Chapter 9: Memory
James Rowland Angell
Memory and Imagination.-- A considerable portion of the mental events which we examined in the last chapter as instances of imagination, might with propriety have been described as phases of memory. In our common use of the term " memory," we mean to indicate such processes as involve recollection in any fashion whatever. We say in this way that our memory informs us that Napoleon was imprisoned at St. Helena; that 8 x 7=56; that yesterday was rainy, etc. We also speak of remembering that on a certain occasion we made a certain remark to a certain individual. Evidently these illustrations might all be described as cases of reproductive imagination, for they all involve reproductive imagery. We may be reasonably sure at once, then, that memory and imagination have one point at least in common, i. e., the image.
But there is one important difference between memory, in the more precise meaning of the word, and mere imagination, which makes it desirable to devote a separate chapter to its study. We might go on indefinitely having similar, or even identical, images pass through our minds, and, if we did not recognise them as having been previously portions of our experience, we should never in any strict sense be able to speak of our having a memory process. In memory, our consciousness not only re-presents old experiences to us, but we are aware of the images thus brought to us as actually standing for items of our previous states of consciousness. If I am turning over in my mind the wisdom of making a
(185) journey to India, the thoughts which come into my mind are brought there by some form of reinstatement of knowledge which I have gained on some earlier occasion. Productive, or reproductive, processes of imagery are at work. But my attention may be wholly monopolised with the reference of these thoughts to the future. They may not at any point in my thinking present themselves as mere exponents of my antecedent experiences. I think of India as an interesting country, and my attitude is of course determined by things which I have previously learned about it. But this fact of my having gotten my information in some moment of my earlier life may drop wholly out of sight in my enthusiasm over the knowledge itself. Clearly, then, there is a distinction between the mere reappearance of ideas in consciousness, and the fact of memory, as involving recognition of these ideas as elements in my own past history.
Definition of Memory.-- We may define memory, then, with more preciseness than we have before attempted, by quoting James' words. " Memory proper-- is the knowledge of an event or fact, of which meantime we have not been thinking with the additional consciousness that we have thought, or experienced it before."
Analysis of Memory. -- Let us take a specific instance of memory as thus defined and examine it. Suppose we attempt to recall where we were and what we were doing at 10 o'clock on the fifteenth day of last month. Ordinarily we shall be obliged to begin by remembering upon what day of the week that month began, and this in turn may require our remembering upon what day the present month came in. Let us suppose that we find in this way that the fifteenth of the preceding month fell upon a Tuesday. If our life is subject to a fixed routine, this will generally suffice to give us the clue to our whereabouts and doings at the hour suggested. After a moment's reflection we remember, perhaps, that we were in the library reading American history, and upon a little
(186) more reflection we may recall what other persons were in the room, and what portions of the text we were reading.
Memory and Association, or Cerebral Habit.-- This analysis at once reveals what we shall find true in any case we may select, i. e., that we call back our memory ideas, or images, by means of ideas which are associated with them. In order to solve the problem set us by the question in our illustration, we began by calling into mind ideas which we knew to be connected with the solution. In this way, little by little, we obtain the clue to our occupation at the time suggested. Memory depends, then, for its operation upon the principle of association, and this principle is in the last analysis identical with the law of habit in the cortical processes of the cerebrum, as was shown in the previous chapter.
Memory and Imagery.-- If we inquire into the nature of the mental content which has passed through our consciousness in any such case of memory, we find that it is made up of images-visual, auditory, motor, etc. When we reach the goal of our endeavour, and succeed in recalling our presence in the library, we discover that the content of our thought is not only made up of images, but that over and above this fact is to be remarked the peculiar character of the imagery. Just in the measure in which our recollection is detailed and confident, we shall ordinarily find the imagery profuse and exact in its representation of the temporal and spatial order of the events and objects present to consciousness in the original experience. This consideration affords us, therefore, a practical distinction between the imagery involved in mere reproductive imagination and that employed in memory. We can symbolise the matter as in the accompanying diagram (figure 57). In reproductive imagination the image X brings with it only the images Y and Z, and these are insufficient to give it a specific setting in time and space. In memory, the image a brings with it the extensive cluster of images b, c, d, etc., which serve to reinstate with
(187) some approach to completeness the experience which they purport to represent. There is commonly a difference, then, both in the quantity and the character of the imagery found in memory as distinct from reproductive imagination. All memory is reproductive imagination. But not all reproductive imagination is memory, as we have defined it.
