MEMORY.
=Analysis of the Phenomenon of Memory.=--Memory proper, or secondary
memory as it might be styled, is the knowledge of a former state of mind
after it has already once dropped from consciousness; or rather _it 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_.
The first element which such a knowledge involves would seem to be the
revival in the mind of an image or copy of the original event. And it is
an assumption made by many writers that such revival of an image is all
that is needed to constitute the memory of the original occurrence. But
such a revival is obviously not a _memory_, whatever else it may be; it
is simply a duplicate, a second event, having absolutely no connection
with the first event except that it happens to resemble it. The clock
strikes to-day; it struck yesterday; and may strike a million times ere
it wears out. The rain pours through the gutter this week; it did so
last week; and will do so _in sæcula sæculorum_. But does the present
clock-stroke become aware of the past ones, or the present stream
recollect the past stream, because they repeat and resemble them?
Assuredly not. And let it not be said that this is because clock-strokes
and gutters are physical and not psychical objects; for psychical
objects (sensations, for example) simply recurring in successive
editions will remember each other _on that account_ no more than
clock-strokes do. No memory is involved in the mere fact of recurrence.
The successive editions of a feeling are so many independent events,
each snug in its own skin. Yesterday's feeling is dead and buried; and
the presence of to-day's is no reason why it should resuscitate along
with to-day's. A farther condition is required before the present image
can be held to stand for a _past original_.
That condition is that the fact imaged be _expressly referred to the
past_, thought as _in the past_. But how can we think a thing as in the
past, except by thinking of the past together with the thing, and of the
relation of the two? And how can we think of the past? In the chapter on
Time-perception we have seen that our intuitive or immediate
consciousness of pastness hardly carries us more than a few seconds
backward of the present instant of time. Remoter dates are conceived,
not perceived; known symbolically by names, such as 'last week,' '1850';
or thought of by events which happened in them, as the year in which we
attended such a school, or met with such a loss. So that if we wish to
think of a particular past epoch, we must think of a name or other
symbol, or else of certain concrete events, associated therewithal. Both
must be thought of, to think the past epoch adequately. And to 'refer'
any special fact to the past epoch is to think that fact _with_ the
names and events which characterize its date, to think it, in short,
with a lot of contiguous associates.
But even this would not be memory. Memory requires more than mere dating
of a fact in the past. It must be dated in _my_ past. In other words, I
must think that I directly experienced its occurrence. It must have that
'warmth and intimacy' which were so often spoken of in the chapter on
the Self, as characterizing all experiences 'appropriated' by the
thinker as his own.
A general feeling of the past direction in time, then, a particular date
conceived as lying along that direction, and defined by its name or
phenomenal contents, an event imagined as located therein, and owned as
part of my experience,--such are the elements of every object of
memory.
=Retention and Recall.=--Such being the phenomenon of memory, or the
analysis of its object, can we see how it comes to pass? can we lay bare
its causes?
Its complete exercise presupposes two things:
1) The _retention_ of the remembered fact; and
2) Its _reminiscence_, _recollection_, _reproduction_, or _recall_.
Now _the cause both of retention and of recollection is the law of habit
in the nervous system, working as it does in the 'association of
ideas.'_
=Association explains Recall.=--Associationists have long explained
_recollection_ by association. James Mill gives an account of it which I
am unable to improve upon, unless it might be by translating his word
'idea' into 'thing thought of,' or 'object.'
