How do our
brains remember information that we try to store on it? It has been a task of
scientists, psychologists and probably even philosophers to understand why we
remember some information and forget the other. Twentieth and twenty first
centuries have experienced explosion in technological findings and the further
we go the more exactly we can answer the questions on how human memory works.
It is not a
secret that memory is one of the most important functions or our brains. If you
lost it you would probably not remember where you live, who your wife is, or
even your own name.
However,
memory is responsible for far more daily activities than just remembering facts
and figures. When we see some object or we touch something, all of these senses
exist for a second or a few more before a nervous impulse disappears. Now,
brains have a task to keep those senses, establish connection with other
similar ones, assign to other senses and also decide whether to take any kind
of action or not. If memory did not preserve the senses, our brains would not
be able to process them before they disappear and we would lose them
indefinitely.
Differences
between memory types are not very clear
Working
memory is something which we direct our attention to for some time. When we pay
attention to some specific object we get very small amount of information and
this information changes a few times per second. Working memory is necessary
for us to function in the world, and short term as well as long term memory
guarantees that we will use acquired information properly: remember our
schedule, or a poem that we have to recite tomorrow, or the outline of
presentation that we will have to deliver for our master work defense.
However,
memory is still a science of “shadows”. There isn’t a unilateral agreement how
one can separate working memory from short term memory, because both of them
are not stable. Opposite to the long term memory that is able to store large
quantity of information for a long time, short term memory is quite limited.
Some tests
show that short term memory processes only some information elements such as:
numbers, letters, and sequences of numbers or even full words that we
understand as a whole. Large numbers are difficult to remember. If one has to
remember a long telephone number, chunking might help here. This is what short
term memory will be able to do. By means of that one can increase the size of
short term memory and we tend to take advantage of that whether we know it or not.
Short term
memory depends much on the fact whether we understand the things we want to
remember and they are known to us or they are unknown and abstract. It is much
better to remember more often used words and pictures where portrayed objects
are known to us rather than trying to remember abstract and unknown things.
You will be
able to remember a picture with twenty celebrities in it (and say whom you saw
in the picture (when asked)) than twenty people whom you do not know.
Repetition
of memories
It is quite
clear now that we remember meaningful and recognizable words or images, because
short term memory tends to repeat them in order to remember them better. So, a
word that you may have recently heard will be repeated in your subconscious
mind, so that short term memory could recreate it. The same can be said about
images. Only those words and images can be kept in short term memory that are
periodically recreated and if this process is somehow blocked than remembering
may cease in a few seconds.
It is also
obvious now that brains have two different and specific ways for remembering
words and images. This is the reason why some people remember images better
while others are good at remembering sounds. If you see a known image you will
remember it much easier than an image you see for the first time. However, you
can apply sound in order to remember that specific image. You may loudly say
for yourself characteristics of the image (it is green, big, soft and etc.).
This should help.
Recreated
and remembered information
Short term
memory can keep memories that are based both on sound and image types of
remembering, but only for a few seconds, because both of the methods consume
large resources of our brains.
Therefore,
long term memory takes into account both types of remembering while short term
memory is trying to recreate our memories. We can state that short term memory
is learning quite fast, but remembers poorly, while long term memory is
learning very slow, but remembers very well. In order for information to get to
long term memory it has to be recreated a lot of times. Some believe that this
process is performed by sound and visual remembering parts of the brain and
when this information disappears from short term memory, long term memory
starts recreating this new information on its own.
This has
been tested a lot of times, especially when people were asked to repeat words
that have been shown to them. Most people were able to remember the first and
last words, but forgot those that were in the middle. This proves the fact that
the first words had gotten into long term memory, the last ones into short term
memory and those in the middle were on their way from one type of memory to
another.
Various
types of memories
Short term
memory usually deals with sound and image remembering types. Long term memory
can also be divided into various types. Episodic memory keeps our reminiscences
about our experiences and actions. This is where our personal experience is
stored on anything we experienced in the past: first love, childhood summer
camps, first driving lesson and etc. Semantic memory stores all of our factual
information such as circle of our best friends with their names and addresses,
calculus, understanding of general statements such as: “Sun rises in the east
and goes down in the West”. Episodic and semantic memories are often joined
into one category that is often called declarative memory, which encompasses
our entire subconscious mind. It is this information that we do know and when
asked about daily routine and activity we can answer those questions because of
declarative memory.
Procedural
memory stores our reminiscences on how to perform various actions: for example
how to write letters x, w and z. We can use this knowledge without thinking and
it is quite difficult to describe how we do it. We do it automatically. Could
you explain how you drive a car? You just do it without thinking about it.
One thing is
common for all these three memory types and that is that they let us to
remember what we have already experienced, learned or done. This is the reason
they are called “retrospective memory” and it is different from perspective
memory. Perspective memory let us to remember things that we intend to do in
the future. For example, that we have a planned meeting, or that we have to buy
some food before going home.
Memorization
process is very slow
Recording
information on long term memory can be a very long process that may last a few
hours. However, when that new information is finally recorded on our brains it
becomes permanent.