Transcript Memory slide show

MEMORY

Take a minute to list all the things that
our memory is useful for.

Now think about all the things that we
wouldn’t be able to do if we did not
have our memory.
-tying shoelaces
-remembering faces
-no friends
-no self-concept
-no personal identity

Human memory is not a single organ.

Technically we do not actually have a
memory- we have different memory
systems.

Memory consists of a collection of
complex interconnected systems, each of
which serves a different purpose and
operates in a very different way.

Despite these differences, all memory
systems have some functions in commonthey each receive, process and store
information for future use.

When we receive sensory information the
brain must select what information will be
attended to, processed and stored in the
various memory systems and what will be
eliminated and therefore not stored in
memory. If this process did not occur our
memory systems would be overloaded with
unimportant information.

In terms of people who are said to have
“lost” their memory- this is generally a
reference to a situation where one or more
memory systems have malfunctioned.

To have no memory at all you would
probably be unconscious or dead.
MEMORY AS AN INFORMATION
PROCESSING SYSTEM
Most psychologists view memory as an
active information-processing system that
receives, organises, stores and recovers
information.

This description compares memory to a
computer in terms of the way information
is processed.

Like a computer, memory does not passively
receive and store new information.

Instead, it actively alters and organises incoming
information so that it can be stored in a way that is
relatively easily retrieved.

Memory and a computer are also comparable in
the way that they each deal with information in a
sequence involving three key processes: encoding,
or conversion of information into a useable form; its
storage or retention after being encoded; and its
recovery or retrieval when needed.
ENCODING

Information that is received and stored in
memory must be converted from its raw sensory
state to a form that the brain can process and
use.

New information must also be placed, or
represented, in some form- sound, visual image,
touch or meaning- in the memory system.

The entire process of converting information into
a useable form or code that can be stored in
memory is called encoding.
STORAGE

Next, information must be retained by the
information-processing system.

Storage is the retention of information over time.

Personal computers usually store information on
a hard drive, whereas human memory stores
information in the brain.
RETRIEVAL

Finally, the information is retrieved, or located
and taken out of storage when it is needed.

Retrieval is the process of locating and
recovering the stored information from
memory so that we are consciously aware of
it.

The retrieval of some information is very easy
and quick, such as your name or birth date.

Other information is harder to retrieve such
as something you learnt in year 7 science.

In these instances we often rely on cues to
retrieve information that has been stored in
memory.
Copy out this diagram
MEASURES OF RETENTION

What methods do we use to test what has been
retained in memory?

Teachers generally use tests or exams. But is
your performance on a test or exam a reliable
measure of how much information you have
retained in memory?

There are different types of questions teachers
ask, including multiple-choice questions,
true/false questions, fill-in-the-blanks, short
answer, and essay questions.

Research shows that the amount of information
that will be retrieved from memory is, at least
partly, dependent on the type of question asked.

There are three main kinds of measures that are
used to determine how much information has
been retained: recall, recognition and relearning.
RECALL

What are the names of the 7 dwarfs?

In order to answer this question, you would have
searched through your long-term memory, tried to
locate the information required, and either have
produced or not produced the correct information.
RECALL

This approach to measuring the amount of
information retained in memory is a test of
recall.

Recall involves being asked to reproduce
information with the fewest possible cues
to assist retrieval.

In an experiment used to measure recall as a
measure of retention, participants might be
required to learn a list of randomly selected
words. Then, after a period of time, they may be
required to write, in any order, as many of the
words off the list as they can.

This method is called free recall. Free recall is
involved when participants are only asked to
remember as much information as possible, in no
particular order.

If participants were asked to recall a list of words
in the order in which they were presented,
researchers would be asking for serial recall.

Sometimes the general cue we are provided
with to search information in our long-term
memory is too general and the list of possible
matches is too long.

Cued recall makes use of specific cues to aid
retrieval. For example; being given the first letter
of each of the 7 dwarfs names.
RECOGNITION

Which of the following are the names of
the 7 dwarfs?
-Bashful
-Happy
-Grumpy
-Pop
-Sleepy
-Goofy
-Dopey
-Sneezy
-Doc
-Grouchy
RECOGNITION

Recognition involves identifying the correct
information from among alternatives, such as in the
previous question.

Generally we can retrieve more information when
tested by the recognition method than we can with
the recall method because the recognition method
provides more cues that assist in the location and
retrieval of information from long-term memory.

In an exam situation, students typically
prefer M/C questions or true/false
questions to an essay or short answer
questions.

