MEMORY
Every hour of our lives we call upon memory to supply us with some fact
or detail from out our past. Let memory wholly fail us, and we find
ourselves helpless and out of joint in a world we fail to understand. A
poor memory handicaps one in the pursuit of education, hampers him in
business or professional success, and puts him at a disadvantage in
every relation of life. On the other hand, a good memory is an asset on
which the owner realizes anew each succeeding day.
1. THE NATURE OF MEMORY
Now that you come to think of it, you can recall perfectly well that
Columbus discovered America in 1492; that your house is painted white;
that it rained a week ago today. But where were these once-known facts,
now remembered so easily, while they were out of your mind? Where did
they stay while you were not thinking of them? The common answer is,
"Stored away in my memory." Yet no one believes that the memory is a
warehouse of facts which we pack away there when we for a time have no
use for them, as we store away our old furniture.
WHAT IS RETAINED.--The truth is that the simple question I asked you is
by no means an easy one, and I will answer it myself by asking you an
easier one: As we sit with the sunlight streaming into our room, where
is the darkness which filled it last night? And where will all this
light be at midnight tonight? Answer these questions, and the ones I
asked about your remembered facts will be answered. While it is true
that, regardless of the conditions in our little room, darkness still
exists wherever there is no light, and light still exists wherever there
is no darkness, yet for this particular room _there is no darkness when
the sun shines in_, and _there is no light when the room is filled with
darkness_. So in the case of a remembered fact. Although the fact that
Columbus discovered America some four hundred years ago, that your house
is of a white color, that it rained a week ago today, exists as a fact
regardless of whether your minds think of these things at all, yet the
truth remains as before: for the particular mind which remembers these
things, _the facts did not exist while they were out of the mind_.
_It is not the remembered fact which is retained_, BUT THE POWER TO
REPRODUCE THE FACT WHEN WE REQUIRE IT.
THE PHYSICAL BASIS OF MEMORY.--The power to reproduce a once-known fact
depends ultimately on the brain. This is not hard to understand if we go
back a little and consider that brain activity was concerned in every
perception we have ever had, and in every fact we have ever known.
Indeed, it was through a certain neural activity of the cortex that you
were able originally to know that Columbus discovered America, that your
house is white, and that it rained on a day in the past. Without this
cortical activity, these facts would have existed just as truly, but
_you_ would never have known them. Without this neural activity in the
brain there is no consciousness, and to it we must look for the
recurrence in consciousness of remembered facts, as well as for those
which appear for the first time.
HOW WE REMEMBER.--Now, if we are to have a once-known fact repeated in
consciousness, or in other words _remembered_, what we must do on the
physiological side is to provide for a repetition of the neural activity
which was at first responsible for the fact's appearing in
consciousness. The mental accompaniment of the repeated activity _is the
memory_. Thus, as _memory is the approximate repetition of
once-experienced mental states or facts, together with the recognition
of their belonging to our past, so it is accomplished by an approximate
repetition of the once-performed neural process in the cortex which
originally accompanied these states or facts_.
The part played by the brain in memory makes it easy to understand why
we find it so impossible to memorize or to recall when the brain is
fatigued from long hours of work or lack of sleep. It also explains the
derangement in memory that often comes from an injury to the brain, or
from the toxins of alcohol, drugs or disease.
DEPENDENCE OF MEMORY ON BRAIN QUALITY.--Differences in memory ability,
while depending in part on the training memory receives, rest ultimately
on the memory-quality of the brain. James tells us that four distinct
types of brains may be distinguished, and he describes them as follows:
Brains that are:
(1) Like _marble_ to receive and like _marble_ to retain.
(2) Like _wax_ to receive and like _wax_ to retain.
(3) Like _marble_ to receive and like _wax_ to retain.
(4) Like _wax_ to receive and like _marble_ to retain.
The first type gives us those who memorize slowly and with much heroic
effort, but who keep well what they have committed. The second type
represents the ones who learn in a flash, who can cram up a lesson in a
few minutes, but who forget as easily and as quickly as they learn. The
third type characterizes the unfortunates who must labor hard and long
for what they memorize, only to see it quickly slipping from their
grasp. The fourth type is a rare boon to its possessor, enabling him
easily to stock his memory with valuable material, which is readily
available to him upon demand.
