268 Attention organic excitations of different kinds. I could easily lapse into a reminiscent mood, letting these impressions suggest to me scenes from my past life. I could easily give the rein to my imagination, thinking of the further business of the day, anticipating some event that is to happen in the near or distant future. But I am, in fact, perfectly well able to ignore all distractions, and to devote myself entirely to a single self-chosen idea, — the idea of the problem that awaits solution. It is true, then, that this idea is clear and central, while all the other conscious processes of the moment are obscure and marginal. But it seems to be true, also, that the clearness of the idea is rather a matter of the mind's own concen-_ tration than of any character of the idea itself. Besides, I can turn my mind, if I like, to something entirely_diffjexejit; I cjmj2[iye_ up the problemwhenever I fee^ disposed.
That is the situation in attention, as popular psychology sees it. We must take up the implied challenge, and see whether our own methods can throw any further light upon the question.
§ j6. The Development of Attention. — Attention, as the term is popularly understood, has two forms. It may be passive and involuntary, or it may be active and voluntary. These forms are, in fact, characteristic of different stages in mental development; they differ simply in complexity, as earlier and later; they show us the same type of con- sciousness, but at different periods of our mental growth. It will, however, clear the ground if we now enquire wherein their difference consists, and what are the conditions of their occurrence.
There is, in the first place, an attention that we are compelled to give and are powerless to prevent. Or, to put the same thing in other words, there are impressions that we cannot help attending to, that take consciousness by storm. Intensive stimuli belong to this class. Loud sounds, bright lights, strong tastes and smells, severe § y6. The Development of Attention 269 pressures, extreme temperatures, intense pains, — all these are clear in virtue of their intensity; they attract our attention, as the phrase goes, in spite of ourselves; they force their way to the focus of consciousness, whatever the obstacles that they have to overcome. In the same way, there are certain qualities that irresistibly draw the atten- tion: here belong in the writer's experience — though there are very considerable differences between individu- als— the taste of bitter, the smell of musk, the sight of yellow. A stimulus that is repeated, again and again, is I p^V* likely to attract the attention, even if at first it is entirely/ c / c / unremarked. Sudden stimuli, and sudden changes of stim- \J ulus, have the same effect. So with movement: the ani-^ mal or bird that crosses the landscape, the melody that v rises and falls to a steady, uniform accompaniment, the insect that crawls over our hand as we lie upon the grass, these things constrain us to attend to them. Novelty, \ too, arrests the attention. The novel impression is, in \ psychological terms, the impression that finds no associ- ates when it enters consciousness; that stands alone, in isolation. Such an impression, if it is at all intensive, becomes clear in its own right; it is startling, just as the sudden stimulus is surprising and the moving stimulus ia disturbing^ And lastly, paradoxical as it sounds, impres- sions that are in a sense the reverse of novel claim the attention, — impressions that fit in with, are associated to, the present trend of consciousness. The collector, the in- ventor, the expert are roused to keen attention by stimuli which the rest of the world pass without notice. Most of the striking coincidences in life are accounted for by this law: you are thinking about certain things, and something happens that, because you are thus thinking and because 270 Attention 270 Attention it is akin to the subject of your thought, captures your attention. What a remarkable coincidence! you cry: but if you had been thinking of something else, there would have been no coincidence. The man in Mr. Kipling's story who wondered, years after the event, how in the world he could have written such good stuff as that, had written under this same law of attention; for when you are thoroughly absorbed in a topic, relevant facts and ideas crowd in upon consciousness; the mind stands wide open to them, while it is fast locked against the irrelevant; and you surpass yourself.
Here, then, is a fairly long list. Intensity, quality, repe- tition, suddenness, movement, novelty, congruity with the present contents of consciousness, are one and all deter- minants of attention. When they appear, we have to attend to them, even if we have grounds for attending elsewhere. Attention thus determined, attention at the first stage, is usually termed passive or involuntary atten- tion. Unfortunately, a passive implies an active; and active attention is, as we shall see, a misnomer. Other names have been suggested; but we shall do best to speak simply, in this connection, of primary attention.