M/C and true/false questions involve
recognising the correct response from
among a small number of alternatives,
whereas essay question require recall,
where there are very few cues.
RELEARNING

Most people have times when they are unable to
recall or to recognise information that has been
stored in long-term memory.

Even though they are unable to retrieve this
information, it does not necessarily mean that it
has been forgotten.

Relearning or the method of savings, involves
learning information again that has been
previously learned and stored in long-term
memory.

If information is learned more quickly the
second time it is assumed that there must
be some information retained from the first
learning experience, whether we realise it
or not.
HERMANN EBBINGHAUS

Ebbinghaus did an experiment using nonsense syllables
(eg. Jux, kuv). Nonsense syllables are often used in
memory research instead of words so that retention is
not affected by the words having some sort of meaning
or association with words already stored in memory.
When Ebbinghaus measured his memory for what he
had learned, he found that even if he could not
remember a single item from the original list, he could
relearn the list much quicker a second time than he had
been able to with the original list. This indicated that
some information had been retained from the initial
learning.

This is also called the method of savings
because it can be calculated using the
following formula.

Savings = (no. of trials for original learning) – (no. of trials for relearning) x 100
(no. of trials for original learning)
1
Eg.

10 – 5 x 100 = 50%
10
1
A savings score can also be calculated on the
basis of the time taken to relearn information.
Savings = (time taken for original learning) – (time for relearning) x 100
(time for original learning)
1
RELATIVE SENSITIVITY OF
MEASURES OF RETENTION

Recall, recognition and relearning differ in
their relative sensitivity as measures of
retention. The sensitivity of a measure of
retention refers to its ability to assess the
amount of information that has been
stored in memory.

Recall tends to be the least sensitive
measure of retention, relearning tends to
be the most sensitive measure of
retention, and recognition tends to be less
sensitive than relearning but more
sensitive than recall.




In a study by Nelson (1978) on the three measures of
retention, 24 university students were used as
participants.
The experiment consisted of three stages- the initial
learning stage, a stage in which recall and recognition
of the initial learning were tested and finally a
relearning stage.
In the first stage, participants were given a series of
number-word pairs to learn, such as 49-party and 95horse.
The second stage of the experiment required the
participants to participate in the testing and relearning
stages of the experiment.

In the testing stage, participants were required to
complete two different types of tests. The first was a test
of recall where the participants were given the original
number as a cue and were asked to provide the
association word that went with it. The second test was
similar but required the participants to name the
associated words from a list of 20-10 of which were the
original words and 10 of which were new, unrelated
words. The third stage of the experiment involved
relearning the words from the previous list which had
been incorrectly recalled and 10 new word pairs. They
were then given a recall test on both the new information
and the old information.

The results showed that a mean score of
48% of the target words were correctly
recalled, and 69% were correctly
recognised in the testing. Furthermore the
percentage of target words correctly
recalled during the relearning stage was
significantly higher for the old items (88%)
than for new items.

v
STAGES OF MEMORY

The Atkinson-Shiffrin model (named after two
psychologists) describes human memory as consisting of
three distinguishable kinds of memory, with each one
representing a stage through which information passes in a
sequential way.
-Sensory memory
-Short-term memory
-Long-term memory

Although these three memory systems are
viewed as separate sub-systems of memory, they
each operate simultaneously and interact in
many ways.

Within each stage of memory, information
processing involves encoding, storage and
retrieval of information.

According to this model, when information is
received from the environment, it passes from
sensory memory to short-term memory and then
to long-term memory.

Each stage of memory differs in terms of its
function (the role it plays), its capacity (the
amount of information it can hold at any given
moment) and its duration (the length of time it
can hold information).




Sensory memory is the entry point for new
information into the memory system.
Anything that is not attended to in sensory
memory is then lost.
If the information is attended to it is then
passed on to short-term memory where it is
stored for up to 20 seconds.
If an effort is made to retain this information it
is then transferred to long-term memory, if not
it is lost.
SENSORY MEMORY

Sensory memory is the entry point of memory-the
initial stage of the memory system in which all of the
stimuli that bombard our senses are retained in their
original sensory form (not encoded) for a very brief
time.

It is assumed to be unlimited in capacity.

An important function of sensory memory is that it
stores sensory impressions long enough for them to
slightly overlap one another.

This means that we see the world as continuous and
not as a series of disconnected visual images or
sounds.

Sensory information remains in sensory memory just
long enough for it to be attended to and selected to
be transferred to short-term memory (STM).

We are not consciously aware of the majority of
information that enters our sensory memory.

