Simple Image and Feeling

Conceptions and apparitions [sensations and images] are nothing really but motion in some internal substance of the head; which motion not stopping there, but proceeding to the heart, of necessity must there either help or hinder the motion which is called vital; when it helpeth, it is called pleasure; but when such motion weakeneth or hindereth the vital motion, then it is called pain.—Thomas Hobbes

§ 17. Simple Images.—Common sense draws a sharp distinction between our present perception of an object or event, and our later revival of it in memory; and psychologists have been accustomed, in the same way, to distinguish the simple sensation, the elementary process in perception, from the simple image, the elementary process in memory. In fact, however, it is very doubtful if there is any real psychological difference between sensation and image. The statement is often made that the image is weaker, fainter, more fleeting than the corresponding sensation. Thus, the great philosopher David Hume (1711-1776) wrote: “All the perceptions of the human mind resolve themselves into two distinct kinds, which I shall call impressions and ideas. [Hume’s terminology is different from ours.] The difference between these consists in the degrees of force and liveliness, with which they strike upon the mind.” Hume himself admits that “in sleep, in a fever, in madness, or in any very violent emotions of soul, our ideas may approach to our impressions; as on the other hand it sometimes happens that our impressions are so faint and low, that we cannot distinguish them from our ideas.” It is certain that sensation and image are often confused; and some writers have accordingly proposed to drop the term ‘image’ and to replace it by ‘secondary sensation.’ Let us look at the facts.

There is no department of sense in which sensation stops entirely when its stimulus is removed; in all cases, even in that of sound, the sensation is prolonged, for a longer or shorter time, and either after an interval or without interruption, in what is called the positive after-image. Blow out a match in the dark, and wave the glowing stem about; you see complete circles or figures of eight; the sensation persists, although the stimulus has passed from one part of the retina to another. In some departments, the positive is followed by a negative after-image; we have already mentioned the antagonistic after-images of sight. So the removal of a continued warm stimulus leaves a sensation of coolness; and the swimming in the head that you feel while twirling round is followed, when you come to rest, by a swimming in the opposite direction. Lastly, the name of memory after-image has been given to an experience which is most familiar, perhaps, in the taking of dictation; as you write the words last spoken, the speaker’s voice still rings in your ears; the sound hangs for a few seconds, as if arrested, and your pen is guided by the mental echo. Similarly, an attentive glance at an object may set up a sort of photographic image that remains distinct for several seconds.

All the after-images are sensory in character. So too are the memory colours that we habitually lay over familiar objects (p. 63), and that make us see snow as white and gold as yellow and coal as black, just because they are ordinarily or typically white and yellow and black. So also are the recurrent images, those troublesome and haunting images to which most of us are subject at times: the tunes that run in our head and that we cannot get rid of, the rows of figures that obsess us after a long morning of calculation, the bright disc that keeps cropping up after we have spent several hours at the microscope. So, again, are the images that serve to complete and round out an imperfect perception. A favourite device of modern advertising is to outline the human figure only in part and to leave the remainder to the imagination; and you will perhaps notice, if you look attentively at such a figure, that the outline, so far as the suggestion of the neighbouring lines is unambiguous, is indeed completed in image, black on white or colour on colour; only where the completion is uncertain do the images fail. These tied images, so called because they are unequivocally bound up with the sensory portion of the perception, occur also in the sphere of sound; a missing orchestral part, if it is familiar, may be clearly heard by the conductor.

Not everyone has recurrent images; and perhaps only a large minority have tied images. The image—even if we decide that it is only a secondary sensation, psychologically indistinguishable from sensation—nevertheless represents a later stage of biological development than the sensation proper, and our equipment of images is correspondingly variable; your own experience may be richly imaginal, while your friend, under the same conditions, has hardly a trace of imagery. Those who do possess recurrent and tied images agree that they are distinguished from sensations rather by their context, by the presence or absence of certain other processes, than by any difference of nature. The same thing holds of those abnormal phenomena to which Hume referred. Hallucinatory images are by no means uncommon in the drowsy period that precedes sleep; we hear the telephone bell, or we hear our name called; some of us—there are, again, great differences in individuals—have hallucinations of sight. Dream images also differ markedly from individual to individual; but the dream is nearly always accepted as a real event. One of the most puzzling facts in this connection is the occurrence of concomitant or synÆsthetic images. In the commonest case, that of coloured hearing, any auditory stimulus arouses, along with the appropriate sensation of hearing, whether tone or noise, a visual image of light or colour. The sound of the word Tuesday, for instance, may be seen as a light grey-green followed by a yellow! We might suppose, at first thought, that coloured hearing is due to association, to a connection between sight and hearing set up in childhood and continued into adult life; but the evidence points to some inborn connection in the nervous system; coloured hearing tends strongly to run in families. Moreover, we know of no natural or normal association of colours with tones, although the attempt has often been made to illustrate music by colours; the recent colour-scoring of the Russian composer Scriabin is, for instance, nothing more than an idiosyncrasy, and will make no general or permanent appeal to the musical public. There are many other kinds of synÆsthesia, besides this connection of sight and sound; and we have no reason to think that every instance is to be explained in just the same way; in all cases, however, we have a particular sensation uniformly accompanied by another, which we may call either a secondary sensation or an image of sensory character.

