Recall of learning and iteration
is what makes learning useful.
This does not mean that learning and memory are the same thing.
Learning is how the things that we learn are connected to the things we
have learned in the past. Memory, on the other hand, is our ability to
recall those things that we have learned. A lot of memory research has
shown that memory is greatly improved by repetition but this site
maintains that this is misleading. It is true that it can be shown on a
cellular level that neuron connections are made stronger faster and
efficient by repeating their activation. This is because repeated
activation increases the myelin
wrapping around axons that connect the neurons. However, we know that
in learning there is no such thing as true repetition. In fact ever
time we learn something we are changing what we learned previously.
Sometimes we are merely adding to what we know, but most often we are
modifying one idea or understanding and thus are replacing it with a
better more accurate idea.
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. Consider, the repetition involved
in learning a skill is no repetition at all, but rather iteration.
Each repeated action is actually a variation enabling us to adjust what
we are doing and so improve our actions. Every time we recall, relearn,
or reacquaint ourselves with something we have learned previously, we
are adding new connections. Sometimes they are a complete revision but
always there are some new connections. The mere fact that the recall or
relearning takes place at a different place or time insures there are
new connections. 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 repetition as it is in fact iteration and not repetition at all.
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.
in the sense of iteration 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 the part of the
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 create short feedback loops between neurons and
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
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
We know that new neurons are formed in the
hipocampus by means of neurogenisis. But what is the purpose of these
new neurons if it is not to store new memories? This site holds that
the purpose of these new neurons is to connect fibers that run from the
hipocampus to every part of the cortex. In other words although
connections in a fully formed brain run from the hypocampus to every
neuron in the cortex they only connect when a new neuron formed in the
hipocampus makes that connection. When such connections are made in
this way we hold that a memory is formed. In the beginning each memory
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. Instead its like all parcels being sent to a
central hub before being resorted and sent to their destinations. Neurons in the cerebral
cortex could be
connected more directly to one another. They could be directly
connected in the neocortex the layer just under the cortex. Alas, as was pointed out
earlier, it would simply take too long for a memory to be formed by
forming new synapses and growing axons. However, we can suppose that
even while the
memory is being maintained by the neuron in the hippocampus that
synapses still bud, dendrites still proliferate, and axons still extend
all in an effort
to connect up with other neurons that are firing at the same moment.
Although there are no special fibers to connect the neurons in
the cortex, 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 previous to when they
are about to be forgotten.
these new pathways become strong and shorter in length, they would be
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 iteration of
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 iterations 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 iteration and elaboration
in the early stages of memory consolidation would be of help, but more
spaced iteration 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. Iteration 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 be 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. The process would not stop there
but continue throughout life. Each time a memory was recalled or
it would try to find a shorter faster path.
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 or improving the
it more memorable. Of course these three things are actually only one
thing looked at from three different perspectives.
Memory loss. There
are three ways we can lose memories.
The brain can be damaged causing memories to be erased, memories can be
suppressed or memories can simply fade as part of natural attrition.
Brain damage as forgetting.
If a brain is damaged not only can how a brain works change but
memories or parts of memories can simply be erased. Parts of the brain
such as the cortex and the hipocampus which are involved in memory are
obvious areas that can cause memory loss if damaged. Information lost
in this way can be recovered, if it is only a part memory, by
reconstruction based on clues left in the remaining information. But
loss caused in this manner can greatly change memories especially as
new information is added with each recall.
Suppression as forgetting.
Suppression is how the brain replaces one memory or part of a memory
with a new superior memory. Suppression then is an essential function
of learning. A signal is sent usually by the executive parts of the
brain located mostly in the prefrontal lobes that suppresses a memory
that it does not activate in circumstances where it previously did. An
old theory about the world is suppressed so that a newer superior
theory can be activated instead. An old habit is suppressed so that a
newer better habit can be activated instead. An old action is
suppressed so a newer faster, cleaner, smoother action can be activated
instead. Sometimes these inhibiting signals can be used to suppress
painful memories which psychologists call repression. Painful
memories of this sort are not usually lost because they have strong
emotions attached. However other memories like old theories, old
habits, and old actions will gradually weaken and die, although not for
a long time.
that time the old memories can still be accessed because they are not
gone just suppressed.
Sometimes it is necessary to revive such old memories such as when
going to a country where they drive on the left after driving on the
right for a long while. Memories that are seemingly lost through
if they are not actually
can usually be fully recovered.
Natural attrition as forgetting
is a massive spam filter.
