Chapter III
(p. 93) that reaction-time is shorter when one concentrates his attention on the expected movement than when one concentrates it on the expected signal. Herr Münsterberg found that this is equally the case when the reaction is no simple reflex, but can take place only after an intellectual operation. In a series of experiments the five fingers were used to react with, and the reacter had to use a different finger according as the signal was of one sort or another. Thus when a word in the nominative case was called out he used the thumb, for the dative he used another finger; similarly adjectives, substantives, pronouns, numerals, etc., or, again, towns, rivers, beasts, plants, elements; or poets, musicians, philosophers, etc., were co-ordinated each with its finger, so that when a word belonging to either of these classes was mentioned, a particular finger and no other had to perform the reaction. In a second series of experiments the reaction consisted in the utterance of a word in answer to a question, such as "name an edible fish," etc.; or "name the first drama of Schiller," etc.; or "which is greater, Hume or Kant?" etc.; or (first naming apples and cherries, and several other fruits) "which do you prefer, apples or cherries?" etc.; or "which is Goethe's finest drama?" etc.; or "which letter comes the later in the alphabet, the letter L or the first letter of the most beautiful tree?" etc.; or "which is less, 15 or 20 _minus_ 8?"[357] etc. etc. etc. Even in this series of reactions _the time was much quicker token the reacter turned his attention in advance towards the answer than when he turned it towards the question_. The shorter reaction-time was seldom more than one fifth of a second; the longer, from four to eight times as long.
To understand such results, one must bear in mind that in these experiments the reacter always knew in advance in a general way the _kind_ of question which he was to receive, and consequently the _sphere within which_ his possible answer lay.[358] In turning his attention, therefore, from the outset towards the answer, those brain-processes in him which were connected with this entire 'sphere' were kept sub-excited, and the question could then discharge with a minimum amount of lost time that particular answer out of the 'sphere' which belonged especially to it. When, on the contrary, the attention was kept looking towards the question exclusively and averted from the possible reply, all this preliminary sub-excitement of motor tracts failed to occur, and the entire process of answering had to be gone through with _after_ the question was heard. No wonder that the time was prolonged. It is a beautiful example of the summation of stimulations, and of the way in which expectant attention, even when not very strongly focalized, will prepare the motor centres, and shorten the work which a stimulus has to perform on them, in order to produce a given effect when it comes.
THE INTIMATE NATURE OF THE ATTENTIVE PROCESS.
We have now a sufficient number of facts to warrant our considering this more recondite question. And two physiological processes, of which we have got a glimpse, immediately suggest themselves as possibly forming in combination a complete reply. I mean
1. _The accommodation or adjustment of the sensory organs_; and
2. _The anticipatory preparation from within of the ideational centres concerned with the object to which the attention is paid._
1. The sense-organs and the bodily muscles which favor their exercise are adjusted most energetically in sensorial attention, whether immediate and reflex, or derived. But there are good grounds for believing that even intellectual attention, attention to the _idea_ of a sensible object, is also accompanied with some degree of excitement of the sense-organs to which the object appeals. The preparation of the ideational centres exists, on the other hand, wherever our interest in the object--be it sensible or ideal--is _derived_ from, or in any way connected with, other interests, or the presence of other objects, in the mind. It exists as well when the attention thus derived is classed as passive as when it is classed as voluntary. So that on the whole we may confidently conclude--since in mature life we never attend to anything without our interest in it being in some degree derived from its connection with other objects--that _the two processes of sensorial adjustment and ideational preparation probably coexist in all our concrete attentive acts._
The two points must now be proved in more detail. First, as respects the sensorial adjustment.
That it is present when we attend to _sensible_ things is obvious. When we look or listen we accommodate our eyes and ears involuntarily, and we turn our head and body as well; when we taste or smell we adjust the tongue, lips, and respiration to the object; in feeling a surface we move the palpatory organ in a suitable way; in all these acts, besides making involuntary muscular contractions of a positive sort, we inhibit others which might interfere with the result--we close the eyes in tasting, suspend the respiration in listening, etc. The result is a more or less massive organic feeling that attention is going on. This organic feeling comes, in the way described on page 302, to be contrasted with that of the objects which it accompanies, and regarded as peculiarly ours, whilst the objects form the not-me. We treat it as a sense of our _own activity_, although it comes in to us from our organs after they are accommodated, just as the feeling of any object does. Any object, if _immediately_ exciting, causes a reflex accommodation of the sense-organ, and this has two results--first, the object's increase in clearness; and second, the feeling of activity in question. Both are sensations of an 'afferent' sort.
But in _intellectual_ attention, as we have already seen, (p. 300), similar feelings of activity occur. Fechner was the first, I believe, to analyze these feelings, and discriminate them from the stronger ones just named. He writes:
"When we transfer the attention from objects of one sense to those of another, we have an indescribable feeling (though at the same time one perfectly determinate, and reproducible at pleasure), of altered _direction_ or differently localized tension (_Spannung_). We feel a strain forward in the eyes, one directed sidewise in the ears, increasing with the degree of our attention, and changing according as we look at an object carefully, or listen to something attentively; and we speak accordingly of _straining the attention_. The difference is most plainly felt when the attention oscillates rapidly between eye and ear; and the feeling localizes itself with most decided difference in regard to the various sense-organs, according as we wish to discriminate a thing delicately by touch, taste, or smell.
"But now I have, when I try to vividly recall a picture of memory or fancy, a feeling perfectly analogous to that which I experience when I seek to apprehend a thing keenly by eye or ear; and this analogous feeling is very differently localized. While in sharpest possible attention to real objects (as well as to after-images) the strain is plainly forwards, and when the attention changes from one sense to another only alters its direction between the several external sense-organs, leaving the rest of the head free from strain, the case is different in memory or fancy, for here the feeling withdraws entirely from the external sense-organs, and seems rather to take refuge in that part of the head which the brain fills; if I wish, for example, to recall a place or person it will arise before me with vividness, not according as I strain my attention forwards, but rather in proportion as I, so to speak, retract it backwards."[359]
In myself the 'backward retraction' which is felt during attention to ideas of memory, etc., seems to be principally constituted by the feeling of an actual rolling outwards and upwards of the eyeballs, such as occurs in sleep, and is the exact opposite of their behavior when we look at a physical thing. I have already spoken of this feeling on page 300.[360] The reader who doubts the presence of these organic feelings is requested to read the whole of that passage again.
* * * * *
It has been said, however, that we may attend to an object on the periphery of the visual field and yet not accommodate the eye for it. Teachers thus notice the acts of children in the school-room at whom they appear not to be looking. Women in general train their peripheral visual attention more than men. This would be an objection to the _invariable and universal_ presence of movements of adjustment as ingredients of the attentive process. Usually, as is well known, no object lying in the marginal portions of the field of vision can catch our attention without at the same time 'catching our eye'--that is, fatally provoking such movements of rotation and accommodation as will focus its image on the fovea, or point of greatest sensibility. Practice, however, enables us, _with effort_, to attend to a marginal object whilst keeping the eyes immovable. The object under these circumstances never becomes perfectly distinct--the place of its image on the retina makes distinctness impossible--but (as anyone can satisfy himself by trying) we become more vividly conscious of it than we were before the effort was made. Helmholtz states the fact so strikingly that I will quote his observation in full. He was trying to combine in a single solid percept pairs of stereoscopic pictures illuminated instantaneously by the electric spark. The pictures were in a dark box which the spark from time to time lighted up; and, to keep the eyes from wandering betweenwhiles, a pin-hole was pricked through the middle of each picture, through which the light of the room came, so that each eye had presented to it during the dark intervals a single bright point. With parallel optical axes the points combined into a single image; and the slightest movement of the eyeballs was betrayed by this image at once becoming double. Helmholtz now found that simple linear figures could, when the eyes were thus kept immovable, be perceived as solids at a single flash of the spark. But when the figures were complicated photographs, many successive flashes were required to grasp their totality.