Coming back to the normal life, we have next to note the part played in certain minds by habitual images. Just as, in Wagner’s operas, the performer comes upon the stage to the accompaniment of some characteristic musical phrase, some ‘motive,’ as it is called, which recurs again and again as he enters and reenters to take his share of the action, so in minds of the imaginal type such general notions as ‘virtue’ and ‘commerce’ and ‘summer’ may regularly call up mental pictures, little groups of images, which illustrate or characterise the notions: thus, virtue may be pictured mentally by the flash of a human figure, standing very upright. These pictures are usually incomplete, mere impressionist sketches; but they may remain unchanged for years.

Finally, we come to the images which enter into our ideas of memory and of imagination. We discuss these ideas later; here we need only say that the psychological distinction between sensation and image, if it is to be drawn at all, must be drawn between sensation and the free images of memory and imagination, and cannot be drawn earlier. Some psychologists believe that a memory-image can always be distinguished from a sensation, that the two processes differ in their intrinsic nature. It is difficult to put the question to the test of experiment; but what evidence we have seems to look the other way. We shall do best to suspend judgement.

The word ‘image’ is unfortunately used, as the foregoing paragraphs have shown, both for the simple image and for groups or clusters of images; thus, the recurrent image and the habitual image are always complex. Summing up our results, with this warning in mind, we may say that positive and negative after-images, memory colours, and synÆsthetic images are definitely sensory in character; that the simple images which make up memory after-images, recurrent and tied and habitual images, hallucinations and dreams, appear to be of the same kind; and that the simple images which compose our ideas of memory and imagination may or may not be intrinsically different from sensations. The simple image may therefore be defined as an elementary mental process, akin to sensation and perhaps indistinguishable from it, which persists when the sensory stimulus is withdrawn or appears when the sensory stimulus is absent. We may say further that, while every normal person has very much the same equipment of sensations, there are great individual differences in the matter of secondary sensations or images; in some cases they are interwoven into the whole tissue of experience, in others they are infrequent or even lacking; we shall see presently how they may be replaced. In general, images of sight and sound are common; then come images of touch and temperature, and then again images of taste and smell, which are uncommon; organic images are very rare. KinÆsthetic images undoubtedly occur, and probably occur frequently; but they are likely to blend with kinÆsthetic sensations, and so to escape notice.

§ 18. Simple Feelings and Sense-Feelings.—Many of our experiences are indifferent; but many of them, again, are pleasant or unpleasant. These two words, pleasant and unpleasant, denote elementary mental processes of a different sort from sensations and images; they are known as simple feelings. The term ‘feeling’ is itself even more ambiguous than the term ‘image’; it is natural to speak of ‘feeling’ a strain or effort, a warmth or cold; but we shall henceforth use it only in its technical meaning, to indicate the way in which stimuli affect us, pleasantly or unpleasantly. We must discard altogether the words pleasure and pain, although they have long been current as the names of the simple feelings, and although they are much less clumsy than pleasant and unpleasant. We discard them because pain is a sensation (p. 43); and pains, while usually unpleasant, may at times be pleasant; the scratching that relieves an itch and the nip of the wind on a brisk winter’s day are both pains, but they are also both pleasant.

The main difference between sensation and simple feeling is that a feeling cannot be made the object of direct attention. Try to attend to the pleasantness or unpleasantness of an experience, and the feeling evaporates, eludes you; it is like clutching a ghost; you find yourself beyond the feeling, so to speak, and face to face with some obtrusive sensation or image that you had no wish to meet. This peculiarity of feeling must, of course, be taken account of in our conduct of the psychological method of observation. The formula of observation (p. 19) was:

psychological (vivid experience ? full report).

