Recall of learning and iteration
question. So here is my question; if there is no true
repetition in learning, need there be any true repetition in memory?
There does not seem to be any good reason to believe that repetition as
mentioned in the research on memory is any more un-extended or
unaltered repetition than there is in learning. The research into
memory indicates that both repetition and elaboration are essential to
the ability to recall information. It should be pointed out however,
that it is possible that repetition alone without elaboration may not
actually conducive to enabling recall at all. Although all the books
talk about the importance of repetition, this seems to ignore the fact
that true repetition is essentially impossible to generate.
may have a part to play in consolidation of memory, but it may not be
quite in the way people have thought. Repetition may aid in
consolidating memory mostly because it provides the memory with further
opportunity for elaboration. Elaboration may be what is critical rather
than the repetition itself. Be that as it may, even if repetition is in
fact important in itself in improving memory function, this may still
not be sufficient to recommend the use of drills in creating easily
"Why Do I Need a Teacher When I've Got Google?" Ian Gilbert
sums it up like this:
rote learning work? Yes absolutely. Repetition reinforces connections
between brain cells leading to better myelination and the creation of
what can be lasting long-term memories. There are two significant
downsides though. One, it is as boring as hell and demands high degrees
of motivation of learners, self control and the sort of boredom
threshold you would associate with train spotting or reality TV. Two,
despite being effective it is not efficient. You may be achieving the
results you want to achieve with your classes, so you are working
effectively, but are you working efficiently? Could you, by using
different memory strategies and techniques, achieve the same result by
working less? Could you even achieve better results by working
current neurological wisdom about memories is that they reside in
specific places in the brain this site holds that there is sufficient
evidence to consider an alternative idea. This site wishes to propose
that memories are a web of connections. We know that when more
connections are added to a memory, the memory becomes more elaborated
and thus has more meaning. This site considers that this process
incidentally creates more entry points for reaching the memories. The
more connections there are to a memory, the more different directions
your thinking could be taking and still arrive at the memory. The more
connections there are the more pathways there are to the memory and
thus the easier it is to find the memory and activate its recall.
seems to do two things. One it causes myelin to wrap around the axons
connecting the neurons which in turn allow the signal to move faster,
more strongly and more easily. But in skill learning the main function
is to obtain finer and finer control of the activity by the timing and
strength of the signal. Two it would seem to also activate the
generation and growth of new synapses, dendrites and axons when they
are activated. In his book
"Brain Rules" John Medina gives us a description of how the
hippocampus and the cerebral cortex are connected and work together in
first army [of nerves] is the cortex, that
wafer-thin layer of nerves that blankets a brain... The second is a bit
of a tongue twister, the medial temporal lobe. It houses another
familiar old soldier, the oft mentioned hippocampus. Crown jewel of the
limbic system, the hippocampus helps shape the long-term character of
many types of memory...
the cortex and the medial temporal lobe are cabled together tells the
story of long-term memory formation. Neurons spring from the cortex and
snake their way over to the lobe, allowing the hippocampus to listen in
on what the cortex is receiving. Wires also erupt from the lobe and
wriggle their way back to the cortex returning the eavesdropping favor.
The loop allows the hippocampus to issue orders to previously
stimulated cortical regions while simultaneously gleaning
information from them. It also allows us to form memories...
A conjecture about memory.
As you may know, science as yet has not discovered how memories are
formed. However, this site has extrapolated a conjecture as to how
memories may possibly be brought into being. It should be noted that
this idea has not been tested in any way, and so cannot even be
designated a theory. It is plain and simple speculation. But it does
seem to fit a lot of what is known so far about memory formation. As
such it may have as much validity as the similar speculation that
memories reside in a fixed single location.
This conjecture is based on the idea that memories may simply be
complex webs of connections between neurons. This would necessitate
that meaning is just how the bits of brain are connected together and
how they tend to fire in unison as a circuit. This would account for
the fact, that when we add more connections through elaboration, the
memory becomes both more meaningful and more easily recalled. More
connections would mean more meaning and incidentally more entry points
which would mean it could be activated by entering the circuit in more
ways thus improving recall. The question that was put, was simply to
ask how brain structures might function to develop such webs of
the most important rule for brains is that 'neurons that fire together
wire together'. Neuroscience research has produced a great deal of
support for this idea, so our conjecture starts with it. So the
question is, "How does this happen?" The simplest solution would be
that when neurons in the cortex fire at the same time they tend to
sprout new synapses which connect to other neurons or that have axons
the are growing in the direction of the other neurons that are firing
at the same moment and that this extending growth would continue until
the two or more neurons that fired at the same moment eventually
connect up. The problem with this solution is that to grow new synapses
and maybe dendrites and even axons so that they reach far distant areas
of the brain would take a long time to accomplish perhaps years. This
does not seem to be a likely solution.
new synapses do seem to be involved. In her book
"The Creative Brain" Nancy C. Andreasen says:
"In this particular case,
when the neuron is stimulated to a sufficient degree to create a memory
that needs to be preserved, a variety of chemical messages are sent to
the cell nucleus, where in turn genes are expressed and send messages
back out to the synapse that say: 'build more synapses and create new
synaptic connections so that you can keep this information for a long
The process then, would have
to be more complex. What we do know is that the formation of memories
has something to do with neurogenesis and the creation of new neurons
especially in the brain structure called the hippocampus. There are
many theories about how memories are stored in the brain. In
Seung suggests that memories may be stored in in the part of the brain
called the hippocampus. He says:
hippocampus belongs to the medial temporal lobe... Some researchers
believe that the hippocampus serves as the "gateway" to memory; they
theorize that it stores information first and later transfers it to
other regions like the neocortex."
site holds that memories are not likely to be stored in a particular
area of the brain as suggested above, but rather reside in the
connections themselves and how different areas of the brain are
connected up. If this is the case the hippocampus may simply act as a
device to facilitate the connecting of one part of the brain
us suppose that the formation of each new memory depends on the
existence and development of a single new neuron. We can further
suppose that each new neuron coming into existence in the hippocampus
connects via its synapses to the complex of white fibers that connect
the hippocampus to every part of the cortex known to encode declarative memories.