Attrition type forgetting's purpose is to prevent bad changes which
memories and help produce good changes that produce accurate and
detailed memories. The
problem is that the more memories there are, the
more difficult they are to find just as spam fills up your email and
makes finding useful email difficult. Also the more memories there are,
the more they tend to overlap
and leak into one another. The more memories there are the more likely
there are to be similar memories. The more similar
the more easily
they can be confused with one another and the more easily they
will bleed into one another. Forgetting, by reducing the number of
memories sharpens the differences between memories thus preventing
memories bleeding into one another. We tend to forget those memories
that have little emotional intensity attached and those we have no
occasion to recall. Our brains work on the assumption that memories
do not have strong emotions attached and or are not recalled often must
be unimportant. This
means if we do not recall something the memory will
tend to wither and die unless it has strong emotions attached. Despite
that if a memory contains a lot of
elaboration there is a good chance it be recalled in the future even
though it has not been recalled for a long while. Forgetting depends on both
recall and the
likelihood of recall.
Memories lost through this kind of attrition can be recovered if only
parts are lost by means of reconstruction from clues residing in the
bits of memory that are left. This should work better than for brain
damage as the clues should be better and more abundant.
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."
Memories tend to
change over time. They seem to be unstable. This is 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
memories change has to do with how they are stored and accessed. It is
said this is a function of a memory's storage
and retrieval strength. Storage strength enables the planning
mapping of reality in memory. Retrieval strength enables the continual
updating and accessing of what is relevant in memory.
Storage strength increases with familiarity, the number of times the
memory is accessed. Accessed can mean recalled, but it can also mean
studied, tested or any kind of revisiting of the
strength is about memory starting off being impermanent. A memory
starts off in short term memory. It has an initial storage strength
based on the amount of associations it makes with other memories
residing in our brains and the intensity of those associations. Storage
strength does not weaken but is rather in constant danger of
disappearing. If not revisited it will completely disappear. If there
no intense associations attached to it it will disappear quickly. If
intense associations attached to it will last longer but it
disappear. However, if a memory is revisited it will last quite a bit
longer from the time of that revisitation. In fact, each time a memory
is revisited the amount of storage strength increases allowing the
memory to survive a longer and longer time after each
we think about this it becomes obvious that we can get the most out of
storage strength by not revisiting a memory until it is about to
disappear. That way we get the most time available for recollection for
the least amount of revisitations. So as we revisit each memory they
last longer and longer in short term memory until they reach a
condition of lasting so long they become a permanent memory and are
to then be in long term memory. It might seem that storage strength is
a function of repetition in that the number of times a memory is
recalled increases storage strength. However, whether a memory is
recalled or not from a statistical point of view depends on
the number of pathways leading to it. It is far to simple to
see storage strength as function of repetition. It depends on
elaboration as much as specific repetition. Then too, the number of
times a memory is recalled is not as important as when those recalls
take place. Ultimately memories are allowed to disappear unless they
prove to be useful and storage strength is a judgment of how useful
each memory is.
Retrieval strength. Retrieval strength on the
other hand is about how quickly a memory comes to mind. The
number of pathways to a memory, the intensity of those pathways, and
how recently it has been revisited are the main things that govern the
strength of retrieval strength. While retrieval strength is also
improved by the number of revisitations of the memory it is clearly
more greatly increased by the sheer number of associations connecting
to that memory and the intensity of those associations and when the
memory was last recalled. When we revisit
a memory retrieval strength is high and it gradually weakens as time
goes bye. If it is revisited again the amount of associations to it
goes up and its retrieval strength goes up because of that, but then it
weakens again until the next time it is revisited. Each time a memory
is revisited its retrieval strength comes back stronger than the last
time it was revisited but then it weakens till the next time it is
each time a memory is revisited it starts to weaken
but it weakens more slowly with each successive revisitation. This
process goes on forever. It is still working even after the memory has
gone into long term memory. This seems to be true of even the
longest existing, most
stable, long-term memories. If a memory has been in long term memory
for a long term without being revisited it seems it falls back into
short term memory if it is revisited. 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
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 but not brought into consciousness. 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 aspect concepts interchangeably with those
that stand for object concepts. 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" of neurons that are activated with a memory get more
myelin wrapped around
them, making them stronger and quicker. On the other hand the
that are inhibited from becoming active, or are simply not activated,
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 of adults. They
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 meant 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 immutable understanding of what it is
we are still deleting 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 appearance. 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 meant to be infinitely flexible
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 eligible 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 strongly
and thus distort or change the original episode. The only way to avoid
contamination is to make each recall is supplemented with new
information that more accurately describes the episodic memory. For
instance recalling the memory could prompt the investigation of an
account of the episode by somebody else which could more accurately
modify your own account which could be biased by your memories and
beliefs acting as a perceptual filter.
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 iterated, 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.
working memory. Chunking
is invaluable in enabling working memory to perform efficiently.
Although working memory can only hold about seven units or concepts at
a time by means of chunking working memory can be enabled to deal with
and manipulate large amounts of units concepts and
Concepts can be divided into aspects or elements and added together
into stories, theories and larger concepts.
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 implicit memory operates through a
mental process from explicit memory. Instead of connecting to the
hippocampus implicit memories connect to the cerebellum and the dorsolateral striatum.