In the case of sensation, the observer is set or disposed, beforehand, to attend to sensation and to report upon sensation; the sensation comes, and is attended to; and the report which follows is determined, under the influence of the preliminary set or disposition, by the nature of the sensation. In the case of feeling, the observer is set to attend to sensation, but to report upon the feeling which accompanies the sensation; the sensation comes and is attended to; and the report then describes, under the influence of the preliminary set, the feeling which accompanied the sensation. That sounds a little paradoxical; but the method is not difficult in practice; and it has the advantage that we can use all manner of sensory stimuli (colours, tones, everything) in our study of feeling.

We find, first of all, that pleasant and unpleasant are really opposites; the colour or tone that is most often reported as pleasant is least often reported as unpleasant, and conversely. An obvious result? Not at all; for what is obvious to common sense demands very careful consideration at the hands of science; and the fact that, in this instance, common sense turns out to be right does not at all mean that we should have been justified in taking it for granted. We find, secondly, that intensity of feeling behaves like intensity of sensation (p. 67); the more pleasant or unpleasant an experience is, the more must the stimulus be changed if we are to feel a difference; and the less pleasant or unpleasant it is, the less change need be made to produce a change of feeling.

There is no convincing evidence of any qualities of feeling other than pleasant and unpleasant. There is evidence, on the other hand, that the simple feelings form intimate and characteristic blends with sensations, and especially with kinÆsthetic and organic sensations; we may call such blends sense-feelings. Every sensory stimulus, even so local and trifling a thing as a tone of moderate intensity, sets up a widespread organic disturbance: a result that is natural, perhaps, in view of the manifold interconnections within the nervous system, but that we are nevertheless likely to overlook. This organic stir brings out kinÆsthetic and organic sensations which may form the body of a sense-feeling, developed round about the disturbing tone, and giving it a peculiar tinge of feeling that it would not otherwise possess. The same thing holds of other stimuli. We can distinguish six types or classes of these sense-feelings: the agreeable and disagreeable, the exciting and subduing, and the straining and relaxing. Tastes and smells are preeminently agreeable or disagreeable. Deep tones are solemn and serious, that is, subduing; high tones are cheerful and playful, that is, exciting. The painter’s ‘warm’ colours, red and yellow, are exciting; his ‘cold’ blues are subduing; the gloom of a darkened room is positively depressing. Warmth and cold are themselves exciting and subduing. The straining and relaxing feelings are dependent upon the temporal course and succession of sensations; the interminable pedal-point in E? with which Wagner begins the Ring sets up a feeling of tension which is relaxed when the B? is added, only to grow again, and again relax when new tones are introduced; and if you follow the strokes of a slow-beating metronome you get a similar alternation of the two sense-feelings. Notice that the six names are all alike class-names; the sense-feelings themselves appear in numberless variety; but any particular sense-feeling may be referred to one or more of the classes. Notice also that the paired names are all opposites: a sense-feeling may be agreeably exciting, or agreeably subduing, but it cannot be excitingly subduing; and so on with the rest. Remember finally that the simple feeling taken alone, and not blended with sensory qualities into a sense-feeling, is always a bare pleasant or unpleasant.

We must next discuss the organic disturbances that accompany feeling itself. We know that feelings ‘express’ themselves in various ways; we blush for shame and pale from fear; we shake with rage, and our ‘heart beats high’ with hope. Now it is possible to measure all these organic changes; to record the rate and height of pulse, for instance, or the variation in the volume of a limb according as blood flows into it or is withdrawn from it; physiology puts the necessary instruments at our disposal. The observer may therefore be harnessed to some such system of recording apparatus, and may be subjected to some pleasant or unpleasant stimulus; he reports what he feels, and the experimenter is able to compare the report with the record from the instrument. The results of work of this sort are summed up in the following table; where a + stands for an increase, and a-for a decrease, of rate or height or volume, as the case may be.

The table asserts that, during a pleasant experience, our pulse is slowed and heightened; blood flows from the trunk into the extremities; and our breathing quickens and, perhaps, grows more shallow. During an unpleasant experience, the reverse of all these things takes place.

The pleasant and unpleasant experiences here referred to are, of course, agreeable and disagreeable sense-feelings; and we have the right to correlate the organic changes with pleasant and unpleasant feeling only because they remain the same so long as feeling remains the same, whatever may be the character of the sensory stimulus. There can be no doubt that similar tables may presently be made out for the other sense-feelings; indeed, that must be the case, in so far as the sense-feelings are stable blends of simple feeling with sensations. But it is not easy, in the case of the other pairs, to secure a stable blend, to keep the nature of the ‘excitement’ or the ‘relaxation’ just the same from experiment to experiment; and we shall therefore make no attempt here to list their bodily expressions. We come back to the general subject of expression when we deal with emotion (§ 51).