However when we direct our attention to it in order to
store it in STM we become consciously aware of it.

Incoming sensory information is stored in separate
sub-systems called sensory registers and it is
believed that there is a separate sensory register for
each of the senses.
ICONIC MEMORY

Iconic Memory is the name given to visual sensory
memory, or the memory of visual sensory information.

Visual images in their original sensory form are usually
retained in iconic memory for one-third of a second.

Sperling’s experiment.
PHOTOGRAPHIC MEMORY

Some people are able to remember highly detailed scenes as
if the actual event were occurring before them.

These people are said to have eidetic memory. These
memories are said to be an exact replica of a visual image
that persists over time without distortion.

These can last sometimes for days or weeks.

View this image for 30 seconds and then answer the
following questions.
1.
2.
3.
4.
5.
6.
How many bows are on the girls apron?
Is the hemline of the girl’s dress above or
below her knees?
How many flowers are in bloom on the taller
plant?
How many whiskers are there on the cat in the
tree?
How many stripes are on the cat’s tail?
What is the girl wearing in her hair?
ECHOIC MEMORY

Echoic Memory is the name given to
auditory sensory information, or the
memory of auditory sensory information.

It is called echoic memory because the
sounds linger in it like an echo.
The main difference between iconic and echoic
memory is the duration of time that they are able to
hold on to information.
Iconic (visual) Memory About 0.2-0.4 seconds
Echoic (auditory)
Memory
About 3-4 seconds

The availability of this information for 3-4
seconds is generally long enough to select
what has been heard for further processing
and interpretation before the sound
disappears completely.

Auditory information must also be held for
long enough for all parts of speech within a
list of words to be identified.
SHORT-TERM MEMORY

Short-term memory (STM) is a memory system
with a limited storage capacity in which
information is stored for a relatively short period
of time (unless renewed in some way).

STM stores information temporarily but for a
longer time than sensory memory.

Generally items in STM can be retained fairly
well for the first few seconds.

After 12 seconds, recall begins to decline and
by about 18 seconds almost all of the
information disappears entirely if it has not
been renewed in some way.

Information can be renewed in STM and
retained for longer through use or by
constantly repeating it.
STM AS WORKING MEMORY

Many psychologists prefer to use the term
working memory rather than STM.

Working memory is the active part of
memory where information you are
consciously aware of is actively ‘worked’
on.

Working memory works on information from sensory
memory and LTM.

Information from sensory memory is processed in
working memory and information is extracted from LTM
to be used and manipulated in working memory.
Imagining
- Problem-solving
- Analysing
- Reasoning
- Comprehending
- Planning
all involve working memory.
-

Psychologist Allan Baddeley proposed that working
memory consists of three sub-systems.
-
One system for verbal memory
Another for visual information
And a central executive that processes the
information from the other two sub-systems.
-
-
Verbal working memory (also called phonological
loop) stores a limited number of sounds
(phonemes), such as words, for a short period of
time.

Baddeley argued
that the longer it
takes to
pronounce each
word impacts on
the amount of
information you
can retain in
short-term
memory.
Burma
Switzerland
Greece
Nicaragua
Tibet
Afghanistan
Iceland
Venezuela
Malta
Philippines
Laos
Madagascar

Visual working memory (also called the
visuospatial sketchpad) temporarily stores visual
information, such as the location and nature of
objects in the environment.

The central executive integrates information from
the verbal and visual storage systems, as well as
information received from long-term memory.

It works on the information from the other two subsystems.
The central executive has a role in:
- Calculating mental arithmetic tasks
- Decision making
- Analysing an image of modern art
- Planning strategies
- Coordination of behaviour
- Suppressing (holding back) irrelevant information
from our conscious thinking
- Helps decide what to do and what not to do next
Does not store information.

DURATION OF STM
Information can be kept in STM for longer
than the usual maximum of 18-20 seconds
by maintenance rehearsal.
CAPACITY OF STM

Compared to sensory memory and long-term
memory, STM is very limited in storage capacity.

If you have an average storage capacity you should
be able to recall around seven numbers in a row. If
you were given eleven numbers this would not be
quite as easy.

The limited capacity of seven bits of information in
short-term memory was first described by George
Miller in 1956.

Millers research indicated that STM has a
capacity of holding between five and nine
units of information at any one time.

7+2

Rarely are we able to hold any more than 7 +
2 pieces of information in STM regardless of
what type of information it is.