"Now it is interesting," he says, "to find that, although we keep steadily fixating the pin-holes and never allow their combined image to break into two, we can, nevertheless, before the spark comes, keep our attention voluntarily turned to any particular portion we please of the dark field, so as then, when the spark comes, to receive an impression only from such parts of the picture as lie in this region. In this respect, then, our attention is quite independent of the position and accommodation of the eyes, and of any known alteration in these organs; and free to direct itself by a conscious and voluntary effort upon any selected portion of a dark and undifferenced field of view. This is one of the most important observations for a future theory of attention."[361]
Hering, however, adds the following detail:
"Whilst attending to the marginal object we must always," he says, "_attend at the same time_ to the object directly fixated. If even for a single instant we let the latter slip out of our mind, our eye moves towards the former, as may be easily recognized by the after-images produced, or by the muscular sounds heard. The case is then less properly to be called one of translocation, than one of unusually wide _dispersion_, of the attention, in which dispersion the largest share still falls upon the thing directly looked at,"[362]
and consequently directly accommodated for. Accommodation exists here, then, as it does elsewhere, and without it we should lose a part of our sense of attentive activity. In fact, the _strain_ of that
## activity (which is remarkably great in the experiment) is due in part
to unusually strong contractions of the muscles needed to keep the eyeballs still, which produce unwonted feelings of pressure in those organs.
* * * * *
2. But if the peripheral part of the picture in this experiment be not physically accommodated for, what is meant by its sharing our attention? What happens when we 'distribute' or 'disperse' the latter upon a thing for which we remain unwilling to 'adjust'? This leads us to that second feature in the process, the '_ideational preparation_' of which we spoke. _The effort to attend to the marginal region of the picture consists in nothing more nor less than the effort to form as clear an idea as is possible of what is there portrayed._ The idea is to come to the help of the sensation and make it more distinct. It comes with effort, and such a mode of coming is the remaining part of what we know as our attention's 'strain' under the circumstances. Let us show how universally present in our acts of attention this reinforcing imagination, this inward reproduction, this anticipatory thinking of the thing we attend to, is.
It must as a matter of course be present when the attention is of the intellectual variety, for the thing attended to then _is_ nothing but an idea, an inward reproduction or conception. If then we prove ideal construction of the object to be present in _sensorial_ attention, it will be present everywhere. When, however, sensorial attention is at its height, it is impossible to tell how much of the percept comes from without and how much from within; but if we find that the _preparation_ we make for it always partly consists of the creation of an imaginary duplicate of the object in the mind, which shall stand ready to receive the outward impression as if in a matrix, that will be quite enough to establish the point in dispute.
In Wundt's and Exner's experiments quoted above, the lying in wait for the impressions, and the preparation to react, consist of nothing but the anticipatory imagination of what the impressions or the reactions are to be. Where the stimulus is unknown and the reaction undetermined, time is lost, because no stable image can under such circumstances be formed in advance. But where both nature and time of signal and reaction are foretold, so completely does the expectant attention consist in premonitory imagination that, as we have seen (Footnote 273; pp. 373, 377), it may mimic the intensity of reality, or at any rate produce reality's motor effects. It is impossible to read Wundt's and Exner's pages of description and not to interpret the '_Apperception_' and '_Spannung_' and other terms as equivalents of _imagination_. With Wundt, in particular, the word _Apperception_ (which he sets great store by) is quite interchangeable with both imagination and attention. All three are names for the excitement from within of ideational brain-centres, for which Mr. Lewes's name of _preperception_ seems the best possible designation.
Where the impression to be caught is very weak, the way not to miss it is to sharpen our attention for it by preliminary contact with it in a stronger form.
"If we wish to begin to observe overtones, it is advisable, just before the sound which is to be analyzed, to sound very softly the note of which we are in search.... The piano and harmonium are well fitted for this use, as both give overtones that are strong. Strike upon the piano first the _g'_ [of a certain musical example previously given in the text]; then, when its vibrations have objectively ceased, strike powerfully the note _c_, in whose sound _g'_ is the third overtone, and keep your attention steadily bent upon the pitch of the just heard _g'_; you will now hear this tone sounding in the midst of the _c_.... If you place the resonator which corresponds to a certain overtone, for example _g'_ of the sound _c_, against your ear, and then make the note _c_ sound, you will hear _g'_ much strengthened by the resonator.... This strengthening by the resonator can be used to make the naked ear attentive to the sound which it is to catch. For when the resonator is gradually removed, the _g'_ grows weaker; but the attention, once directed to it, holds it now more easily fast, and the observer hears the tone _g'_ now in the natural unaltered sound of the note with his unaided ear."[363]
Wundt, commenting on experiences of this sort, says that
"on carefully observing, one will always find that one tries first to recall the image in memory of the tone to be heard, and that then one hears it in the total sound. The same thing is to be noticed in weak or fugitive visual impressions. Illuminate a drawing by electric sparks separated by considerable intervals, and after the first, and often after the second and third spark, hardly anything will be recognized. But the confused image is held fast in memory; each successive illumination completes it; and so at last we attain to a clearer perception. The primary motive to this inward activity proceeds usually from the outer impression itself. We hear a sound in which, from certain associations, we suspect a certain overtone; the next thing is to recall the overtone in memory; and finally we catch it in the sound we hear. Or perhaps we see some mineral substance we have met before; the impression awakens the memory-image, which again more or less completely melts with the impression itself. In this way every idea takes a certain time to penetrate to the focus of consciousness. And during this time we always find in ourselves the peculiar _feeling_ of attention.... The phenomena show that an _adaptation_ of attention to the impression takes place. The surprise which unexpected impressions give us is due essentially to the fact that our attention, at the moment when the impression occurs, is not accommodated for it. The accommodation itself is of the double sort, relating as it does to the intensity as well as to the quality of the stimulus. Different qualities of impression require disparate adaptations. And we remark that our feeling of the _strain_ of our inward attentiveness increases with every increase in the strength of the impressions on whose perception we are intent."[364]
The natural way of conceiving all this is under the symbolic form of a brain-cell played upon from two directions. Whilst the object excites it from without, other brain-cells, or perhaps spiritual forces, arouse it from within. The latter influence is the 'adaptation of the attention.' _The plenary energy of the brain-cell demands the co-operation of both factors:_ not when merely present, but when both present and attended to, is the object fully perceived.
A few additional experiences will now be perfectly clear. Helmholtz, for instance, adds this observation to the passage we quoted a while ago concerning the stereoscopic pictures lit by the electric spark.
"These experiments," he says, "are interesting as regards the part which attention plays in the matter of double images.... For in pictures so simple that it is relatively difficult for me to see them double, I can succeed in seeing them double, even when the illumination is only instantaneous, the moment I strive to _imagine in a lively way how they ought then to look_. The influence of attention is here pure; for all eye movements are shut out."[365]
In another place[366] the same writer says:
"When I have before my eyes a pair of stereoscopic drawings which are hard to combine, it is difficult to bring the lines and points that correspond, to cover each other, and with every little motion of the eyes they glide apart. _But if I chance to gain a lively mental image (Anschauungsbild) of the represented solid form_ (a thing that often occurs by lucky chance), I then move my two eyes with perfect certainty over the figure without the picture separating again."