The new neuron would in that case not contain a memory, but rather act
as a device to connect the various parts of the cortex that have become
currently active. Because these connections are already in place the
new neurons could connect up to all the active cortical areas fairly
quickly. How might this come about? When cortical neurons become active
they would send those signals to the hippocampus via their many
connectors. The new neuron be attracted to the charged axons and
dendrites and would quickly connect to those active fibers
thus connecting all the incoming signals. It would then collect all
those signals and send them back as a whole to all the cortical neurons
are the connectors in the brain. In her book
"The Creative Brain" Nancy C. Andreasen says:
"Each of these neurons is
designed to make multiple connections to other neurons. The nerve cells
multiply their connective capabilities by sending out dendrites, which
in turn expand by adding spines. Along the spines are multiple
synapses. At the axonal end of the neuron there are also axon terminals
containing synapses. The synapses are the real 'action sites' within
the brain. There are different types of neurons, as defined by their
number of axons and the complexity of their dendrites, and we do not
have an accurate way to estimate the total number of synapses in the
entire human brain. A typical estimate is that each nerve cell
possesses approximately 1,000 to 10,000 synapses.
our brains form during fetal life, nerve cells grow and establish
connections to one another. Some of them are hard wired and genetically
determined, but many are shaped by our experiences. Each neuron does
its work by talking across synapses to multiple other neurons at more
or less the same time, and each of those neurons are talking to many
others. (The technical term for for these interacting neurons is neural
neural circuits of the brain are designed to monitor and modulate one
another. Sometimes the connections send excitatory signals, and
sometimes they send negative, or inhibitory, signals. Some connections
connections create short feedback loops between neurons and some have
long loops that spread across longer spans of the brain.
It is estimated that a large feedback loop
covering the entire brain takes only five or six synapses."
one or more of the synapses fire and allow the signal to proceed
depends on the strength of the incoming signal which in turn depends on
the amount of myelin wrapped around its axon. The more times a signal
travels along an axon, the more myelin wraps around it, the better and
stronger and faster the signal will travel along it in the future. The
wrapping of the myelin not only increases the strength speed and
efficiency of the signal but also determines the path the signal will
In the beginning memories may be connected
through a single neuron in the hippocampus. But this is not the most
efficient way for neurons in the cortex to be connected. They could be
connected more directly to one another. Alas, as was pointed out
earlier, this would simply take too long for the instantaneous
formation of a memory. However, we can suppose that even while the
memory is being maintained by the neuron in the hippocampus that
synapses bud, dendrites proliferate, and axons extend all in an effort
to connect up with other neurons that are firing at the same moment.
There are no special fibers to connect the neurons in different part of
the cortex but here is what might happen. Gradually over perhaps years
these cortical neurons would become more directly connected up. So it
would take a long time, but so what, the memory is intact as long as
the neuron in the hippocampus remains undamaged and is fired off at
regular intervals that correspond with times just previous to when they
are about to be forgotten.
these new pathways would become strong enough, they would be used in
preference to the long connections going through the neuron in the
hippocampus and the need for that neuron in the hippocampus would
diminish, and it would eventually die off leaving the memory in cortex
fully connected up, without the hippocampus playing a part any longer.
All this requires that the memory be activated often over a long period
of time, possibly many years. This process would ensure that the number
of neurons in the hippocampus never get to be too many, for as new ones
would be forming old ones would be dying off. This leaves us with a
situation quite different to how memory is usually thought of, where in
the cortex a memory would not just be in one place. Such a memory could
perhaps be activated at any or all of the connected junctures that make
it up. This could be thousands of places in the cortex. Not only that
but these same junctures could also be part of other memories.
The webs or matrices of
memory. If our memories are, as suggested, complex webs of
connections of neurons scattered across the cortex, then repetition
would accomplish two things simultaneously. It would strengthen the
connecting axons by the wrapping of extra myelin around them to protect
and optimize them. But at the same time it would add more connections
(even if those connections were only those that connected the memory to
the time and place at which the recall took place. Details would be
difficult to recall because they would be at the periphery of the
memory and not always activated each time the memory as whole was
activated. On the other hand the central core of the memory which John
Medina calls the gist of the memory would be easy to recall because
that is what would always be activated each time the the memory was
recalled. To find a memory a person would have to navigate through a
maze of connections, but the central core of a memory, the gist of the
memory, would be found because it would be surrounded by so many entry
paths while the details would have few entry paths.
would then follow, that a thousand
repetitions of activating a memory would have little effect if they all
occurred in rapid succession, because their importance would involve
two essential functions. One function would be the putting off the
natural process of neurons and their connections atrophying when they
are not being activated. The other function would be the making sure
that the any two neurons involved in the memory and thus fired when the
memory is active would continue to extend neural connections toward one
another. A strongly connected memory through repetition and elaboration
in the early stages of memory consolidation would be of help, but more
spaced repetition and elaboration over time would make sure the process
continued. What the brain would need is convincing that the memory is
needed, and thus cause it to stop or postpone the otherwise entropic
process that starts the moment the memory is minted. Repetition at
regular intervals over a long period of time could interrupt the dieing
off of connections at the very moment when it is most needed, when it
is just about to happen and the memory is just about to disappear
of the problems with the above conjecture, about how memories are
that we are still not sure that axons and dendrites continue to grow
much after the first sixteen or so years of life. However, even if this
growth does not occur much in adults this does not necessarily
invalidate this conjecture. There is another theory mentioned in
Sebastian Seung's book
"Connectome" where he suggests that synapses may
not be created on demand but rather created randomly. He says:
"Perhaps synapse creation is
a random process. Recall that neurons are connected to only a subset of
the neurons that they contact. Perhaps every now and then a neuron
randomly chooses a new partner from its neighbors and creates a
synapse. ...Synapse creation alone, however, would eventually lead to a
network that is wasteful. In order to economize , our brains would need
to eliminate the new synapses that aren't used for learning. ...You
could think of this as a kind of survival of the 'fittest' for
synapses. Those involved in memory are the 'fittest' and get stronger.
