the intermediary, hypnoidal states. When the redistribution of thresholds in the hypnoidal states brings about a fall of thresholds due to predisposition to and further cultivation of dissociations, the result is hypnosis; when the redistribution in the hypnoidal states brings about a rise of thresholds, the result is sleep.

                   Biologically regarded, sleep is as much an instinct as hunger or sex.

           Phylogenetically and ontogenetically, the sleep-states of higher animals are developed out of undifferentiated, intermediary, subwaking, hypnoidal-like states found in the resting states of the lower representatives of animal life. The hypnoidal state is the primitive rest state out of which sleep arises. Briefly put, the hypnoidal state is the germ of sleep.

           Physiologically and psychologically regarded, sleep is an actively induced passive state in relation to the external environment; the psycho-physiological systems have their thresholds raised in relation to external stimulations; the rise of threshold is induced by a mass of impressions possessing little or no variability, by limitation or by relative withdrawal of stimulations, or what is the same, by monotony of stimulations and by limitation of voluntary movements.


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