Again, writing of retinal rivalry, Helmholtz says:
"It is not a trial of strength between two sensations, but depends on our fixing or failing to fix the attention. Indeed, there is scarcely any phenomenon so well fitted for the study of the causes which are capable of determining the attention. It is not enough to form the conscious intention of seeing first with one eye and then with the other; _we must form as clear a notion as possible of what we expect to see. Then it will actually appear_."[367]
In figures 37 and 38, where the result is ambiguous, we can make the change from one apparent form to the other by imagining strongly in advance the form we wish to see. Similarly in those puzzles where certain lines in a picture form by their combination an object that has no connection with what the picture ostensibly represents; or indeed in every case where an object is inconspicuous and hard to discern from the background; we may not be able to see it for a long time; but, having once seen it, we can attend to it again whenever we like, on account of the mental duplicate of it which our imagination now bears. In the meaningless French words '_pas de lieu Rhône que nous_,' who can recognize immediately the English 'paddle your own canoe'?[368] But who that has once noticed the identity can fail to have it arrest his attention again? When watching for the distant clock to strike, our mind is so filled with its image that at every moment we think we hear the longed-for or dreaded sound. So of an awaited footstep. Every stir in the wood is for the hunter his game; for the fugitive his pursuers. Every bonnet in the street is momentarily taken by the lover to enshroud the head of his idol. The image in the mind _is_ the attention; the _preperception_, as Mr. Lewes calls it, is half of the perception of the looked-for thing.[369]
[Illustration: FIGS. 37 & 38.]
It is for this reason that men have no eyes but for those aspects of things which they have already been taught to discern. Any one of us can notice a phenomenon after it has once been pointed out, which not one in ten thousand could ever have discovered for himself. Even in poetry and the arts, some one has to come and tell us what aspects we may single out, and what effects we may admire, before our æsthetic nature can 'dilate' to its full extent and never 'with the wrong emotion.' In kindergarten instruction one of the exercises is to make the children see how many features they can point out in such an object as a flower or a stuffed bird. They readily name the features they know already, such as leaves, tail, bill, feet. But they may look for hours without distinguishing nostrils, claws, scales, etc., until their attention is called to these details; thereafter, however, they see them every time. In short, _the only things which we commonly see are those which we preperceive_. and the only things which we preperceive are those which have been labelled for us, and the labels stamped into our mind. If we lost our stock of labels we should be intellectually lost in the midst of the world.
* * * * *
Organic adjustment, then, and ideational preparation or preperception are concerned in all attentive acts. An interesting theory is defended by no less authorities than Professors Bain[370] and Ribot,[371] and still more ably advocated by Mr. N. Lange,[372] who will have it that the ideational preparation itself is a consequence of muscular adjustment, so that the latter may be called the essence of the attentive process throughout. This at least is what the theory of these authors practically amounts to, though the former two do not state it in just these terms. The proof consists in the exhibition of cases of intellectual attention which organic adjustment accompanies, or of objects in thinking which we have to execute a movement. Thus Lange says that when he tries to imagine a certain colored circle, he finds himself first making with his eyes the movement to which the circle corresponds, and _then_ imagining the color, etc., as a consequence of the movement.
"Let my reader," he adds, "close his eyes and think of an extended object, for instance a _pencil_. He will easily notice that he first makes a slight movement [of the eyes] corresponding to the straight line, and that he often gets a weak feeling of innervation of the hand as if touching the pencil's surface. So, in thinking of a certain sound, we turn towards its direction or repeat muscularly its rhythm, or articulate an imitation of it."[373]
But it is one thing to point out the presence of muscular contractions as constant concomitants of our thoughts, and another thing to say, with Herr Lange, that thought is _made possible_ by muscular contraction alone. It may well be that where the object of thought consists of two parts, one perceived by movement and another not, the part perceived by movement is habitually called up first and fixed in the mind by the movement's execution, whilst the other part comes secondarily as the movement's mere associate. But even were this the rule with all men (which I doubt[374]), it would only be a practical habit, not an ultimate necessity. In the chapter on the Will we shall learn that movements themselves are results of images coming before the mind, images sometimes of feelings in the moving part, sometimes of the movement's effects on eye and ear, and sometimes (if the movement be originally reflex or instinctive), of its natural stimulus or exciting cause. It is, in truth, contrary to all wider and deeper analogies to deny that any quality of feeling whatever can directly rise up in the form of an idea, and to assert that only ideas of movement can call other ideas to the mind.
So much for adjustment and preperception. The only third process I can think of as always present is the inhibition of irrelevant movements and ideas. This seems, however, to be a feature incidental to voluntary attention rather than the essential feature of attention at large,[375] and need not concern us particularly now. Noting merely the intimate connection which our account so far establishes between attention, on the one hand, and imagination, discrimination, and memory, on the other, let us draw a couple of practical inferences, and then pass to the more speculative problem that remains.
* * * * *
The practical inferences are pedagogic. First, _to strengthen attention in children_ who care nothing for the subject they are studying and let their wits go wool-gathering. The interest here must be 'derived' from something that the teacher associates with the task, a reward or a punishment if nothing less external comes to mind. Prof. Ribot says:
"A child refuses to read; he is incapable of keeping his mind fixed on the letters, which have no attraction for him; but he looks with avidity upon the pictures contained in a book. 'What do they mean?' he asks. The father replies: 'When you can read, the book will tell you.' After several colloquies like this, the child resigns himself and falls to work, first slackly, then the habit grows, and finally he shows an ardor which has to be restrained. This is a case of the genesis of voluntary attention. An artificial and indirect desire has to be grafted on a natural and direct one. Reading has no immediate attractiveness, but it has a borrowed one, and that is enough. The child is caught in the wheelwork, the first step is made."
I take another example, from M. B. Perez:[376]
"A child of six years, habitually prone to mind-wandering, sat down one day to the piano of his own accord to repeat an air by which his mother had been charmed. His exercises lasted an hour. The same child at the age of seven, seeing his brother busy with tasks in vacation, went and sat at his father's desk. 'What are you doing there?' his nurse said, surprised at so finding him. 'I am,' said the child, 'learning a page of German; it isn't very amusing, but it is for an agreeable surprise to mamma.'"
Here, again, a birth of voluntary attention, grafted this time on a sympathetic instead of a selfish sentiment like that of the first example. The piano, the German, awaken no spontaneous attention; but they arouse and maintain it by borrowing a force from elsewhere.[377]
Second, take that mind-wandering which at a later age may trouble us _whilst reading or listening to a discourse_. If attention be the reproduction of the sensation from within, the habit of reading not merely with the eye, and of listening not merely with the ear, but of articulating to one's self the words seen or heard, ought to deepen one's attention to the latter. Experience shows that this is the case. I can keep my wandering mind a great deal more closely upon a conversation or a lecture if I actively re-echo to myself the words than if I simply hear them; and I find a number of my students who report benefit from voluntarily adopting a similar course.[378]
Second, _a teacher who wishes to engage the attention of his class must knit his novelties on to things of which they already have preperceptions_. The old and familiar is readily attended to by the mind and helps to hold in turn the new, forming, in Herbartian phraseology, an '_Apperceptionsmasse_' for it. Of course it is in every case a very delicate problem to know what 'Apperceptionsmasse' to use. Psychology can only lay down the general rule.
