The Principles of Psychology, Vols. 1-2

dividuals afflicted with the mania that they are victims of persecution, may all belong to the auditory type ; and that the predominance of a certain kind of imagination may predispose to a certain order of hallucinations, and perhaps of delirium. 'The moto7' type remains — perhaps the most Interesting of all, and certainly the one of which least is known. Persons who belong to this type [les moteurs^ in French, motiles, as Mr. Galton proposes to call them in English] make use, in memory, reasoning, and all their intellectual operations, of images derived from movement. In order to understand this important point, it is enough to remember that 'all our perceptions, and in particular the important ones, those of sight and touch, contain as integral elements the movements of our eyes and limbs ; and that, if movement is ever an essential factor in our really seeing an object, it must be an equally essential factor when we see the same object in imagination ' (Ribot).* For example, the complex impression of a ball, which is there, in our hand, is the resultant of optical impressions of touch, of muscular adjustments of the eye, of the movements of our fingers, and of the muscular sensations which these yield. When we imagine the ball, its idea must include the images of these muscular sensations, just as it includes those of the retinal and epidermal sensations. They form so many motor images. If they were not earlier recognized to exist, that is because our knowledge of the muscular sense is relatively so recent. In older psychologies it never was mentioned, the number of senses being restricted to five.

" There are persons who remember a drawing better when they have followed its outlines with their finger. Lecoq de Boisbaudran used this means in his artistic teaching, in order to accustom his pupils to draw from memory. He made them follow the outlines of figures with a pencil held in the air, forcing them thus to associate muscular with visual memory. Galton quotes a curious corroborative fact. Colonel Moncrieff often observed in North America young Indians who, visiting occasionally his quarters, interested themselves greatly in the engravings which were shown them. One of them followed with care with the point of his knife the outline of a drawing in the Illustrated London News, saying that this was to enable him to carve it out the better on his return home. In this case the motor images were to

* [I am myself a very poor visualizer, and find that I can seldom call to mind even a single letter of the alphabet in purely retinal terms. I must trace the letter by running my mental eye over its contour in order that the image of it shall have any distinctness at all. On questioning a large number of other people, mostly students, I find that perhaps half of them say they have no such difficulty in seeing letters mentally. Many affirm that they can see an entire word at once, especially a short one like ' dog,' with no such feeling of creating the letters successively by tracing them With the eye.— W. J J

reinforce the visual ones. The young savage was a motor. "^ . . . When one's motor images are destroyed, one loses one's remembrance of movements, and sometimes, more curiously still, one loses the power of executing them. Pathology gives us examples in motor aphasia, agraphia, etc. Take the case of agraphia. An educated man, knowing how to write, suddenly loses this power, as a result of cerebral injury. His hand and arm are in no way paralytic, yet he caimot write. Whence this loss of power ? He tells us himself : he no longer knows how. He has forgotten how to set about it to trace the letters, he has lost the memory of the movements to be executed, he has no longer the motor images which, when formerly he wrote, directed his hand. . . . Other patients, affected with word-blindness, resort to these motor images precisely to make amends for their other deficiency. . . . An individual affected in this way cannot read letters which are placed before his eyes, even although his sight be good enough for the purpose. This loss of the power of reading by sight may, at a certain time, be the only trouble the patient has. Individuals thus mutilated succeed in reading by an ingenious roundabout way which they often discover themselves : it is enough that they should trace the letters with their finger to understand their sense. What happens in such a case ? How can the hand supply the place of the eye ? The motor image gives the key to the problem. If the patient can read, so to speak, with his fingers, it is because in tracing the letters he gives himself a certain number of muscular impressions which are those of writing. In one word, the patient reads by writing (Charcot): the feeling of the graphic movements suggests the sense of what is being written as well as sight w^ould."f

The imagination of a blind-deaf mute like Laura Bridgman must be confined entirely to tactile and motor material. All Uivd persons must belong to the * tactile ' and * motile^ types of the French authors. When the young man whose cataracts were removed by Dr. Franz was shown different geometric figures, he said he " had not been able to form from them the idea of a square and a disk until he perceived a sensation of what he saw in the points of his fingers, as if he really touched the objects." %

