An Introduction to Psychology Translated from the Second German Edition · Wilhelm Max Wundt
CONSCIOUSNESS AND ATTENTION
If psychologists are asked, what the business of psychology is, they generally make some such answer as follows, if they belong to the empirical school: that this science has to investigate the facts of consciousness, its combinations and relations, so that it may ultimately discover the laws which govern these relations and combinations. Now although this definition seems quite perfect, it is really to some extent a vicious circle. For if we ask further, what is this consciousness which psychology investigates? the answer will be, "It consists of the sum total of facts of which we are conscious." In spite of this, our definition is the simplest, and therefore for the present it will be well for us to keep to it. All objects of experience have this peculiarity, namely, that we cannot really define them but only point to them, and if they are of a complex nature analyse them into their separate qualities. Such an analysis we call a description. We will therefore best be able to answer more accurately the question as to the nature of psychology by describing as exactly as possible all the separate qualities of that consciousness, the content of which psychological investigation has to deal with.
This diagram represents the separate beats by notes, and the accent shows those beats that are subjectively emphasised. Row A shows an ascending beat, and row B a descending one. Now if it happens that we can at will hear into the beats of the metronome an ascending or a descending beat (A or B), i.e. we can hear one and the same beat now emphasised and now unemphasised, then we may regard the instrument as suitable for all the psychological experiments to be described in the following pages. Although the experiment described was only meant to serve as a test for the metronome, yet we can derive from it a remarkable psychological result. For we notice in this experiment that it is really extraordinarily difficult to hear the beats in absolutely the same intensity, or, to put it in other words, to hear unrhythmically. Again and again we recur to the ascending or descending beat. We can express this phenomenon in this sentence: Our consciousness is rhythmically disposed. The reason of this scarcely lies in a specific quality, peculiar to consciousness alone, but it clearly stands in the closest relationship to our whole psycho-physical organisation. Consciousness is rhythmically disposed, because the whole organism is rhythmically disposed. The movements of the heart, of breathing, of walking, take place rhythmically. In a normal state we certainly are not aware of the pulsations of the heart, but we do feel the movements of breathing, and they act upon us as very weak stimuli. Above all, the movements of walking form a very clear and recognisable background to our consciousness. Now our means of locomotion are in a certain sense natural pendulums, the movements of which generally follow with a certain regularity, as with the pendulum of the metronome. Therefore whenever we receive impressions in consciousness at similar stated intervals, we arrange them in a rhythmical form similar to that of our own outward movements. The special form of rhythm, ascending or descending, is within certain limits left to our own free choice, just as with the movements of locomotion, which may take the form of walking, of running, of jumping, and lastly of all different kinds of dances. Our consciousness is not a thing separated from our whole physical and mental being, but a collection of the contents that are most important for the mental side of this being.
We can obtain a further result from the experiment with the metronome described above, if we change the length of the ascending or descending row of beats. In our diagram each row, A and B, contains sixteen separate beats, or, taking one rise and fall together, eight double beats. If we listen attentively to a row of beats of this length when the metronome is going at a medium rapidity of, say, 1 to 1 1/2 seconds, and then after a short pause repeat a row of exactly the same length, we recognise immediately the identity of the two. In the same way a difference will be immediately noticed, if the second row is only by one beat longer or shorter than the first. It is immaterial whether we beat in ascending or descending rhythm. Now it is obvious that such an immediate recognition of the identity of two successive rows is only possible if each of them is in consciousness as a whole. It is not at all necessary for both of them to be in consciousness at the same time. We can see at once that consciousness must grasp them as wholes, if we consider for one moment an analogous case, e.g. the recognition of a complex visual image.
If we look, for example, at a regular hexagon for a short time, and then cast another glance at the same figure, we recognise at once that both images are identical. Such a recognition is impossible if we divide the figure up into several parts and show these parts separately. Just as the two visual images appeared in consciousness as wholes, so must each of our rows of beats appear as a whole, if the second is to call up a similar impression to the first. The difference consists in this, that the hexagon was perceived in all its parts at once, whereas the beats followed each other in succession. Just because they follow in this way, such a row of beats possesses this advantage, that we can thereby determine precisely how far we can extend such a row so that it is still possible to grasp it in consciousness as a whole. It has been proved by such experiments that sixteen successive beats, alternately rising and falling, or so-called 2/8 time, is the maximum for such a row, in order that all the separate elements may still find room in our consciousness. We may therefore consider such a row as a measure for the scope of consciousness under these given conditions. At the same time it appears that this measure is, between certain limits, independent of the rapidity of succession of the beats. A grasping together of the row as a whole becomes, however, impossible, when the beats follow each other so slowly that no rhythm may be heard, or when the rapidity is so great that the 2/8 time is lost, and the mind tries to group the beats together in a more complicated rhythm. The former limit lies at about 2 1/2 seconds, and the latter at 1 second.