The particular type of brain we possess is given us through heredity,
and we can do little or nothing to change the type. Whatever our type of
brain, however, we can do much to improve our memory by obeying the laws
upon which all good memory depends.
2. THE FOUR FACTORS INVOLVED IN MEMORY
Nothing is more obvious than that memory cannot return to us what has
never been given into its keeping, what has not been retained, or what
for any reason cannot be recalled. Further, if the facts given back by
memory are not recognized as belonging to our past, memory would be
incomplete. Memory, therefore, involves the following four factors: (1)
_registration_, (2) _retention_, (3) _recall_, (4) _recognition_.
REGISTRATION.--By registration we mean the learning or committing of the
matter to be remembered. On the brain side this involves producing in
the appropriate neurones the activities which, when repeated again
later, cause the fact to be recalled. It is this process that
constitutes what we call "impressing the facts upon the brain."
Nothing is more fatal to good memory than partial or faulty
registration. A thing but half learned is sure to be forgotten. We
often stop in the mastery of a lesson just short of the full impression
needed for permanent retention and sure recall. We sometimes say to our
teachers, "I cannot remember," when, as a matter of fact, we have never
learned the thing we seek to recall.
RETENTION.--Retention, as we have already seen, resides primarily in the
brain. It is accomplished through the law of habit working in the
neurones of the cortex. Here, as elsewhere, habit makes an activity once
performed more easy of performance each succeeding time. Through this
law a neural activity once performed tends to be repeated; or, in other
words, a fact once known in consciousness tends to be remembered. That
so large a part of our past is lost in oblivion, and out of the reach of
our memory, is probably much more largely due to a failure to _recall_
than to _retain_. We say that we have forgotten a fact or a name which
we cannot recall, try as hard as we may; yet surely all have had the
experience of a long-striven-for fact suddenly appearing in our memory
when we had given it up and no longer had use for it. It was retained
all the time, else it never could have come back at all.
An aged man of my acquaintance lay on his deathbed. In his childhood he
had first learned to speak German; but, moving with his family when he
was eight or nine years of age to an English-speaking community, he had
lost his ability to speak German, and had been unable for a third of a
century to carry on a conversation in his mother tongue. Yet during the
last days of his sickness he lost almost wholly the power to use the
English language, and spoke fluently in German. During all these years
his brain paths had retained the power to reproduce the forgotten words,
even though for so long a time the words could not be recalled. James
quotes a still more striking case of an aged woman who was seized with a
fever and, during her delirious ravings, was heard talking in Latin,
Hebrew and Greek. She herself could neither read nor write, and the
priests said she was possessed of a devil. But a physician unraveled the
mystery. When the girl was nine years of age, a pastor, who was a noted
scholar, had taken her into his home as a servant, and she had remained
there until his death. During this time she had daily heard him read
aloud from his books in these languages. Her brain had indelibly
retained the record made upon it, although for years she could not have
recalled a sentence, if, indeed, she had ever been able to do so.
RECALL.--Recall depends entirely on association. There is no way to
arrive at a certain fact or name that is eluding us except by means of
some other facts, names, or what-not so related to the missing term as
to be able to bring it into the fold. Memory arrives at any desired fact
only over a bridge of associations. It therefore follows that the more
associations set up between the fact to be remembered and related facts
already in the mind, the more certain the recall. Historical dates and
events should when learned be associated with important central dates
and events to which they naturally attach. Geographical names, places or
other information should be connected with related material already in
the mind. Scientific knowledge should form a coherent and related whole.
In short, everything that is given over to the memory for its keeping
should be linked as closely as possible to material of the same sort.
This is all to say that we should not expect our memory to retain and
reproduce isolated, unrelated facts, but should give it the advantage
of as many logical and well grounded associations as possible.
RECOGNITION.--A fact reproduced by memory but not recognized as
belonging to our past experience would impress us as a new fact. This
would mean that memory would fail to link the present to the past. Often
we are puzzled to know whether we have before met a certain person, or
on a former occasion told a certain story, or previously experienced a
certain present state of mind which seems half familiar. Such baffling
mental states are usually but instances of partial and incomplete
recognition. Recognition no longer applies to much of our knowledge; for
example, we say we remember that four times six is twenty-four, but
probably none of us can recall when and where we learned this fact--we
cannot _recognize_ it as belonging to our past experience. So with ten
thousand other things, which we _know_ rather than remember in the
strict sense.
