Page:EB1911 - Volume 22.djvu/594

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573
PSYCHOLOGY
[MEMORY AND ASSOCIATION

of the other. What tells in retrospect is the series a b c d e, &c.; what tells in the wearisome present is the intervening ttt₃, &c., or rather the original accommodation of which these temporal signs are the residuum. For, as we have seen elsewhere, the intensity of a presentation does not persist, so that in memory the residuum of the most intense feeling of tedium may only be so many t’s in a memory-continuum whose surviving members are few and uninteresting. But in the actual experience, say, of a wearisome sermon, when the expectation of release is continually balked and attention forced back upon a monotonous dribble of platitudes, the one impressive fact is the hearer's impatience. On the other hand, so long as we are entertained, attention is never involuntary, and there is no continually deferred expectation. Just as we are said to walk with least effort when our pace accords with the rate of swing of our legs regarded as pendulums, so in pastimes impressions succeed each other at the rate at which attention can be most easily accommodated, and are such that we attend willingly.[1] We are absorbed in the present without being unwillingly confined to it; not only is there no motive for retrospect or expectation, but there is no feeling that the present endures. Each impression lasts as long as it is interesting, but does not continue to monopolize the focus of consciousness till attention to it is fatiguing, because uninteresting. In such facts, then, we seem to have proof that our perception of duration rests ultimately upon quasi-motor acts of varying intensity, the duration of which we do not directly experience as duration at all. They do endure and their intensity is a function of their duration; but the intensity is all that we directly perceive. In other words, it is here contended that what Locke called an instant or moment—“the time of one idea in our minds without the succession of another, of one wherein therefore we perceive no succession at all”—is psychologically not “a part in duration” in that sense in which, as he says, “we cannot conceive any duration without succession” (Essay, ii. 16, 12).

But, if our experience of time depends primarily upon acts of attention to a succession of distinct objects, it would seem that Is time Discrete or Continuous? time, subjectively regarded, must be discrete and not continuous. This, which is the view steadily maintained by the psychologists of Herbart's school, was implied if not stated by Locke, Berkeley and Hume. Locke hopelessly confuses time as perceived and time as conceived, and can only save himself from pressing objections by the retort, “It is very common to observe intelligible discourses spoiled by too much subtlety in nice divisions.” But Berkeley and Hume, with the mathematical discoveries of Newton and Leibnitz before them, could only protest that there was nothing answering to mathematical continuity in our experience. And, whereas Locke had tried to combine with his general psychological account the inconsistent position that “none of the distinct ideas we have of either [space or time] is without all manner of composition,” Berkeley declares, “For my own part, whenever I attempt to frame a simple idea of time, abstracted from the succession of ideas in my mind, which flows uniformly and is participated by all beings, I am lost and embrangled in inextricable difficulties. I have no notion of it at all, only I hear others say it is infinitely divisible, and speak of it in such a manner as leads me to harbour odd thoughts of my existence. . . . Time therefore being nothing, abstracted from the succession of ideas in our minds, it follows that the duration of any finite spirit must be estimated by the number of ideas or actions succeeding each other in that same spirit or mind” (Principles of Knowledge, i. § 98), Hume, again, is at still greater pains to show that “the idea which we form of any finite quality is not infinitely divisible, but that by proper distinctions and separations we may run this idea up to inferior ones, which will be perfectly simple and indivisible . . . that the imagination reaches a minimum, and may raise up to itself an idea of which it cannot conceive any subdivision, and which cannot be diminished without a total annihilation” (Human Nature, pt. ii. § 1, Green's ed., pp. 334 seq.).