The cerebellum ("little
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 is
located behind the top part of the brain stem (where the spinal cord
meets the brain) and is made of two hemispheres (halves).
The cerebellum receives information from the sensory systems, the
spinal cord, and other parts of the brain and then regulates motor
movements. The cerebellum coordinates voluntary movements such as
posture, balance, coordination, and speech, resulting in smooth and
balanced muscular activity. It is also important for learning motor
involved in implicit memory.
The dorsolateral striatum is essential in the
creation of procedural
memory or motor learning. which is associated
the acquisition of habits. It is the main neuronal cell nucleus linked
to procedural memory. It is part of the the basal ganglia
circuit. Overall the basal ganglia receive a large amount of
input from cerebral
and after processing, send it back to cerebral cortex via
cortex sends excitatory input to the striatum. The
striatum sends its
output on to the globus pallidus. The globus pallidus can
also be excited
by cortical activity, namely by a pathway that travels through the
nucleus first. The globus pallidus is really divided into two
only one of which sends output (yet again inhibitory!) to the thalamus
to cortex, thus completing the loop.
information processing pathways diverge from the striatum, both acting
in opposition to each other in the control of movement, they allow for
association with other needed functional structures. One pathway is
the other is indirect and all pathways work together to allow for a
functional neural feedback loop. Many looping circuits connect back at
the striatum from other areas of the brain; including those from the
emotion-center linked limbic cortex, the reward-center linked and other
regions related to movement. The main looping circuit
involved in the motor skill part of procedural memory is usually called
the cortex basal ganglia thalamus cortex loop.
Either the cerebellum, the dorsolateral striatum
or the whole basal ganglia
may possibly play a similar role in implicit memory as the hippocampus
does in explicit memory.
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.
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 be accessed in a search. So
could be said that the amount of elaboration increases the possibility
of use. Conversely the amount of use increases the amount of
elaboration. 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 the 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. Elaborate encoding is
accomplished in two quite different ways:
Initial elaborate encoding.
can be accomplished at the time of initial encoding. 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. Initial encoding is determined by the
intensity of the attention payed to the information, which maximizes
the storage strength of the memory, and the breadth of the attention
payed to the information, which maximizes the amount of detail
remembered. Intensity and breadth of attention are good if we want to
retain the memory but not so if we wish to forget the
Subsequent elaborate encoding.
Or it can be further elaborated with each successive retrieval of the
memory. This additional information added at the time of retrieval can
be good if it comes from accurate sources such as when we are studying
or we get an alternative view of the same incident from different
observers. But it can also lead to inaccuracies where one memory is
mixed with a similar memory or information that is itself not accurate
is added such as when someone tells us, we experienced something, and
come to believe it although it never happened.
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, 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 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 days. This site holds that we should not be
surprised by this state of affairs. We should expect memories to become
damaged or partially forgotten over time. We should expect bits of
information to become lost.
We might expect 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 surviving mostly intact over time, other than massive
whole areas of the brain. On the other hand mere recall does not
prevent memories becoming mixed up or added to by the very process of
reproductive retrieval. Everything appears to break down
over time why not memories? It has been found, however, that memories
reactivated over spaced periods of time tend to prevent this
deterioration from occurring or atleast slow it down.
can be facilitated by circumstances at
the time of imprinting and circumstances at the time of recall.
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.
at the time of
Memories can be facilitated by circumstances at the
time of recall or any form of revisiting the memory. This too depends
on the amount of attention being paid to the the information.
at the time of
recall and at the time of imprinting. Memories are usually
facilitated by circumstances at the time of both imprinting and recall.
Effort full attention.
Elaborate encoding can be accomplished through effort full attention at
the time of imprinting. The person endeavors to pay attention and thus
may be interpreted
as follows: If we pay attention various associations are formed between
this incoming information and information already residing within
our heads. These associations give the new information
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
effort full attention is easily lured away by sufficient distraction. Effort full
attention also has to be used when we are revisiting memories. Thus
when we study or perform in a test we also use effort full
attention, automatic processing. On the other hand interest
focus attention automatically and effortlessly. This in turn causes
elaborate encoding to be automatically imprinted as memory and can
cause memories to revisited likewise effortlessly. We do not
have to use effort full attention to focus, we are instead focused by
interest. Interest comes in many forms but the strongest form comes
from that brain function that continually scans all incoming sensory
data for signs of a threat. This function automatically focuses our
attention on anything that might be threatening to us. In his book
John Medina gives an example of automatic
processing where intense associations are formed by means of emotional
excitement 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 that focus attention. This interest that supports
efortless automatic processing
comes in a number of different flavors.