IS VOLUNTARY ATTENTION A RESULTANT OR A FORCE?
When, a few pages back, I symbolized the 'ideational preparation' element in attention by a brain-cell played upon from within, I added 'by other brain-cells, or by some spiritual force,' without deciding which. The question 'which?' is one of those central psychologic mysteries which part the schools. When we reflect that the turnings of our attention form the nucleus of our inner self; when we see (as in the chapter on the Will we shall see) that volition is nothing but attention; when we believe that our autonomy in the midst of nature depends on our not being pure effect, but a cause,--
_Principium quoddam quod fati fœdera rumpat,_ _Ex infinito ne causant causa sequatur--_
we must admit that the question whether attention involve such a principle of spiritual activity or not is metaphysical as well as psychological, and is well worthy of all the pains we can bestow on its solution. It is in fact the pivotal question of metaphysics, the very hinge on which our picture of the world shall swing from materialism, fatalism, monism, towards spiritualism, freedom, pluralism,--or else the other way.
It goes back to the automaton-theory. If feeling is an inert accompaniment, then of course the brain-cell can be played upon only by other brain-cells, and the attention which we give at any time to any subject, whether in the form of sensory adaptation or of 'preperception,' is the fatally predetermined _effect_ of exclusively material laws. If, on the other hand, the feeling which coexists with the brain-cells' activity reacts dynamically upon that activity, furthering or checking it, then the attention is in part, at least, a _cause_. It does not necessarily follow, of course, that this reactive feeling should be 'free' in the sense of having its amount and direction undetermined in advance, for it might very well be predetermined in all these particulars. If it were so, our attention would not be _materially_ determined, nor yet would it be 'free' in the sense of being spontaneous or unpredictable in advance. The question is of course a purely speculative one, for we have no means of objectively ascertaining whether our feelings react on our nerve-processes or not; and those who answer the question in either way do so in consequence of general analogies and presumptions drawn from other fields. As mere _conceptions_, the effect-theory and the cause-theory of attention are equally clear; and whoever affirms either conception to be true must do so on metaphysical or universal rather than on scientific or particular grounds.
* * * * *
As regards _immediate sensorial attention_ hardly any one is tempted to regard it as anything but an effect.[379] We are 'evolved' so as to respond to special stimuli by special accommodative acts which produce clear perceptions on the one hand in us, and on the other hand such feelings of inner activity as were above described. The accommodation and the resultant feeling _are_ the attention. We don't bestow it, the object draws it from us. The object has the initiative, not the mind.
_Derived attention, where there is no voluntary effort, seems also most plausibly to be a mere effect._ The object again takes the initiative and draws our attention to itself, not by reason of its own intrinsic interest, but because it is connected with some other interesting thing. Its brain-process is connected with another that is either excited, or tending to be excited, and the liability to share the excitement and become aroused is the liability to 'preperception' in which the attention consists. If I have received an insult, I may not be actively thinking of it all the time, yet the thought of it is in such a state of heightened irritability, that the place where I received it or the man who inflicted it cannot be mentioned in my hearing without my attention bounding, as it were, in that direction, as the imagination of the whole transaction revives. Where such a stirring-up occurs, organic adjustment must exist as well, and the ideas must innervate to some degree the muscles. Thus the whole process of involuntary derived attention is accounted for if we grant that there is something interesting enough to arouse and fix the thought of whatever may be connected with it. This fixing _is_ the attention; and it carries with it a vague sense of activity going on, and of acquiescence, furtherance, and adoption, which makes us feel the
## activity to be our own.
This reinforcement of ideas and impressions by the pre-existing contents of the mind was what Herbart had in mind when he gave the name of _apperceptive_ attention to the variety we describe. We easily see now why the lover's tap should be heard--it finds a nerve-centre half ready in advance to explode. We see how we can attend to a companion's voice in the midst of noises which pass unnoticed though objectively much louder than the words we hear. Each word is _doubly_ awakened; once from without by the lips of the talker, but already before that from within by the premonitory processes irradiating from the previous words, and by the dim arousal of all processes that are connected with the 'topic' of the talk. The irrelevant noises, on the other hand, are awakened only once. They form an unconnected train. The boys at school, inattentive to the teacher except when he begins an anecdote, and then all pricking up their ears, are as easily explained. The words of the anecdote shoot into association with exciting objects which react and fix them; the other words do not. Similarly with the grammar heard by the purist and Herbart's other examples quoted on page 418.
Even where the attention is voluntary, it is possible to conceive of it as an effect, and not a cause, a product and not an agent. The things we attend to _come to us_ by their own laws. Attention _creates_ no idea; an idea must already be there before we can attend to it. Attention only fixes and retains what the ordinary laws of association bring 'before the footlights' of consciousness. But the moment we admit this we see that the attention _per se_, the _feeling_ of attending need no more fix and retain the ideas than it need bring them. The associates which bring them also fix them by the interest which they lend. In short, voluntary and involuntary attention may be essentially the same. It is true that where the ideas are intrinsically very unwelcome and the effort to attend to them is great, it seems to us as if the frequent renewal of the effort were the very cause by which they are held fast, and we naturally think of the effort as an original force. In fact it is only to the _effort to attend_, not to the mere _attending_, that we are seriously tempted to ascribe spontaneous power. We think we can make more of it _if we will_; and the amount which we make does not seem a fixed function of the ideas themselves, as it would necessarily have to be if our effort were an effect and not a spiritual force. But even here it is possible to conceive the facts mechanically and to regard the effort as a mere effect.
Effort is felt only where there is a conflict of interests in the mind. The idea A may be intrinsically exciting to us. The idea Z may derive its interest from association with some remoter good. A may be our sweetheart, Z may be some condition of our soul's salvation. Under these circumstances, if we succeed in attending to Z at all it is always with expenditure of effort. The 'ideational preparation,' the 'preperception' of A keeps going on of its own accord, whilst that of Z needs incessant pulses of voluntary reinforcement--that is, we have the _feeling_ of voluntary reinforcement (or effort) at each successive moment in which the thought of Z flares brightly up in our mind. Dynamically, however, that may mean only this: that the associative processes which make Z triumph are really the stronger, and in A's absence would make us give a 'passive' and unimpeded attention to Z; but, so long as A is present, some of of their force is used to inhibit the processes concerned with A. Such inhibition is a partial neutralization of the brain-energy which would otherwise be available for fluent thought. But what is lost for thought is converted into feeling, in this case into the peculiar feeling of effort, difficulty, or strain.
The stream of our thought is like a river. On the whole easy simple flowing predominates in it, the drift of things is with the pull of gravity, and effortless attention is the rule. But at intervals an obstruction, a set-back, a log-jam occurs, stops the current, creates an eddy, and makes things temporarily move the other way. If a real river could feel, it would feel these eddies and set-backs as places of effort. "I am here flowing," it would say, "in the direction of greatest resistance, instead of flowing, as usual, in the direction of least. My effort is what enables me to perform this feat." Really, the effort would only be a passive index that the feat was being performed. The agent would all the while be the total downward drift of the rest of the water, forcing _some_ of it upwards in this spot; and although, _on the average_, the direction of least resistance is downwards, that would be no reason for its not being upwards now and then. Just so with our voluntary acts of attention. They are momentary arrests, coupled with a peculiar feeling, of portions of the stream. But the arresting force, instead of being this peculiar feeling itself, may be nothing but the processes by which the collision is produced. The feeling of effort may be 'an accompaniment,' as Mr. Bradley says, 'more or less superfluous,' and no more contribute to the result than the pain in a man's finger, when a hammer falls on it, contributes to the hammer's weight. Thus the notion that our effort in attending is an original faculty, a force additional to the others of which brain and mind are the seat, may be an abject superstition. Attention may have to go, like many a faculty once deemed essential, like many a verbal phantom, like many an idol of the tribe. It may be an excrescence on Psychology. No need of it to drag ideas before consciousness or fix them, when we see how perfectly they drag and fix each other there.