Memory and Recognition.-- One still more important peculiarity is noticeable in this ease of memory which we are analysing. After we have, by means of associated images, gotten into mind our whereabouts and acts at the time named,
and after the imagery portraying our situation has been developed in consciousness, it is still necessary, if this is not all to be futile, that we should recognise, identify, and assent to the images thus brought before our notice, as indicating the actual experience to be recalled. This fact of recognition we have previously emphasised as a distinguishing mark of memory when compared with imagination. It seems to be an ultimate and unanalysable property of consciousness. But however much it may baffle our attempts to dissect it, there can be no question of its fundamental import, and we must accordingly take account of it.
Memory an Outgrowth of Recognition.-- It seems on the whole probable that memory, in the meaning of our definition, has grown out of a cruder process of recognition which,
(188) although it is now no longer sole proprietor of the activity, still accompanies the memory act in its elaborate forms as a basal and indispensable characteristic. If we examine, for example, the actions of an infant, we very early observe evidences of the recognition of objects. Thus, the mother's face, the sounds of preparing food, the contact sensations occasioned when clothing is put on or off, are all of them recognised at a period when it would be hazardous to assume that any independent memory imagery has as yet become disengaged from the general sensory continuum of consciousness. Clearly then, the recognition process may begin with conscious events which are dominantly of the sensory and perceptual kind; whereas our contact with it thus far in our study has been primarily in connection with representational activities of the centrally initiated character.
Psychophysical Conditions of Sensory Recognition.-- When we consider the neural conditions under which sensory recognition arises in the young babe, it is immediately suggested to us that recognition depends primarily upon the reexcitation of pathways in the nervous system over which nervous impulses have previously travelled. The psychical thrill which such stimulation sets up finds an echo in the organism, which is probably the beginning of recognition. If we take this fact of recognition, in connection with the other facts we noticed when describing the beginnings of habit, we shall secure a deeper insight into the mode of development peculiar to the process here at issue.
Take the case of a child learning to recognise its mother At first, when the mother takes the child up to be fed, the visual, tactual, and gustatory stimulations set up miscellaneous movements which are in the main uncoordinated and utterly variable. Little by little, however, as these sense impressions are repeated, and their agreeable consequences are experienced, the movements tend, after the manner we have already described, to settle down into the relatively coordinated
(189) groups which the experience encourages. Smiling, gurgling, jerking the limbs in movements anticipatory of being taken UP rapidly appear and become fixed as habits.
Very quickly, then, these repeated sense impressions set up sensory-motor coordinations, of which the conscious process of recognition is the psychical accompaniment. These impressions promptly come to mean certain movements. Indeed, the movements are actually initiated by the impressions, and recognition is the mental state which observes, assents to, and in a sense guides, these physiological responses. The psychophysical activity in recognition does not involve merely a repetition of these sense stimulations; it involves a reinstatement of a sensory-motor cycle, and the recognition factor, as we isolate this on the psychological side, is simply the peculiar quale which belongs to this cycle. As these responses become more and more automatic, the psychical part of the activity tends to evaporate, as we have so often pointed out. In just the measure in which this occurs do we cease to feel any clear, definite, vital sense of familiarity, any tingling thrill of recognition. This is illustrated in adult life by the " matter of course " manner in which we respond to the thousand and one objects which we see every day-the books, papers, inkstand and pens on our desks, the tables, chairs, windows and lamps in our rooms, the trees on our familiar streets, the shape and colour of our own houses, etc. We recognise all these things of course, but it is with a relatively automatic, dim kind of consciousness, which contrasts sharply with the vivacity and distinctness of the feeling which we get upon first seeing these same objects after prolonged absence. We may feel moderately confident, therefore, that recognition of the sensory variety rests upon the reinstatement of acquired sensory-motor coordinations; i. e., on the genetic side it displays a period of conflict of impulses and movements with maladjustment, a period of increasingly efficient adaptation, and a final period in which the conscious factor tends to drop out,
(190) sometimes apparently doing this, sometimes stopping just short of disappearance.
