Popular Science Monthly/Volume 40/April 1892/Involuntary Movements I
By JOSEPH JASTROW, Ph. D.,
PROFESSOR OF EXPERIMENTAL AND COMPARATIVE PSYCHOLOGY IN THE UNIVERSITY OF WISCONSIN.
QUITE a number of delusions find a common point of origin in the wide-spread belief that our thoughts and actions are to be completely explained by reference to what our consciousness tells us and what our will directs. The equally important realm of the unconscious and the involuntary is too apt to be overlooked. It is true that we are ready to admit that, in some unusual and semi-morbid conditions, persons will show these untoward phenomena; but we are slow to believe that they have any bearing upon the soundly reasoned and skillfully directed actions of our own intelligence. Accordingly, when from time to time there comes to the front some phenomenon diverging from the ordinary experience of mankind and apparently revealing obscure laws, we fly to some unproved and extreme explanation, and fail to recognize in our daily unconscious and involuntary activity the true source of the apparent mystery. While it is very reasonable to trust the verdict of our consciousness, yet it is equally desirable that tins confidence should be accompanied by an understanding of the conditions under which the evidence is presumably valid and when likely to mislead. Sense deceptions, faulty observation, exaggeration, neglect, fallacy, illusion, and error abound on all sides and emphasize the need of a calm judgment, a well-equipped intellect, a freedom from haste and prejudice, an appreciation of details and nice distinctions, in the determination of truth and the maintenance of mental health.
For these and other reasons it is important to demonstrate experimentally the readiness with which normal individuals may be made to yield evidence of unconscious and involuntary processes. When, some years ago, the American public was confronted with the striking phenomena of muscle-reading, the wildest speculations were indulged in regarding its true modus operandi; and the suggestion that it was due to unconscious indications skillfully interpreted was ridiculed, mainly for the reasons that this explanation was hardly applicable to certain extreme instances involving considerable good fortune, other and subtler modes of interpretation, as well as some exaggeration in the accounts, and that so many worthy and learned persons were absolutely certain that they had given no indications whatever. For a time the view that mind-reading was muscle-reading rested upon rather indirect evidence, and upon modes of reasoning that do not
The Automatograph.—When in use a screen is interposed concealing the apparatus from the subject. There is also a sheet of paper on the upper glass plate, which has been removed to show the glass balls.
carry great conviction to the ordinary mind. To supplement this evidence by a clear exposition of the naturalness and regularity of these involuntary movements is our present task.
Inasmuch as the movements in question are often very slight, delicate apparatus is necessary, the description of which may properly precede an account of the results. There is first a strong wooden frame, holding a heavy plate glass, fifteen Indies square, and mounted on three brass legs, with screw adjustments by means of which the plate may be brought into exact level. Upon the plate glass are placed in the form of a triangle three very perfectly turned and polished brass balls, and upon the balls rests a thin crystal plate glass fourteen inches square, set in a light wooden frame. Covering the upper glass is a sheet of paper, and upon the paper the subject lightly rests the finger-tips of one hand. When all is properly adjusted, and glass and balls are rubbed smooth with oil, it is quite impossible to hold the apparatus still for more than a few seconds; the slightest unsteadiness or movement of the hand at once sets the apparatus going. If one closes his eyes and thinks intently of something, one readily forms the conviction that the glass remains quiet, but a bystander is equally convinced of the opposite. The rest of the apparatus is designed to give a permanent record of these movements. Fastened to the light frame containing the upper glass is a slender rod some ten inches long, bearing at its end a cork, and piercing the cork is a small glass tube that serves to hold a snugly fitting glass rod. The rod is drawn to a smooth rounded point, and when in position rests upon a piece of glazed paper that has been blackened over an oil-flame, and is smoothly stretched over a small glass plate. The point of the rod thus records easily and accurately every movement of the hand that is imparted to the upper plate, and by the manner of its adjustment accommodates itself to all irregularities of movement or surface. Inasmuch as the main purpose of the apparatus is to write involuntary movements, it may not be amiss to name it the "automatograph," and speak of the record it yields as an "automatogram."