3. THE STUFF OF MEMORY
What are the forms in which memory presents the past to us? What are the
elements with which it deals? What is the stuff of which it consists?
IMAGES AS THE MATERIAL OF MEMORY.--In the light of our discussion upon
mental imagery, and with the aid of a little introspection, the answer
is easy. I ask you to remember your home, and at once a visual image of
the familiar house, with its well-known rooms and their characteristic
furnishings, comes to your mind. I ask you to remember the last concert
you attended, or the chorus of birds you heard recently in the woods;
and there comes a flood of images, partly visual, but largely auditory,
from the melodies you heard. Or I ask you to remember the feast of
which you partook yesterday, and gustatory and olfactory images are
prominent among the others which appear. And so I might keep on until I
had covered the whole range of your memory; and, whether I ask you for
the simple trivial experiences of your past, for the tragic or crucial
experiences, or for the most abstruse and abstract facts which you know
and can recall, the case is the same: much of what memory presents to
you comes in the form of _images_ or of _ideas_ of your past.
IMAGES VARY AS TO TYPE.--We do not all remember what we call the same
fact in like images or ideas. When you remembered that Columbus
discovered America in 1492, some of you had an image of Columbus the
mariner standing on the deck of his ship, as the old picture shows him;
and accompanying this image was an idea of "long agoness." Others, in
recalling the same fact, had an image of the coast on which he landed,
and perchance felt the rocking of the boat and heard it scraping on the
sand as it neared the shore. And still others saw on the printed page
the words stating that Columbus discovered America in 1492. And so in an
infinite variety of images or ideas we may remember what we call the
same fact, though of course the fact is not really the same fact to any
two of us, nor to any one of us when it comes to us on different
occasions in different images.
OTHER MEMORY MATERIAL.--But sensory images are not the only material
with which memory has to deal. We may also recall the bare fact that it
rained a week ago today without having images of the rain. We may recall
that Columbus discovered America in 1492 without visual or other images
of the event. As a matter of fact we do constantly recall many facts of
abstract nature, such as mathematical or scientific formulæ with no
imagery other than that of the words or symbols, if indeed these be
present. Memory may therefore use as its stuff not only images, but also
a wide range of facts, ideas and meanings of all sorts.
4. LAWS UNDERLYING MEMORY
The development of a good memory depends in no small degree on the
closeness with which we follow certain well-demonstrated laws.
THE LAW OF ASSOCIATION.--The law of association, as we have already
seen, is fundamental. Upon it the whole structure of memory depends.
Stating this law in neural terms we may say: Brain areas which are
_active together at the same time tend to establish associative paths_,
so that when one of them is again active the other is also brought into
activity. Expressing the same truth in mental terms: If two facts or
experiences _occur together in consciousness_, and one of them is later
recalled, it tends to cause the other to appear also.
THE LAW OF REPETITION.--The law of repetition is but a restatement of
the law of habit, and may be formulated as follows: The _more
frequently_ a certain cortical activity occurs, the more easily is its
repetition brought about. Stating this law in mental terms we may say:
The more often a fact is recalled in consciousness the easier and more
certain the recall becomes. It is upon the law of repetition that
reviews and drills to fix things in the memory are based.
THE LAW OF RECENCY.--We may state the law of recency in physiological
terms as follows: The _more recently_ brain centers have been employed
in a certain activity, the more easily are they thrown into the same
activity. This, on the mental side, means: The more recently any facts
have been present in consciousness the more easily are they recalled. It
is in obedience to this law that we want to rehearse a difficult lesson
just before the recitation hour, or cram immediately before an
examination. The working of this law also explains the tendency of all
memories to fade out as the years pass by.
THE LAW OF VIVIDNESS.--The law of vividness is of primary importance in
memorizing. On the physical side it may be expressed as follows: The
_higher the tension_ or the more intense the activity of neural centers
the more easily the activity is repeated. The counterpart of this law in
mental terms is: _The higher the degree of attention_ or concentration
when the fact is registered the more certain it is of recall. Better far
one impression of a high degree of vividness than several repetitions
with the attention wandering or the brain too fatigued to respond. Not
drill alone, but drill with concentration, is necessary to sure
memory,--in proof of which witness the futile results on the part of the
small boy who "studies his spelling lesson over fifteen times," the
while he is at the same time counting his marbles.