Information stored in STM is lost primarily
through decay (not being used) and
displacement (being pushed out) by new
information.
Chunking Information

We can get around the limited capacity of long-term
memory.

One way is to learn the information well enough to
transfer it to long term memory, which has an unlimited
storage capacity.

Another way is to put more information into each of the 7
+ 2 units that can be stored in STM.
DNVRCEWVDCSV
 NSW
VCR
VCE
DVD

People are usually able to recall more of the second
set of letters even though it is made up of exactly the
same letters.

This is a demonstration of chunking.

Chunking is the grouping or packing of separate bits
of information into a larger single unit or ‘chunk’ of
information.

Chunks can be take many forms. They can be
numbers, images, words, sentences, phrases or
abbreviations. (BHP, RACV, CSIRO).

What examples of chunking have you come across in
everyday life?
Phone numbers
Car registration number plates



In sum, STM is a working memory system with
limited capacity and duration in which informationoften stored in verbal form-is lost rapidly unless it is
rehearsed.

STM is used to work on new information or
information retrieved from LTM, to select and process
ongoing information and to store memories for a
short duration.
Effects of rehearsal

Rehearsal is the process of actively manipulating
information so that it can be retained in memory.

There are two types of rehearsal:
-
Maintenance rehearsal
Elaborative rehearsal
-
Maintenance Rehearsal

Maintenance rehearsal involves repeating the
information being remembered over and over again
to retain it in short term memory.

When you hear something for the first time and go
over it and over it so that you don’t forget it, you are
using maintenance rehearsal.

Maintenance rehearsal can be verbal, which involves
the use of words. It can also be non-verbal, involving
visual or spatial information.

When the information is verbal, maintenance
rehearsal can occur vocally, by saying the information
aloud over and over; or sub-vocally, by silently
repeating the information in your head.

Whether maintenance rehearsal is verbal, visual or
spatial, provided it is not interrupted, information can
be retained indefinitely in STM.

This does not necessarily mean that this information
will automatically be transferred into LTM.

When information is continually renewed in STM
through the rehearsal process, the amount of new
information that can enter is restricted because of the
limited capacity of STM.
Elaborative rehearsal

Elaborative rehearsal generally involves organising and
dealing with new information in terms of its meaning.

Elaborative rehearsal is the process of linking new
information in a meaningful way with information already
stored in memory or with other new information, to aid in
its storage and retrieval from long term memory.

Elaborative rehearsal is a more active process than
maintenance rehearsal.

It is also more effective than maintenance rehearsal
as it helps to ensure that information is encoded well.

When we relate new information to personal
experiences and our personal situation, encoding is
enhanced and therefore we are more likely to
remember it. This is called the self-reference effect.
Using elaborative rehearsal to improve your
memory
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Elaborative rehearsal has a number of practical applications
for students. The learning of new information is more likely
to be retained in LTM when you:
Think about what the new information means
Ask questions about the new information
Link new information to previously learned information
Create visual images relevant to the new information
Link the new information to personal experiences or your
personal situation.
Consolidation theory

Consolidation theory proposes that physical
changes to the neurons in the brain occur when
something new is being learned, and immediately
following learning.

This theory also proposes that if memory is disrupted
during the consolidation phase, information may not
be processed in LTM and will therefore be lost.

Material being transferred into LTM is vulnerable to
disruption for up to 30 minutes.
LONG-TERM MEMORY

Long-term memory is the relatively permanent
memory system that holds vast amounts of
information for a long period of time.

It is a different kind of memory system to STM.

LTM differs from STM in several ways: how
information is retrieved, the form in which information
is stored and the way in which information is
forgotten.

LTM has to be organised in a way that enables the
efficient retrieval of information.

We retrieve information from LTM using retrieval
cues. This can be intentional or unintentional.

In either case, only the specific information relevant
to the cue is retrieved rather than the entire contents
of LTM.

Remarkably it takes only a few seconds to search
through this huge storehouse of information to find
the information required.

Information retrieved from LTM is held in working
memory while it is being used. Once it is no longer
required, it can be returned into LTM for further
storage.

If we are unable to retrieve specific information from
LTM, it is because of poor organisation of the
information during encoding and storage or failure to
use the appropriate retrieval cue.

If information is not properly stored it is difficult to
locate and retrieve.

STM stores information in terms of the physical
qualities of an experience, especially sounds.

In contrast, LTM stores information semantically, that
is in terms of its meaning.

In terms of forgetting, LTM differs from STM in that it
does not only last longer but it is in fact permanent.