At first blush we are perhaps disposed to accept this account of our time-perception, as Wundt, e.g. does, and to regard the attribution of continuity as wholly the result of after-reflection.[2] But it may be doubted if this is really an exact analysis of the case. Granted that the impressions to which we chiefly attend are distinct and discontinuous in their occupation of the focus of consciousness, and that, so far, the most vivid element in our time-experience is discrete; granted further that in recollection and expectation such objects are still distinct—all which seems to imply that time is a mere plurality—yet there is more behind. The whole field of consciousness is not occupied by distinct objects, neither are the changes in this field discontinuous. The experimental facts above-mentioned illustrate the transition from a succession the members of which are distinctly attended to to one in which they are indistinctly attended to, i.e. are not discontinuous enough to be separately distinguished. Attention does not move by hops from one definite spot to another, but, as Wundt himself allows, by alternate diffusion and concentration, like the foot of a snail, which never leaves the surface it is traversing. We have a clear presentation discerned as A or B when attention is gathered up; and, when attention spreads out, we have confused presentations not admitting of recognition. But, though not recognizable, such confused presentations are represented, and so serve to bridge over the comparatively empty interval during which attention is unfocused. Thus our perception of a period of time is not comparable to so many terms in a series of finite units any more than it is to a series of infinitesimals. When attention is concentrated in expectation of some single impression, then, no doubt, it is brought to a very fine point (“zugespitzt,” as Herbart would say); and a succession of such impressions would be represented as relatively discrete compared with the representation of the scenery of a day-dream. But absolutely discrete it is not and cannot be. In this respect the truth is rather with Herbert Spencer, who, treating of this subject from another point of view, remarks, “When the facts are contemplated objectively, it becomes manifest that, though the changes constituting intelligence approach to a single succession, they do not absolutely form one” (Psychology, i. § 180).

On the whole, then, we may conclude that our concrete time-experiences are due to the simultaneous representation of a series of definite presentations both accompanied and separated by more or fewer indefinite presentations more or less confused; that, further, the definite presentations have certain marks or temporal signs due to the movements of attention; that the rate of these movements or accommodations is approximately constant; and that each movement itself is primarily experienced as an intensity.

Experimental Investigations concerning Memory and Association.

30. Of the vast mass of experimental work undertaken in recent years, that relating to memory and association is probably the most important. A brief account of some of it is therefore offered at this point, by way of illustrating the character of the “new psychology.”

The learning and retaining of a stanza of poetry, say, is obviously a function of many variables, such as the mode of presentation (whether the words are heard only, or heard and seen, or both heard, seen and spoken aloud), the length, familiarity with the words and ideas used, the number of repetitions, the attention given, &c. Familiarity of course implies previous learning and retaining; the first essential, therefore, in any attempt to study these processes from the beginning, is the exclusion of this factor. Accordingly Ebbinghaus, the pioneer in experiments of this kind,[3] devised the new material, which is now regularly employed, namely, closed monosyllables, not themselves words, and strung together promiscuously into lines of fixed length so as never to form words: bam, rit, por, sig, nef, gud, &c., is an instance of such “senseless verses.” With very slight attention most persons would be able to reproduce three or four such syllables on a single reading or hearing; and by greater concentration six or seven might be so reproduced. This maximum, called sometimes the “span of pretension,” has been repeatedly made the subject of special inquiry. In idiots it is found, as might be expected, remarkably low; in school children it increases rapidly between the ages of eight and fourteen, and then remains almost stationary, individual differences being small compared with the striking differences that appear when longer lines make repetitions necessary.[4] This comparatively constant span of prehension is doubtless

  1. To this rate the “indifference point” mentioned above is obviously related. It has also been called “adequate time” or “optional time.” It is, however, a tempo that varies with the subject-matter attended to; when effective attention is more difficult the tempo is slower than it is when to attend is easy.
  2. Cf. Wundt, Logik, i. 432.
  3. H. Ebbinghaus, “Ueber das Gedächtniss: Untersuchungen zur experimentellen Psychologie” (1885).
  4. Cf. J. Jacobs and F. Galton on the “Span of Prehension,” Mind, (1887), pp. 75 sqq.; Bourdon, “Influence de l'âge sur la mémoire immédiate,” Rev. phil. (1894) xxxviii., 148 sqq.