* * * * *
I have stated the effect-theory as persuasively as I can.[380] It is a clear, strong, well-equipped conception, and like all such, is fitted to carry conviction, where there is no contrary proof. The feeling of effort certainly _may_ be an inert accompaniment and not the
## active element which it seems. No measurements are as yet performed
(it is safe to say none ever will be performed) which can show that it contributes energy to the result. We _may_ then regard attention as a superfluity, or a 'Luxus,' and dogmatize against its causal function with no feeling in our hearts but one of pride that we are applying Occam's razor to an entity that has multiplied itself 'beyond necessity.'
But Occam's razor, though a very good rule of method, is certainly no law of nature. The laws of stimulation and of association may well be indispensable actors in all attention's performances, and may even be a good enough 'stock-company' to carry on many performances without aid; and yet they _may_ at times simply form the background for a 'star-performer,' who is no more their 'inert accompaniment' or their 'incidental product' than Hamlet is Horatio's and Ophelia's. Such a star-performer would be the voluntary effort to attend, if it were an original psychic force. Nature _may_, I say, indulge in these complications; and the conception that she has done so in this case is, I think, just as clear (if not as 'parsimonious' logically) as the conception that she has not. To justify this assertion, _let us ask just what the effort to attend would effect if it were an original force_.
It would deepen and prolong the stay in consciousness of innumerable ideas which else would fade more quickly away. The delay thus gained might not be more than a second in duration--but that second might be _critical_; for in the constant rising and falling of considerations in the mind, where two associated systems of them are nearly in equilibrium it is often a matter of but a second more or less of attention at the outset, whether one system shall gain force to occupy the field and develop itself, and exclude the other, or be excluded itself by the other. When developed, it may make us act; and that act may seal our doom. When we come to the chapter on the Will, we shall see that the whole drama of the voluntary life hinges on the amount of attention, slightly more or slightly less, which rival motor ideas may receive. But the whole feeling of reality, the whole sting and excitement of our voluntary life, depends on our sense that in it things are _really being decided_ from one moment to another, and that it is not the dull rattling off of a chain that was forged innumerable ages ago. This appearance, which makes life and history tingle with such a tragic zest, _may_ not be an illusion. As we grant to the advocate of the mechanical theory that it may be one, so he must grant to us that it may _not_. And the result is two conceptions of possibility face to face with no facts definitely enough known to stand as arbiter between them.
Under these circumstances, one can leave the question open whilst waiting for light, or one can do what most speculative minds do, that is, look to one's general philosophy to incline the beam. The believers in mechanism do so without hesitation, and they ought not to refuse a similar privilege to the believers in a spiritual force. I count myself among the latter, but as my reasons are ethical they are hardly suited for introduction into a psychological work.[381] The last word of psychology here is ignorance, for the 'forces' engaged are certainly too delicate and numerous to be followed in detail. Meanwhile, in view of the strange arrogance with which the wildest materialistic speculations persist in calling themselves 'science,' it is well to recall just what the reasoning is, by which the effect-theory of attention is confirmed. It is an argument from analogy, drawn from rivers, reflex actions and other material phenomena where no consciousness _appears_ to exist at all, and extended to cases where consciousness seems the phenomenon's essential feature. _The consciousness doesn't count,_ these reasoners say; it doesn't exist for science, it is _nil_; you mustn't think about it at all. The intensely reckless character of all this needs no comment. It is making the mechanical theory true _per fas aut nefas_. For the sake of that theory we make inductions from phenomena to others that are startlingly _unlike_ them; and we assume that a complication which Nature has introduced (the presence of feeling and of effort, namely) is not worthy of scientific recognition at all. Such conduct may conceivably be _wise_, though I doubt it; but scientific, as contrasted with metaphysical, it cannot seriously be called.[382]
INATTENTION.
Having spoken fully of attention, let me add a word about _inattention_.
We do not notice the ticking of the clock, the noise of the city streets, or the roaring of the brook near the house; and even the din of a foundry or factory will not mingle with the thoughts of its workers, if they have been there long enough. When we first put on spectacles, especially if they be of certain curvatures, the bright reflections they give of the windows, etc., mixing with the field of view, are very disturbing. In a few days we ignore them altogether. Various entoptic images, _muscæ volitantes_, etc., although constantly present, are hardly ever known. The pressure of our clothes and shoes, the beating of our hearts and arteries, our breathing, certain steadfast bodily pains, habitual odors, tastes in the mouth, etc., are examples from other senses, of the same lapse into unconsciousness of any too unchanging content--a lapse which Hobbes has expressed in the well-known phrase, "_Semper idem sentire ac non sentire ad idem revertunt_."
The cause of the unconsciousness is certainly not the mere blunting of the sense-organs. Were the sensation important, we should notice it well enough; and we can at any moment notice it by expressly throwing our attention upon it,[383] provided it have not become so inveterate that inattention to it is ingrained in our very constitution, as in the case of the _muscæ volitantes_ the double retinal images, etc. But even in these cases artificial conditions of observation and patience soon give us command of the impression which we seek. The inattentiveness must then be a habit grounded on higher conditions than mere sensorial fatigue.
Helmholtz has formulated a general law of inattention which we shall have to study in the next chapter but one. Helmholtz's law is that we leave all impressions unnoticed which are valueless to us as signs by which to _discriminate things_. At most such impressions fuse with their consorts into an aggregate effect. The upper partial tones which make human voices differ make them differ as wholes only--we cannot dissociate the tones themselves. The odors which form integral parts of the characteristic taste of certain substances, meat, fish, cheese, butter, wine, do not come as odors to our attention. The various muscular and tactile feelings that make up the perception of the attributes 'wet,' 'elastic,' 'doughy,' etc., are not singled out separately for what they are. And all this is due to an inveterate habit we have contracted, of passing from them immediately to their import and letting their substantive nature alone. They have formed connections in the mind which it is now difficult to break; they are constituents of processes which it is hard to arrest, and which differ altogether from what the processes of catching the attention would be. In the cases Helmholtz has in mind, not only we but our ancestors have formed these habits. In the cases we started from, however, of the mill-wheel, the spectacles, the factory din, the tight shoes, etc., the habits of inattention are more recent, and the manner of their genesis seems susceptible, hypothetically at least, of being traced.
How _can_ impressions that are not needed by the intellect be thus shunted off from all relation to the rest of consciousness? Professor G. E. Müller has made a plausible reply to this question, and most of what follows is borrowed from him.[384] He begins with the fact that
"When we first come out of a mill or factory, in which we have remained long enough to get wonted to the noise, we feel as if something were _lacking_. Our total feeling of existence is different from what it was when we were in the mill.... A friend writes to me: 'I have in my room a little clock which does not run quite twenty-four hours without winding. In consequence of this, it often stops. So soon as this happens, I notice it, whereas I naturally fail to notice it when going. When this first began to happen, there was this modification: I suddenly felt an undefined uneasiness or sort of void, without being able to say what was the matter; and only after some consideration did I find the cause in the stopping of the clock.'"