"There is," he says, "a state of mind familiar to all men, in which we
are said to remember. In this state it is certain we have not in the
mind the idea which we are trying to have in it. How is it, then, that
we proceed, in the course of our endeavor, to procure its introduction
into the mind? If we have not the idea itself, we have certain ideas
connected with it. We run over those ideas, one after another, in hopes
that some one of them will suggest the idea we are in quest of; and if
any one of them does, it is always one so connected with it as to call
it up in the way of association. I meet an old acquaintance, whose name
I do not remember, and wish to recollect. I run over a number of names,
in hopes that some of them may be associated with the idea of the
individual. I think of all the circumstances in which I have seen him
engaged; the time when I knew him, the persons along with whom I knew
him, the things he did, or the things he suffered; and if I chance upon
any idea with which the name is associated, then immediately I have the
recollection; if not, my pursuit of it is vain. There is another set of
cases, very familiar, but affording very important evidence on the
subject. It frequently happens that there are matters which we desire
not to forget. What is the contrivance to which we have recourse for
preserving the memory--that is, for making sure that it will be called
into existence when it is our wish that it should? All men invariably
employ the same expedient. They endeavor to form an association between
the idea of the thing to be remembered and some sensation, or some idea,
which they know beforehand will occur at or near the time when they wish
the remembrance to be in their minds. If this association is formed and
the association or idea with which it has been formed occurs, the
sensation, or idea, calls up the remembrance, and the object of him who
formed the association is attained. To use a vulgar instance: a man
receives a commission from his friend, and, that he may not forget it,
ties a knot in his handkerchief. How is this fact to be explained? First
of all, the idea of the commission is associated with the making of the
knot. Next, the handkerchief is a thing which it is known beforehand
will be frequently seen, and of course at no great distance of time from
the occasion on which the memory is desired. The handkerchief being
seen, the knot is seen, and this sensation recalls the idea of the
commission, between which and itself the association had been purposely
formed."
In short, we make search in our memory for a forgotten idea, just as we
rummage our house for a lost object. In both cases we visit what seems
to us the probable _neighborhood_ of that which we miss. We turn over
the things under which, or within which, or alongside of which, it may
possibly be; and if it lies near them, it soon comes to view. But these
matters, in the case of a mental object sought, are nothing but its
_associates_. The machinery of recall is thus the same as the machinery
of association, and the machinery of association, as we know, is nothing
but the elementary law of habit in the nerve-centres.
=It also explains retention.= And this same law of habit is the machinery
of retention also. Retention means _liability_ to recall, and it means
nothing more than such liability. The only proof of there being
retention is that recall actually takes place. The retention of an
experience is, in short, but another name for the _possibility_ of
thinking it again, or the _tendency_ to think it again, with its past
surroundings. Whatever accidental cue may turn this tendency into an
actuality, the permanent _ground_ of the tendency itself lies in the
organized neural paths by which the cue calls up the memorable
experience, the past associates, the sense that the self was there, the
belief that it all really happened, etc., as previously described. When
the recollection is of the 'ready' sort, the resuscitation takes place
the instant the cue arises; when it is slow, resuscitation comes after
delay. But be the recall prompt or slow, the condition which makes it
possible at all (or, in other words, the 'retention' of the experience)
is neither more nor less than the brain-paths which _associate_ the
experience with the occasion and cue of the recall. _When slumbering,
these paths are the condition of retention; when active, they are the
condition of recall._
[Illustration: FIG. 62.]
=Brain-scheme.=--A simple scheme will now make the whole cause of memory
plain. Let _n_ be a past event, _o_ its 'setting' (concomitants, date,
self present, warmth and intimacy, etc., etc., as already set forth),
and _m_ some present thought or fact which may appropriately become the
occasion of its recall. Let the nerve-centres, active in the thought of
_m_, _n_, and _o_, be represented by _M_, _N_, and _O_, respectively;
then the _existence_ of the _paths_ symbolized by the lines between _M_
and _N_ and _N_ and _O_ will be the fact indicated by the phrase
'retention of the event _n_ in the memory,' and the _excitement_ of the
brain along these paths will be the condition of the event _n_'s actual
recall. The _retention_ of _n_, it will be observed, is no mysterious
storing up of an 'idea' in an unconscious state. It is not a fact of the
mental order at all. It is a purely physical phenomenon, a
morphological feature, the presence of these 'paths,' namely, in the
finest recesses of the brain's tissue. The recall or recollection, on
the other hand, is a _psycho-physical_ phenomenon, with both a bodily
and a mental side. The bodily side is the excitement of the paths in
question; the mental side is the conscious representation of the past
occurrence, and the belief that we experienced it before.