This means that forgetting occurs in LTM not
because the memory is gone, but because we are
unable to retrieve it.
Types of LTM

Psychologists have distinguished between two types of
LTM storage, each with distinctly different properties.

These are procedural memory and declarative memory.
Two types of declarative memory have also been
described. They are called episodic memory and
semantic memory.
Procedural memory

Procedural memory is the memory of actions and
skills that have been learned previously and involves
knowing ‘how to do something’.

How to drive a car
How to ride a bike
How to use a computer


Procedural memories are also called implicit memories
because it is often difficult to recall when or how we
learned to perform the sequence of actions required
to do something.
Declarative memory

Declarative memory is the memory of specific facts
or events that can be brought consciously to mind
and explicitly stated or ‘declared’.

Consequently declarative memories are also called
explicit memories.

Identifying a type of flower
Explaining a statistics formula
Describing the events of a movie you have seen



When distinguishing between declarative
and procedural memory psychologists
often refer to declarative memory as
involving ‘knowing what’ and procedural
memory as ‘knowing how’.
Episodic memory

Episodic memory is the declarative memory system
that holds information about specific events or
personal experiences.

Like a mental diary, recording the autobiographical
episodes we experience.

What you ate for breakfast
The birth of a brother or sister
Going to the dentist
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
Semantic memory

Semantic memory is the declarative memory system
that stores the information that we have about the
world.

It includes our specialised knowledge in areas of
expertise, academic knowledge of the kind learned in
school, rules, everyday general knowledge, the
meaning of words.

Semantic memories seem to involve facts that do not
depend on a particular place or time but are simply
facts.
Organisation of information in
LTM

One of LTM’s most distinctive features is its
organisation of information. The task of retrieving
information from LTM is very different to retrieving
information from STM.

In STM there is only a choice of 7 + 2 pieces of
information to choose from, however LTM stores
such a vast amount of information that there is a
need for some form of information to assist the
storage and retrieval process.

Research has found that information stored in LTM is
organised in meaningful clusters of related
categories.

Eg. Fruit types, names, occupations.

Research findings also indicate that information is
also linked or associated with other information
stored in LTM.

There is also considerable research evidence that
suggests that recall from LTM is better when we
further organise the information stored there.

Bower and Clark experiment.
Semantic network theory

Information in LTM is both organised and associated
with other information held in the LTM system. The
semantic network theory is one theory that describes
how this is done.

Semantic network theory proposes that information
in LTM is organised systematically in the form of
overlapping networks or grids of concepts that are
interconnected and interrelated by meaningful links.

According to this model, each concept, called a node
is linked with a number of other nodes.

This means that when we retrieve information, the
activation of one node causes other related nodes to
be activated also.

In reality, LTM contains thousands of concepts, each
with very many connections.

This system of storing information in terms of
meaning is quite an effective means of storage which
enables effective and efficient retrieval of information.
According to the semantic network theory:
 retrieval begins with someone searching a particular
region
 then tracing associations for links among memories
in that region, rather than randomly searching the
vast information stores in LTM.

It also proposes that a specific retrieval cue activates
relevant nodes, which in turn activate other nodes to
which they are linked.

The shorter the link between nodes the
stronger the association, the less time it
takes to activate related concepts to which
they are linked.

The longer the link between nodes the
weaker the association between them and
the longer it takes to activate the
information that is further away.

The more nodes that are activated, the
quicker the retrieval of information from
LTM.
Serial Position Effect

To test whether STM is a separate sub-system of
memory from LTM, psychologists have studied
people’s memory of lists of words, numbers and
other information.

A consistent finding has occurred: which words
are recalled from the list tends to depend on their
serial position.

The Serial Position Effect is a research finding that
suggests that recall is better for items at the end
and beginning of the list than for items in the middle
of the list.

The Primacy Effect describes superior recall of
items at the beginning of a list.

The Recency Effect describes superior recall of
items at the end of a list.

Together with the relatively low recall of items from
the middle of the list, this pattern makes up the
serial position effect.
What causes the serial position
effect?

The most acceptable explanation relates to
differences between STM and LTM.

If recall occurs immediately after learning, the last
few items are remembered first because they are still
in STM.

The first few items are remembered most because
the received more attention and rehearsal than other
items and are therefore transferred into LTM.

Items around the middle of the list are presented
too late to be adequately rehearsed and
transferred into LTM and too early to be held in
STM without rehearsal and are therefore likely to
be forgotten.

If participants are asked to recall the list 30
seconds after learning, the serial position effect is
not as prominent as this goes beyond the limits
of STM.