Such a row arises if we let different intensities of accent enter, say the strongest at the beginning of the row, a medium one in the middle, and a weak one in the middle of each of the two halves of the whole row, as in the diagram above. The strongest emphasis is denoted by three accents, the medium one by two, and the weak ones by one. This transition to more complicated rhythms is to a great degree dependent upon the rapidity of the beat, as well as upon our will. With long intervals it is very difficult to go beyond the simple 2/8 time. With short ones a certain exertion is necessary to withstand the impulse of transition to more complicated rhythms. When listening unconcernedly to the beats of the metronome when the interval between the beats is 1/2 second or less, the above-described 4/4 time generally appears. This groups together eight beats into one unity, whereas the 2/8 time only embraces two beats. Now if we measure the scope of consciousness for such a complicated row of beats, we find that five bars of 4/4 time can be grouped together and grasped as a whole; and if this row is repeated after a short interval, it can be recognised as identical with the preceding row. Here, then, we have forty beats as the scope of consciousness for this complicated rhythm, whereas with the most simple rhythmical arrangement we had only sixteen beats. This scope of forty seems to be the greatest we can attain by any means. We can, it is true, voluntarily call forth more complicated rhythmic arrangements, e.g. 6/4 time. But such an increase in the number of beats in the rhythmic arrangement demands a certain exertion, and the length of the row that can be grouped together as one whole does not increase, but decreases.
In these experiments a further remarkable quality of consciousness appears, which is closely connected to the rhythmical disposition of consciousness. The three degrees of emphasis, which the diagram of 4/4 time shows, form a maximum of differentiation which cannot be surpassed. Counting the unaccented beat as well, we arrive at a scale of intensity of four grades as the highest limit in the gradation of the intensity of impressions. This value clearly determines the rhythmical arrangement of the whole row, and with it the comprehension of this in consciousness, just as on the contrary the rhythm of the beats determines the number of gradations in intensity, which are necessary in the arrangement of the row of beats as supports for the comprehension by consciousness. Both factors therefore stand in close relationship to each other. The rhythmical disposition of consciousness demands certain limits for the number of grades of emphasis, and these on their part demand that specific rhythmical disposition which is peculiar to the human consciousness.
The more extensive the rows of beats become, which we join together in the experiments described, the more clearly does another important phenomenon of consciousness appear. If we pay attention to the relation between a beat, perceived in a certain given moment, and one that has immediately preceded it, and if we further compare this latter with a beat further back in the row that is being grouped together as a whole, differences of a certain kind between all these impressions appear. They are quite different from the variations in intensity and emphasis. To describe them we do best to make use of expressions, which were first of all formed in all languages to describe the perception of visual impressions, where the same differences also appear and are relatively independent of differences in the intensity of light. These expressions are "clearness" and "distinctness." Their meanings almost coincide, but still they differ inasmuch as they denote different sides of the faculty of perception. "Clearness" refers more to the special constitution of the impression itself; "distinctness" to the relation of the impression to other impressions from which it seems to stand out. Let us transfer these conceptions in a generalised sense to the content of consciousness.
One row of beats clearly shows in each of its separate elements the most varying degrees of clearness and distinctness. They all in a regular manner bear upon the beat that is affecting consciousness at the moment. This beat is the one that is most clear and most distinct. The ones immediately preceding are most like this one, whereas those that lie further back lose more and more in clearness. If the beat furthest away lies so far back that the impression has absolutely disappeared, then we speak in a picturesque way of a sinking beneath the threshold of consciousness. For the opposite process we have at once the picture of a rising above the threshold. In a similar sense for that gradual approach to the threshold of consciousness, which we notice in our experiments in the beats that lie further back, we use the expression "a darkening," and for the reverse process "a brightening" of the content of consciousness. With the use of these expressions we can formulate in the following manner the condition necessary for the comprehension of a whole consisting of many parts, e.g. a row of beats: a comprehension as a whole is possible as long as no part sinks beneath the threshold of consciousness.