It is worth noting that all the members of our list are of a kind to produce a powerful effect upon the nervous system. Intensive stimuli naturally set up intensive nervous excitations; and inten- sive excitations will not be easily checked or obscured by rival excitations. The qualitative stimuli that compel attention appeal to some peculiar susceptibility of the nervous system. Repeated stimuli have a cumulative influence. Sudden stimuli impinge upon nervous elements that have recently been free from stimu- lation of their particular kind, that is, upon elements of a high degree of excitability; and it is also probable that the excitations which they arouse suffer less dispersion and diffusion, within the § j6. The Development of Attention 271 nervous system, than those set up by the gradual application of stimulus. Moving stimuli affect different nervous elements in quick succession; there is no possibility of fatigue or of sensory adaptation; in a way, therefore, the action of the moving stimu- lus is cumulative. Novel stimuli, being isolated stimuli, arouse excitations which are not interfered with by others; their action is akin to that of sudden stimuli. As for the effect of congruity with consciousness, it is clear that the more nearly an incoming excitation coincides with an excitation already in progress, the more easily will it make its way within the nervous system, and the more dominant will it become. The novel and the familiar may thus have a similar excitatory value.
Primary attention, however, represents a genetic stage, the ear- liest stage of attentional development. Hence it is not enough to look at its determinants physiologically; we must also view them biologically. And if we do this, some of them at any rate take on a new significance. Any nervous system will be powerfully impressed by intensive stimuli; any organism that has risen high enough in the scale of evolution to have a consciousness made up in part of ideas, of memories and imaginations, will be power- fully impressed by stimuli that are__congruent with those ideas: it is precisely to such stimuli that the gates of the nervous system lie open. But what of novelty and suddenness and movement? These have a special biological meaning: fr>rfh_p npiv and the, sud- (ly\ den and the moviiTg^jire^pjQbable sources of danger, and the crea- ture that failed to attend to them would soon have ceased to exist.
There are, however, many occasions when, so far from «^ the impression's drawing and riveting our attention, it 4$*^ seems that we are holding our attention by main force upon the impression. A problem in geometry does not appeal to us as a thunder-clap does. The thunder-clap takes unquestioned possession of consciousness. The problem has only a divided claim upon us: there is con- stant temptation to wander away from it and to attend to something else. We continue attending; but we have to 5 272 Attention 5 272 Attention make ourselves attend. In many of the psychological experiments that we have described, the object of atten- tion— an obscure organic sensation, a minute qualitative difference — is something which of itself, so far from at- tracting notice, would seem to be eminently fitted to escape it. Attention to such an object is usually termed active or voluntary attention; we shall call it secondary attention. For it is not really active attention, if the adjective im- plies anything like a special and spontaneous mental activ- ity. It is simply the resultant of a conflict of primary ""•^attentions. There are rival claimants for the chief place consciousness, and the standing-room is limited. So he attention, as we say, is divided; or perhaps it oscillates etween the various impressions presented. Secondary attention is attention under difficulties, attention in fare of ompetitors, attention with distraction. But that is its whole secret; it has no novel feature.
Secondary attention is a necessary consequence of a complicated nervous organisation. Let us take an imaginary case: the case of an animal endowed with two sense-organs, an eye and an ear. Suppose that such an animal is exposed, at the same moment, to two different stimuli, a bright light in front of it and a loud sound at its side. It cannot afford to neglect either. Hence it will attend, first, to the stimulus which has the greater attractive force; but then, having attended to that, it will at once turn its attention to the other: and so there will be a seesaw of light and sound at the focus of consciousness, a quick succession of primary atten- tions. This, as we shall see presently, is not all of the psychologi- cal story; but it is the essential point.
Now take a case that lies nearer home. Suppose that you are in your room, preparing for to-morrow's examination, and that you hear an alarm of fire in a neighbouring street. Both ideas, the idea of examination and the idea of fire, are imperative; there is a conflict. The cortex is set in one part for work: and this set- § y6. The Development of Attention 273 ting is reinforced by a large number of associated excitations, — the nervous processes corresponding to ideas of the examination mark, the consequences of failure, and so on. The cortex is set in another part for going to the fire: and this setting is similarly reinforced, by the processes corresponding to the ideas of a run in the fresh air, an exciting scene, a possible rescue, and so on. I «^ The struggle may last some little time, and its effects may persist^ ^r A for a while after you have made your choice. So long as there is] ^jf any trace of it, your attention is secondary or ' active ' attention. ' There is yet a third stage in the development of atten- tion; and this consists in nothing else than_a_relap5e_inlg Vif^ ' primary attention. As we work at our problem in geometry, we gradually become interested and absorbed; and presently the problem gains the same forcible hold over us that the thunder-clap has from the moment of its ap- pearance in consciousness. The difficulties have been overcome; the competitors have been vanquished; the distraction has disappeared. There could hardly be a stronger proof of the growth of secondary out of primary attention than this fact, of everyday experience, that sec- ondary attention is continually reverting to the primary form.