Can we now say anything definite about the nervous correlate of the simple feelings? Can we say what is going on in the nervous system when we feel pleasantly or unpleasantly? Unfortunately no: we have many theories, but no positive knowledge. There is, however, one view of feeling which has persisted from Aristotle to the present day; and we must say a word about it, if only because you cannot read far in psychology without running against some form of it, and you should not blindly accept it. We may call it the biological theory of feeling. Aristotle said that pleasure (we must now use the old-fashioned terms) accompanies the unimpeded exercise of any faculty, that is, the healthy exercise of any mental faculty upon its appropriate object; and that pain accompanies impeded activity. In more modern language, pleasure is for Aristotle a matter of efficiency. Herbert Spencer puts the same idea into evolutionary language; “pains are the correlatives of actions injurious to the organism, while pleasures are the correlatives of actions conducive to its welfare.” Does this statement really mean, though, that a man’s personal pleasures are always good for him and his personal pains bad for him?—because, if that is meant, it is not difficult to think of any number of cases to the contrary. No, not quite that; Spencer would qualify by saying that nature can only strike an average for the species; she cannot attend in detail to the individual; the sentence means that on the whole, in the long run, pleasures are good and pains are bad for us. We might reply that it is rather a poor average that makes the tearing off of a finger nail so exquisitely painful, though the loss hardly matters, and that allows the ravages of pulmonary tuberculosis to run so long a course before warning is given to the suffering organism. But let us offer a definite objection: a surgical operation is not pleasant; yet it may be the one thing necessary to save life. Spencer has his answer: “special and proximate pleasures and pains must be disregarded out of consideration for remote and diffused pleasures and pains.” In that case, however,—if the feelings are merely witnesses to the state of affairs at the moment, and not prophets of the future,—the correlation does not help us very much; nature’s achievement is less important, even for the species, than it seemed at first. Or take another objection: I am overheated, and I sit in a cooling draught; the result is catarrh or pneumonia; yet the coolness was pleasant. To be sure, says the biologist; and the local effect was good for you; the testimony of the feelings is limited in space as I have just acknowledged it to be limited in time. Again, however, we must rejoin that, in that event, the correlation is of less importance to the race than it was asserted to be; if things that are ‘sweet in the mouth’ are going to be ‘bitter in the belly’ we want to know it; it is small comfort to be told that the organ of taste is benefited by the pleasant sweetness. And so the argument might go on.

There is yet another difficulty. “Every pleasure,” says Spencer, “increases vitality; every pain decreases vitality. Every pleasure raises the tide of life; every pain lowers the tide of life.” Yet we read elsewhere that “pleasures are the incentives to life-supporting acts, and pains the deterrents from life-destroying acts.” Pain, then, is thoroughly bad for us, because it is detrimental to life; but pain at the same time is thoroughly good for us, because it prevents our doing what is detrimental to life. Pain as detrimental ought to have been eliminated by natural selection; pain as warning of what is detrimental has been conserved by natural selection. Can the two points of view be reconciled?

It would be foolish and overhasty to reject outright the biological view of feeling; the very fact that it has lasted through so many centuries and, in some form or other, has appealed to so many psychologists—the quotation which heads this chapter is a case in point!—raises a presumption in its favour. Our conclusion must rather be this: that general formulas, which need to be qualified almost as soon as they are phrased, and which lay themselves open to all kinds of specific objections, cannot help us to a psychology of feeling—or of anything else. When we have found out, by detailed experimental work, what the nervous correlate of simple feeling really is, then we may perhaps advance to some general biological view; but the detailed work must come first.

Questions and Exercises

(1) Answer the questions printed on pp. 255, 256 of F. Galton’s Inquiries into Human Faculty and Its Development (Everyman’s Library, E. P. Dutton & Co., New York; price 35 cents). When you have answered them, read Galton’s discussion of mental imagery, pp. 57 ff. (You will find many other interesting things in the book; for instance, the discussion of synÆsthesia, pp. 105 ff.)

(2) Try to secure a memory after-image, (a) by glancing attentively at a lamplit study-table, and then closing the eyes; and (b) by listening attentively to a short musical phrase or to a dictated sentence. How do you distinguish this image from a positive after-image?

(3) Describe the tied images that you find in the following figure.