Psychophysical Conditions of Ideational Recognition - When we recognise ideas, or images, in distinction from perceptions, as having previously occupied our consciousness, the strictly mental features of the case do not differ materially from those we have just described. We are ordinarily, perhaps, more definitely aware of the fringe of suggested images with which an idea that we recognise promptly surrounds itself, although this is apparently not an invariable feature of recognition. But the production of an emotional reaction, or mood, which we may name the familiarity feeling, is common to both the sensory and the ideational forms of recognition. Generally, but not always, the act of recognition is agreeable, and this, too, is true whether the act be of the sensory or the ideational kind. Probably the mere act of recognition is, as such, always agreeable, although the object, or content of the thought recognised, is of course sometimes quite otherwise. Moreover, both kinds of recognition, sensory and ideational, may vary almost indefinitely as regards the distinctness and the degree of elaboration belonging to the various parts of the process. We may thus find that an idea which comes into our mind-for example, the visual image of some person's face calls up the vague feeling " familiar," " seen before," and nothing more. Or it may surround itself with a number of other images and we may at once recognise it as the face of a speaker whom we heard last week. In both cases, and in all instances of recognition, however, it must be remembered that the mental act of explicit recognition is something unique; something which is not simply synonymous with these accompanying conditions which we are describing. When we get these accompanying conditions we get the act too, and when they are all absent, the act is apparently absent. But the mental relating of the remembered idea, or the remembered perception, to the
(191) past is something distinctly additional to and beyond these concomitants.
On the physiological side it seems probable that ideational recognition is much like sensory recognition, save as regards the neural processes which initiate it. The sense organ activity is clearly not the immediate predecessor of the cortical action underIying recognition in the case of its ideational form. But the motor response is essentially identical, and its cortical basis is, for all we can see, of a similar character. The matter can be put diagrammatically, as in the accompanying figure (58). In the case of sensory recognition
the process starts in the sense organ (SO) and is transmitted to the sensory regions of the cortex (SC), arousing perception. Thence it is transmitted to other cortical centres (C1, C2, etc.), resulting in the arousal of supplementary ideas, which serve to give the perception its place in past experience, and the process is then carried over to the motor regions (MC), and thus out into the voluntary and involuntary muscles, producing the habitual response in completion of the sensory-motor cycle. In ideational recognition the process is of the same character, save that now the sense organ origin of the cortical excitation is lacking. The process starts, so far as we can discern, in some cortical centre like C1. At all events, if a sensory process is really responsible for the result, it lies so far back in the series of cortical activities that we
(192) cannot confidently connect it with the result. It ought not to be necessary to point out that the actual motor reactions characterising these processes of recognition may be of an extremely rudimentary and fragmentary kind. But the tendency to make the movements, with its indication of a degree of innervation in the mortor (sic) cortex, seems to be a genuine part of the act.
Remembering and Forgetting.-- It has already been abundantly emphasised that memory (using the term from this point on to the end of the chapter in the broader sense of common parlance, as equivalent to recollection in its various forms) depends in the last analysis upon the retentiveness of the nervous tissues. When we are not occupied with a thought, or an image, so far as we know, the thought, or image, simply goes out, ceases to exist. Certain psychologists prefer to think of these psychological facts as stored up in the mind in the form of what they call "psychical dispositions," or tendencies. But however it may fare with this last mentioned theory, the modifications of the cortical tissues which our experiences bring about are certainly relatively durable; and when the cortex is called upon to resuscitate a previous experience, it summons the appropriate centres, with their imbedded modifications, to perform again the action previously executed. This is apparently the physical basis of imagination and memory. In one sense, therefore, it is probable that no item of our lives is ever literally and entirely forgotten. Even if we find it impossible, as we sometimes do, voluntarily to recall a certain idea, we must believe that the experience in which we originally encountered it has left its indelible impress upon the substance of the brain, whose action will in consequence be somewhat different from that which it might have manifested had the experience in question never befallen us.
Despite this belief, forgetfulness is a constant and often exasperating characteristic of daily life. It also has a useful
(193) function, which we do not always recognise. From the psychophysical point of view we obtained the most important explanation of the value of forgetting when we were examining the facts about attention. In the chapter devoted to attention we found that consciousness is seemingly never impartial in its response to the objects presented to it. It is always primarily concerned with some particular portion of the objective field. It neglects this and attends to that, it is dimly aware of this and keenly cognisant of that. Now, if memory is dependent upon the modifications which neural stimulations impress upon the cerebral cortex, and if consciousness and cortical action run parallel with one another, as we have seen is apparently the case, it holds to reason that those items in any experience which procure our undivided and concentrated attention must succeed in leaving deeper and more permanent traces in the cortical tissues than do those to which we attend in the margin of consciousness, or than those over which we pass uninterestedly. Although the undoubted tendency of the brain is to register and store up all the impressions which are imposed upon it, the gradual change of organic structures must inevitably bring it about that some of the less deeply engraved modifications should gradually become so faint and so disused as to render them practically inert and incompetent to participate vitally in the operations of memory. Temporary functional disconnections of brain centres that normally are connected are familiar to all of us. I know my friend's middle name perfectly well, and yet when asked for it a moment ago I could not command it. Some momentary stoppage of the associated pathways in the cortex ' checked the attempt at recall. -Many of the most serious disorders of insanity involve this kind of disconnection and disintegration among ideas, of course much exaggerated. One primary reason for our forgetfulness, therefore, is found in the process of attention. We must expect to forget a goodly part of all those items of experience to which we
(194) do not lend a vigorous and forceful attention. The only compensation for the lack of such concentration is found in the tedious process of repetition, by means of which we may, with even indifferent attention, grind gradually into our brain tissues any material which we desire to retain.