For the most obvious differences in the clearness and distinctness of the content of consciousness, we generally use two other expressions, which, like our former ones of darkening and brightening, illustrate the meaning. We say that that element of consciousness, which is mostly clearly apprehended, lies in the fixation-point of consciousness, and that all the rest belongs to the field of consciousness. In our metronome experiments, therefore, the beat, that is at the moment affecting consciousness, lies in this subjective fixation-point, whereas the preceding beats, the further back they stretch, the more do they belong merely to this subjective field. This latter we may picture to ourselves as a region surrounding the fixation-point, which becomes gradually darker towards the periphery and at last is bounded by the threshold of consciousness.
In this last figure of speech we have already suggested that the so-called fixation-point of consciousness denotes in general only the ideal middle point of a central region, within which several impressions can be clearly and distinctly apprehended. So in one row of beats the beat heard at a certain moment would lie within the fixation-point; yet the immediately preceding beats are still clear and distinct enough, in order to be included within the same narrow region, which contrasts with the more extensive field by reason of its greater clearness. The psychological process agrees also in this respect with the expressions we have borrowed from the sense of sight, where we have a single point of the field of vision as fixation-point, around which a great number of impressions may be clearly perceived. Only because of this are we able to apprehend a larger image in a single moment, e.g. to read a word. For this central part of the field of our consciousness, which immediately surrounds the subjective fixation-point, the practical necessity of language has already coined a word, which has been accepted by psychology. We call that psychical process, which is operative in the clear perception of a narrow region of the content of consciousness, attention. When impressions, or any other content, at a certain moment are remarkable for their special clearness in comparison to the other elements in consciousness, we say that they lie within the focus of attention. Keeping to our former figure, we imagine this as the central region that surrounds the subjective fixation-point, and it is cut off by a more or less clearly defined boundary-line from the larger and darker field that surrounds it. And this immediately gives rise to a new experimental problem, which forms an important supplement to the above-described measurement of the whole scope of consciousness. The problem consists in answering the question that immediately arises, How big is this narrower scope of attention?
Rhythmical rows of beats, because of the arrangement of the successive impressions in them, were excellently suited to determine the total scope of consciousness. But because of this very same quality they can give us little help in solving our second problem. For it is obvious that just that connection between the focus of attention and the wider field of consciousness, that the rhythm of a row of beats causes--this connection makes a clear boundary between these two regions impossible. We notice clearly enough that along with the beat that is directly affecting consciousness a few of the preceding ones also fall within the focus of attention, but how many remains uncertain. The sense of sight obviously offers us more favourable conditions. We must, however, first of all note the fact that the physiological conditions of vision in themselves limit the apprehension of an extended object, not taking into account the psychological boundary of clear perception. The keenest differentiation of impressions is limited to the so-called region of clearest vision, which surrounds the fixation-point. The reader can test this for himself by fixating the middle letter "_o_" in the following diagram of letters from a distance of about 20-25 cm, while keeping one eye closed.
We can in this position, by directing our attention alone to the outlying parts of the field of vision, still recognise letters, which lie at the sides of our figure, as, for example, the _h_ at the top or the _i_ at the right-hand side. To carry out this experiment a little practice in fixation is required, since in natural vision we are always inclined to direct our line of vision to that point, to which our attention is turned. If, however, we practise letting our attention wander over the different parts of the field of vision while keeping the same fixation-point, it will soon be clear to us that the fixation-point of attention and the fixation-point of the field of vision are by no means identical. They can by practice be separated, and the attention can be directed to a point in indirect vision, i.e. a point lying to this or to that side of the line of vision. From this we see that clear perception in the psychological sense and clear vision in the physiological sense do not necessarily coincide.
For example, if we fixate the middle letter _o_, and at the same time direct our attention to the "_n_" at the right-hand side, we also perceive clearly the letters that surround _n_, i.e. _f g s i_, whereas the letters around _o_, i.e. _h t i n_, seem to retreat into the darker field of consciousness. This diagram of letters has been printed so large, that when we look at it from a distance of 20-25 cm. it almost corresponds in scope to the region of clearest vision, taking as a measure for this the recognisability of letters of the size of those printed in this book. We see, therefore, at once from the above-described observations, that the scope of the focus of attention and the region of clearest vision in the physiological sense differ widely from each other. The latter, under the conditions of observation we have chosen, comprises a far wider field than the former. In our figure there are 95 letters: If it were possible simultaneously clearly to perceive in the psychological sense all the objects clearly seen physiologically, then we should be able by fixating the point _o_ to perceive all these letters. This is, however, by no means the case. At one given moment we can differentiate only a few, which surround the fixation-point of attention, whether this coincides with the objective fixation-point of the field of vision, as in ordinary vision, or whether it lies in any way outside of this point owing to a severance of the two fixation-points.