Those not involved get weaker, and are finally eliminated."
could mean that although synapses may not created in response to the
need for a new memory many new synapses may be created randomly in
response to increases in the formation of memories.
we take out the possibility of growth of neuron pathways and plug in
"Neural Darwinism" the conjecture about declarative memory formation is
still viable. In this case we would have to consider that there may be
many possible pathways between two neurons in the cortex and although
the initial one created by a new neuron in the hypocampus would be
strongest at first this would eventually be replaced by a more direct
path through the neocortex. Let us suppose that initially when a memory
is first laid down two different pathways are created, one that goes to
the hypocampus as has been explained already, and one that goes through
the neocortex in a long laborious twisting and back tracking journey
through the tangle of neuronic connections. Sometimes, with luck, this
path may be shorter than the one through the hypocampus, but usually it
would be much much longer. Let us further suppose that every time we
recall the memory that connects these two neurons in the cortex that
both these pathways are activated. Not only that, but because of the
random appearance of new synapses connecting new neurons, maybe another
pathway may open up that is shorter or maybe several shorter pathways
open up and maybe all of these now activate and form a circuit. The
next time the memory is recalled the shorter pathway may be activated
while the longer one may be inhibited and not activate. After
considerable time and recall and the finding of shorter and shorter
pathways and the deactivation of the longer pathways, the path through
the neocortex could become quite short indeed. This could be so much
so, that the path that includes the hypocampus may not be
itself be inhibited and deactivated.
We know that memories tend to
change over time. They seem to be unstable. This would be consistent
with our theory above as elaboration would be essential to
consolidating any concept, action or memory. Sometimes memories change
for the better, and sometimes they change for the worse, but they
change. This seems to be true of even the longest existing, most
stable, long-term memories. In his book
John Medina puts it like this:
"There is increasing evidence that when previously consolidated
memories are recalled from long-term storage into consciousness, they
revert to their previously labile, unstable natures. Acting as if newly
minted into working memory, these memories may need to become
reprocessed if they are remain in a durable form. ...If consolidation
is not a sequential one time event but one that occurs repeatedly every
time a memory trace is reactivated, it means permanent storage exists
in our brains only for those memories we choose not to recall! Oh, good
Memory as change.
Change, as is expressed often on this site, means learning. Changing
memory is something that does not make a lot of sense in terms of how
we understand computers. In a computer if something is saved it is
stored in a particular area of the computer (the hard drive) in a
perfect form to be recalled. This is not how the brain works. There is
no decision to save in the brain. Short-term memory becomes long-term
memory if it is activated often, that is if it is relearned or
recalled. Saving, if we could still call it that, takes place over a
long period of time. But, as suggested above, learning and thus memory
is not mostly about repetition but rather iteration where what is
learned is constantly extended and thus changing. Recall, it is being
suggested here, may work in the same way, adding associations every
time a memory is recalled.
associations? Well every time you recall something there are thousands
of new associations just waiting to be attached. First there are the
associations with what ever the reason was that you made the effort to
recall, or the intrusive external event that triggered the memory to
automatically pop into consciousness. These are particularly strong
associations. Then there are the associations that comprise the
external environment at the time when you in the process of recalling,
and probably the thoughts you have had during and just after the
recall. These are weaker often unconscious associations, but they are
we can be pretty sure of three things about memory. The elaboration of
a memory makes it more memorable, expansion of a memory through
iteration makes the memory more memorable, and using the memory makes
it more memorable. Of course these three things are actually only one
thing looked at from three different perspectives.
Consolidation of memories.
John Medina in his book
"Brain Rules" explains consolidation as follows:
first a memory trace is flexible, labile, subject to amendment, and at
great risk for extinction. Most of the inputs we encounter in a given
day fall into this category. But some memories stick with us. Initially
fragile, these memories strengthen with time and become remarkably
persistent. They eventually reach a state where they appear to be
infinitely retrievable and resistant to amendment. As we shall see,
however, they may not be as stable as we think. Nonetheless, we call
these forms long-term memories."
of memories. Neuroscientists tend to talk about many
different types of memory. There are three major types of memory which
in turn can be further divided into other types of memory. They are
explicit memory or declarative memory (long-term memory, short-term
memory and working memory) and implicit memory or non declarative
memory (procedural memory).
or declarative memory.
Long-term memory is usually divided into, semantic memory and episodic
Semantic memory is the type of memory that deals with meaning and
structures made up of meanings. That is it the memory of concepts and
statements that are constructed from concepts.
associations. Semantic memories are structures of hundreds
semantic associations that go to make up each concept in a thought, and
the stringing together of these concepts into further meaningful
structures that could be declared as statements. This is the type of
memory discussed in this site's section on meaningfulness. The
associations in this type of memory are what provide the meaning of a
word, a concept, a sentence, a text. These associations by linking
together produce an abbreviated or symbolic form of the memory. Words
for instance are symbols that stand for concepts. Words then are
associated with all the elements that make up their meaning but when we
recall a concept from memory we will in all likelihood recall only the
word into consciousness. In a similar way when we recall some text we
will recall only the gist (the meaning) and not word for word text. The
brain abbreviates information so it can be processed efficiently.