Forgetting has its use, however, in freeing us from the incubus of much utterly valueless experience. On the whole we remember fairly well those things which are of practical importance to us. Were our minds so organised as to retain with impartial accuracy all the events in our experience, and were their total capacity to remain unchanged, we should find our intellectual possibilities immensely curtailed by the obtrusion of the insignificant and irrelevant. While we are occasionally incommoded by forgetting, it is undoubtedly on the whole an added source of efficiency in our mental operations, that we find the unimportant elements of our knowledge so frequently dropping out of our memories.
Defects in Recollection.-- We obtain an interesting sidelight upon normal memory processes by observing some of the common defects and abnormalities. to which it is subject. These are in the main exaggerations of common and familiar deficiencies. Thus, in one form of mental disorder everything is forgotten the moment it passes out of the range of perception. We observe in ourselves the counterpart of this case, when after reading a sentence, for instance, we find, as occasionally occurs to all of us, that for a few moments we are absolutely unable to remember anything about it, and often must ignominiously read it again. The opposite type of abnormality is met with in the form of vastly heightened sensitivity to impressions, which can then be recalled with marvellous accuracy and detail. The mathematical prodigies who can recall lists of a hundred or more figures after a single glance are cases in point. With most of us the only phenomenon closely corresponding to this is found in our ability to recall experiences which have been characterised by intense
(195) emotional disturbance. The details of some episode in which we have been greatly terrified may linger in our memories with a vividness which rivals the distinctness of the original experience. Again, the memory of events during a severe illness may be almost wholly lost. A similar obliviscence as to the occurrences preceding a severe accident is very frequent.
An interesting disease of memory which furnishes striking confirmation of our conclusions concerning the dependence of memory and imagination upon the image consists in the loss of memory for specific forms of sensory material. Thus, the visual memory may be entirely lost, so that one cannot recall how objects look. Or the auditory images of words may be obliterated. If the imagery which is lost be of the variety chiefly employed by the patient in his thinking, the result is inevitably most disastrous, reducing the victim to a condition bordering upon imbecility.
Another curious disturbance of memory, with which most of us are familiar, is found in the experience of a feeling that we have previously been in the place where we are at the moment, or a feeling that we have previously said the words we are now saying, while as a matter as fact we know that we cannot possibly have been in the given situation, nor have spoken the words. Many explanations have been advanced for this phenomenon, which still remains, however, obscure as to its origin. It probably arises from different causes at different times, and is, perhaps, most often to be regarded as primarily a disturbance of emotional processes connected with the " familiarity feeling."
Lastly there are numerous abnormalities in which the order of remembered events and the time of their occurrence is distorted; things are persistently " remembered," which never occurred, and imaginary events are interpolated among real events, in a manner which baffles analysis. The counterparts of these last named defects in our own every-day life will suggest themselves at once.
When memory begins to decay under the advance of age there is a remarkable uniformity in the order in which certain kinds of knowledge disappear, and in many cases of insanity a similar order of disintegration is observed. Thus, the mem- ory of proper names is among the earliest of the losses, and the more concrete are our ideas, the earlier do we lose the memory of the words for them. Abstract ideas which depend very largely for their existence in our thought upon the words which we use to designate them are by virtue of the law of habit much more persistent; because the word is in this case bound up much more widely and intimately with our use of the idea. So it comes about that the memory of adjectives and verbs, conjunctions and prepositions, outlives that of most nouns and proper names. The objects for which nouns are our verbal symbols we can, and frequently do, think of in terms of imagery other than that of words, e. g., visual, tactual, etc. Consequently the memory of these words is less deeply imbedded in the brain tissues, and when this tissue decays such memories are the first to suffer extinction.