That the stopping of an unfelt stimulus may itself be felt is a well-known fact: the sleeper in church who wakes when the sermon ends; the miller who does the same when his wheel stands still, are stock examples. Now (since every impression falling on the nervous system must propagate itself somewhither), Müller suggests that impressions which come to us when the thought-centres are preoccupied with other matters may thereby be blocked or inhibited from invading these centres, and may then overflow into lower paths of discharge. And he farther suggests that if this process recur often enough, the side-track thus created will grow so permeable as to be used, no matter what may be going on in the centres above. In the acquired inattention mentioned, the constant stimulus always caused disturbance _at first_; and consciousness of it was extruded successfully only when the brain was _strongly excited_ about other things. Gradually the extrusion became easier, and at last automatic.
The side-tracks which thus learn to draft off the stimulations that interfere with thought cannot be assigned with any precision. They probably terminate in organic processes, or insignificant muscular contractions which, when stopped by the cessation of their instigating cause, immediately give us the feeling that something is gone from our existence (as Müller says), or (as his friend puts it) the feeling of a void.[385]
Müller's suggestion awakens another. It is a well-known fact that persons striving to keep their attention on a difficult subject will resort to movements of various unmeaning kinds, such as pacing the room, drumming with the fingers, playing with keys or watch-chain, scratching head, pulling mustache, vibrating foot, or what not, according to the individual. There is an anecdote of Sir W. Scott, when a boy, rising to the head of his class by cutting off from the jacket of the usual head-boy a button which the latter was in the habit of twirling in his fingers during the lesson. The button gone, its owner's power of reciting also departed.--Now much of this activity is unquestionably due to the overflow of emotional excitement during anxious and concentrated thought. It drains away nerve-currents which if pent up within the thought-centres would very likely make the confusion there worse confounded. But may it not also be a means of drafting off all the irrelevant sensations of the moment, and so keeping the attention more exclusively concentrated upon its inner task? Each individual usually has his own peculiar habitual movement of this sort. A downward nerve-path is thus kept constantly open during concentrated thought; and as it seems to be a law of frequent (if not of universal) application, that incidental stimuli tend to discharge through paths that are already discharging rather than through others, the whole arrangement might protect the thought-centres from interference from without. Were this the true _rationale_ of these peculiar movements, we should have to suppose that the sensations produced by each phase of the movement itself are also drafted off immediately by the next phase and help to keep the circular process agoing. I offer the suggestion for what it is worth; the connection of the movements themselves with the continued effort of attention is certainly a genuine and curious fact.
FOOTNOTES:
[322] Bain mentions attention in the Senses and the Intellect, p. 558, and even gives a theory of it on pp. 370-374 of the Emotions of the Will. I shall recur to this theory later on.
[323] "The first and most important, but also the most difficult, task at the outset of an education is to overcome gradually the inattentive dispersion of mind which shows itself wherever the organic life preponderates over the intellectual. The training of animals ... must be in the first instance based on the awakening of attention (cf. Adrian Leonard, _Essai sur l'Education des Animaux_, Lille, 1842), that is to say, we must seek to make them gradually perceive separately things which, if left to themselves, would not be attended to, because they would fuse with a great sum of other sensorial stimuli to a confused total impression of which each separate item only darkens and interferes with the rest. Similarly at first with the human child. The enormous difficulties of deaf-mute- and especially of idiot-instruction is principally due to the slow and painful manner in which we succeed in bringing out from the general confusion of perception single items with sufficient sharpness." (Waitz, Lehrb. d. Psychol., p. 632.)
[324] Elements, part i, chap. ii, _fin._
[325] Lectures on Metaphysics, lecture xiv.
[326] Nature, vol. iii, p. 281 (1871).
[327] If a lot of dots or strokes on a piece of paper be exhibited for a moment to a person in _normal_ condition, with the request that he say how many are there, he will find that they break into groups in his mind's eye, and that whilst he is analyzing and counting one group in his memory the others dissolve. In short, the impression made by the dots changes rapidly into something else. In the _trance-subject_, on the contrary, it seems to _stick_; I find that persons in the hypnotic state easily count the dots in the mind's eye so long as they do not much exceed twenty in number.
[328] Mr. Cattell made Jevons's experiment in a much more precise way (Philosophische Studien, iii, 121 ff.). Cards were ruled with short lines, varying in number from four to fifteen, and exposed to the eye for a hundredth of a second. When the number was but four or five, no mistakes as a rule were made. For higher numbers the tendency was to under- rather than to over-estimate. Similar experiments were tried with letters and figures, and gave the same result. When the letters formed familiar words, three times as many of them could be named as when their combination was meaningless. If the words formed a sentence, twice as many of them could be caught as when they had no connection. "The sentence was then apprehended as a whole. If not apprehended thus, almost nothing is apprehended of the several words; but if the sentence as a whole is apprehended, then the words appear very distinct."--Wundt and his pupil Dietze had tried similar experiments on rapidly repeated strokes of sound. Wundt made them follow each other in groups, and found that groups of twelve strokes at most could be recognized and identified when they succeeded each other at the most favorable rate, namely, from three to five tenths of a second (Phys. Psych., ii, 215). Dietze found that by mentally subdividing the groups into sub-groups as one listened, as many as forty strokes could be identified as a whole. They were then grasped as eight sub-groups of five, or as five of eight strokes each. (Philosophische Studien, ii, 362.)--Later in Wundt's Laboratory, Bechterew made observations on two _simultaneously_ elapsing series of metronome strokes, of which one contained one stroke more than the other. The most favorable rate of succession was 0.3 sec., and he then discriminated a group of 18 from one of 18 + 1, apparently. (Neurologisches Centralblatt, 1889, 272.)
[329] Revue Scientifique, vol. 39, p. 684 (May 28, 1887).
[330] Cf. Chr. Wolff: Psychologia Empirica, § 245. Wolff's account of the phenomena of attention is in general excellent.
[331] Pflüger's Archiv, xi, 429-31.
[332] Physiol. Psych., 2d ed. ii, pp. 238-40.
[333] _Ib._ p. 262.
[334] Physiol. Psych., 2d ed. ii, 264-6.
[335] This was the original 'personal equation' observation of Bessel. An Observer looked through his equatorial telescope to note the moment at which a star crossed the meridian, the latter being marked in the telescopic field of view by a visible thread, beside which other equidistant threads appear. "Before the star reached the thread he looked at the clock, and then, with eye at telescope, counted the seconds by the beat of the pendulum. Since the star seldom passed the meridian at the exact moment of a beat, the observer, in order to estimate fractions, had to note its position at the stroke before and at the stroke after the passage, and to divide the time as the meridian-line seemed to divide the space. If, e.g., one had counted 20 seconds, and at the 21st the star seemed removed by _ac_ from the meridian-thread _c_, whilst at the 22d it was at the distance _bc_; then, if _ac: bc_:: 1: 2, the star would have passed at 21 1/8 seconds. The conditions resemble those in our experiment: the star is the index-hand, the threads are the scale; and a time-displacement is to be expected, which with high rapidities may be positive, and negative with low. The astronomic observations do not permit us to measure its absolute amount; but that it exists is made certain by the fact than after all other possible errors are eliminated, there still remains between different observers a personal difference which is often much larger than that between mere reaction-times, amounting ... sometimes to more than a second." (_Op. cit._ p. 270.)
[Illustration: FIG. 35.]
[336] Philosophische Studien, ii, 601.