We spoke just now of making a choice between work for the examination and going to the fire. The making of a choice means, of course, that the stronger of the two conflicting forces, the rival excitatory processes, has won the day; and the traces of the struggle that persist after the choice has been made mean that the victory has not been absolutely complete. If experiences of the sort are often repeated, so that a habit is set up, — a habit of work or a habit of play, — then the struggle is brief, and second- ary attention is quickly replaced by primary.
The mention of habit leads us to a further, and a very impor- tant point. This nervous system of ours, which is the scene of T 7 274 Attention the conflict in secondary attention, has a long evolutionary his- tory. We are not all born equal; we are born with nervous sys- tems that bear upon them a certain hereditary stamp, that already have within them lines of less and lines of greater functional re- sistance. The poet, we say, is born and not made; and to a certain extent, if the phrase is permitted, we are all of us born and not made. On the other hand, the child's nervous system is exceedingly plastic and impressionable; it is easily moulded by education; so that, to quote another current saying, habit may become second nature. The leanings and aptitudes and predilections that we show in adult life are, then, the resultant of two influences, heredity and education, nature and nurture. Now the important point in the present connection is this: that the side which finally proves to be the stronger, in the struggle of secondary attention, need not necessarily be the consciously stronger. The conflict between working and going to the fire may lead to a victory for work, in spite of the fact that conscious- ness is more fully occupied by fire-ideas than it is by work-ideas. The nervous system, in virtue of its own bias or leaning,Jjas brought up further reinforcements on the side of work, and these i reinforcements have directed or guided consciousness although they^are_n.ot themselves represented in consciousness.
The guiding influence of nervous bias is not a matter of infer- ence, still less a matter of speculation; it can be demonstrated in the psychological laboratory. Suppose that we are measuring the time required to reply to a spoken word by another word of the same class or kind: to associate dog to cat, table to chair, and so on. The experimenter prepares a long list of words: cat, chair, and so forth. Then he explains to the observer the precise nature of the experiment: I shall call out certain words, he says, and you are to reply, as quickly as you can, with words of the same class; if I say horse, you will mention some other animal, and if I say pen, you will mention something else that has to do with writing. The observer understands, and the experiment begins. Suppose, further, that the experiments have been contin- ued for some days. The experimenter has no need to repeat his explanation at every sitting \ the observer takes it for granted that he is still to reply with a coordinate word. And suppose, finally, that some day, after a week's work, the experimenter interrupts the series, and asks: Are you thinking about what I told you to do? The observer, fearing that he has made some error, and feeling very repentant, will say: No! to tell the truth I had absolutely forgotten all about it; it had gone altogether out of my mind; have I done anything wrong? He had not done any- thing wrong; but his answer shows that a certain tendency, im- pressed upon his nervous system by the experimenter's original explanation, has been effective to direct the course of his_ideas long after its conscious rorre1atehas_ disappeared. And what happens here, in theTaboratory, happens every day of our lives in the wider experience outside the laboratory.
In summary, then, attention appears in the human mind at three stages of development: as primary atten- tion, determined by various influences that are able to produce a powerful effect upon the nervous system; as sec- ondary attention, during which the centre of conscious- ness is held by a certain perception or idea, but is held in face of opposition; and lastly as derived primary attention, when this perception or idea has gained an undisputed ascendency over its rivals. The attentive con- sciousness is at first simple; it then becomes complex, — reaching, indeed, in cases of hesitation and deliberation, a very high degree of complexity; and then it simplifies again. Looking at life in the large, we may say that the period of training or education is a period of secondary attention, and that the following period of achievement and mastery is a period of derived primary attention. Looking at experience more in detail, we see that educa- tion itself consists, psychologically, in the alternation of the two attentions: h^JbiLJs_jiiade_th£_Jjasis— aLlurther acquisition, and acquisition — gained with pains — passes I 276 Attention I 276 Attention in its turn into habit; the cycle recurs, so long as the orgalvTsnTretainTlts nervous plasticity. Secondary atten- tion thus appears, everywhere, as a stage of transition, of conflict, of waste of nervous energy, though it appears at [\ the same time as the necessary preliminary to a stage of real knowledge.