Fig. 1.— ↦ Reading Colors. Time of record, 95 seconds.
In all the figures A represents the beginning of the record, Z the end. In Figs. 4 and 6 the numbers 1, 2, 3, 4 indicate the points of the record 15, 30, 45, 600 seconds—in Fig. 11, 30, 60, 90, 120 seconds—after the start. The arrow indicates the direction in which the object attended to was situated. The tracings are permanently fixed by bathing them in a weak solution of shellac and alcohol.
Various means may be employed to hold the attention of the subject in a definite direction, and in all he is instructed to think as little as possible of his hand, making an effort, if he chooses, to keep it from moving. A large screen is interposed between the subject and the record to prevent him from indirectly seeing what is going on. On the wall facing him, some eight feet distant, are some small patches of color, the names of which he is asked to call out. The colors are small enough to necessitate close attention in their distinction, and the record of the hand, after the subject has been employed in this way for a minute or two, is usually quite significant. An average result is presented in Fig. 1. The hand Fig. 2. — Reading Colors arranged in Three Rows. Shows movement of the hand parallel with movement of the attention. Time of record, 90 seconds. The first line was read in this direction ↧, the second in this ↥, the third in this ↧. At the turn from the second to the third line the record is interrupted. moves clearly and directly toward the wall where the colors hang; the movement is at times halting and uncertain, but its general trend is unmistakable. Moreover, the result can not in general be anticipated, not alone because there are marked differences between individuals in the readiness with which they will manifest involuntary movements, but also because the intensity of the attention and the momentary condition of the subject are important and variable factors in the result. With very good subjects it becomes quite safe to predict the general nature of the result, and the different tracings of the same subject 1 )ear a family resemblance to one another.
A more unusual but very striking form of involuntary movement is shown in Fig. 2. As before, the subject's attention was fixed upon the colors on the wall, but these were arranged in three rows, the first being read from left to right, the second from right to left, and the third from left to right again. The record plainly indicates where the change of direction of reading took place; the correspondence between the movements of the hand and of the attention is perfect, while the movements are unusually direct and extensive. The originator of this record is the best of our subjects, in the sense that the involuntary movements are largest and most predictable.
We may substitute reading from a printed page for the naming of colors and obtain a very similar result. An example is given in Fig. 3, showing, as before, the movement of the hand toward the object of attention.
Fig. 3.— ↦ Reading Printed Page. Time of record, 45 seconds.
The attention may be directed to a sound as well as to a visual impression; this may be conveniently done by listening to the strokes of a metronome. In order to further strengthen the attention the subject is required to count the strokes, the usual rate being one hundred and forty per minute.
Fig. 4.— ↦ Counting the Strokes of a Metronome. Time of record, 70 seconds. It also illustrates slight hesitation before the movement toward the metronome begins.
The result—a typical illustration is given in Fig. 4—shows that the hand moves toward the metronome. If the metronome be placed in front of the subject in one experiment and behind Fig. 5.—Counting the Strokes of a Metronome. Shows the oscillation of the movements with the strokes of the metronome. him in the next, an interesting contrast may be observed. The effect of close attention to the regular strokes of a metronome may show itself in another way. We all appreciate how strong is the tendency to beat time to enlivening music, by tapping with the hands, or stamping with the feet, or nodding with the head; and Dr. Lombard has shown that music is capable of effecting such thoroughly involuntary movements as a sudden rise of the leg when the patella of the knee is struck. It is not surprising, therefore, to find evidences of periodic movements in these automatograms, and in some instances, such as Fig. 5, this pervades the whole record. Here the hand moves to and fro, keeping time—not accurately at all, but in a general way—with the strokes of the metronome.
Fig. 6.— ↦ Counting the Oscillations of a Pendulum. Time of record, 45 seconds.
