Transcript 1. Models of Memory - gleneaglesyear12psychology

How is information processed?
Memory as information
processing
Encoding – converting information to a
useable form
 Storage – retaining information in
memory
 Retrieval – information recovered from
memory when needed

MODELS OF MEMORY

A “model” is used to represent, describe
and explain memory and its components
and processes. Typically models of
human memory are in visual diagrams.

No single model has been shown to
capture all aspects of human memory.
But some models of memory have been
more influential than others.
MODELS OF MEMORY

Three models of memory will be examined
in this unit of study:
 Atkinson and Shiffrin’s (1968) multistore model
- describes memory as having 3 components
 Baddeley and Hitch’s (1974) model of working
memory
- changed views on roles and functioning of
short term memory
 Craik and Lockhart’s (1972) levels of processing
framework
○ - emphasised the importance of the “depth” at
which we process information in determining how
well info is stored for retrieval when needed.
MODELS OF MEMORY

1960’s saw shift in assumption that
memory was a single system to the idea
that 2 or maybe 3 memory systems were
involved.

Atkinson and Shiffrin’s multi store model
was so influential it was also called the
“modal model” as it was representative of
many similar models presented at the time.
It was also known as the “stage model” as
the flow of information moves through
stages in the 3 components of memory.
Atkinson-Shiffrin’s multi-store model of memory

Info passes through 3 levels of memory as it is encoded,
stored and retrieved

Sensory Register – Short Term store– Long Term store

Each component or store represents a place where
information is held and processed.

This model has structural features that do not vary , E.g.
The three levels of memory

Each store encodes and processes information in
different ways, but they operate simultaneously and
interact.

Also Control processes that will differ between people,
E.g. deciding what type of rehearsal to use, or what
search strategy to employ
ATKINSON & SHIFFRIN’S MODEL

Sensory register is the entry point for all new information
into memory from the external environment.

Stores vast quantities of incoming visual information for
up to several hundred milliseconds.

Sensory info attended to is transferred to the Short Term
store.

If sensory info is NOT attended to it’s “memory trace” or
neural imprint simply decays and disappears forever.

In some cases info can bypass the STM and transfer
directly to the LTM store. But Atkinson and Shiffrin did not
explain how or why this occurred. Instead, they allowed
for the possibility that it COULD occur.
ATKINSON & SHIFFRIN’S MODEL

They considered the possibility that there may be
different sensory registers for different types of sensory
information.
e.g. Separate visual, auditory etc.
The Short Term store or “temporary working memory” was
described as the location where information is
manipulated so that it is held to perform everyday
functions.
The Short Term store holds all information we are
consciously aware of at any point in time.
The Short Term store receives information both from the
sensory registers and the Long Term store.
The Short Term store has a limited capacity (unlike the
sensory registers which are unlimited). It can hold up to
around 7 items of information at the same time.
ATKINSON & SHIFFRIN’S MODEL

Information can only be held in the Short
Term store for about 30 seconds unless
a conscious effort is made to keep it
there longer. This can be achieved
through a process such as “rehearsal”.
e.g. Intentionally repeating the info over
and over such as remembering a phone
number is a form of “rehearsal”.
Actually using the information in some
way is also a form of “rehearsal”.
REHEARSAL

Rehearsal is a “crucial” process for the Short Term store.

Rehearsal enables the information to be further encoded
and transferred to the Long Term store for more
permanent storage.

With no rehearsal, the memory trace it formed in the brain
“decays” and the information is lost forever.

Continual rehearsal allows the information to remain in
the Short Term store as long as it is needed.

Continual rehearsal “regenerates” or “renews” the
information in the memory trace, thus making it a stronger
memory when transferred to the Long Term store.
LONG TERM STORE

Holds information relatively permanently in a highly organised
way and has essentially an unlimited capacity.

Information in the Long Term store doesn’t usually “decay” and
is stored for up to a lifetime.

We can fail to retrieve information from the Long Term store.

Inability to retrieve was thought by Atkinson & Shiffrin is the
result of the use of ineffective search strategies to find the right
memory trace for that information.