Professor Strieker of Vienna, who seems to have the motile form of imagination developed in unusual strength, * It is hardly needful to say that in modern primary education, in which the blackboard is so much used, the children are taught their letters, etc., by all possible channels at once, sight, hearing, and movement. f See an interesting case of a similar sort, reported by Farges, in TEd c^phale, 7me An nee, p. 545. has given a very careful analysis of "his own case in a couple of monographs with which all students should become familiar.* His recollections both of his own movements and of those of other things are accompanied invariably by distinct muscular feelings in those parts of his body which would naturally be used in effecting or in following the movement. In thinking of a soldier marching, for example, it is as if he were helping the image to march by marching himself in his rear. And if he suppresses this sympathetic feeling in his own legs, and concentrates all his attention on the imagined soldier, the latter becomes, as it were, paralyzed. In general his imagined movements, of whatsoever objects, seem paralyzed the moment no feelings of movement either in his own eyes or in his own limbs accompany them.f The movements of articulate speech play a predominant part in his mental life.

"When after my experimental work I proceed to its description, as a rule I reproduce in the first instance only words, which I had already associated with the perception of the various details of the observation whilst the latter was going on. For speech plays in all my observing so important a part that I ordinarily clothe phenomena in words as fast as I observe them." X Most persons, on being asked in what sort of terms they imagine words, will say * in terms of hearing.' It is not until their attention is expressly drawn to the point that they find it difficult to say whether auditory images or motor images connected with the organs of articulation predominate. A good way of bringing the difficulty to consciousness is that proposed by Strieker : Partly open your mouth and then imagine any word with labials or dentals in it, such as * bubble,' * toddle.' Is your image under these conditions distinct ? To most people the image is at first * thick,' as the sound of the word would be if they tried to pronounce it with the lips parted. Many can never imagine the words

* Studien aber die Sprachvorstellungen (1880), and Studien tiber die Bewegungsvorstellungen (1882). f Prof. Strieker admits that by practice he has succeeded in making bis eye-movements ' act vicariously ' for his leg-movements in imagining men walking. clearly with the mouth open ; others succeed after a few preliminary trials. The experiment proves how dependent our verbal imagination is on actual feelings in lips, tongue» throat, larynx, etc. "When we recall the impression of a word or sentence, if we do not speak it out, we feel the twitter of the organs just about to come to that po'.nt. The articulating parts— the larynx, the tongue, the lips— are all sensibly excited ; a suppressed articulation is in fact the material of our recollection, the intellectual manifestation, the idea of speech. "*

The open mouth in Strieker's experiment not only prevents actual articulation of the labials, but our feeling of its openness keeps us from imagining their articulation, just as a sensation of glaring light will keep us from strongly imagining darkness. In persons whose auditory imagination is weak, the articulatory image seems to constitute the whole material for verbal thought. Professor Strieker says that in his own case no auditory image enters into the words of which he thinks, f Like most psychologists, however, he makes of his personal peculiarities a rule, and says that verbal thinking is normally and universally an exclusively motor representation. I certainly get auditory images, both of vowels and of consonants, in addition to the articulatory images or feelings on which this author lays such stress. And I find that numbers of my students, after repeating his experiments, come to this conclusion. There is at first a difficulty due to the open mouth. That, however, soon vanishes, as does also the difficulty of thinking of one vowel whilst continuously sounding another. What probably remains true, however, is that most men have a less auditory and a more articulatory verbal imagination than they are apt to be aware of.

t Studien iiber Sprachvorstellungen, 28, 31, etc. Cf. pp. 49-50, etc. Against Strieker, see Sturapf, Tonpsychol, 155-162, and Revue Philosophique, xx. 617. See also Pauihan, Rev. Philosophique, xvi. 405 Strieker replies to Pauihan in vol. xviii. p. 685. P. retorts in vol. xix p. 118. Strieker reports that out of 100 persons questioned he found onlj one who had no feeling in his lips when silently thinking the letters M B, P; and out of 60 only two who were conscious of no internal articulation whilst reading (pp 59-60).