5. RULES FOR USING THE MEMORY
Much careful and fruitful experimentation in the field of memory has
taken place in recent years. The scientists are now able to give us
certain simple rules which we can employ in using our memories, even if
we lack the time or opportunity to follow all their technical
discussions.
WHOLES VERSUS PARTS.--Probably most people in setting to work to commit
to memory a poem, oration, or other such material, have a tendency to
learn it first by stanzas or sections and then put the parts together to
form the whole. Many tests, however, have shown this to be a less
effective method than to go over the whole poem or oration time after
time, finally giving special attention to any particularly difficult
places. The only exception to this rule would seem to be in the case of
very long productions, which may be broken up into sections of
reasonable length. The method of committing by wholes instead of parts
not only economizes time and effort in the learning, but also gives a
better sense of unity and meaning to the matter memorized.
RATE OF FORGETTING.--The rate of forgetting is found to be very much
more rapid immediately following the learning than after a longer time
has elapsed. This is to say that of what one is going to forget of
matter committed to memory approximately one-half will fall away within
the first twenty-four hours and three-fourths within the first three
days. Since it is always economy to fix afresh matter that is fading out
before it has been wholly forgotten, it will manifestly pay to review
important memory material within the first day or two after it has once
been memorized.
DIVIDED PRACTICE.--If to commit a certain piece of material we must go
over it, say, ten different times, the results are found to be much
better when the entire number of repetitions are not had in immediate
succession, but with reasonable intervals between. This is due, no
doubt, to the well-known fact that associations tend to take form and
grow more secure even after we have ceased to think specifically of the
matter in hand. The intervals allow time for the associations to form
their connections. It is in this sense that James says we "learn to swim
during the winter and to skate during the summer."
FORCING THE MEMORY TO ACT.--In committing matter by reading it, the
memory should be forced into activity just as fast as it is able to
carry part of the material. If, after reading a poem over once, parts of
it can be repeated without reference to the text, the memory should be
compelled to reproduce these parts. So with all other material.
Re-reading should be applied only at such points as the memory has not
yet grasped.
NOT A MEMORY, BUT MEMORIES.--Professor James has emphasized the fact,
which has often been demonstrated by experimental tests, that we do not
possess a memory, but a collection of memories. Our memory may be very
good in one line and poor in another. Nor can we "train our memory" in
the sense of practicing it in one line and having the improvement extend
equally to other lines. Committing poetry may have little or no effect
in strengthening the memory for historical or scientific data. In
general, the memory must be trained in the specific lines in which it is
to excel. General training will not serve except as it may lead to
better modes of learning what is to be memorized.
6. WHAT CONSTITUTES A GOOD MEMORY
Let us next inquire what are the qualities which enter into what we call
a good memory. The merchant or politician will say, "Ability to remember
well people's faces and names"; the teacher of history, "The ability to
recall readily dates and events"; the teacher of mathematics, "The power
to recall mathematical formulæ"; the hotel waiter, "The ability to keep
in mind half-a-dozen orders at a time"; the manager of a corporation,
"The ability to recall all the necessary details connected with the
running of the concern." While these answers are very divergent, yet
they may all be true for the particular person testifying; for out of
them all there emerges this common truth, that _the best memory is the
one which best serves its possessor_. That is, one's memory not only
must be ready and exact, but must produce the right kind of material; it
must bring to us what we need in our thinking. A very easy corollary at
once grows out of this fact; namely, that in order to have the memory
return to us the right kind of matter, we must store it with the right
kind of images and ideas, for the memory cannot give back to us anything
which we have not first given into its keeping.
A GOOD MEMORY SELECTS ITS MATERIAL.--The best memory is not necessarily
the one which impartially repeats the largest number of facts of past
experience. Everyone has many experiences which he never needs to have
reproduced in memory; useful enough they may have been at the time, but
wholly useless and irrelevant later. They have served their purpose, and
should henceforth slumber in oblivion. They would be but so much rubbish
and lumber if they could be recalled. Everyone has surely met that
particular type of bore whose memory is so faithful to details that no
incident in the story he tells, no matter however trivial, is ever
omitted in the recounting. His associations work in such a tireless
round of minute succession, without ever being able to take a jump or a
short cut, that he is powerless to separate the wheat from the chaff; so
he dumps the whole indiscriminate mass into our long-suffering ears.