To obtain similar results for a visual impression, a silently swinging pendulum is used, the subject watching the oscillations and counting them. The result is more frequently a movement toward the pendulum, Fig. 6, but occasionally there appear periodic movements Fig. 7.— ↦ Counting Pendulum Oscillations. Time of record, 80 seconds. Shows movement toward the pendulum at first, and then movements synchronous with its oscillations. due to the pendulum. A very excellent instance of the latter appears in Fig. 7. We may more closely approximate the ordinary experiment of the muscle-reader by giving the subject some object to hide, say a knife, and then asking him to place his hand upon the automatograph and think intently of the place of concealment. As before, there is a movement of the hand, and on the basis of the general direction of this movement one may venture a prediction of the direction in which the knife lies. The results will show all grades of success, from complete failure to an accurate localizing of the object, but as good a record as Fig. 8 is not infrequent. In this case the eyes are closed, and we have not the aid of the senses
Fig. 8.— ↦ Thinking of a Hidden Object. Time, 30 seconds.
in maintaining a concentrated attention; moreover, the position of the subject may not be suited to a ready movement in the direction of the hidden object.
A further interesting mode of concentrating the attention consists in thinking of a building or locality in the neighborhood; a very good record obtained in this way appears in Fig. 9.
The peculiar line of Fig. 10 was obtained in an experiment in which a book was slowly carried about the room, the subject being required to continuously read from the page. It is evident that the hand followed the movement of the attention, not precisely
Fig. 9.— ↤ Thinking of a Locality. Time, 120 seconds. Also illustrates initial hesitancy followed by steady movement toward the object of thought.
in a circle, but in an irregular outline, closing in upon itself. The great differences between individuals which the experience of the muscle-reader would lead us to expect are not lacking here. Some movements are direct and extensive, others circuitous Fig. 10.—Reading from Printed Page, the page being moved about the subject. and brief. Fig. 11 is a good type of a small movement, though it is quite constantly toward the object of the attention. This may be contrasted with another record in which there is a movement of six and a half inches in forty-five seconds. In some cases the first impulse carries the hand toward the object of thought, and is followed by considerable hesitation and uncertainty. A marked example of this tendency may be seen in Fig. 12. There is, too, an opposite type, in which the initial movements are variable, and the significant movement toward the object of thought comes later, when there is perhaps some fatigue. This tendency appears somewhat in Figs, 4 and 9.
How far these movements are involuntary or unconscious must be largely determined by the subjective experiences of those who execute them. While here, as elsewhere, there is some difference among individuals, the consensus of opinion indicates that the subject exercises no essential control over the results; and as a rule he is considerably surprised when the results are first shown to him. At times he becomes conscious of the loss of equilibrium of the apparatus, but the indication is rarely sufficiently definite to inform him of the direction of the movement. Not infrequently Fig. 11.— ↦ Counting Pendulum Oscillations. Time, 120 seconds. Illustrates slow and indirect movement. the movement is unconsciously performed, and is accompanied by a strong conviction that the apparatus has been stationary. In several cases an intentional simulation of the movements was produced for comparison with the other records; the difference between the two is considerable. An objective mode of determining the precise nature of the movements is certainly desirable, but the subjective experiences are entitled to weighty consideration.
No elaborate comment upon the significance of these results is necessary. They merely outline the initial steps in the study of involuntary movements, and leave much to be done to complete our knowledge of the details and variations of this interesting but
Fig. 12.— ↦ Counting Strokes of Metronome. Time of record, 90 seconds. Illustrates initial directness of movement followed by hesitancy.
subtle phenomenon. The results go sufficiently far, perhaps, to indicate how readily one may obtain permanent records of involuntary movements, and how closely related these are to the processes upon which the success of the muscle-reader depends. They bear a striking corroboration of the view that all thought is only more or less successfully repressed action, and that, as an eminent muscle-reader puts it, all willing is either pushing or pulling.
The skin of the giraffe, according to M. H. Bryden, is remarkably thick, reaching in some parts three centimetres. A complete specimen, for mounting, is worth from thirteen to twenty-three dollars. The author asserts that the animal easily escapes detection in its natural condition by the resemblance of its long neck to the trunk of a tree.