The presence of related information in the Long Term store may
also result in “interference” with the required information, thus
disrupting the retrieval process.
Atkinson-Shiffrin’s multi-store model of memory





Important aspects of this model are:
Structural features – permanent built in
features of memory that do not vary from
one situation to another.
Eg. Three different stores of memory each
with specific function, capacity and duration
Control processes – selected by the
individual and may vary across different
situations. They are consciously controlled
by the individual.
Eg. Attention, rehearsal, retrieval (choice of
search strategy)
Atkinson-Shiffrin’s multi-store model of memory

The model was based on extensive and substantial
research findings 40 years ago but some of the underlying
assumptions has since been built upon, challenged or
even refuted by more recent research.

E.g. 3 stage sequential flow of information is too simple
E.g. Evidence for a separate sensory register for auditory info and
haptic (touch) info as well as possibly for all other senses.
Psychologists now refer to a “sensory memory system”
STM – a number of separate interacting components not
a single store
 Rehearsal does not guarantee retention
 LTM – 3 distinct sub systems, memory not retrieved but
reconstructed

NEW FINDINGS ON SHORT TERM
STORE

Atkinson & Shiffrin identified characteristics of
Short Term store that still remain accurate.
 E.g. Storage capacity and duration, fundamental
roles
 However we now believe Short Term store to be not
a single store but a number of separate, interacting
components or sub-systems that process different
types of information (Baddeley, 2009) – supported by
evidence from neuroimaging techniques that have
matched STM and other stores with physical
locations in the brain.
TYPES OF REHEARSAL

Psychologists now distinguish between
different types of rehearsal in STM.

Maintenance rehearsal (simple repitition
over and over) does not guarantee transfer
into LTM

Elaborative rehearsal now considered to
better promote encoding for long term
storage.
LONG TERM MEMORY

Psychologists now view LTM not as a single
memory component but a set of different subsystems or stores (such as episodic or
procedural memory) each of which processes
and stores different types of information.

Retrieval from LTM is also now no longer
thought to be as the info was originally stored.
E.g. Memories of experiences can be
“constructions” that we build or rebuild
sometimes in ways that lead to distortions of
memory or even “false memories”.
Atkinson-Shiffrin’s multi-store model of memory
Atkinson-Shiffrin’s multi-store model of memory
Sensory Memory

The entry area of memory, all stimuli which bombard our senses
are retained in their original form for a very brief time in memory
sub systems called sensory registers

The info received is assumed to be the exact copy of the original
i.e. “raw” sensory form rather than encoded.

Stores info long enough for each sensory impression to slightly
overlap the next, so we perceive the world around us as continuous
rather than a series of disconnected visual images or sounds.
 E.g. wave pen back and forth in front of your face – an example of visual
sensory memory at work.

There is probably a sensory register for each sense and each
retains sensory info for different periods of time.

We cannot consciously manipulate info in sensory memory or
extend the time period info is retained there. E.g. reading and
aware of feel of watch on your wrist
ICONIC MEMORY


From the Greek word “icon” which means “image”.
Iconic Memory: Visual sensory memory. Images only
last in iconic memory for about one third (0.3) of a
second. Long enough for the identification of the
stimulus to begin.
Activity – close eyes for one minutes, hold hand about
25 cm from face then open and close eyes – should
see an image of your hand that fades away in less than
a second (Ellis, 1987)
e.g. movies – separate frames, sparklers in figure 8’s.

U.S. Psychologist George Sperling (1960) PROVED
THAT IT EXISTED!
SPERLING’S RESEARCH (1960)

Used a tachistoscope to briefly present
participants with sets of 12 letters arranged in
a pattern as shown on the next slide.

The 12 letters were projected on a screen for
about 1/20 of a second – this time was too
brief for eye movements to occur which is why
it was chosen.

Participants were then required to verbally
report as many letters as they saw. Sperling
found that most could recall only 4 or 5 letters.
With such short exposure, reporting all the
letters was impossible.
SPERLING’S RESEARCH (1960)

However, most participants reported that for an instant they had
seen ALL of the letters, but by the time they could say 4 or 5 of
them the image of the remaining letters had faded.

Sperling wanted to test that ALL letters were actually seen so he
conducted a further experiment where he sounded a tone after
a pattern of letters were flashed on the screen and found
participants (once having learned the partial report system)
were perfectly accurate. High, middle and low tones were used
to indicate which set of letters were required to be recalled.

The results then indicated that the whole pattern of 12 letters
had been momentarily stored in iconic memory after the pattern
left the screen.

Delaying the tone longer and longer allowed Sperling to
determine how quickly the images faded from iconic memory.