Meaning is a web of associations that we hold in memory although we
only access this central core of what it is.
Medina points out that a word on a list is best remembered if we we
make an effort to associate it with as much meaning as possible. The
concept or word apple is much less elaborately encoded than say his
Aunt Mabel's apple pie. The concept or word apple however, has very
elaborate encoding including all the associations needed to give
meaning to that word or concept. If when we try to remember the word we
concentrate on the number of diagonal lines in the word we are ignoring
all the elaboration at our disposal. If instead we think about Aunt
Mabel's apple pie the meaning is very elaborate. Aunt Mabel's
apple pie deals with not one but three strong concepts, pies, apples
and Aunt Mabel. On top of this there is the fantastic smell of the pie,
the delicious taste of the pie, its texture, its usual visual
appearance, how it made us feel, etc. Aunt Mabel's pie can be very
intrusive. Sudden exposure to pies, apples, aunt Mabel, pie smells, pie
tastes may all invoke Aunt Mabel's apple pie into our stream of
about memory webs. It is in this type of semantic memory that
it is easiest to see how memories could be webs of connections. The way
to get a glimpse of how webs of connections might coalesce into
memories is to start with the basic units of semantic memory, the
concepts themselves, and more specifically concepts of objects. An
object concept is a concrete form existing in the world. We know what
these object concepts are because we know their meaning. These object
concepts come in many sorts. One sort of object concept is a specific
object. Such objects are Betsy the cow, Fido the dog, Bradley the man,
Australia the country, and Mabel the yacht. Such object concepts are
not a class or a category, or if they are, they are a category with
only one member. Also they do not have to have specific names. They can
be something like my blue pen or your red scarf. Most object concepts
however are a class or a category and thus have many members. The most
useful of these object concepts are the next level of abstraction. Such
object concepts are a category which has specific objects as its
Let us consider the object concept "ball". We all know what a ball is,
but how do we know it? It is suggested here that we know what a ball is
because of its connections to memories of specific balls. The concept
ball has probably thousands, no millions, no billions of connections.
Every time you saw a ball, felt a ball, played ball, bounced a ball,
heard about a ball, thought about a ball, the connections would be made
and activated. This site holds that it is these connections when
activated that give the concept "ball" its meaning, that they are in
fact that meaning.
Consider the concept of a sphere. A sphere is an aspect of a ball.
While most balls are fairly spherical, some footballs are more egg
shaped. Although a sphere is not really an object at all we often use
the words that stand for those concepts interchangeably. You might
describe a sphere as being ball shaped. But this is not really correct.
In fact the opposite is true most balls can properly be described as
being spherical. When the concept ball is activated the concept sphere
is also activated as part of its meaning. Following from our theory a
sphere unlike a ball would not have such a large number of connections.
It would have only a few connections. However it is still a strong
concept because it has a very strong connection to the concept ball and
when the concept sphere is activated the concept ball, would for the
most part, be activated also as part of its meaning, even though the
reverse is more correct. In this way every concept would be a fantastic
web of connections. Remember in just six connections you can probably
connect to any neuron in the entire brain.
formation. So how might these concepts be built up as we
learn and grow? What we know about building memories is that the
"connecting axons" that are activated get more myelin wrapped around
them, making them stronger and quicker, while the "connecting axons"
that are inhibited from becoming active, tend to wither and die. Let us
suppose then, that when forming connections children select members
that seem, for whatever reason, similar to them. Let us call these
theories about what concepts are, or concepts that do not match
concepts as they are understood by a particular culture. They would be
sort of potential concepts or incorrect concepts. These incorrect
concepts would be useful for building an internal model of reality, but
fairly useless for communicating with others.
Thus infants would have to modify the connections as they gained
information about what others in their culture accepted as being
connected, or as being members of that concept category. For this to
happen some connections would continue to be activated while others
would be inhibited from being activated. The axons that continued to be
activated would continue to be part of the meaning of the concept and
the axons that were inhibited from being activated, would die off and
no longer be a part of the meaning of the concept. On the other hand a
child might miss some members of a concept category and have to modify
the concept by adding members. This would simply be a matter of firing
the various connections and at the same time adding the new
connections. They would be more weakly connected at first but would get
stronger, the more they were activated as part of the whole concept
Semantic memories then are concepts, or complex interrelations of
concepts (stories), and they are ment to be changed each time they are
remembered. While they may seem like static unchanging things they are
in fact constantly in the process of changing. Every experience of an
object, every recall of it, provides us with more information about it
and even when we think we have an imutable understanding of what it is
we are still deleating some connections that are not quite right, we
are adjusting other connections, and still adding new connections. Not
only does our understanding of concepts constantly change but also
often the objects themselves change. A concept like a ball may not
change but living concepts like animals, insects and humans get older,
lose body parts and change in appearence. Concepts of place also
change. Trees grow, die, change their leaves. Man made structures like
buildings also change as they are built and knocked down. For
this reason semantic memories are ment to be infinitely flexable
constantly expanding and contracting to fit the current state of
final note about this conjecture.
The problem with this conjecture is that it still does not explain how
the brain finds a memory in order to activate it. And how would the
brain know when it has found it? Answers even speculative
simply beget more questions.
Episodic memory is the type of memory that deals with an event or
episode in ones own life where a whole lot of information was attended
to, and was thus processed into associations that are all welded
together in to a whole unit of memory.
associations. Episodic memories are structures of hundreds of
episodic associations that go to make up these episodes or events. In
"Brain Rules" John Medina tells a story about an episodic
memory of playing fetch with a huge Labrador, that surprised him by
coming out of a lake and shaking water all over him. He continues:
was occurring in my brain in those moments? As you know the cortex
quickly is consulted when a piece of external information invades our
brains - in this case, a slobbery, soaking wet Labrador. The instant
those photons hit the back of my eyes, my brain converts them into
patterns of electrical activity and routes the signals to the back of
my head (the visual cortex in the occipital lobe). Now my brain can see
the dog. In the initial moments of this learning I have transformed the
energy of light into an electrical language my brain fully understands.