The only hypothesis, in short, to which the facts of inward experience
give countenance is that _the brain-tracts excited by the event proper,
and those excited in its recall, are in part_ DIFFERENT _from each
other_. If we could revive the past event without any associates we
should exclude the possibility of memory, and simply dream that we were
undergoing the experience as if for the first time. Wherever, in fact,
the recalled event does appear without a definite setting, it is hard to
distinguish it from a mere creation of fancy. But in proportion as its
image lingers and recalls associates which gradually become more
definite, it grows more and more distinctly into a remembered thing. For
example, I enter a friend's room and see on the wall a painting. At
first I have the strange, wondering consciousness, 'Surely I have seen
that before,' but when or how does not become clear. There only clings
to the picture a sort of penumbra of familiarity,--when suddenly I
exclaim: "I have it! It is a copy of part of one of the Fra Angelicos in
the Florentine Academy--I recollect it there." Only when the image of
the Academy arises does the picture become remembered, as well as seen.
=The Conditions of Goodness in Memory.=--The remembered fact being _n_,
then, the path N--O is what arouses for _n_ its setting when it _is_
recalled, and makes it other than a mere imagination. The path M--N, on
the other hand, gives the cue or occasion of its being recalled at all.
_Memory being thus altogether conditioned on brain-paths, its excellence
in a given individual will depend partly on the_ NUMBER _and partly on
the_ PERSISTENCE _of these paths_.
The persistence or permanence of the paths is a physiological property
of the brain-tissue of the individual, whilst their number is altogether
due to the facts of his mental experience. Let the quality of permanence
in the paths be called the native tenacity, or physiological
retentiveness. This tenacity differs enormously from infancy to old age,
and from one person to another. Some minds are like wax under a seal--no
impression, however disconnected with others, is wiped out. Others, like
a jelly, vibrate to every touch, but under usual conditions retain no
permanent mark. These latter minds, before they can recollect a fact,
must weave it into their permanent stores of knowledge. They have no
_desultory_ memory. Those persons, on the contrary who retain names,
dates and addresses, anecdotes, gossip, poetry, quotations, and all
sorts of miscellaneous facts, without an effort, have desultory memory
in a high degree, and certainly owe it to the unusual tenacity of their
brain-substance for any path once formed therein. No one probably was
ever effective on a voluminous scale without a high degree of this
physiological retentiveness. In the practical as in the theoretic life,
the man whose acquisitions _stick_ is the man who is always achieving
and advancing, whilst his neighbors, spending most of their time in
relearning what they once knew but have forgotten, simply hold their
own. A Charlemagne, a Luther, a Leibnitz, a Walter Scott, any example,
in short, of your quarto or folio editions of mankind, must needs have
amazing retentiveness of the purely physiological sort. Men without this
retentiveness may excel in the _quality_ of their work at this point or
at that, but will never do such mighty sums of it, or be influential
contemporaneously on such a scale.
But there comes a time of life for all of us when we can do no more than
hold our own in the way of acquisitions, when the old paths fade as fast
as the new ones form in our brain, and when we forget in a week quite as
much as we can learn in the same space of time. This equilibrium may
last many, many years. In extreme old age it is upset in the reverse
direction, and forgetting prevails over acquisition, or rather there is
no acquisition. Brain-paths are so transient that in the course of a few
minutes of conversation the same question is asked and its answer
forgotten half a dozen times. Then the superior tenacity of the paths
formed in childhood becomes manifest: the dotard will retrace the facts
of his earlier years after he has lost all those of later date.
So much for the permanence of the paths. Now for their number.
It is obvious that the more there are of such paths as M--N in the
brain, and the more of such possible cues or occasions for the recall of
_n_ in the mind, the prompter and surer, on the whole, the memory of _n_
will be, the more frequently one will be reminded of it, the more
avenues of approach to it one will possess. In mental terms, _the more
other facts a fact is associated with in the mind, the better possession
of it our memory retains_. Each of its associates becomes a hook to
which it hangs, a means to fish it up by when sunk beneath the surface.