Training and Development of Memory Processes.-- It is evident that any effort to train the memory must, if it is to succeed, be based upon the employment of such principles as are natural and inherent in the memory process itself.
Now the first of these principles involves factors which are largely mechanical in their nature. If the cortical basis of recollection is resident in the modifications of nervous tissue, brought about by the impressions which pour in upon us, it is clear that anything. which will augment the permanency -of these modifications, or increase their number, will in so far make towards the preservation of the accompanying psychical processes and the establishment of an efficient memory. Experience certainly justifies this statement, for we find that any impressions which we can make extremely vivid are likely to be retained in memory for a longer time than would be the case if the impressions were less intense. Such vivid
(197) experiences are always productive of deep-seated neural excitement, and we may reasonably suppose that their ready retention and recall is a sign of the depth of the nervous modification produced by them. Similarly, the mere repetition of an impression must serve sooner or later to set up relatively permanent modifications in the brain tissue, and so indirectly accomplish permanency of retention in the mind. These points we have already touched upon in our account of association in the previous chapter.
It is not often easy in a practical way to enhance the effectiveness of our memories through rendering emotionally vivid the impressions we wish to preserve. But so far as we can succeed in focalising our attention exclusively upon the matter in hand, so far we do make gains in vividness, and the importance for efficient memory processes of concentrated attention is based upon precisely this fact. Speaking from an empirical point of view, it seems probable that the immense variation in the memory processes of different people is largely connected with this difference in ability to concentrate attention. The habit of giving oneself with complete abandon to the undertaking immediately in hand is one of the most significant clues to the securing of an alert and accurate memory.
Obviously it is simple enough to make use of repetition. We may either do this by giving ourselves over and over again the same sense stimulation, as when we repeat a name which we wish to remember; or we may, after the manner of the modern elementary schools, present the same object to a number of different senses, as when we listen to the sound of the name, then speak it, then write it and look at the written word. In such ways we can increase the depth of the cortical modifications, corresponding to some single sense department, or we can increase the number of cortical areas affected by the stimulus. In either case we evidently increase the total amount of cortical modifications, and so better the
(198) chances, not only for the permanent retention, but also for easy and ready recall. The more pathways there are in the brain leading to the stimulation of any special activity) the more likely is it that the given activity can be promptly aroused. The more ideas there are in the mind connected with any given idea, the more chances there are for the latter to be expeditiously produced when needed.
As a matter of fact all memory processes depend in some measure upon this mechanical factor, but it becomes relatively less important as the general level of intellectual development rises. There are many things which children must necessarily get at first in a largely mechanical fashion. Learning to spell, for example, is in English largely a mechanical accomplishment, the available rational elements being chiefly conspicuous by their absence. But for adult undertakings it is a poor memory which responds only to mechanical incitements. Nevertheless, our modern education, with its extensive desertion of all verbatim methods of memorising, is undoubtedly in danger of pouring the baby out with the bath, of discarding a method useful in its place, even though not useful in all places.
Logical Method of Memorising.-- The most important factor in assisting the establishment of broad and sound memory processes is of a practical and logical character. If we can once knit up a fact to be remembered with a group of other already known facts with which it is intimately related, we often come to see the entire group as mutually dependent upon, or explanatory of, one another. And thus we find we can retain in memory the total mass more efficiently than we could a much smaller number of items, so long as they remain unrelated. Such an interrelating of the facts has in a sense the effect of reducing the mass to a single mental fact. A child being taught the method of long division in arithmetic, or the method of determining the square root of a number, finds the successive steps in the process
(199) extremely difficult to keep straight, so long as the procedure is based simply upon the memory of the rule, which states dogmatically the order of the various operations to be performed. But as soon as the relation of the several steps to one another is clearly apprehended, as soon as the real nature of the process is understood, the verbatim memory of the rule becomes a superfluity, which may be forgotten with entire impunity. The several facts represented by the separate arithmetical operations all flow together as integral parts of a larger whole, to which they are seen to be essential. Thereafter, the nightmare of a forgotten rule is banished. In a certain sense, however, the rule can hardly be forgotten as long as the clear apprehension of the relations involved remains. For the rule is simply the verbal formulation of these relations. But under such conditions one's action is free, intelligent, and independent, instead of blind, and slavish to a mere rule-of-thumb.