Beholding this action required the coordination of thousands of
cortical regions dedicated to visual processing.
same is also true of other energy sources. My ears pick up the sound
waves of the dog's loud bark, and I convert them into the same
brain-friendly electrical language to which the photons patterns were
converted. These electrical signals will also be routed to the cortex,
but to the auditory cortex instead of the visual cortex. ...This
conversion and this individual routing is true of all energy sources
coming into my brain, from the feel of the sun on my skin to the
instant I unexpectedly and unhappily got soaked by the dog shaking off
lake water. Encoding involves all of our senses, and their processing
centers are scattered throughout the brain.
one 10-second encounter with an overly friendly dog, my brain recruited
hundreds of different brain regions and coordinated the electrical
activity of millions of neurons. My brain was recording a single
episode, and doing so over vast neural distances, all in about the time
it takes to blink your eye."
associations are often only peripherally encoded in a memory. In this
case one focuses attention on a specific item of interest, and much of
the other information is ignored and unprocessed. However, although
this peripheral information is not part of what is recalled in the
memory trace, it does provide some pathways for activating the memory.
This it turns out is very important for enabling recall of any sort. It
has been found that the most significant way we can help people
remember something, is to put them in an environment as close as
possible to the one where they first encoded the information.
episodes of episodic memory are usually understood to be constructed or
built up in exactly the same way as semantic memories. This makes
memory episodes unreliable. While each episode only occurs once it must
be recalled many times in order to become eligable to go into long term
storage. However every recall is an opportunity to contaminate the
memory. It is a catch 22. the more it is recalled the easier it is to
remember it but the more it is recalled the more it becomes
contaminated. Every recall adds more associations and if those
associations are often the same ones they can become stronly associated
and thus distort or change the original episode.
The relationship between short-term memory and working memory is
interpreted in various ways by different theories, but it is usually
understood that the two concepts are distinct. Working memory is a
theoretical framework that refers to structures and processes used in
temporarily storing and manipulating information. Working memory could
also be understood as
being working attention. Short-term memory generally refers to the
short-term storage of information only, and it does not entail the
manipulation or organization of information held in the memory. Thus
while there are short-term memory elements in working memory models,
the concept of short-term memory is usually conceived as being distinct
from information manipulating components.
memory is labile, unstable and of limited duration. It is tending to
spontaneously decay from the moment it comes into existence. In order
to overcome this limitation of short-term memory, and retain
information for longer, information has to be periodically repeated, or
rehearsed. This is called covert rehearsal. It can be performed either
by articulating it out loud, or by mentally simulating such
articulation. In this way, information can re-enter the short-term
store and be retained for a further period.
Chunking is a process with which the amount of information a human can
hold in short-term memory can be expanded. Chunking is performed by
organizing material into meaningful groups. Although the average person
may only retain about four different units in short-term memory,
chunking can greatly increase a person's recall capacity. For instance,
in recalling a phone number, a person could chunk the digits into three
groups: first, the area code (such as 215), then a three-digit chunk
(123) and lastly a four-digit chunk (4567). This method of remembering
phone numbers is far more effective than trying to remember a string of
10 digits. Practice and the usage of existing information in long-term
memory can lead to additional improvements in one's ability to use
chunking. In one testing session, an American cross-country runner was
able to recall a string of 79 digits after hearing them only once by
chunking them into different running times.
Working memory is a busy temporary workspace, rather like a desktop,
that the brain uses to process newly acquired information. Working
memory is the processor part of consciousness. The man whose legacy
best characterizes this process is Alan Braddeley who described working
memory as a three component model; auditory, visual and executive.
working memory. The auditory part of working memory is the
part that deals with sound. It is the part that retains linguistic
information and processes it.
working memory. The visual part of working memory is the part
that allows some visual information to be retained in memory and
processed. Braddeley saw it acting as a sort of imaging-spatial sketch
working memory. The executive part of working memory is the
part that keeps track of individual threads of thought and which keeps
them separate and keeps each together as a chunk of information. Thus
professional chess players can play several opponents at once and keep
each game separate in their minds.
Implicit or non
memory is a type of memory in which previous experiences aid in the
performance of a task without conscious awareness of these previous
experiences. Evidence for implicit memory arises in priming, where
subjects show improved performance on tasks for which they have been
subconsciously prepared. Implicit memory also leads to the
illusion-of-truth effect, which suggests that subjects are more likely
to rate as true statements those that they have already heard,
regardless of whether they are true or not.
into implicit memory indicates that it operates through a different
mental process from explicit memory. Instead of connecting to the
hippocampus implicit memories connect to the cerebellum ("little
brain"). This is a structure located at the rear of the brain, near the
spinal cord. It looks like a miniature version of the cerebral cortex,
in that it has a similar wavy, or convoluted surface. The cerebellum
probably plays a similar role in implicit memory as the hippocampus
does in explicit memory. It is essential in the learning of
both procedural memory, and motor learning.
memories are often called non declarative memories because although we
do not recall them into consciousness as we perform them we could not
declare them if we did.
They are activated as an activity or a skill and
accomplished without you having to consciously think about doing it. It
is automatically activated when we wish to use it.
memory. In daily life, people rely on implicit memory every
day in the form of procedural memory. This type of memory allows people
to remember how to drive their car or ride a bicycle without
consciously thinking about these activities. It allows us to build up
skills requiring co-ordination and fine motor control such as playing a
musical instrument, or playing a sport or reacting to defend yourself.