Together, they form a network of attachments by which it is woven into
the entire tissue of our thought. The 'secret of a good memory' is thus
the secret of forming diverse and multiple associations with every fact
we care to retain. But this forming of associations with a fact, what is
it but _thinking about_ the fact as much as possible? Briefly, then, of
two men with the same outward experiences and the same amount of mere
native tenacity, _the one who_ THINKS _over his experiences most, and
weaves them into systematic relations with each other, will be the one
with the best memory_. We see examples of this on every hand. Most men
have a good memory for facts connected with their own pursuits. The
college athlete who remains a dunce at his books will astonish you by
his knowledge of men's 'records' in various feats and games, and will be
a walking dictionary of sporting statistics. The reason is that he is
constantly going over these things in his mind, and comparing and
making series of them. They form for him not so many odd facts, but a
concept-system--so they stick. So the merchant remembers prices, the
politician other politicians' speeches and votes, with a copiousness
which amazes outsiders, but which the amount of thinking they bestow on
these subjects easily explains. The great memory for facts which a
Darwin and a Spencer reveal in their books is not incompatible with the
possession on their part of a brain with only a middling degree of
physiological retentiveness. Let a man early in life set himself the
task of verifying such a theory as that of evolution, and facts will
soon cluster and cling to him like grapes to their stem. Their relations
to the theory will hold them fast; and the more of these the mind is
able to discern, the greater the erudition will become. Meanwhile the
theorist may have little, if any, desultory memory. Unutilizable facts
may be unnoted by him and forgotten as soon as heard. An ignorance
almost as encyclopædic as his erudition may coexist with the latter, and
hide, as it were, in the interstices of its web. Those who have had much
to do with scholars and _savants_ will readily think of examples of the
class of mind I mean.
In a system, every fact is connected with every other by some
thought-relation. The consequence is that every fact is retained by the
combined suggestive power of all the other facts in the system, and
forgetfulness is well-nigh impossible.
=The reason why cramming is such a bad mode of study= is now made clear. I
mean by cramming that way of preparing for examinations by committing
'points' to memory during a few hours or days of intense application
immediately preceding the final ordeal, little or no work having been
performed during the previous course of the term. Things learned thus in
a few hours, on one occasion, for one purpose, cannot possibly have
formed many associations with other things in the mind. Their
brain-processes are led into by few paths, and are relatively little
liable to be awakened again. Speedy oblivion is the almost inevitable
fate of all that is committed to memory in this simple way. Whereas, on
the contrary, the same materials taken in gradually, day after day,
recurring in different contexts, considered in various relations,
associated with other external incidents, and repeatedly reflected on,
grow into such a system, form such connections with the rest of the
mind's fabric, lie open to so many paths of approach, that they remain
permanent possessions. This is the _intellectual_ reason why habits of
continuous application should be enforced in educational establishments.
Of course there is no moral turpitude in cramming. Did it lead to the
desired end of secure learning, it were infinitely the best method of
study. But it does not; and students themselves should understand the
reason why.
=One's native retentiveness is unchangeable.= It will now appear clear
that _all improvement of the memory lies in the line of_ ELABORATING THE
ASSOCIATES of each of the several things to be remembered. _No amount of
culture would seem capable of modifying a man's_ GENERAL
_retentiveness_. This is a physiological quality, given once for all
with his organization, and which he can never hope to change. It differs
no doubt in disease and health; and it is a fact of observation that it
is better in fresh and vigorous hours than when we are fagged or ill. We
may say, then, that a man's native tenacity will fluctuate somewhat with
his hygiene, and that whatever is good for his tone of health will also
be good for his memory. We may even say that whatever amount of
intellectual exercise is bracing to the general tone and nutrition of
the brain will also be profitable to the general retentiveness. But more
than this we cannot say; and this, it is obvious, is far less than most
people believe.