Dr. Carpenter tells of a member of Parliament who could repeat long
legal documents and acts of Parliament after one reading. When he was
congratulated on his remarkable gift, he replied that, instead of being
an advantage to him, it was often a source of great inconvenience,
because when he wished to recollect anything in a document he had read,
he could do it only by repeating the whole from the beginning up to the
point which he wished to recall. Maudsley says that the kind of memory
which enables a person "to read a photographic copy of former
impressions with his mind's eye is not, indeed, commonly associated with
high intellectual power," and gives as a reason that such a mind is
hindered by the very wealth of material furnished by the memory from
discerning the relations between separate facts upon which judgment and
reasoning depend. It is likewise a common source of surprise among
teachers that many of the pupils who could outstrip their classmates in
learning and memory do not turn out to be able men. But this, says
Whately, "is as reasonable as to wonder that a cistern if filled should
not be a perpetual fountain." It is possible for one to be so lost in a
tangle of trees that he cannot see the woods.
A GOOD MEMORY REQUIRES GOOD THINKING.--It is not, then, mere
re-presentation of facts that constitutes a good memory. The pupil who
can reproduce a history lesson by the page has not necessarily as good a
memory as the one who remembers fewer facts, but sees the relations
between those remembered, and hence is _able to choose what he will
remember_. Memory must be _discriminative_. It must fasten on that which
is important and keep that for us. Therefore we can agree that "_the art
of remembering is the art of thinking_." Discrimination must select the
important out of our mental stream, and these images must be associated
with as many others as possible which are already well fixed in memory,
and hence are sure of recall when needed. In this way the old will
always serve as a cue to call up the new.
MEMORY MUST BE SPECIALIZED.--And not only must memory, if it is to be a
good memory, omit the generally worthless, or trivial, or irrelevant,
and supply the generally useful, significant, and relevant, but it must
in some degree be a _specialized memory_. It must minister to the
particular needs and requirements of its owner. Small consolation to you
if you are a Latin teacher, and are able to call up the binomial theorem
or the date of the fall of Constantinople when you are in dire need of a
conjugation or a declension which eludes you. It is much better for the
merchant and politician to have a good memory for names and faces than
to be able to repeat the succession of English monarchs from Alfred the
Great to Edward VII and not be able to tell John Smith from Tom Brown.
It is much more desirable for the lawyer to be able to remember the
necessary details of his case than to be able to recall all the various
athletic records of the year; and so on.
In order to be a good memory for _us_, our memory must be faithful in
dealing with the material which constitutes the needs of our vocations.
Our memory may, and should, bring to us many things outside of our
immediate vocations, else our lives will be narrow; but its chief
concern and most accurate work must be along the path of our everyday
requirements at its hands. And this works out well in connection with
the physiological laws which were stated a little while since, providing
that our vocations are along the line of our interests. For the things
with which we work daily, and in which we are interested, will be often
thought of together, and hence will become well associated. They will be
frequently recalled, and hence more easily remembered; they will be
vividly experienced as the inevitable result of interest, and this goes
far to insure recall.
7. MEMORY DEVICES
Many devices have been invented for training or using the memory, and
not a few worthless "systems" have been imposed by conscienceless fakers
upon uninformed people. All memorizing finally must go back to the
fundamental laws of brain activity and the rules growing out of these
laws. There is no "royal road" to a good memory.
THE EFFECTS OF CRAMMING.--Not a few students depend on cramming for much
of their learning. If this method of study would yield as valuable
permanent results, it would be by far the most sensible and economical
method to use; for under the stress of necessity we often are able to
accomplish results much faster than when no pressure is resting upon us.
The difficulty is, however, that the results are not permanent; the
facts learned do not have time to seek out and link themselves to
well-established associates; learned in an hour, their retention is as
ephemeral as the application which gave them to us.
Facts which are needed but temporarily and which cannot become a part of
our body of permanent knowledge may profitably be learned by cramming.