This kind of self protection interest focuses our attention to enable
us to protect ourselves from threat by activating the reticular system
that prepares us for fighting or fleeing. Threats also activate
associations so intense that the
memories when imprinted have strong storage strength and retrieval
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
the information. Intellectual interest can produce strong storage
strength and retrieval strength but starts out in a delicate easily
interest occurs where some strong emotion
rivets our attention on some event or episode. This can also be used as
way of re-enabling effort full attention but can also establish
attention. Fear is of course part of reticular activation and produces
strong memories. However other emotions such as joy, excitement, awe,
disgust and even worry can attach as associations that are just as
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 effort full attention. Surprise is of
course an emotion but one deserving a special mention and is also
linked to reticular activation.
Interest. Humor is a kind of surprise. It too can rivet our
attention on some event or episode. Likewise it can also
be used as way of re-enabling effort full attention. But it is just
in creating effortless attention. It glues associations to memories with
strong retrieval and storage strengths.
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 effortlessly. Stories have
been used to
imprint memories long before recorded history in the rhymes and songs
Interest. Simplicity in 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 effortless attention. It
may also be
that the gist has by its very nature many handles on it that connect
easily and strongly with many associations to information already
memory more means easier to find and effortless attention.
John Medina says "The
more elaborately we encode information
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 focus attention. 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
more 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 be retrieved
from long term memory when needed.
Context focuses attention.
use effort full attention we focus on the elements we wish to remember
and associate those elements to other memories already imprinted in our
this is not all that happens. Other, usually weaker associations, are
also formed with other incoming data, although we do not pay specific
attention to it. These peripheral associations form a context for the
information to be memorized, which seems to take place on an
unconscious level. These peripheral associations, provide
extra door handles for opening up memories. These
peripheral associations of context are recorded with
memory although in a way that precludes their be recalled with that
memory. They instead provide more pathways to
the memory enabling easier access to the memory or a higher probability
of the memory being recalled.
initial experiment showing contextual associations focusing attention
was done by Godden and Braddeley with scuba divers learning or making
memories in an underwater environment. It was clearly shown in this
experiment that when the memories were tested those who took the test
on land did far worse than those who were tested in an underwater
environment. Many experiments later it had been shown clearly that this
was a general rule. Learn in one environment and you will be far more
able to access those memories if you are returned to the same
environment. The same result was found with study. Study in one place
and you will most effectively recall the information if tested in the
same place. But it is more than about environments (its about
environmental cues). Any association
present while learning or studying can be helpful in accessing the
memory. Study with blue grey cards be tested with bluegrey cards. You
will do better if your instructor is your tester (the tester is another
enviromental cue). If music is playing
while you are learning you will access more memories if the same music
is playing. If you are in a particular mood when studying then try to
be in the same mood when being tested. If you took drugs when studying
take the same drug for the exam.
may not seem very helpful, as for the most part, we have no control
over the circumstances of where we are tested. However, when we are trying
to retrieve a memory
we are actually trying to find a path to that memory. Strong cues if
they turn up provide quick access to the memory. But contextual
associations or contextual cues provide many many paths to the same
memory and one contextual cue has a greater statistical chance of
turning up when we need it than any strong cue. So
if we vary where learn and study we are increasing the number of
peripheral associations and thus increasing the statistical probability
that some of them will come up. It has been shown in studies that there
is an advantage in simply learning or studying in two different
locations if one is to be tested in a third location. There was an
improvement in recall of 40% for people who studied in two as compared
with those who studied in one location. Why? The only possible answer
is more associations or cues.
too is true for any kind of
contextual cue. Thus any kind of variance in how we study will increase
the probability of producing an association with the memories in any
testing environment. Therefore learn and study using as great a variety
of mediums and environments as is possible. Take information in an as
great a number of
senses as possible. Any kind of change in routine will
the probability of useful associations turning up in any environment.
Think of it like this. Change when learning and studying will enable
easier access to the information in a changed testing
or hooks focus attention and summaries aid recall.
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. Newspapers and magazines use headlines and leads to grab our
attention to lure us to read the rest of an article and do so by
attention. Books should also do this. Good hooks produce strong
memories. Think of the old military formula for getting soldiers to
remember. Tell them what you are going to tell them, tell them, tell
them what you told them. The first part of this formula, which is by
far the most important part, is a precis, brief or outline used to hook
us into what is come and that arrests our attention. The last part is a
summary that provides a skeleton that can be used to flesh out and
rebuild the information in recall.
and reflection focus attention when recalling. 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."
alternating targets or interleaving focuses attention.
It had long been thought that any kind of distraction impinging of
focused learning would be detrimental to memorizing. Like so many
common sense ideas this also tuned out to be false.
is just an example of evolution at
work where early homosapiens had to learn in an environment
where distraction was the norm and learning without distraction was
impossible. We have therefore become adapted to learn best when we are
often distracted or when we have to quickly move from learning about
one thing to learning about something else. There are many good
however, why changing from learning one thing to learning another might
improve learning overall.
Firstly breaks. We
need breaks when focusing attention and distractions provide breaks.
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. Likewise, when studying, it is probably
a good idea to have a break after ten minutes, and if possible indulge
in entertaining activity during the break.
