Types of Memory
There are 3 types of memory:
- The shortest-term memory.
- Has the ability to retain impressions of sensory information after
the original stimuli have ended.
- Acts as a kind of “buffer” for stimuli received through the five
senses of sight, hearing, smell, taste and touch which are
retained accurately but very briefly.
- Acts as a kind of “scratch-pad” for temporary recall of the
information which is being processed at any point in time, and
has been referred to as "the brain’s Post-it note”.
- Can be thought of as the ability to remember and process
information at the same time.
- It holds a small amount of information (typically around 7 items or
even less) in mind in an active, readily-available state for a short
period of time (typically from 10 to 15 seconds, or sometimes up
to a minute).
- Intended for storage of information over a long period of time.
- Actually decays very little over time, and can store a seemingly
unlimited amount of information almost indefinitely.
- Encode to some extent by sound.
Different types of Long-Term Memory
2 main types of long-term memory:
Explicit (Declarative) Memory
Implicit (Procedural) Memory
(“knowing what”) is memory of facts and events,
and refers to those memories that can be
it consists of information that is explicitly stored
and retrieved, although it is more properly a
subset of explicit memory.
can be further sub-divided into episodic memory
and semantic memory.
Represents our memory of experiences and
specific events in time in a serial form, from
which we can reconstruct the actual events that
took place at any given point in our lives.
It is the memory of autobiographical events
(times, places, associated emotions and other
contextual knowledge) that can be explicitly
is a more structured record of facts, meanings,
concepts and knowledge about the external
world that we have acquired.
refers to general factual knowledge, shared with
others and independent of personal experience
and of the spatial/temporal context in which it
(“knowing how”) is the unconscious memory of skills and
how to do things, particularly the use of objects or
movements of the body.
It is composed of automatic sensorimotor behaviors that
are so deeply embedded that we are no longer aware of
them and once learned, these "body memories" allow us
to carry out ordinary motor actions automatically.
Previous experiences aid in the performance of a task
without explicit and conscious awareness of these
Encoding and Retrieval
Encoding and retrieval are intricately linked to
memory. They refer to the processes of moving
information to and from short-term memory
(STM) and long-term memory (LTM),
Short – Term
Long – Term
Encoding involves linking new information to existing knowledge in
order to make the new information more meaningful. The quality of
this process is related to the degree with which new information can
be integrated or assimilated with existing knowledge. Much
encoding involves labeling thoughts with words, but pictorial or
other forms may be used as well. Students should be directed
during the encoding process to insure that accurate information is
moved to LTM.
A different view of encoding is espoused by some researchers.
According to Herrmann, Raybeck and Gutman, "registration in an
incidental memory task is called encoding." In other
words, encoding involves the unintentional storage of information in
long-term memory. They label intentional registration "learning".
Retrieval involves drawing on existing knowledge. It forms the basis
for all new knowledge. Retrieval of prior knowledge during learning
directly affects the amount of new information that can be
processed. At-risk students often have low funds of previous
knowledge, hampering retrieval and, therefore, the learning
A distinction between retrieval and realizing, again based on the
issue of intentionality, is made by some authors. "In an intentional
memory task, remembering is deliberately influenced by directing
attention to certain contents in the working memory. This type of
remembering is called retrieval. Retrieval may be conceived as
realizing plus emergence produced by intentional manipulations”
Herrmann, Raybeck and Gutman. Unintentional remembering is
referred to as realizing. "Retrieval is more likely to result in
[remembering] useful information than realizing since retrieval
deliberately goes after certain memories whereas realizing occurs
without a purpose” Herrmann, Raybeck and Gutman.
Purposes of Encoding and Retrieval
The purpose of encoding strategies is to improve one's
ability to transfer information from short-term memory
(STM) to long-term memory (LTM). These strategies
involve the development of schemes or networks in order
to move information into LTM.
The purpose of retrieval strategies is to improve one's
ability to transfer information from long-term memory back
to short-term memory.
Advantages of Encoding
and Retrieval Strategies
Academically, encoding and retrieval strategies influence one's
ability to perform well when evaluated by instructors. Though
testing is the most common form of evaluation, and encoding
and retrieval strategies have the greatest impact on a student's
performance on examinations, evaluation may take the form of
class participation and group activities as well.
In addition, encoding and retrieval strategies may improve one's
ability to remember information from reading assignments.
Effective comprehension and retention of reading materials is
vital for class participation, taking exams, and other tasks.
Theories of forgetting :
☺Trace Decay - -The longer the time, the more the
memory trace decays and as a consequence more
information is forgotten.
☺Displacement -when STM is 'full', new information
displaces or 'pushes out’ old information and takes its
☺Interference -It was assumed that memory can be
disrupted or interfered with by what we have previously
learned or by what we will learn in the future.
Two ways in which interference can cause forgetting:
♦Retroactive interference occurs when new information
interferes with the retrieval process of information in LTM.
♦Proactive interference occurs when information in LTM
interferes with the ability to recall newly learned
☺Retrieval failure - information may be available but
Retrieval cues can be:
External / Context - in the environment, e.g. smell, place etc.
Internal / State - inside of us, e.g. physical, emotional, mood,