Once we have learned some skill to a sufficient
level there is a process which helps to make those actions or reactions
automatic, thereby allowing them to sink to a merely physiological
level, and to be performed without attention. When riding a bike we may
however, modify our performance consciously going this way or that on
the bike, or go faster or slower. But the schema of bike riding is
unconscious. Of course when you are learning a skill you have to think
about it often, and break it down into manageable units or schemas that
can then be manipulated more easily. This is another type of chunking.
As you continue to learn these schemas gradually sink out of
consciousness into automatic activity. There is much about this in the
Art of Learning"
by Josh Waitzkin. This is covered more extensively on this site in the
section on thin slicing,
which deals with the creativity of the unconscious.
facilitation. Memories can be facilitated by circumstances at
the time of imprinting and circumstances at the time of recall.
Facilitation at the time of
recall. Memories can be facilitated by circumstances at the
time of recall as explained above by placing people in an environment
as similar as possible to the environment where the memory was first
imprinted. This is clearly because these peripheral associations of the
environment are recorded with the the actual memory although they may
not be recalled with that memory. They instead provide more pathways to
the memory enabling easier access to the memory.
Facilitation at the
time of imprinting.
Memories can be facilitated by circumstances at the time of imprinting
in many different ways but all of them depend on the amount of
attention being paid to the to the information. This may be interpreted
as follows: If we pay attention various associations are formed between
this incoming information and and information already residing within
our heads. These associations give the new information meaning. But
this is not all that happens. Other, usually weaker associations, are
also formed with other information present, although not paid specific
attention to. These peripheral associations form a context for the
information to be memorized, which seems to take place on an
unconscious level. These are the peripheral associations, mentioned
above, that provide extra door handles for opening up memories.
Memories can last minutes, days, months, years or a lifetime. How long
memories last depends on how often they are used and how elaborately
they are connected or linked to other memories. Memory experts tend to
think of these as two different process, but is this necessarily the
case? We know, for instance, that if connections are not used they
disconnect and the cells involved tend to die off. Memories with lots
of connections would also be more likely to accessed in a search. So it
could be said that the amount of elaboration increases the possibility
of use. In any case it is clear that these two processes are
inextricably bound together. The amount of elaboration increases the
possibility of use and use determines whether the association remain
elaborate or whether they die off.
encoding. The researchers have called this elaboration of
associations elaborate encoding. Elaborate encoding is all about
meaning. That is to say, the more associations or connections to other
information the more meaning, and thus the more easily memorized. Most
of this elaborate encoding takes place in the first few moments of
processing information into memory and this site holds that it is the
most important consideration in memory. Elaborate encoding is
accomplished in two quite different ways.
Elaborate encoding can be accomplished through effortful attention
where the person endeavors to pay attention and thus remember
something. If one tries to accomplish memory imprinting through making
an effort to pay attention, one will tend to fail after about ten
minutes, depending on how boring the information is. On top of this
effortful attention is easily lured away by sufficient distraction.
attention, automatic processing. On the other hand interest
can focus attention automatically and effortlessly. This in turn causes
elaborate encoding to be automatically imprinted as memory. In his book
John Medina gives an example of automatic
processing as follows:
type of encoding is automatic, which can be illustrated by talking
about what you had for dinner last night, or The Beatles. The two came
together for me on the evening of an amazing Paul McCartney concert I
attended a few years ago. If you were to ask me what I had for dinner
before the concert and what happened on stage, I could tell you about
both events in great detail. Though the actual memory is very complex
(composed of spatial locations, sequences of events, sights, smells,
tastes, etc.) I did not have to write down some exhaustive list of its
varied experiences, then try to remember the list in detail just in
you asked me about my evening. This is because my brain employed a
certain type of encoding scientists call automatic processing. It is
the kind occurring with glorious unintentionality, requiring minimal
attentional effort. It is is very easy to recall data that has been
encoded by this process. The memories seem bound all together into a
cohesive, readily retrievable form.
of interest. This interest that supports automatic processing
comes in a number of different flavors.
Interest. Intellectual interest occurs where similar
information has brought pleasure previously and thus we anticipate this
information will also bring pleasure, thus focusing our attention on
Interest. Emotional interest occurs where some strong emotion
rivets our attention on some event or episode. This can also be used as
way of re-enabling effortful attention.
Interest. Surprise interest occurs where something unusual or
unexpected rivets our attention on some event or episode. This can also
be used as way of re-enabling effortful attention.
Interest. Story interest occurs where the information comes
in the form of a story. The interconnectedness of a story provides its
own way of automatically focusing attention. Stories have been used to
imprint memories long before recorded history.
Interest. Simplicity interest occurs where information has
been presented in a compressed form, where the gist of some idea or
concept has been teased out and conveyed in an understandable way. The
brain seems to recognize this gist as having already performed much of
its work and favors it with strong focus of attention. It may also be
that the gist has by its very nature many handles on it that connect
strongly with many associations to information already residing within
memory more means easier to find. John Medina says "The
more elaborately we encode information
at the moment of learning, the stronger
the memory. ...The trick for business professionals, and for educators
is to present bodies of information so compelling that the audience
does this on their own, spontaneously engaging in deep elaborate
While associations that enhance the meaning of some memory obviously
make it more memorable, other associations the are only peripheral or
contextual will also enhance memory retrieval because they provide more
links or handles for opening the memory. The more associations of any
sort added to a memory the easier it is to remember. It follows that
the more interesting something is, the more associations are added
effortlessly and automatically to it. Makes you wonder why things are
so boring at schools doesn't it.
examples. The more the person focuses on the meaning of the
presented information, the more elaborately the encoding is processed.