We may now return to our analytical study of the atten- tive consciousness. There are three stages of attention, but there is only one type of attentive consciousness; the three stages show differences of complexity, but not dif- ferences of kind.
In the meantime, it may prevent a possible misunderstanding if we say, explicitly, that the greater complexity of consciousness f in secondary attention does not necessarily mean a greater num- ber of constituent mental processes. The single object of pri- mary attention may be extremely complex; the competing objects ' of secondary attention may be relatively simple. The complexity, then, is a complexity, not necessarily of conscious contents, but rather of conscious pattern, of the disposition of the contents. In primary attention, consciousness flows smoothly within a definite channel; in secondary attention, its course is zigzag, meandering through various channels. The number of mental processes given in secondary attention may be, and often is, much larger than the number given in primary attention; but the characteristic difference between the two consciousnesses lies elsewhere. Cojiscjousness in primary attention may be repre- sen.tedjiy,a series of parallel straight lines, each standing for some m^jTtgL-pr^^^ss tha<- fnjoy^J^J^Lj^IIIHL duration; conscious- ness in secondary attention must be ^represented— hy_a pattern of shorter and variously directed oblique— lines, each standing for some mental process whose progress has been arrested by the advent of a rival.
§ yy. The Two Levels of Consciousness. — The rough analysis of § 75 led us to conclude that the attentive § "jy. The Tivo Levels of Consciousness 277 t Fig. 40. Diagram of the Attentive Conscious- ness. The stream of consciousness, outlined by the thin line of the Fig., is supposed to be moving towards you from the plane of the paper; the thick lines represent the neural channel in which the stream is flowing.
consciousness is always arranged in a dual pattern of clear and obscure, focus and margin. We might represent it by means of two con- centric circles, the inner and smaller bounding the region of clearness, or containing what is called the object of at- tention, and the outer and larger bounding the region of obscurity or of inattention. A more serviceable dia- gram, however, is one that represents the stream of con- sciousness as running at two different levels, the higher that of the clear and the lower that of the obscure pro- cesses in consciousness. We shall make use of this dia- gram in what follows.
Let us begin by making an observation for ourselves. Figure 41 is a puzzle picture; it is a drawing of the left hemisphere of the brain, but it is something else also. Look at it, and try to find what it conceals. While you are searching, the whole drawing is at the upper level of consciousness, and the rest of your experience is at the lower level. Suddenly you find what you are looking for: and what happens? Why, the moment you do so, the picture of the brain drops clean away from the upper level: the concealed outlines stand out with all imaginable clear- ness, and the form of the brain is no clearer than the feel of the book in your hand. The first two-level consciousness has been replaced by a second, and the drop of the original object of attention from crest to base of the attention-wave is very striking.
A ttejition In one respect, this observation is not typical. When you have solved the puzzle, you experience a keen satisfaction; and affective processes are not always found in the attentive conscious- ness. In all other respects, the observation appears to the writer * rf/to be typical. Th£_obiect of attention does not glide, bv slow ^degrees^to lh<L higher_level; but rises at a single step; now you v attending ^t^one^thmg^nd now j^ou find yourself_attend i ng jx> Another. It should be said, however, that this view is disputed, y^bome psychologists believe that the attentive consciousness shows, Fig. 41. Drawn by R. Gudden, Frankfurt a. M.
not two different levels, but a single rising and falling slope; they believe, that is, that processes of all possible degrees of clear- ness may coexist in the same consciousness. Others believe that there are more than two levels, — three, for instance: the levels of attention, of inattention, and of a still deeper, subconscious obscurity. We return to the matter again on pp. 290, 302.
The main characteristic of the processes at the upper conscious level is their high degree of clearness. We mentioned clearness, in § 12, among the attributes of sensation, and the term carries its meaning with it. A process is clear or vivid when it is at its best, when it is making the most of itself in experience. Clearness is an intensive attribute, in thesense that it shows ^degrees of more and less; but it is altogether ^ffererri fromintensity pro_pje£. When, for instance, you are listening to a very faint sound, the sensation of noise may be the clearest thing in consciousness, although its intensity is minimal. Indeed, there is no difficulty whatsoever, after a little prac- tice, in distinguishing introspectively between the clearness and the intensity of any given mental process.