Subsequent research by others found that the typical duration
of iconic memory is about 0.2 - 0.4 seconds (Cowan, 1995).
Sperling’s research
PHOTOGRAPHIC MEMORY
(“EIDETIC MEMORY”)

Individual who are able to recall highly detailed scenes as
if the actual event was occurring before them are said to
have an “eidetic memory”.

Eidetic memories involve eidetic images – an exact
replica of a visual image that persists over time without
distortion. (e.g. They literally “see” the relevant page of a
textbook)

Eidetic images can apparently last for prolonged periods
of time (days or even weeks).

Eidetic images most often occur in childhood (5% of
children tested), but are less frequent in adolescence and
rare in adults. (Hilgard, Atkinson & Atkinson 1979)
ECHOIC MEMORY

Echoic Memory – Auditory sensory memory (i.e. the brief sensory
memory for incoming auditory information).

Echoic sounds like echo. Echoic memory stores sounds for 3 to 4
seconds e.g. clap hands together once and see how the sound
remains for a brief time and then fades away.

Echoic memory functions like iconic memory but stores sounds
(instead of visual images) in their original sensory form.

Main difference between echoic and iconic memory is the length of
time it takes information to fade.

The time is long enough in echoic memory to allow the availability
of auditory information to be retained so it can be selected for
further processing and interpretation before the sound disappears
completely. e.g. reading a novel and someone asks you a
question
ECHOIC MEMORY

You are aware someone is speaking but since your attention is
focused elsewhere you don’t immediately comprehend the
message. Within a couple of seconds you say “what”? but then
answer the question before it is repeated. You have retrieved this
information form echoic memory

Echoic memory stores the tail-end of the question temporarily while
earlier parts of the question are being processed into STM. It’s
possible the “what” is said just before the last parts of the message
in echoic memory are transferred to STM.

Important role in language comprehension, particularly in
understanding speech, as speech is a blend of successively spoken
sounds that are heard. When you hear a word pronounced a series
of individual sounds are heard, one at a time. Word identification
can only happen when all sounds of the word are heard, so auditory
information needs to be stored long enough for all sounds involved
to be received. It enables storage of all sounds that make a word
so the word can be processed as a whole

Com…. puter, Com…munism, Com….pete
ECHOIC MEMORY

If echoic memory was as brief as iconic memory, then
speech might sound like a series of separate, distinct
sounds instead of meaningful words, phrases and
sentences.

A typical echoic memory experiment – participant reads a
story and told to ignore any spoken words they hear as
they read (typically numbers e.g. 7, 2, 5)
When signal sounds participant is asked to recall
numbers just heard and research shows they can typically
repeat accurately the last few numbers they have heard if
the signal is presented immediately after the last spoken
number and recall ability diminishes with increased delay
between number and signal to respond up to about 10
seconds.
Afterwards participants reported a vague awareness of
hearing numbers spoken but after the signal they could
shift their attention to the numbers and repeat them.
ECHOIC MEMORY

Rate of fade of information from sensory
memory varies between senses.

Information is lost and replaced so rapidly in
the sensory registers that we are rarely aware
of our capability for retaining sensory
information.

Sensory memory may also act as a type of
filter to keep out irrelevant information that is
unimportant to us and prevent cluttering the
sensory stores.
HAPTIC SENSORY MEMORY

Haptic or tactile sensory memory is
believed to involve a sensory register that
retains physical sensations of touch
(possibly from tensions of internal muscles)
for about 1 – 2 seconds.

It enables us to combine a series of touch
sensations and to play a role in identifying
objects we can’t see. E.g. Playing a song
on guitar, sharp pencil on back of hand.
DEJA VU

Deja vu is French for “already seen”.

Deja vu is described as the brief and intense feeling that
something happening now has happened before in
exactly the same way, but without you being able to recall
exactly when or where.

Some people believe it is evidence of psychic
experiences, reincarnation or even dreams coming true
but there is no scientific evidence for this.

Analysis of more than 30 survey method studies (Brown,
2004) it was found that 68% of individuals reported having
experience deja vu at least once in their life. He also
found the incidence of deja vu decreases steadily over the
lifespan. 20-24 year olds had the highest yearly
experience averaging almost three per year and people in
their early forties averaged less than one per year. A
small minority (16%) of people claim to have one once a
month.
DEJA VU

According to Brown (2003) a typical deja
vu is triggered by some kind of visual
scene and the intense feelings of familiarity
last for only a few seconds.