The lawyer needs many details for the case he is trying, which not only
are valueless to him as soon as the case is decided, but would
positively be in his way. He may profitably cram such facts. But those
facts which are to become a permanent part of his mental equipment, such
as the fundamental principles of law, he cannot cram. These he must have
in a logical chain which will not leave their recall dependent upon a
chance cue. Crammed facts may serve us during a recitation or an
examination, but they never really become a part of us. Nothing can take
the place of the logical placing of facts if they are to be remembered
with facility, and be usable in thinking when recalled.
REMEMBERING ISOLATED FACTS.--But after all this is taken into
consideration there still remain a large number of facts which refuse to
fit into any connected or logical system. Or, if they do belong with
some system, their connection is not very close, and we have more need
for the few individual facts than for the system as a whole. Hence we
must have some means of remembering such facts other than by connecting
them with their logical associations. Such facts as may be typified by
the multiplication table, certain dates, events, names, numbers,
errands, and engagements of various kinds--all these need to be
remembered accurately and quickly when the occasion for them arises. We
must be able to recall them with facility, so that the occasion will not
have passed by before we can secure them and we have failed to do our
part because of the lapse.
With facts of this type the means of securing a good memory are the same
as in the case of logical memory, except that we must of necessity
forego the linking to naturally related associates. We can, however,
take advantage of the three laws which have been given. If these methods
are used faithfully, then we have done what we can in the way of
insuring the recall of facts of this type, unless we associate them with
some artificial cue, such as tying a thread around our finger to
remember an errand, or learning the multiplication table by singing it.
We are not to be too ready to excuse ourselves, however, if we have
forgotten to mail the letter or deliver the message; for our attention
may have been very lax when we recorded the direction in the first
place, and we may never have taken the trouble to think of the matter
between the time it was given into our keeping and the time we were to
perform the errand.
MNEMONIC DEVICES.--Many ingenious devices have been invented to assist
the memory. No doubt each one of you has some way of your own of
remembering certain things committed to you, or some much-needed fact
which has a tendency to elude you. You may not tie the traditional
string around your finger or place your watch in the wrong pocket; but
if not, you have invented some method which suits your convenience
better. While many books have been written, and many lectures given
exploiting mnemonic systems, they are, however, all founded upon the
same general principle: namely, that of _association of ideas_ in the
mind. They all make use of the same basis for memory that any of us use
every time we remember anything, from the commonest event which occurred
last hour to the most abstruse bit of philosophy which we may have in
our minds. They all tie the fact to be remembered to some other fact
which is sure of recall, and then trust the old fact to bring the new
along with it when it again comes into the mind.
Artificial devices may be permissible in remembering the class of facts
which have no logical associates in which we can relate them; but even
then I cannot help feeling that if we should use the same care and
ingenuity in carefully recording the seemingly unrelated facts that we
do in working out the device and making the association in it, we should
discover hidden relations for most of the facts we wish to remember, and
we should be able to insure their recall as certainly and in a better
way than through the device. Then, also, we should not be in danger of
handing over to the device various facts for which we should discover
relations, thus placing them in the logical body of our usable
knowledge where they belong.
8. PROBLEMS IN OBSERVATION AND INTROSPECTION
1. Carefully consider your own powers of memory and see whether you can
decide which of the four types of brain you have. Apply similar tests to
your classmates or a group of school children whom you have a chance to
observe. Be sure to take into account the effects of past training or
habits of memory.
2. Watch in your own memorizing and also that of school children for
failures in recall caused by lack of proper associations. Why is it
particularly hard to commit what one does not understand?
3. Observe a class in a recitation or an examination and seek to
discover whether any defects of memory revealed are to be explained by
lack of (1) repetition, (2) recency, (3) vividness in learning.
4. Make a study of your own class and also of a group of children in
school to discover their methods of memorizing. Have in mind the rules
for memorizing given in section 5 of this chapter.
5. Observe by introspection your method of recall of historical events
you have studied, and note whether _images_ form an important part of
your memory material; or does your recall consist chiefly of bare
_facts_? In how far does this depend on your method of _learning_ the
facts in the first place?
6. Carefully consider your experience from cramming your lessons. Does
the material learned in this way stay with you? Do you _understand_ it
and find yourself able to _use_ it as well as stuff learned during a
longer interval and with more time for associations to form?