Mixing physical skill practice not only provides breaks in attention
but has overall memory retention benefits. Although it has always been
the case that coaches mixed practice for training in sports to allow
recovery periods for various muscle groups it was previously considered
to be a limitation in our ability to repeat actions and not as an aid
for learning. However, it has now been repeatedly shown
that varied practice of any physical skill works
far better than focused continual practice in improving skills. Kerr
and Booth who first drew attention to this phenomenon with their
beanbag experiment (tossing small beanbags onto bullseyes set
distances)put it like this: "Varied
practice is more effective than the focused kind, because it forces us
to internalize general rules of motor adjustment that apply to any
hittable targets." Goode and Magill looked at
practice for long and short serves in badminton and again random
learning beat focused learning hands down. Goode and Margill had their
own hunch as presented by Benedict Carey in his book
"How We Learn": "Interfering
with concentrated or repetitive practice forces people to make
continual adjustments ... building a general dexterity that, in turn,
sharpens each specific skill. All that adjusting during a
mixed-practice session ... also enhances transfer. Not only is each
skill sharper; its performed well regardless of context, whether
indoors or out, from the right side of the court or the left. The
general goal of practice is to transfer to a game. A game
situation varies from event to event, making random testing the best
condition to appraise the effectiveness of practice."
Thirdly whole learning.
Mixing practice of any sort (not just physical skills) has overall
memory retention benefits. Schmidt and Bjork produce a paper in 1992
called "New Conceptualizations in Practice" in which they looked at
practice pertaining to motor, verbal, academic as well as athletic
skills. In that paper they concluded the following: "At
the most superficial level it appears that systematically altering
practice so as to encourage additional, or at least different,
information processing activities can degrade performance during
practice, but at the same time have the effect of generating greater
performance capabilities." Carey puts it like this: "...varied
practice produces slower apparent rate of improvement in each single
practice session but a greater accumulation of skill and learning over
Mixing practice greatly aids our ability to discriminate, which is
not only an important type of memory, but is also an important skill we
need to use in identifying the cues essential for recalling specific
memories. Kornell and Bjork showed in a study that people were much
better at identifying an artistic style in painting, if the style had
been initially identified in a mixed random group of paintings, instead
of being identified in groups each containing only one artistic style.
This may be because we discriminate by identifying how styles differ
from one another rather than identifying how styles are similar. Bjork
and Kornell called this mixing of styles interleaving (a cognitive
science word meaning mixing related but distinct material during a
Doug Rohrer a high school
Math teacher realized that his
students were having problems solving math problems, not because they
did not know how to solve the problems, but because they were having
trouble identifying each type of math problem when it occurred on a
test. If the students could identify each type of problem, he reasoned,
they would then recall how to solve that type of problem. Rohrer and
Taylor conducted their own study and found that presenting problems in
a mixed or random group, as opposed to presenting problems all of the
same type, improved students ability to identify types of problems and
thus improved students ability to solve each type of problem. Carey in
his book explains it as follows: "Mixing
problems during study forces us to identify each type of problem and
match it to the appropriate kind of solution. We are not only
discriminating between the locks to be cracked we are connecting each
lock with the right key." Rohrer put it this way: "If
the homework says 'The Quadratic Formula' at the top of the page, you
just use that blindly. There's no need to ask whether it's appropriate.
You know it is before doing the problem."
is likely that interleaving will improve any kind of learning as it
gives us experience with identifying abstact groupings and connecting
them with specific memories. Interleaving also prepares us for dealing
unexpected as is normal in real world experience. Carey in his book has
this to say in conclusion: "Mixed
practice doesn't just build overall dexterity and prompt active
discrimination. It helps prepare us for life's curveballs, literal and
Fifthly the Zeigarnik effect.
A student of Kurt Lewin called Bluma Zeigarnik was given a research
project by Lewin when he noticed that the waiters, where they were
eating, never wrote orders down although they were always
accurate. Yet on being
questioned, after the bill was paid, could remember almost nothing of
order. It was not a matter of the time as sometimes the bill was paid
quickly and sometimes it took half an hour or longer. Although the
original idea was to discover if the completion of the task caused the
memory to be lost. The research, however, discovered something
discovered that the interruptions and distractions in the waiters work
actually shocked the brain causing the information to be continually
rehearsed in working memory. In his book
"How We Learn" Carey explains:
still more trials, Zeigarnik found she could maximize the effect of
interruption on memory by stopping people at the moment when they were
most engrossed in their work. Interestingly, being interrupted at the
'worst' time seemed to extend memory the longest. 'As everyone knows,'
Zeigarnik wrote, 'it is far more disturbing to be interrupted just
before finishing a letter than when one has only begun.'"