They are most common when people are
fatigued or emotionally distressed, in the
evening or in the company of others rather
than alone. Well educated people and
people who travel frequently have a higher
incidence of deja vu experiences.
DEJA VU

Scientific explanations proposed include:
 Neurological possibilities – e.g. Brain malfunction
 Psychological explanations – e.g. Memory
malfunction or inattentional blindness (not really
paying attention to surroundings and when focusing
attention a split second later the surroundings are
perceived as suddenly and inexplicably familiar
(Hockenbury & Hockenbury, 2006)
Wade and Tavris (1990) explain deja vu in terms of
sensory memory, suggesting it may occur when info
entering sensory memory “short circuits” or fails to
complete it’s normal route and must therefore be
reprocessed. The familiar feeling is because you did
experience the exact same situation but only a
fraction of a second before, but you are also unable
to determine when the initial processing occurred.
Atkinson-Shiffrin’s multi-store model of memory
Short Term Memory

Also referred to as Working Memory – it has a limited
storage capacity unless info is renewed in some way.

Helps store info while you work on it

In STM the information is no longer an exact replica of
the sensory stimulus but an encoded (or representation)
of one.

Atkinson & Shiffrin model proposed information is stored
in STM in verbal form such as words or numbers.
Subsequent research has found that STM also stores
non-verbal forms of information such as visual, spatial
and auditory representations (Baddeley, Eysenck &
Anderson, 2009)
SHORT TERM MEMORY


o
o
Duration: 18 – 20 seconds (recall starts to decline after
about 12 seconds)
Capacity: 5 – 9 pieces of information
Research by Margaret and Lloyd Peterson (1959) on
duration used trigrams (qlg, jfb, mwt) and a distracter
(interference task) to prevent rehearsal and after a delay
of between 3 to 18 seconds they were asked to recall
the trigrams.
By 18 seconds participants had forgotten almost all the
trigrams.
With no interference task (e.g. counting backwards) their
performance was much better – probably due to
rehearsal.
CAPACITY OF SHORT TERM
MEMORY

US psychologist George Miller (1956) first described the limited
capacity of about seven bits of information, plus or minus two
for STM.

Estimates of STM capacity come from research tasks requiring
memory of simple lists of data of different lengths (numbers,
letters, unrelated words, nonsense syllables).

The length of the list that the participants can recall half the time
is considered to represent the capacity of STM (Miller, 1956).

Research includes using Chinese characters in non-Western
cultures and the capacity is the same. (Yu et al., 1985)

When info is temporarily retrieved from LTM for use in STM it
fills up space in the STM. E.g. Unable to remember telephone
number just looked up after thinking about what you are going
to say.
SHORT TERM MEMORY

Information is lost though decay (fading) or displacement
(being pushed out) by new info (Reitman, 1974).

Forgetting what you want to say in a conversation while
listening to what the other person is saying. Listening
prevents rehearsal and thus the information can be lost
from STM. E.g. research on calling directory assistance
when operator said “have a nice day” after giving the
number resulted in poorer recall of the number compared
to if the operator said nothing. (Schilling & Weaver, 1983)

Forgetting a name after being introduced to someone can
also be explained by displacement or fading info from
STM as you are engaged in conversation or noticing other
aspects of the person you don’t have the chance to
rehearse the new name.
WORKING MEMORY

“Working memory” is used to emphasise
the active part of memory where info we
are consciously aware of is actively
“worked on” in a variety of ways.
Mental processes of working memory include:
 Interpretation of emotions and feelings
 Language comprehension
 Daydreaming
 Creativity
 Problem solving, analysing, reasoning,
planning and decision making.
WORKING MEMORY

Working memory provides a temporary
storage facility and mental “workspace”
for information currently being used in
some conscious cognitive activity.
(Baddeley, 1999)
Besides whenever I learn
something new it pushes
something old out of my
brain…..Remember when I
took that home wine
making course and I forgot
how to drive.
Displacement
Improving STM capacity

Chunking: The grouping or “packing” of separate bits of
information into larger bits or units that can be
remembered as single units or “chunks” of information.

Chunking can increase the amount of information held in
STM.