Professor Strieker himself has acoustic images, and can imagine the sounds of musical instruments, and the peculiar voice of a friend. A statistical inquiry on a large scale, into the variations of acoustic, tactile, and motor iiijagination, would probably bear less fruit than Galton's inquiry into visual images. A few monographs by competent observers, like Strieker, about their own peculiarities, would give much more valuable information about the diversities which prevail.*

Tomh'images are very strong in some people. The most vivid touch-images come when we ourselves barely escape local injury, or when we see another injured. The place * I think it must be admitted that some people have no vivid substantive images in any department of their sensibility. One of my students, an intelligent youth, denied so pertinaciously that there was anything in his mind at alt when he thought, that I was much perplexed by his case. I myself certainly have no such vivid play of nascent movements or motor images as Professor Strieker describes. When I seek to represent a row of soldiers marching, all I catch is a view of stationary legs first in one phase of movement and then in another, and these views are extremely imperfect and momentary. Occasionally (especially when I try to stimulate my imagination, as by repeating Victor Hugo's lines about the regiment, " Leur pas est si correct, sans tarder ni courir, Qu'on croit voir des ciseaux se farmer et s^ouvrir,")

I seem to get an instantaneous glimpse of an actual movement, but it is to the last degree dim and uncertain. All these images seem at first as if purely retinal. I think, however, that rapid eye-movements accompany them, though these latter give rise to such slight feelings that they are almost impossible of detection. Absolutely no leg-movements of my own are there ; in fact, to call such up arrests my imagination of the soldiers. My optical images are in general very dim, dark, fugitive, and contracted. It would be utterly impossible to draw from them, and yet I perfectly well distinguish one from the other. My auditory images are excessively inadequate reproductions of their originals. I have no images of taste or smell. Touch-imagination is fairly distinct, but comes very little into play with most objects thought of. Neither is all my thought verbalized; for I have shadowy schemes of relation, as apt to terminate in a nod of the head or an expulsion of the breath as in a definite word. On the whole, vague images or sensations of movement inside of my head towards the various parts of space in which the terms I am thinking of either lie or are momentarily symbolized to lie together with movements of the breath through my pharynx and nostrils, form a by no means inconsiderable part of my thought-stuff. I doubt whether my difficulty in giving a clearer account is wholly a matter of inferior power of introspective attention, though that doubtless plays its part. Attention, ceteris pa^ibtts, must always be inferior in proportion lo the feebleness of the internal images which are offered it to bold on to.

may then actually tingle with the imaginary sensation — perhaps not altogether imaginary, since goose-flesh, paling or reddening, and other evidences of actual muscular contraction in the spot may result. " An educated man," says a writer who must always be quoted when it is question of the powers of imagination,* "told me once that on entering his house one day he received a shock from crushing the finger of one of his little children in the door. At the moment of his fright he felt a violent pain in the corresponding finger of his own body, und this pain abode with him three days."

The same author makes the following discrimination, wiiich probably most men could verify : " On the skin I easily succeed in bringing out suggested sensationfc wherever I will. But because it is necessary to protract the mental effort I can only awaken such sensations as are in their nature prolonged, as warmth, cold, pressure. Fleeting sensations, as those of a prick, a cut, a blow, etc., I am unable to call up, because I cannot imagine them ex ahrupto with the requisite intensity. The sensations of the former order I can excite upon any part of the skin ; and they may become so lively that, whether I will or not, I have to pass my hand over the place just as if it were a real impression on the skin." f

Meyer's account of his own visual images is very interesting ; and with it we may close our survey of differences between the normal powers of imagining in different individuals* "With much practice," he says, " I have succeeded in making it possible for me to call up subjective visual sensations at will. I tried all my experiments by day or at night with closed eyes. At first it was very difficult. In the first experiments which succeeded the whole picture was luminous, the shadows being given in a somewhat less strong bluish light. In later experiments I saw the objects dark, with bright outlines, or rather I saw outline drawings of them, bright on a dark ground. I can compare these drawings less to chalk drawings on a blackboard than to drawings made with phosphorus on a dark wall at night, though the phosphorus would show luminous vapors which were absent from my lines. If I wished, for example, to see a face, without intending that of a particular person, I saw the outline of a profile against the dark background. When I tried to repeat an eX«