Zeigarnik effect simply states that anything that interrupts the
completion of a task will increase the likelhood of it's recall and the
more disturbing the interruption the more durable the memory will be
and more easily the memory will be recalled. .
in recall focuses attention on that memory and is desirable.The
work or have to work to retrieve a memory the greater the increase in
our ability to retrieve that memory again and the more accessible that
memory becomes. This has been called desirable
"How we learn" Carey trys to explain how desirable
difficulty might work as follows: "When
the brain is retrieving studied text,
names, formulars, skills, or anything else, it is doing
something harder than when it simply sees the information again, or
The extra effort deepens the resulting storage and retrieval strength.
We know the facts or skills better because we retrieved them ourselves,
we didn't merely review them." Carey also quotes researcher Roediger
who goes further: "When
we successfully retrieve a fact ... we then re-store it in memory in a
different way than we did before. Not only has the storage level
spiked; the memory itself has new and different connections. It's now
linked to other related facts that we've also retrieved. The network of
cells holding the memory has itself been altered. Using our memory
changes our memory in ways we don't anticipate."
only that but also when
memories come easily, attention does not have to be focused, and so we
tend to think that a memory will always remain, but in truth the
is true. Without focused attention when recalling, memories tend to
overconfidence in their permanance leads to surprising amounts of
forgetting. This overconfidence we tend to have in the permanance and
durability of memories is called the fluency illusion. Sure we know the
information now but when we are tested at a later date we are amazed to
discover the information has evaporated from memory or cannot be found.
trying to remember information, instead of just looking it up, we avoid
this fluency illusion because trying to remember forces us to focus our
attention. We can then compare what we remembered with what is in our
notes and further elaborate the information by correcting or improving
the memory, thus ensureing it will be more accurately remembered in the
future. Obviously then, trying to remember some item of information and
then looking it up is far more effective in improving a memory than
simply looking it up.
surprise us that difficulty or working hard to recall should improve
memories after all it is working our muscles hard that makes them grow
and tiny fractures in our bones that cause them to grow stronger.
the closer we are to forgetting sumething the harder we have to
work to remember it and the more recent a memory the less hard we have
to work to remember it. So, the closer we are to forgetting something
the more benifit we get from trying to remember it, because we have to
work hard to remember it.
a good idea to take advantage of desirable difficulty, is to try and
recall and reorganize information from memory, before going to your
notes when studying. The information you got right, by working hard to
remember it and reorganize it into a new form, will become indelibly
etched in your brain. What you got wrong or distorted, and then were
able to correct
later from your notes, will also be strongly etched in your memory.
(Indeed recent research now indicates that getting answers wrong on one
test may improve those answer memories if corrected soon after testing.
This could mean those students who got the wrong answers on one test
may remember better for the next test than those students that got the
answers right.) Pretests where one takes a test on information before
learning the information also works as the mere trying to retrieve an
answer that is not in memory somehow prepares the brain to atach
emotional intensity and prepared associations or cues to the memory
when the information is eventually learned.
reviewing in this way, is combined with reviewing when we are just
about ready to forget, we create a very effective study program.
Similar effects can be accrued by being tested or preferably
administering tests on yourself.
obviously, self testing can take the form of explaining the
learned material to another person. This not only ensures that we work
hard to remember what we have learned (which strengthens the
also ensures that the information is internally consistant and
compatable with other people's reality. In this way we can explain why
teaching is good for improving both memory and understanding.
use of desirable difficulty
these ways is
a win win for remembering.
Strong first impressions build
durable and accessible memories by focusing attention.
The associations formed when a memory is first imprinted is far more
important than those formed on the occasions of its recall.
Associations formed when memories are first encoded are more intense
and have greater breadth. In his book
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 off 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."
in recall improve accessibility and durability of memory by
we are trying to make make memories more accessible and durable, such
when we study, we tend to make a long continuous effort. Experimental
studies have shown, however, that this kind of binge relearning is not
efficient or effective. There are many reasons why this is the
of all, remember, effort full attention is only effective for about
ten minutes at a time. Pushing ourselves to continue to focus on
relearning beyond ten minutes without a break is probably counter
productive unless interest renders it effortless.
Also, remember, each
time we recall a memory its retrieval strength begins to weaken and its
storage strength is usually of limited duration after which the memory
will be forgotten. The most effective and efficient way to relearn or
to study is to wait until the memory is about to be forgotten and then
relearn it. This means finding the least number of times for relearning
continuously durable memory. Memories recalled just before being
forgotten are greatly strengthened lasting far longer. If, however, we
relearn after the memory has been forgotten, this works too, just not
as well. If we relearn a while before the memory is going to be
forgotten, we are flying in the face of one of the brains primary
functions. When we try to relearn something we already know our brains
are resistant. Why should our brains waste time and effort relearning
something we already know. Our brains resist and we have to expend even
more effort to relearn it.
or studying has been said to work
best in fixed, spaced
intervals. This is not totally efficient because it does not take the
optimum, and increasing, periods till forgetting into account, but it
strategy. This is especially true if it is performed 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."
number of studies have now been done that clearly show how intervals
can be made more efficient in this regard. One of the first solid looks
at spacing was done by a 19 year old Polish college student Piotr
Wozniak who was trying to learn English. He had lots of other classes
his time but he needed a larger English vocabulary to be proficient in
all of them. In his book
"How We Learn" Benedict Cary has the following
information about Wosniak. "He
found that, after a single study session, he could recall a new word
for a couple of days. But if he restudied on the next day the word was
retrievable for about a week. After a third review session, a week
the second, the word was retrievable for nearly a month. Wosniak
"Intervals should be as long as possible to obtain the minimum
frequency of repetitions, and to make the best of the so-called spacing
effect...Intervals should be short enough to ensure that the knowledge
is still remembered."