[337] Physiol. Psych., 2d ed. ii, 273-4; 3d ed. ii, 339; Philosophische Studien, ii, 621 ff.--I know that I am stupid, but I confess I find these theoretical statements, especially Wundt's, a little hazy. Herr v. Tschisch considers it impossible that the perception of the index's position should come in too late, and says it demands no
## particular attention (p. 622). It seems, however, that this can hardly
be the case. Both observers speak of the difficulty of seeing the index at the right moment. The case is quite different from that of distributing the attention impartially over simultaneous momentary sensations. The bell or other signal gives a momentary sensation, the index a continuous one, of motion. To note any one _position_ of the latter is to _interrupt_ this sensation of motion and to substitute an entirely different percept--one, namely, of position--for it, during a time however brief. This involves a sudden change in the manner of attending to the revolutions of the index; which change _ought_ to take place neither sooner nor later than the momentary impression, and _fix_ the index as it is then and there visible. Now this is not a case of simply getting two sensations at once and so feeling them--which would be an harmonious act; but of _stopping one_ and changing it into another, whilst we simultaneously get a third. Two of these acts are discrepant, and the whole three rather interfere with each other. It becomes hard to 'fix' the index at the very instant that we catch the momentary impression; so we fall into a way of fixing it either at the last possible moment before, or at the first possible moment after, the impression comes.
This at least seems to me the more probable state of affairs. If we fix the index before the impression really comes, that means that we perceive it too late. But why do we fix it _before_ when the impressions come slow and simple, and _after_ when they come rapid and complex? And why under certain conditions is there no displacement at all? The answer which suggests itself is that when there is just enough leisure between the impressions for the attention to adapt itself comfortably both to them and to the index (one second in W.'s experiments), it carries on the two processes at once; when the leisure is excessive, the attention, following its own laws of ripening, and being _ready_ to note the index before the other impression comes, notes it _then_, since that is the moment of easiest action, whilst the impression, which comes a moment later, interferes with noting it again; and finally, that when the leisure is insufficient, the momentary impressions, being the more fixed data, are attended to first, and the index is fixed a little later on. The noting of the index at too early a moment would be the noting of a real fact, with its analogue in many other rhythmical experiences. In reaction-time experiments, for example, when, in a regularly recurring series, the stimulus is once in a while omitted, the observer sometimes reacts as if it came. Here, as Wundt somewhere observes, we catch ourselves
## acting merely because our inward preparation is complete. The
'fixing' of the index is a sort of action; so that my interpretation tallies with facts recognized elsewhere; but Wundt's explanation (if I understand it) of the experiments requires us to believe that an observer like v. Tschisch shall steadily and without exception get an hallucination of a bell-stroke before the latter occurs, and _not hear the real bell-stroke afterwards_. I doubt whether this is possible, and I can think of no analogue to it in the rest of our experience. The whole subject deserves to be gone over again. To Wundt is due the highest credit for his patience in working out the facts. His explanation of them in his earlier work (Vorlesungen üb. Menschen und Thierseele, i, 37-42, 365-371) consisted merely in the appeal to the unity of consciousness, and may be considered quite crude.
[338] Note that the permanent interests are themselves grounded in certain objects and relations in which our interest is immediate and instinctive.
[339] Herbart: Psychologie als Wissenschaft, § 128.
[340] Sir W. Hamilton. Metaphysics, lecture xiv.
[341] Mental Physiol., § 124. The oft-cited case of soldiers not perceiving that they are wounded is of an analogous sort.
[342] Prof. J. M. Cattell made experiments to which we shall refer further on, on the degree to which reaction-times might be shortened by distracting or voluntarily concentrating the attention. He says of the latter series that "the averages show that the attention can be kept strained, that is, the centres kept in a state of unstable equilibrium, for one second" (Mind, xi, 240).
[343] Physiologische Optik, § 32.
[344] "'Genius,' says Helvetius, 'is nothing but a continued attention (_une attention suivie_).' 'Genius,' says Buffon, 'is only a protracted patience (_une longue patience_).' 'In the exact sciences, at least,' says Cuvier, 'it is the patience of a sound intellect, when invincible, which truly constitutes genius.' And Chesterfield has also observed that 'the power of applying an attention, steady and undissipated, to a single object, is the sure mark of a superior genius.'" (Hamilton: Lect. on Metaph., lecture xiv.)
[345] See, e.g., Ulrici: Leib u. Seele, ii, 28; Lotze: Metaphysik, § 273; Fechner, Revision d. Psychophysik, xix; G. E. Müller: Zur Theorie d. sinnl. Aufmerksamkeit, $ 1; Stumpf: Tonpsychologie, i, 71.
[346] Fechner, _op. cit._ p. 271.
[347] Tonpsychologie, i, p. 71.
[348] Compare, on clearness as the essential fruit of attention, Lotze's Metaphysic, § 273.
[349] Elements, part i, chap. ii.
[350] Physiol. Psych., 2d ed. ii, 226.
[351] By a negative value of the reaction-time Wundt means the case of the reactive movement occurring _before_ the stimulus.
[352] _Op. cit._ ii, 239.
[353] The reader must not suppose this phenomenon to be of frequent occurrence. Experienced observers, like Exner and Cattell, deny having met with it in their personal experience.
[354] _Op. cit._ pp. 241-5.
[355] It should be added that Mr. J. M. Cattell (Mind, xi, 33) found, on repeating Wundt's experiments with a disturbing noise upon two practised observers, that the simple reaction-time either for light or sound was hardly perceptibly increased. Making strong voluntary concentration of attention shortened it by about 0.013 seconds on an average (p. 240). Performing mental additions whilst waiting for the stimulus lengthened it more than anything, apparently. For other, less careful, observations, compare Obersteiner, in Brain, i, 439. Cattell's negative results show how far some persons can abstract their attention from stimuli by which others would be disturbed.--A. Bartels (Versuche über die Ablenkung d. Aufmerksamkeit, Dorpat, 1889) found that a stimulus to one eye sometimes prevented, sometimes improved, the perception of a quickly ensuing very faint stimulus to the other.
[356] Cf. Wundt, Physiol. Psych., 1st ed. p. 794.
[357] Beiträge zur Experimentellen Psychologie, Heft i, pp. 73-106 (1889).
[358] To say the very least, he always brought his articulatory innervation close to the discharging point. Herr M. describes a tightening of the head-muscles as characteristic of the attitude of attention to the reply.
[359] Psychophysik, Bd. ii, pp. 475-6.
[360] I must say that I am wholly unconscious of the peculiar feelings in the scalp which Fechner goes on to describe. "The feeling of strained attention in the different sense-organs seems to be only a muscular one produced in using these various organs by setting in motion, by a sort of reflex action, the muscles which belong to them. One can ask, then, with what particular muscular contraction the sense of strained attention in the effort to recall something is associated? On this question my own feeling gives me a decided answer; it comes to me distinctly, not as a sensation of tension in the inside of the head, but as a feeling of strain and contraction in the scalp with a pressure from without inwards over the whole cranium, undoubtedly caused by a contraction of the muscles of the scalp. This harmonizes very well with the German popular expression _den Kopf zusammennehmen_, etc., etc. In a former illness, in which I could not endure the slightest effort of continuous thought, and had no theoretical bias on this question, the muscles of the scalp, especially those of the occiput, assumed a fairly morbid degree of sensibility whenever I tried to _think_." (_Ibid._ pp. 490-491.) In an early writing by Professor Mach, after speaking of the way in which by attention we decompose complex musical sounds into their elements, this investigator continues: "It is more than a figure of speech when one says that we 'search' among the sounds. This hearkening search is very observably a bodily activity, just like attentive looking in the case of the eye. If, obeying the drift of physiology, we understand by attention nothing mystical, but a bodily disposition, it is most natural to seek it in the variable tension of the muscles of the ear. Just so, what common men call attentive looking reduces itself mainly to accommodating and setting of the optic axes.... According to this, it seems to me a very plausible view that quite generally Attention has its seat in the mechanism of the body. If nervous work is being done through certain channels, that by itself is a mechanical ground for other channels being closed." (Wien. Sitzungsberichte, Math. Naturw., xlviii, 2, 297. 1863.)