If we are asked how to go about the creation of these logical relations among the facts with which we wish to equip our memories, the answer will turn upon two points. We must first reflect upon the thing to be remembered, and attempt to give it a setting among the things with which it is most closely connected. No fact ever comes to us wholly isolated from the rest of our knowledge, and most facts bear upon their faces evidence of their most intimate relations. We should at once, then, scrutinise each new fact that comes, and inquire what there is in the series of events or relations to which it belongs that has occasioned its existence. We should ask for the causes which have produced it, and the consequences to which it leads. If we can succeed in setting up relationships of this kind, we find that the new fact becomes a real part of our minds, just as in the case of the arithmetical rules of which we spoke a moment ago. In studying history, for example, such a procedure will mean that we shall try to see any given fact, like a battle, a cession of territory, or a
(200) piece of legislation, in the light of all the facts, political, social, economic, geographical, etc., which may bear upon it ill any significant way. All the important episodes in a historical period will thus be welded together, each throwing light upon the other in a way which makes it natural and easy to recall them.
An ideally perfect mind would involve, among other things, a complete working out of all the relations sustained by a given fact to all other known facts. In actual experience, however, we find that our information is largely stored away on the compartment principle. Our knowledge of history seldom gets any very intimate articulation with our knowledge of astronomy. The events with which each deals do not appeal to us as intrinsically germane. Similarly, our knowledge of exact science seldom interferes in either a theoretical or a practical way with our knowledge of politics; and it is notorious that, for certain persons at least, religious knowl- edge and belief is kept quite distinct from every other intellectual and practical interest.
In the second place, we should always, when possible, proceed at once to make some actual use of the information we are seeking to impress upon our memories. In a certain way the process of reflection, which we have just been describing, necessitates our using the facts we are trying to memorise. But we have in mind here a more overt activity. We saw in the previous chapter that the fundamental function of our memory and imagination is the control which they afford over experience, both past and future. These activities are, moreover, only a sort of half-way house between the sensory stimulus and the motor reaction, of which we have heard so much. The relevant motor expression ought, therefore, to be allowed to occur. If all this be true, we shall have some theoretical foundation for the precept we have just formulated, a precept which is abundantly justified by experience. The sooner and oftener we can apply to some practical under-
(201)-taking a fact we wish to remember, the better the chance of remaining in our minds. Talking about it, writing about it, incorporating it into some manual constructive activity, if it is a fact which will permit such treatment, are all methods of accomplishing the desired result. A mind trained to concentrated logical reflection upon facts, and then further trained to make the earliest feasible application of them in practical ways, is a mind which will achieve the maximal efficiency in its memory processes.
Mnemonic Systems.-- Evidently these methods of training the powers of retention and recall suggest no easy royal road to success. They mean hard work. But they are the only methods which have any large and general significance for the development of the mind. Many catch-penny devices have been hit upon to simplify memorising, and within certain narrow limits such systems have a value. The mnemonic schemes of many so-called " memory systems " illustrate the point. Suppose one has occasion to remember a great many unrelated numbers, like the street addresses of a large group of people. One may greatly facilitate such a feat by first memorising a " form," in which each digit is connected with a consonant, e. g., the 1 with t, 2 with l, 3 with d, etc. The next step is to make a word easily suggested by the person whose name is to be remembered, in which these letters shall occur in proper order. For example, Mr. Smith's number is 122, Mr. Smith is tall. The word tall in the number form means 122 , for the vowels are neglected. For special purposes, such as that of our illustration, such methods can be made very useful. But as ,applied to the acquirement and retention of miscellaneous taking its information they are failures. It requires more time and effort to learn the forms, or frames, and then make the applications, than is required to acccomplish the same result in the ways we have already pointed out.
Idiosyncracies in Form of Recall.-- Many persons have curious individual peculiarities in their methods of recalling
(202) specific kinds of material. Thus, certain people always think of the numerals by means of a kind of visual framework, known as a number form. These number forms are most, various in their shape and size and general character, some of them being seen as coloured in many hues. An example of, one of the simpler types is given in the accompanying sketch. (Figure 59.) A person possessing one of these forms always
sees the numbers about which he is thinking appearing in their appropriate place in the framework. Other persons always think of the months of the year, the days of the week, and even the hours of the day, in similar visual frameworks. All these devices seem to represent the effort of the mind to give a concrete basis to abstract relations. But they are for the most part acquired in early childhood in a perfectly naive way, and apparently indicate native differences in the way different minds get hold of material to be remembered. "Coloured hearing," or chromaesthesia, of which mention was made in the analysis of perception, belongs to the same range of individual idiosyncracy.