* Geo, Herm. Meyer, Untersuchungen iib. d. Physiol, d. Nervenfaser (1843} , p. 233. For other cases see Tuke's Influence of Mind upon Body, chaps, i:. and vii. periment of the elder Darwin I saw only the edges of the die as brigbt lines on a dark ground. Sometimes, however, I saw the die really white and its edges black ; it was then on a paler ground. I could soon at will change between a white die with black borders on a light field, and a black die with white borders on a dark field ; and I can do this at any moment now. After long practice . . . these experiments succeeded better still. I can now call before my eyes almost any object which I please, as a subjective appearance, and this in its own natural color and illumination. I see them almost always on a more or less light or dark, mostly dimly changeable ground. Even known faces I can see quite sharp, with the true color of hair and cheeks. It is odd that I see these faces mostly in profile, whereas those described [in the previous extract] were all full-face. Here are some of the final results of these experiments :

" 1) Some time after the pictures have arisen they vanish or change into others, without my being able to prevent it. ' ' 2) When the color does not integrally belong to the object, I cannot always control it. A face, e.g., never seems to me blue, but always in its natural color ; a red cloth, on the other hand, I can sometimes change to a blue one. " 3) I have sometimes succeeded in seeing pure colors without objects; they then fill the entire field of view.

" 4) I often fail to see objects which are not known to me, mere fictions of my fancy, and instead of them there will appear familiar objects of a similar sort ; for instance, I once tried to see a brass swordhilt with a brass guard, instead of which the more familiar picture of a rapier-guard appeared. " 5) Most of these subjective appearances, especially when they were bright, left after-images behind them when the eyes were quickly opened during their presence. For example, I thought of a silver stirrup, and after I had looked at it a while I opened my eyes and for a long while afterwards saw its after-image.

" These experiments succeeded best when I lay quietly on my back and closed my eyes. I could bear no noise about me, as this kept the vision from attaining the requisite intensity. The experiments succeed with me now so easily that I am surprised they did not do so at first, and I feel as though they ought to succeed with everyone. The important point in them is to get the image suflBciently intense by the exclusive direction of the attention upon it, and by the removal of all disturbing impressions." *

Urn negative after-images which succeeded upon Meyer's imagination when he opened his eyes are a liighlj interesting, though rare, phenomenon. So far as I know there is only one other published report of a similar experience.* It would seem that in such a case the neural process corresponding to the imagination must be the entire tract concerned in the actual sensation, even down as far as the retina. This leads to a new question to which we may now turn — of what is

The commonly-received idea is that it is only a milder degree of the same process which took place when the thing now imagined was sensibly perceived. Professor Bain writes: *' Since a sensation in the first instance diffuses nerve-currents through the interior of the brain outwards to the organs of expression and movement,— the persistence of that sensation, after the outward exciting cause is withdrawn, can be but a continuance of the same diffusive currents, perhaps less intense, but not otherwise different. The shock remaining in the ear and brain, after the sound of thunder, must pass through the same circles, and operate in the same way as during the actual sound. We can have no reason for believing that, in this self-sustaining condition, the impression changes its seat, or passes into some new circles that have the special property of retaining it. Every part actuated after the shock must have been actuated hy the shock, only more powerfully. With this single difference of intensity, the mode of existence of a sensation existing after the fact is essentially the same as its mode of existence during the fact. . . . Now if this be the case with impressions persisting when the cause has ceased, what view are we to adopt concerning impressions reproduced by mental causes alone, or without the aid of the original, as in ordinary recollection ? What is the manner of occupation of the brain with a resuscitated feeling of resistance, a smell or a sound ? There is only one answer that seems admissable. The renewed feeling occupies the very same parts^ and in the same manner, as the original feeling, and no other parts, nor in any other assignable manner. I imagine that if our present knowledge of the brain had been present to the earliest speculators, this is the only

* That of Dr. Ch. Fere in the Revue Philosophique, xx. 364. Johannes Mllller's account of hypnagogic hallucinations floating before the eyes for A few moments after these had been opened, seems to belong more to the category of spontaneous hallucinations (see his Physiology, London, 1842, p. 1394). It is impossible to tell whether the words in Wundt's Vorlesungen, i. 387, refer to a personal experience of his own or not ; probably not. 11 va sans dire that an inferior visualizer like myself can get no such after-images. Nor have I as yet succeeded in getting report of any from my students.