[361] Physiol. Optik, p. 741.
[362] Hermann's Handbuch, iii, i, 548.
[363] Helmholtz: Tonempfindungen, 3d ed. 85-9 (Engl. tr., 2d ed. 50, 51; see also pp. 60-1).
[364] Physiol. Psych., ii, 209.
[365] Physiol. Optik, 741.
[366] P. 728.
[367] Popular Scientific Lectures, Eng. Trans., p. 295.
[368] Similarly in the verses which some one tried to puzzle me with the other day: "_Gui n'a beau dit, qui sabot dit, nid a beau dit elle?_"
[369] I cannot refrain from referring in a note to an additional set of facts instanced by Lotze in his Medizinische Psychologie, § 431, although I am not satisfied with the explanation, fatigue of the sense-organ, which _he_ gives. "In quietly lying and contemplating a wall-paper pattern, sometimes it is the ground, sometimes the design, which is clearer and consequently comes nearer.... Arabesques of monochromic many-convoluted lines now strike us as composed of one, now of another connected linear system, and all without any intention on our part. [This is beautifully seen in Moorish patterns; but a simple diagram like Fig. 39 also shows it well. We see it sometimes as two large triangles superposed, sometimes as a hexagon with angles spanning its sides, sometimes as six small triangles stuck together at their corners.]... Often it happens in revery that when we stare at a picture, suddenly some one of its features will be lit up with especial clearness, although neither its optical character nor its meaning discloses any motive for such an arousal of the attention.... To one in process of becoming drowsy the surroundings alternately fade into darkness and abruptly brighten up. The talk of the bystanders seems now to come from indefinite distances; but at the next moment it startles us by its threatening loudness at our very ear," etc. These variations, which everyone will have noticed, are, it seems to me, easily explicable by the very unstable equilibrium of our ideational centres, of which constant change is the law. We _conceive_ one set of lines as object, the other as background, and forthwith the first set becomes the set we _see_. There need be no _logical_ motive for the conceptual change, the irradiations of brain-tracts by each other, according to accidents of nutrition, 'like sparks in burnt-up paper,' suffice. The changes during drowsiness are still more obviously due to this cause.
[Illustration: FIG. 39.]
[370] The Emotions and the Will, 3d ed. p. 370.
[371] Psychologie de l'Attention (1889), p. 32 ff.
[372] Philosophische Studien, iv, 413 ff.
[373] See Lange, _loc. cit._ p. 417, for another proof of his view, drawn from the phenomenon of retinal rivalry.
[374] Many of my students have at my request experimented with imagined letters of the alphabet and syllables, and they tell me that they can see them inwardly as total colored pictures without following their outlines with the eye. I am myself a bad visualizer, and make movements all the while.--M. L. Marillier, in an article of eminent introspective power which appeared after my text was written (Remarques sur le Mécanisme de l'Attention, in Revue Philosophique, vol. xxvii, p. 566), has contended against Ribot and others for the non-dependence of sensory upon motor images in their relations to attention. I am glad to cite him as an ally.
[375] Drs. Ferrier (Functions of the Brain, §§ 102-3) and Obersteiner (Brain, i, 439 ff.) treat it as the essential feature. The author whose treatment of the subject is by far the most thorough and satisfactory is Prof. G. E. Müller, whose little work Zur Théorie der sinnlichen Aufmerksamkeit, Inauguraldissertation, Leipzig, Edelmann (1874?), is for learning and acuteness a model of what a monograph should be. I should like to have quoted from it, but the Germanism of its composition makes quotation quite impossible. See also G. H. Lewes: Problems of Life and Mind, 3d Series, Prob. 2, chap. 10; G. H. Schneider: Der menschliche Wille, 294 ff., 309 ff.; C. Stumpf: Tonpsychologie, i, 67-75; W. B. Carpenter: Mental Physiology, chap. 3; Cappie in 'Brain,' July 1886 (hyperæmia-theory); J. Sully in 'Brain,' Oct. 1890.
[376] L'Enfant de trois à sept Ans, p. 108.
[377] Psychologie de l'Attention, p. 53.
[378] Repetition of this sort does not confer _intelligence_ of what is said, it only keeps the mind from wandering into other channels. The intelligence sometimes comes in beats, as it were, at the end of sentences, or in the midst of words which were mere words until then. See above, p. 281.
[379] The reader will please observe that I am saying all that can _possibly_ be said in favor of the effect-theory, since, inclining as I do myself to the cause-theory, I do not want to undervalue the enemy. As a matter of fact, one might begin to take one's stand against the effect theory at the outset, with the phenomenon of immediate sensorial attention. One might say that attention causes the movements of adjustment of the eyes, for example, and is not merely their effect. Hering writes most emphatically to this effect: "The movements from one point of fixation to another are occasioned and regulated by the changes of place of the attention. When an object, seen at first indirectly, draws our attention to itself, the corresponding movement of the eye follows without further ado, as a consequence of the attention's migration and of our effort to make the object distinct. The wandering of the attention entails that of the fixation point. Before its movement begins, its goal is already in consciousness and grasped by the attention, and the location of this spot in the total space seen is what determines the direction and amount of the movement of the eye." (Hermann's Handbuch, p. 534.) I do not here insist on this, because it is hard to tell whether the attention or the movement comes first (Hering's reasons, pp. 535-6, also 544-6, seem to me ambiguous), and because, even if the attention to the object does come first, it may be a mere effect of stimulus and association. Mach's theory that the _will to look_ is the _space-feeling itself_ may be compared with Hering's in this place. See Mach's Beiträge zur Analyse der Empfindungen (1886), pp. 55 ff.
[380] F. H. Bradley, "Is there a Special Activity of Attention?" in 'Mind,' xi, 305, and Lipps, Grundtatsachen, chaps. iv and xxx, have stated it similarly.
[381] More will be said of the matter when we come to the chapter on the Will.
[382] See, for a defence of the notion of inward activity, Mr. James Ward's searching articles in 'Mind,' xii, 45 and 564.
[383] It must be admitted that some little time will often elapse before this effort succeeds. As a child, I slept in a nursery with a very loud-ticking clock, and remember my astonishment more than once, on listening for its tick, to find myself unable to catch it for what seemed a long space of time; then suddenly it would break into my consciousness with an almost startling loudness.--M. Delbœuf somewhere narrates how, sleeping in the country near a mill-dam, he woke in the night and thought the water had ceased to flow, but on looking out of the open window saw it flowing in the moonlight, and then heard it too.
[384] Zur Theorie d. sinnl. Aufmerksamkeit, p. 128 foll.
[385] I have begun to inquire experimentally whether any of the measurable functions of the workmen change after the din of machinery stops at a workshop. So far I have found no constant results as regards either pulse, breathing, or strength of squeeze by the hand. I hope to prosecute the inquiry farther (May, 1890).
## CHAPTER XII .
CONCEPTION.
THE SENSE OF SAMENESS.
In