Although these observations as to the simultaneous recognition of haphazardly arranged simple objects, e.g. letters, point decisively to a fairly narrow limitation of the scope of attention, still we cannot give an exact numerical answer by this method as to the size of this scope, as we could by means of our metronome experiments in regard to the scope of consciousness. Still, without any great change and without any complicated apparatus, we can make these visual experiments suffice to answer our question. Our immediate results will, of course, only be valid under the special conditions we set up. For this purpose a great number of such diagrams, with letters arranged in the same manner, must be constructed. The position of the letters in each diagram must be different. Then a fairly large square of white cardboard, with a black point in the middle, is made (as in the figure on p. 19). With this we cover the diagram chosen for the experiment. The observer, who previously must not have seen the diagrams, is told to fixate with one eye the point in the middle, and to keep the other eye closed.
The cover is then taken away rapidly for one moment, and then as rapidly replaced. The rapidity of this procedure must be such that no movement of the eye, or wandering of the attention over the field of vision, can take place, as long as the diagram remains uncovered.[1] Each time we repeat the experiment a new diagram must be chosen, otherwise the individual momentary impression will supplement the preceding ones. If we wish to obtain unambiguous results we must choose conditions which exclude such influences of previous perceptions. Our question will therefore be limited to this: What is the number of simple and new impressions in consciousness that the focus of attention can grasp in one given moment? In reference to this way of stating the question, an objection to our method of experimenting might be raised. It might be objected that a letter is not a simple element of consciousness, and that we ought rather to use simpler objects, e.g. dots. But since these lack all means of differentiation, the carrying out of the experiment would be rendered much more difficult, if not impossible. On the other hand, we must not forget that our familiarity with letters is of the greatest importance. Because of this a letter of ordinary print can be perceived as quickly as a single dot--a fact any one can easily prove for himself by means of observation. Such symbols, because of their characteristic differences, have this advantage, that after a momentary impression they can be easily retained in consciousness, and thus an account of what has been clearly perceived can be given after the experiment. If we carry out the experiments in the manner described, it appears that an unpractised observer can perceive, at most, only 3-4 letters. After a few more experiments this number increases to 6. Of course, as before mentioned, a new diagram must be used in every new experiment. This value 6 cannot be increased by further practice, and it remains the same for different observers. We are therefore entitled to regard it as a constant for attention for the human consciousness.
Miscellaneousness, he can read it at once, without being prepared for it and without previous practice. With isolated elements he could at most grasp six, but here, under exactly the same conditions, the scope is extended to seventeen or more elements without the slightest difficulty. It is clear that this is essentially the same phenomenon that we encountered in our experiments on rhythm with the sense of hearing. The conditions of combination are, however, in so far different, as the stimuli for the sense of sight were simultaneous, whereas for the sense of hearing the whole was made up of simple impressions that followed each other. And with this another difference is connected. A word can only be recognised at a momentary glance, if it has been known to us before as a whole, or with compound words, if their chief parts have been familiar to us. Therefore a word of an absolutely unknown language appears as a complex of unarranged letters, and with such a complex our scope is again limited to six isolated elements.
With a rhythmical row of beats, on the other hand, it is of no consequence what the form of rhythm is that binds them together, since we can think into such a row whatever rhythmical arrangement we choose, as long as it conforms to the general rhythmical disposition of consciousness, i.e. as long as it does not exceed the maximum of three different accents, as we have previously shown. At the same time this requirement shows us that the differences in apprehending a successive and a simultaneous whole, which appear in our experiments with sight and hearing, are in reality only apparent differences. A musical time that is adequate to our sense of rhythm behaves in exactly the same way as a word or sentence that is adequate to our sense of language. Therefore we may presuppose that in the reading, as in the rhythm experiments, it is not the whole of a complex consisting of many elements that is instantaneously grasped by the attention. Only a limited part of such a word falls within the scope of attention, and from this part the psychical power of combination goes over to those other elements that lie in the wider field of consciousness.
Ideas discussed in this chapter
Text from Project Gutenberg, public domain in the United States.