It is, in fact, commonly thought that certain exercises, systematically
repeated, will strengthen, not only a man's remembrance of the
particular facts used in the exercises, but his faculty for remembering
facts at large. And a plausible case is always made out by saying that
practice in learning words by heart makes it easier to learn new words
in the same way. If this be true, then what I have just said is false,
and the whole doctrine of memory as due to 'paths' must be revised. But
I am disposed to think the alleged fact untrue. I have carefully
questioned several mature actors on the point, and all have denied that
the practice of learning parts has made any such difference as is
alleged. What it has done for them is to improve their power of
_studying_ a part systematically. Their mind is now full of precedents
in the way of intonation, emphasis, gesticulation; the new words awaken
distinct suggestions and decisions; are caught up, in fact, into a
preëxisting network, like the merchant's prices, or the athlete's store
of 'records,' and are recollected easier, although the mere native
tenacity is not a whit improved, and is usually, in fact, impaired by
age. It is a case of better remembering by better _thinking_. Similarly
when schoolboys improve by practice in ease of learning by heart, the
improvement will, I am sure, be always found to reside in the _mode of
study of the particular piece_ (due to the greater interest, the greater
suggestiveness, the generic similarity with other pieces, the more
sustained attention, etc., etc.), and not at all to any enhancement of
the brute retentive power.
The error I speak of pervades an otherwise useful and judicious book,
'How to Strengthen the Memory,' by Dr. M. C. Holbrook of New York. The
author fails to distinguish between the general physiological
retentiveness and the retention of particular things, and talks as if
both must be benefited by the same means.
"I am now treating," he says, "a case of loss of memory in a person
advanced in years, who did not know that his memory had failed most
remarkably till I told him of it. He is making vigorous efforts to bring
it back again, and with partial success. The method pursued is to spend
two hours daily, one in the morning and one in the evening, in
exercising this faculty. The patient is instructed to give the closest
attention to all that he learns, so that it shall be impressed on his
mind clearly. He is asked to recall every evening all the facts and
experiences of the day, and again the next morning. Every name heard is
written down and impressed on his mind clearly, and an effort made to
recall it at intervals. Ten names from among public men are ordered to
be committed to memory every week. A verse of poetry is to be learned,
also a verse from the Bible, daily. He is asked to remember the number
of the page in any book where any interesting fact is recorded. These
and other methods are slowly resuscitating a failing memory."
I find it very hard to believe that the memory of the poor old gentleman
is a bit the better for all this torture except in respect of the
particular facts thus wrought into it, and other matters that may have
been connected therewithal.
=Improving the Memory.=--All improvement of memory consists, then, in the
improvement of one's _habitual methods of recording facts_. Methods have
been divided into the mechanical, the ingenious, and the judicious.
The _mechanical methods_ consist in the intensification, prolongation,
and _repetition_ of the impression to be remembered. The modern method
of teaching children to read by blackboard work, in which each word is
impressed by the fourfold channel of eye, ear, voice, and hand, is an
example of an improved mechanical method of memorizing.
_Judicious methods_ of remembering things are nothing but logical ways
of conceiving them and working them into rational systems, classifying
them, analyzing them into parts, etc., etc. All the sciences are such
methods.
Of _ingenious methods_ many have been invented, under the name of
technical memories. By means of these systems it is often possible to
retain entirely disconnected facts, lists of names, numbers, and so
forth, so multitudinous as to be entirely unrememberable in a natural
way. The method consists usually in a framework learned mechanically,
of which the mind is supposed to remain in secure and permanent
possession. Then, whatever is to be remembered is deliberately
associated by some fanciful analogy or connection with some part of this
framework, and this connection thenceforward helps its recall. The best
known and most used of these devices is the figure-alphabet. To remember
numbers, e.g., a figure-alphabet is first formed, in which each
numerical digit is represented by one or more letters. The number is
then translated into such letters as will best make a word, if possible
a word suggestive of the object to which the number belongs. The word
will then be remembered when the numbers alone might be forgotten.[38]
The recent system of Loisette is a method, much less mechanical, of
weaving the thing into associations which may aid its recall.