When you focus on information in this way, you are linking it up with
all the information already residing in your brain that provides
meaning for it. Now as explained previously we usually tend not to
remember examples so much as the gist of the idea, theory or concept.
However, despite that, concrete examples of ideas theories or concepts
are immensely important in forming those ideas, theories or concepts.
While we are still trying to understand an idea, theory or concept a
more abstract explanation can be almost meaningless. What you need is
some concrete examples to ground the information in the real world. How
can this be done? John Medina puts it like this:
does one communicate meaning in such a fashion that learning is
improved? A simple trick involves the liberal use of relevant
real-world examples embedded in the information, constantly peppering
main learning points with meaningful experiences. This can be done by
the leaner studying after class or, better, by the teacher during the
actual learning experience. This has been shown to work in numerous
studies. ...Providing examples is the cognitive equivalent of adding
more handles to the door. Providing examples makes the information more
elaborative, more complex, better coded, and therefore better learned."
may well be that once a central core concept (the gist) has been
formed, concrete examples do not need to be constantly referred to in
working memory and can sink into unconsciousness, only to retrieved
from long term memory when needed.
In the movie business they say that if they haven't hooked you into the
story in the first three minutes of the opening credits the movie will
be a financial failure. In any kind of presentation of information the
first few minutes are are where you have to grab the audience's
attention. In his book
"Brain Rules" John Medina says:
are everything. As an undergraduate, I had a professor who can
thoughtfully be described as a lunatic. He taught a class on the
history of the cinema, and one day he decided to illustrate for us how
art films traditionally depict emotional vulnerability. As he went
through the lecture, he literally began taking off his clothes. He
first took of his sweater and then, one button at a time, began taking
of his shirt down to his T-shirt. He unzipped his trousers, and the
fell around his feet, revealing thank goodness, gym clothes. His eyes
were shining as he exclaimed, 'You will probably never forget now that
some films use physical nudity to express emotional vulnerability. What
could be more vulnerable than being naked?' We were thankful he gave us
no further details of his example. ...If you are a student, whether in
business or education, the events that happen the first time you are
exposed to a given information stream play a disproportionately greater
role in in your ability to to accurately retrieve it at a later date."
Retrieval of memories.
John Medina in his book
"Brain Rules" points out that retrieval of memories is also
conceived of as happening in two different ways also, the library model
and the crime scene model.
Reproductive retrieval. John explains
the library method of retrieval as follows: "In the library
model, memories are stored in our heads the same way books are stored
in a library. Retrieval begins with a command to browse through the
stacks and select a specific volume. Once selected, the contents are
brought into conscious awareness, and the memory is retrieved. This
tame process is sometimes called reproductive retrieval."
John explains the
crime scene method of retrieval as follows:
"The other model imagines our memories to be more like a large
collection of crime scenes Retrieval begins by summoning the detective
to a particular crime scene, which invariably consists of a fragmentary
memory. Upon arrival Mr. Holms examines the the partial evidence
available, Based on inference and guesswork the detective then invents
a reconstruction of what was actually stored. In this model, retrieval
is not the passive examination of a fully reproduced, vividly detailed
book. Rather retrieval is is an active investigative effort to recreate
the facts based on fragments of data."
Decay and muddling of memories. Although it is believed we
use both the above methods in retrieving memories it is fairly clear
that long-term memory is retrieved mostly by reconstructive retrieval.
In fact really accurate, detailed, reproductive retrieval is usually
only good for a few day. This site holds that we should not be
surprised by this state of affairs. We should expect memories to become
damaged over time. We should expect bits of information to become lost.
We might expect the input of a particular sense to disappear out of a
particular memory. We should expect bits of information to be deleted
by the brain because it is not used or seems unimportant. We should
expect memories to become mixed with other similar memories. We should
expect the brain to insert made up information into old damaged
memories in order to make them make sense. Of course as explained
earlier on this page, the more memories are used, the better the
chances of it not being damaged over time, other than massive damage to
whole areas of the brain. On the other hand mere recall does not
prevent memories becoming mixed up. Everything appears to break down
over time why not memories? It has been found however, that memories
reactivated over fixed, spaced periods of time tend to prevent this
deterioration from occurring.
All memories are made up of elements of information coming from all of
our bodies different senses. If our brain is using the reconstructive
method to retrieve a memory, obviously if the memory includes
information from as many senses as possible there is a greater chance
of the memory being reconstructed in a more reliable manner. There are
simply more clues to what the memory was originally. Not only does more
sensory involvement mean more accurate memories but again it also
creates more pathways to the memory and thus a more durable memory.
This is true for both reproductive and reconstructive retrieval.
Taste/Gustatory. Compared to most other animals taste
in human beings is a very poor sense indeed. While taste can contribute
pathways for finding memories and contribute to episodic memory it
provides us with very little useful information unless we train our
Smell/Olfactory. Smell is the oldest most primitive
sense in the brain. Of all the senses it is the only one that is
processed directly without first being mixed with all the other senses.
As with taste is very poor in humans, providing us with little in the
way of useful information. Nevertheless smell provides extremely strong
cues for evoking memories.
Audio/Ecoic. Because of language, and the fact that most of
what is meaningful to us is necessarily understood and communicated in
linguistic form, hearing must be essential in encoding any memory, but
especially so in semantic memory.
Visual/Iconic. Vision is the king of the senses. In humans
visual processing takes up half of the brain's resources. A visual
image is better remembered than a sentence about the same thing.
Memories that include images have a much better chance of being
remembered than memories that do not include images. We remember best
through pictures not through written or spoken words. Animated images
are better remembered than still images.