"Before long, Wosniak was living and learning according to the rhythms
of his system..." The English experiment became an algorithm,
then a personal mission, and finally, in 1987, he turned it into a
software package called Super-Memo. Super-Memo teaches according to
Wosniak's calculations. It provides digital flash cards and a daily
calendar for study, keeping track of when words were first studied and
representing them according to the spacing effect. Each previously
studied word pops up on screen just before that word is about to drop
out of reach of retrieval." This app is easy to
free. Although apps do not exist for all subjects anyone can do
calculations with chunks of data to find optimal study intervals. They
always work out to be intervals that are ever expanding. Many studies
have been done by both scientists and teachers showing this to be
workable for any subject.
1993 the Four Bahricks Study appeared. If Wosniak had established
minimum intervals for learning the Bahrick family established the
maximum learning intervals for lifetime learning. This kind of learning
dealt with lists of words many of which would go past the possibility
retrieval. But being relearned after being forgotten was still
especially as they made a conscious effort to find new cues for the
words greatly increasing the elaboration of each word memory. In his book
"How We Learn"
Benedict Cary says: "After
five years the family scored highest on the list they'd reviewed
according to the most widly spaced, longest running schedule: once
two months for twenty-six sessions." The
Bahrick's study used fixed space intervals in their schedule, but it
seems likely that this type of relearning would also work best with
intervals that are ever expanding rather than of fixed length.
Memories imprinted or relearned through multiple
sensory channels are more accessible and durable.
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
improves memories. Research
has now shown that there is a marked difference in both the
retrieval strength and the storage strength of memories before and
after sleep. Both storage strength and retrieval strength of new
memories are improved after sleep. In the early part of a sleep cycle
there is a type of sleep called slow wave sleep. During the slow wave
sleep it appears that memories from the previous day tend to be
replayed and that we experience these as dreams but do not remember
them as we usually do not wake during slow wave sleep. This means that
some memories are singled out to be replayed and thus made stronger
while other memories are pruned away or discarded. It is a known fact
that during this type of sleep that some synapses are downscaled while
others are reinforced.
also seems to be essential for building a mental map of what we are
to learn. We receive the sensory information while we are awake but we
are not immediately able to comprehend or understand it completely as
information connects with only a limited amount of the other data
stored already in our minds. While we sleep and during the early stages
of REM sleep our brains seem to integrate the
new information with the old information building a structure that fits
it all together. This is also probably experienced as dreams. After
sleep information is not only better remembered
but better understood or comprehended.
REM sleep continues this process of repaying memories becomes more and
more chaotic. As a result the dreams we have in the later REM sleep
become more and more disjointed and transitions more and more abrupt.
As a result earlier experience is connected and more unusual
connections are made and this is thought to be how creative thought may
come into being. Creativity comes about by means of totally random
connections being formed and again this is experienced as
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 but never exactly the same way.
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,
rehearse 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 and actually
difficult if not impossible to accomplish. 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 and
attach it to other memories in our minds. Also 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 which means it is not really repetition at all. 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. It is instead extended and enhanced. 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 in an iteration. If it was simply repeated exactly there
would be no change.
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.The more information there is the better the
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 or idea. More information
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.
Any thing that helps create interest greatly improves memory because it
enables effortless attention.
all senses. Paying attention to information coming from many
different senses enables encoding to be much more elaborate and thus
improves the likelihood of a memory enduring. It also creates many more
paths to reach the memory when attempting to recall it.
Attention is not paid to information that does not seem important to
the brain, but much of that information is recorded peripherally any
way. Most of this peripheral encoding is contextual. When such contexts
of initial encoding are recreated they greatly aid recall of that
Discussion and reflection are self induced form of recall and any form
of recall aids future recall. However discussion and reflection also
greatly elaborate any memory making that memory increasingly durable
created a learning machine in man in a world of constant interruptions
and distractions. Is it any wonder then that we learn or memorize best
in environments filled with distractions and interruptions.
difficulty. When we
work hard at recalling a memory this greatly improves the durability
and accessibility of that memory for future recall.
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 by means of its opening data if an enduring memory is
spaced intervals. Memory is efficiently consolidated if the
memory is relearned just as you reach the point of forgetting it.