=Recognition.=--If, however, a phenomenon be met with too often, and with
too great a variety of contexts, although its image is retained and
reproduced with correspondingly great facility, it fails to come up with
any one particular setting, and the projection of it backwards to a
particular past date consequently does not come about. We _recognize_
but do not _remember_ it--its associates form too confused a cloud. A
similar result comes about when a definite setting is only nascently
aroused. We then feel that we have seen the object already, but when or
where we cannot say, though we may seem to ourselves to be on the brink
of saying it. That nascent cerebral excitations can thus affect
consciousness is obvious from what happens when we seek to remember a
name. It tingles, it trembles on the verge, but does not come. Just such
a tingling and trembling of unrecovered associates is the penumbra of
recognition that may surround any experience and make it seem familiar,
though we know not why.
There is a curious experience which everyone seems to have had--the
feeling that the present moment in its completeness has been experienced
before--we were saying just this thing, in just this place, to just
these people, etc. This 'sense of preëxistence' has been treated as a
great mystery and occasioned much speculation. Dr. Wigan considered it
due to a dissociation of the action of the two hemispheres, one of them
becoming conscious a little later than the other, but both of the same
fact. I must confess that the quality of mystery seems to me here a
little strained. I have over and over again in my own case succeeded in
resolving the phenomenon into a case of memory, so indistinct that
whilst some past circumstances are presented again, the others are not.
The dissimilar portions of the past do not arise completely enough at
first for the date to be identified. All we get is the present scene
with a general suggestion of pastness about it. That faithful observer,
Prof. Lazarus, interprets the phenomenon in the same way; and it is
noteworthy that just as soon as the past context grows complete and
distinct the emotion of weirdness fades from the experience.
=Forgetting.=--In the practical use of our intellect, forgetting is as
important a function as remembering. 'Total recall' (see p. 261) we saw
to be comparatively rare in association. If we remembered everything, we
should on most occasions be as ill off as if we remembered nothing. It
would take as long for us to recall a space of time as it took the
original time to elapse, and we should never get ahead with our
thinking. All recollected times undergo, accordingly, what M. Ribot
calls foreshortening; and this foreshortening is due to the omission of
an enormous number of the facts which filled them. "We thus reach the
paradoxical result," says M. Ribot, "that one condition of remembering
is that we should forget. Without totally forgetting a prodigious
number of states of consciousness, and momentarily forgetting a large
number, we could not remember at all. Oblivion, except in certain cases,
is thus no malady of memory, but a condition of its health and its
life."
=Pathological Conditions.=--Hypnotic subjects as a rule forget all that
has happened in their trance. But in a succeeding trance they will often
remember the events of a past one. This is like what happens in those
cases of 'double personality' in which no recollection of one of the
lives is to be found in the other. The sensibility in these cases often
differs from one of the alternate personalities to another, the patient
being often anæsthetic in certain respects in one of the secondary
states. Now the memory may come and go with the sensibility. M. Pierre
Janet proved in various ways that what his patients forgot when
anæsthetic they remembered when the sensibility returned. For instance,
he restored their tactile sense temporarily by means of electric
currents, passes, etc., and then made them handle various objects, such
as keys and pencils, or make particular movements, like the sign of the
cross. The moment the anæsthesia returned they found it impossible to
recollect the objects or the acts. 'They had had nothing in their hands,
they had done nothing,' etc. The next day, however, sensibility being
again restored by similar processes, they remembered perfectly the
circumstance, and told what they had handled or done.
All these pathological facts are showing us that the sphere of possible
recollection may be wider than we think, and that in certain matters
apparent oblivion is no proof against possible recall under other
conditions. They give no countenance, however, to the extravagant
opinion that absolutely no part of our experience can be forgotten.