Touch/Enactive. Touch is used in two different ways in
remembering. We use it in a declarative memory where we can speak about
how things felt. Like taste and smell its main use in memory is in
awakening memories although it can convey a fair amount of information
if we pay attention to it. Touch is also used in the hidden non
declarative memories which involve the feeling of body movement,
balance, and the feelings in our muscles as they work and perform
Repetition or Iteration in
In his book John Medina makes special mention of repetition as being
important in making memories more enduring and stable. This site takes
the position that this could in fact be very misleading. It seems as if
that this encouragement to repetition could lend itself to activities
that are not conductive to memory improvement at all. We are talking
about two activities that, though related, are in fact quite different.
Both recall and learning can be repeated.
in recall. Repetition in recall could be simply be recalling
the information for no purpose, or for the purpose of rehearsing it so
it will be easily activated for an exam. How effective this might be in
consolidating memory is difficult to estimate. This site is unaware of
any studies done to show that memories recalled where an effort is made
not to add new information are still effective in making those memories
more enduring and stable.
in recall. However, there is no doubt that making use of a
memory does in fact cause it to be recalled, and in the process, makes
the memory more enduring and stable. When we use the information we
have memorized to solve some problem or complete some task, the
information has to be recalled, but it also links the memorized
information to new information in the form of a concrete example of how
the information works and how it is useful. When this happens the
information becomes hugely more elaborated and yet more clearly
understood, as to it how it functions in reality. In this process the
memory is changed and for the better. It becomes a better version of
its previous self. The memory becomes an improved clearer more
understandable iteration of its previous self.
Repetition in learning could be rereading the same information
rehearing the same information or rewatching the same information. It
can be shown that attempting to do this without taking in any new
information could be quite detrimental to remembering. For a start it
is boring. And anything that is boring is very difficult to pay
attention to. The brain has already memorized this. Why would our
brains help us pay attention to information already memorized? Well it
wouldn't would it? So here you are forcing yourself to reread
information you already know, or listening to a lecture that you have
already heard, or rewatching a presentation you have already seen. Is
your memory going to become more durable and stable? Well, maybe, if
your brain lets any of that information be attended to. But also maybe
not. Maybe it just makes the learning task longer more difficult and
unpleasant. This kind of effort can be shown to be very similar to
where information is taken in without meaning to tie it together. There
is a great deal of research that shows that this type of rote learning
is only effective for very short periods of time after which it is
in learning. The key to repetition is to be found in
elaboration. If when we reread a text and we learn something new that
we missed or misunderstood when we read it previously, surely this
makes all the difference. If, when we reread a text, we make new
connections, new associations our interest and attention are easily
maintained. The old information is somewhat activated as the new
information is connected to it, so it is sort of repeated and sort of
not repeated. This is what can be called a memory iteration. Every time
the memory becomes active it changes because each time new information
is added to it.
same is true if we listen to a tape of a lecture we recorded. The
second time through we are actually hearing a different lecture. We are
hearing the parts of the lecture that we missed when we first heard it.
Our attention is not on the old information we have already memorized
but on the information we missed and how it fits together with that
information already memorized. The lecture comes together better, it
connects better with what we already know, and the information we have
now memorized is an extended iteration of what we had remembered
a presentation a second time the same process of iteration occurs. When
you watch a movie for a second time you should see a different movie.
You should pick up on bits you missed. In the same way watching a
presentation for a second time you should experience connections to
what you have already memorized that you missed the first time through,
or experience internal connections within the presentation that you did
not connect together before. The memory of the presentation is a both
more complex and more simple than it had been previously. It is an
improved iteration of its former self.
memory paradox. More information is better memory.
It seems, at first sight, that more information should be more
difficult to remember than less information, but such is not the case.
It seems at first anti intuitive. However, once we understand how
memory works this does make sense. First of all, as explained above,
more information means more pathways that link to the memory and thus
more ways of reaching the memory when we are trying to find it.
However, it is also true the more information we have memorized about a
subject the more that information can be compressed into an abbreviated
or symbolic form that stands for that concept. More information also
allows larger ideas or theories to be compressed in the same way into
core simplifications or gist as John Medina likes to call it. Basically
the more information attended to, at the initial exposure, the better
and more memorable the memory. Like wise, the more new information
added to that memory in subsequent interactions, the more stable and
more enduring the memory.
else helps improve memories?
Any thing that helps create interest greatly improves memory because it
enables effortless attention.
all senses. Paying attention to information coming from all
the senses enables encoding to be much more elaborate and thus greatly
improves the likelihood of a memory enduring. It also creates many more
avenues of reaching the memory when attempting to recall it.
Concrete real world examples are best for anchoring memorized
information in reality, but even abstract examples are useful in
elaborating information and thus making it more memorable.
hook. Any informational sequence must coax you into being
interested in it in the first 3 minutes if an enduring memory is to be
encoded. Such initial interest is essential to how elaborate any memory
will be encoded and thus how enduring that memory will be.
ten minute limit. When making an effort to pay attention to
something one is only vaguely interested in, one is likely to fail
after about ten minutes. John Medina found it very effective to break
up his lectures into 10 minute modules of compressed, essential or core
concepts. After each module he would woo back the interest of his
audience with an example in the form of a story or an example that
would arouse strong emotion or surprise. This he found would keep them
going for the next ten minutes.
and reflection. A great deal of research shows that thinking
about or talking about an event immediately after it has occurred
greatly enhances the memory of that event. It enhances the the
durability of the memory the accuracy of the memory and how detailed
the memory is. John Medina says: "This tendency is of
enormous importance to law enforcement professionals. It is one of the
reasons why it is so critical to have a witness recall information as
soon as is humanly possible after a crime."
spaced intervals. Repetition works best in fixed, spaced
intervals in conjunction with elaboration to form expanding iterative
memories. John Medina says: "Deliberately re-expose yourself
to information more elaborately, and in fixed, spaced intervals, if you
want the retrieval to be the most vivid it can be."