It is, however, a much debated question whether clear- ness and intensity, though distinct attributes of sensation, are not always connected in experience. Does not a rise in clearness mean also a rise in intensity? The very faint sound may be clear, in spite of its weakness: but is it as weak as it would be if it were less clear? In popular phrasing, does not attention intensify its object? We find every possible answer to these questions. Some psycholo- gists believe that change in clearness makes no difference in intensity. Others believe that it makes only an apparent difference. Increase in clearness, they say, means a more independent status in consciousness; and this indepen- dence, this freedom from interference, allows the other attributes of sensation to come to their full conscious eights. Intensity thus makes all the effect that it has in it to make; it appears to be increased, whereas in reality it is simply getting — what without clearness it could not get — fair play in consciousness. Others, again, think that clearness does bring with it an increase of intensity; and yet others assert that it means a decrease. In the writer's judgment, the third of these views, that intensity is raised along with clearness, is the most probable.
280 Attention The belief that change in clearness makes no difference in in- tensity rests upon facts of everyday observation: your surround- ings do not brighten up as you attend to the lamp, the clock does not begin to tick more loudly as you listen to it. But, first, this sort of observation is very unreliable; if you try it for yourself, you will find how far you are from any real comparison of the more clear and the less clear process. And secondly there are facts on the other side: you can hear, with attention, a faint sound that you cannot hear if you do not attend. The next hypothesis, that the change in intensity is only apparent, contains an element of truth; but in so far as it is an attempt to reconcile the first and the third, it will not come into account until the third has been disposed of. The issue lies, therefore, between the third and the fourth views, that attention intensifies and that attention weakens its object; and the test is experiment. There is evidence on both sides; but it appears to the writer that the evidence for weakening is ambiguous, and the evidence for intensification clear and deci- sive. Suppose, for instance, that two sounds, a weaker and a stronger, are presented to the observer in quick succession; and suppose that he gives full attention to the weaker, but that his attention is diverted from the stronger by some interfering stimulus, for instance, by a strong odour. If he judges that the two sounds are of equal intensity, still more if he judges that the objectively weaker sound is the more intensive of the two, we have an increase of intensity with attention or (what is the same thing) a decrease of intensity with distraction. And this is what happens.
It is not at all surprising that we should find an intimate relation between clearness and intensity; for, as we said in § 76, all the conditions of a high degree of clearness are also conditions for the powerful impression of the nervous system. Nor does the connection of the two attributes affect anything that we have said in §§ 62 ff.: for the intensities which obey Weber's Law are, of course, intensities at maximal clearness. — It does not seem probable that clearness brings with it any change in extent or duration. Processes, however, that would ordinarily be curtailed, swamped by stronger processes, may — if § J%. Factors in the Attentive Consciousness 281 they are clear — be followed for a longer time in their course through consciousness, and may thus be apparently lengthened.
We may now interpret Fig. 40 to mean that the pro- cesses at the crest of the attention-wave are both clearer and stronger than the processes at the lower level of con- sciousness. These are the attributes that give the object of attention its special value for memory and imagination and thought.
§ 78. The Kinaesthetic and the Affective Factors in the At- tentive Consciousness. — We may assume that attention, in its beginnings, was a definitely determined reaction of the whole organism — sensory, affective, motor — upon a single stimulus. The strong or sudden or novel or moving thing was perceived, as sight or sound or touch. It was also, as we have said (§ 76), felt as startling or disturbing or sur- prising. The affective element in the experience ex- pressed itself in a change of the great bodily functions. At the same time the animal took up an attitude to the stimulus, in the literal sense; faced it, as peering and listening and frightened animals face such stimuli to-day. At this stage, then, the redistribution of the sensory pro- cesses in consciousness, the clearing of some and the obscuring of others, was accompanied both by affection, and by kinaesthetic sensations due to internal bodily changes and to muscular attitude.
Secondary attention has its origin in a conflict of pri- mary attentions: in the rivalry of clear perceptions and in the struggle of incompatible motor attitudes. The percep- tions may be either pleasant or unpleasant; the motor restlessness will be unpleasant, reflected in an affective un- easiness. We have, now, a survival of this primitive state /