A tentative theory of how memory might work.
information presented above on the surface seems very disconnected but
if the conjectural material presented there is taken a bit further it
is possible to
present a comprehensive scenario of how memory as a whole might work.
proposes that the following is just such scenario.
New cells form. We
are now sure that neurogenesis takes place in the sub-ventricular part of the
brain activating stem cells. These
seed cells divide and then half of them migrate to the area of
the brain that is being used in the new learning. Many of them (perhaps
most) travel to that area of the brain called the hippocampus. This
site holds that these new cells become, not new memories, but rather
of anchors through which new memories might form by connecting to
various parts of the brain (primarily in the cerebral cortex). The
of the hippocampus is highly connected to all parts of the cortex. This
new cell or cells then become a kind of nexus through which all parts
of the new memory are connected. Initially these new memories could be
understood to be short term memories.
Become short term memories.
If these new (short term) memories were not recalled they would tend to
and die. If, on the other hand, they were recalled and elaborated
they would tend to become more permanent as they gather more and more myelin over the connections.
As myelin builds up it not only enables the electrical
impulses to travel faster through the neurons but also protects the
neuron from damage. In this way the neurons involved in the particular
memory become more resilient as well as being less likely to wither and
die. Short term memories could wither away or become stronger depending
on whether they were recalled and elaborated or not. There is also the
possibility that the memory would be only partially recalled and that
therefore parts of it could also become damaged or lost. This would not
necessarily stop the full recall of the memory but would involve the
memory being reconstructed from clues left in good condition in the
neuron connections. The more connections existing the more easily and
accurately this reconstruction would be.
Become long term memories.
This site theorizes that long term memory is not one single state but
rather a succession of different states ever changing and without some
final form. There would be two processes going on both of which would
be attempting to create a better fasted more resilient form of the
memory each time it would be recalled.
existing paths. One process would be trying to find a
better, faster, shorter distance,
between the various points on the cortex and the newly minted neuron
that is acting as a junction box for them. This would emerge because
new growths of dendrites and synapses would occur and be activated
shortening the distance involved in all the connectors.
Duplicate memory structure. The
other process would be trying to create a duplicate of connections
to the same points on the cortex but by making those connections
through the neocortex just under the cortex. This might involve the
elongation of some neurons or new dendrite and synaptic creation. This
duplication could take a lot of time because the pathways might have to
be created by means of neuron growth. However, as explained above it is
also possible this growth could be the result of random synaptic growth
combined with an evolutionary survival of the fittest guiding of
pruning of unused synapses. In any case it would still take
considerable time. In any case, this is very different to the
pathways to and from the hipocampus where the pathways exist and simply
have to be joined together. It is quite possible that this duplicate
memory structure could take many years to complete. While this
duplication is taking place the memory would be in a continuing
changing state where the memory consists of growing numbers of
connections through the neocortex and reducing numbers of connections
that travel down to the hipocampus and back.
At some point all connections with the hippocampus would be severed as
connections through the neocortex cortex would be shorter and therefor
faster. Of course these connection like those going to the hipocampus
and back to the cortex would also build up myelin
in response to being recalled and or elaborated. Thus the memory would
continue to change even after becoming completely disengaged from the
This would explain
why some old memorys remain even after the whole of the hipocampus has
been removed and the brain is no longer able to form
would involve two procedures. It would involve the activation of
the existing pathways of the memory and it would also involve a
reconstruction process where the brain guesses the part of the memory
that had been damaged or had withered and died. It would do this using
clues provided by the memory paths that were still intact.
would then be used to connect new pathways to replace the lost ones.
result of course would not be perfect and would allow the memories to
be more likely to be corrupted over time. However the more connections
or elaborate the memory the more clues that would provide and thus be
less likely to be reconstructed incorrectly.
Memories would be, in this scenario, massive numbers of neurons that
are linked together either by immensely long axons that connect by
growing toward other neurons all existing in the surface of the cortex
or by connections via the dense thicket of other neurons that already
connect up roughly to cortical areas required. These webs of connexions
would be an ongoing ever changing entities. Each recall would cause
changes by creating the further elaboration of additional links and
reconstruction of missing parts from clues. Similarly lack of recall
would also be causing changes by causing parts of the memory to wither
and die. Memories far from being stable structures would
be continually changing, growing, malleable structures.
Memory and life long
long learning ls made possible by certain types of memory. Life long
learning is a habit that is prompted by the pleasure experienced when
learning and particularly the deep learning of academic subjects where
understanding and connectedness to one's map of reality is essential.
Memories formed by means of effort full attention tend to be boring and
unpleasant and are therefore not conducive to the formation of a life
time habit of learning. On the other hand memories formed by means of
effortless attention are highly conducive to the formation of a life
long learning habit. Memories formed out of curiosity, interest,
surprise, awe, and other strong positive emotions are instrumental in
building a life long habit of learning.