MEMORY
1. A DEFINITION
Memory is defined as the ability to store and retrieve information over time. Our
memories allow us to do relatively simple things, such as remembering where we
parked our car or the name of the current president of the United States, but also
allow us to do complex memories, such as how to ride a bike or to write a computer
program.
Moreover, our memories define us as individuals ( they are our experiences, our
relationships, our success and our failures). Without our memories we would not
have a life.
2. MEMORY STAGES
SENSORY MEMORY
It refers to the brief storage of sensory information. Sensory memory lasts only very
briefly and then, unless it is attended to and passes for more processing, is
forgotten.
The purpose of sensory memory is to give the brain some time to process the
incoming sensations, and to allow us to see the world as an unbroken stream of
events rather than individual pieces.
SHORT TERM MEMORY
Most information that gets into sensory memory is forgotten, but information that we
turn our attention to, with the goal of remembering it, may pass into short-term
memory.
Short term memory (STM) is the place where small amounts of information can be
temporarily kept for more than a few seconds but usually for less than one minute.
Information in STM is not stored permanently but rather becomes available for us to
process.
The processes that we use to make sense of, modify, interpret and store information
in STM are known as working memory. STM is limited in both the length and the
amount of information it can hold. Peterson and Peterson (1959) found that
information that was not rehearsed decayed quickly from memory.
One way to prevent the decay of information from short-term memory is to use
working memory to rehearse it. Maintenance rehearsal is the process of repeating
information mentally or out loud with the goal of keeping it in memory
We engage in maintenance rehearsal to keep something that we want to remember
(a person’s name, e-mail address, or phone number) in mind long enough to write
down, use it, or potentially transfer it to long-term memory.
LONG TERM MEMORY
Is the most similar to a permanent storage. Unlike the other 2 types, LTM is relatively
permanent and practically unlimited in terms of storage capacity.
It has been argued that we have enough space in our LTM to memorize every phone
number in the U.S and still function normally in terms of remembering what we do
now. Obviously we don’t use even a fraction of this storage space.
Although it is useful to hold information in sensory and short term memory, we also
rely on our long-term memory (LTM) .
If we want to remember the name of a new boy in class,... to be successful, the
information that we want to remember must be encoded and stored, and then
retrieved.
3. ENCODING AND STORAGE: HOW OUR
PERCEPTIONS BECOME MEMORIES
Encoding is the process by which we place the things that we experience into
memory. Unless information is encoded, it cannot be remembered. Not everything
we experience can be or should be encoded. We tend to encode things that we need
to remember and not bother to encode things that are irrelevant.
One way to improve our memory is to use better encoding strategies. Some ways of
studying are more effective than others. Research has found that we are better able
to remember information if we encode it in a meaningful way.
The brain does not store memories in one unified structure, as might be seen in a
computer's hard disk drive. Instead different types of memory are stored in different
regions of the brain. Long-term memory is typically divided up into two major
headings: explicit memory and implicit memory.
Explicit memory (or declarative memory)
refers to all memories that are consciously available.
Declarative memory has 3 major subdivisions:
- Episodic memory: refers to memory for specific events in time, as well as
supporting their formation and retrieval. Some examples of episodic memory
would be remembering someone’s name and what happened at your last
interaction with each other.
- Semantic memory: refers to knowledge about factual information, such as
the meaning of words. Semantic memory is independent information such as
information remembered for a test.
- Autobiographical memory: refers to knowledge about events and personal
experiences from an individual’s own life. Though similar to episodic memory,
it differs in that it contains only those experiences which directly pertain to the
individual, from across their lifespan.
Implicit memory (procedural memory)
refers to the use of objects or movements of the body, such as how exactly to use a
pencil, drive a car, or ride a bicycle.
4. MEMORY AND DISORDERS.
AMNESIA.
Amnesia is a deficit in memory caused by brain damage or disease, but it can also
be caused temporarily by the use of various sedatives and hypnotic drugs. The
memory can be either totally or partially lost due to the extent of damage that was
caused.
The term is from Ancient Greek, meaning 'forgetfulness'; from α - (a-), meaning
'without, and uvnois (mnesis), meaning 'memory'.
There are two main types of amnesia: retrograde amnesia and anterograde
amnesia
Retrograde amnesia is the inability to retrieve information that was acquired before
a particular date, usually the date of an accident or surgery. In some cases the lost
memory can extend back decades, while in others the person may lose only a few
months of memory.
Anterograde amnesia is the inability to transfer new information from the short-term
store into the long-term store. People with anterograde amnesia cannot remember
things for long periods of time. These two types are not mutually exclusive; both can
occur simultaneously.
HYPERTHYMESIA
Hyperthymesia is a condition that leads people to be able to remember an
abnormally large number of their life experiences in vivid detail.
The word “hyperthymesia” derives from Ancient Greek: hyper- (“excessive”) and
PARAMNESIA.
Paramnesia is memory-based delusion or confabulation, or an inability to distinguish
between real and fantasy memories. For example: Déjà vu, the delusion that a
current event has already been experienced before.