hypothesis that would have occurred to them. For where should a past feeling be embodied, if not in the same organs as the feeling when present ? It is only in this way that its identity can be preserved ; a feeling differently embodied would be a different feeling."* It is not plain from Professor Bain's text whether by the * same parts ' he means only the same parts inside the brain, or the same peripheral parts also, as those occupied by the original feeling. The examples which he himself proceeds to give are almost all cases of imagination of movement, in which the peripheral organs are indeed affected, for actual movements of a weak sort are found to accompany the idea. This is what we should expect. All currents tend to run forward in the brain and discharge into the muscular system ; and the idea of a movement tends to do this with peculiar facility. But the question remains : Do currents run backward, so that if the optical centres (for example) are excited by * association ' and a visual object is imagined, a current runs doivn to the retina also, and excites that sympathetically with the higher tracts ? In other v^ords, can peripheral sense-organs he excited from above, or only from without ? Are they excited in imagination ? Professor Bain's instances are almost silent as to this point. All he says is this :

" We might think of a blow on the hand until the skin were actually irritated and inflamed. The attention very much directed to any part of the body, as the great toe, for instance, is apt to produce a distinct feeling in the part, which we account for only by supposing a revived nerve-current to flow there, making a sort of false sensation, an influence from within mimicking the influences from without in sensation proper. — (See the writings of Mr. Braid, of Manchester, on Hypnotism, etc.)"

If I may judge from my own experience, all feelings of this sort are consecutive upon motor currents invading the skin and producing contraction of the muscles there, the muscles whose contraction gives * goose-flesh ' when it takes place on an extensive scale. I never get a feeling in the skin, however strongly I imagine it, until some actual change in the condition of the skin itself has occurred. The truth seems to be that the cases where peripheral

sense-organs are directly excited in consequence of imagi nation are exceptional rarities, if they exist at all. In common cases of imagination it would seem more natural to suppose that the seat of the process is purely cerebral^ and that the senseorgan is left out. Reasons for such a conclusion would be briefly these : 1) In imagination the starting-point of the process must be in the brain. Now we know that currents usually flow one way in the nervous system ; and for the peripheral senseorgans to be excited in these cases, the current would have to flow backward.

2) There is between imagined objects and felt objects a difference of conscious quality which may be called almost absolute. It is hardly possible to confound the liveliest image of fancy with the weakest real sensation. The felt object has a plastic reality and outwardness which the imagined object wholly lacks. Moreover, as Fechner says, in imagination the attention feels as if drawn backwards to the brain ; in sensation (even of after-images) it is directed forward towards the sense-organ.* The difference between the two processes feels like one of kind, and not like a mere *more' or * less ' of the same.f If a sensation of sound were only a strong imagination, and an imagination a weak sensation, there ought to be a border-line of experience where we never could tell whether we were hearing a weak sound or imagining a strong one. In comparing a present sensation felt with a past one imagined, it will be remembered that we often judge the imagined one to have been tJie stronger (see above, p. 500, note). This is inexplicable if the imagination be simply a weaker excitement of the sensational process.

To these reasons the following objections may be made : To 1) : The current demonstrably does flow backward f V. Kandinsky (Kritische u. klinische Betrachtungen im Gebiete der Sinnestauschungen (Berlin, 1885), p. 135 ff.) insists that in even the liveliest pseudo-hallucinations (see below, Chapter XX), which may be regarded as the intensest possible results of the imaginative process, there Is no outward objectivity perceived in the thing represented, and that a gamer Ahgrund separates these ' ideas' from true hallucination and objectlTe perception.

down the optic nerve in Meyer's and Fere's negative afterimage. Therefore it can flow backward ; therefore it may flow backward in some, however slight, degree, in all imagination.* To 2) : The difference alleged is not absolute, and sensation and imagination are hard to discriminate whera the sensation is so weak as to be just perceptible. At night hearing a very faint striking of the hour by a far-off clock, our imagination reproduces both rhythm and sound, and it is often difiicult to tell which was the last real stroke. So of a baby crying in a distant part of the house, we are uncertain whether we still hear it, or only imagine the soundo Certain violin-players take advantage of this in diminuendo terminations. After the pianissimo has been reached they continue to bow as if still playing, but are careful not to touch the strings. The listener hears in imagination a