Chunking expands short term memory. Chunks can be
numbers, images, words, abbreviations, phrases etc.
Eg. Of chunking telephone numbers. 0407 655 234

Capacity of STM is still 7, but now its 7 bits or chunks
of information
Improving STM Duration

Rehearsal: The process of doing something so that information can be retained
in STM and then retrieved when required. It can be verbal, vocal, non-verbal,
sub-vocal (silently repeating in your head), mental imagery etc.
TWO MAIN TYPES OF REHEARSAL

Maintenance rehearsal: Involves simple, rote repetition of information being
remembered over and over again so it can be retained in STM. Going over and
over it!

Needs to be attended to consciously – not just meaningless repetition.

When the information is visual, maintenance rehearsal involves using something
like an “inner eye” to maintain the image of the object or scene in STM for a
period of time after you first see it.

Maintenance rehearsal does NOT always lead to long-term retention.

One of the limitations of maintenance rehearsal is when information is continually
renewed and maintained in STM the amount of new information that can enter is
restricted because of the limited storage capacity of STM.
ELABORATIVE REHEARSAL

Elaborative rehearsal: Involves the process of linking
new information in a meaningful way with information
already stored in LTM to aid in it’s storage and retrieval
from LTM. More active and more effective, ensures that
information is encoded well.

Elaborative rehearsal is a more active and effortful
process than maintenance rehearsal. It is also more
effective than maintenance rehearsal for remembering
new information as it helps to ensure that information is
encoded well. It is a deeper level of informationprocessing.

Self reference effect : Involves linking new information to
personal experiences and our personal situation in some
way which is meaningful to you.
Levels of processing - Craik and Lockhart
(1972)


Dispute the distinct sub system model
Fergus Craik and Robert Lockhart (1972) proposed a “conceptual framework of
memory” that emphasised the important of the level at which new information is
processed.

They proposed that the level or depth of processing during learning determines how
well it is stored in LTM

Memories are best encoded, organised and stored in LTM by meaning
(“semantically”). If meaning is processed during learning then LTM will be better
than if meaning is not processed.

More meaning – deeper processing – better storage

Processing meaning is not a matter of “meaning or no meaning”. Instead there is a
continuum from shallow to deep processing with levels of processing in between.

Shallow encoding, basic features, repeating lists etc – bad storage
Levels of processing – Craik and Lockhart
(1974)

Attending only to the superficial details
of what is being learned and
remembered would involve shallow
processing.

The more meaning given to new
information, the deeper the level of
processing.
See example on p. 313 (soft, witty etc.)
Levels of processing – Craik and Lockhart
(1974)

Considerable research evidence exists
that indicates LTM is better when we
process new information semantically
(meaningfully).

See example on p. 313 (hat, HOP, bin)

See Fig. 6.23 on p. 313
Levels of processing - Craik and Lockhart –
problems

Levels of processing or depth are hard to
define specifically and to measure

There is no generally accepted means of
measuring different levels of processing in
valid and reliable ways (Baddeley, 1999).

Despite this problem the idea of better
processing and therefore better storage is
supported widely by research.
Suggestions for a deeper level of information
processing (Hockenbury and Hockenbury,
2006)





Make sure you understand the new information by restating it in
your own words
Actively question new information
Think about the potential applications and implications of the
material
Relate the new material to information you already know,
searching for connections that make the new information more
meaningful
Generate your own examples of the concept, especially
examples from your own experiences.

THE ABOVE MENTAL ACTIVITIES INVOLVE ELABORATIVE
REHEARSAL THUS PROMOTING DEEPER PROCESSING
AND ENHANCING YOUR MEMORY FOR NEW
INFORMATION.

See Flag example on p. 314
Alan Baddeley and Graham Hitch’s model of
working memory
Phonological
Loop
storage of verbal
speech information
Central Executive
• Controls attention
• Integrates info from the two
storage sub systems
• does the ‘working out’
Episodic Buffer
Integrates useful LTM
into what currently
being worked on
Pulls together streams
of different info into
‘episodes’ as a
meaningful whole
•The seat of consciousness
The workbench
Visio spatial
Sketchpad
Storage of visual and
spatial information
Baddeley and Hitch’s model of working
memory

It describes the structure and function of
working memory in terms of 3 components:
1.
2.
3.
The phonological loop
The visuo-spatial sketchpad
The central executive
The components are separate and can function
relatively independently but also interact.
The phonological loop and visuo-spatial sketchpad
assumed to be sub-systems of working memory
and the central executive is assumed to be an
“attentional controller”. (Baddeley, 2009)
Baddeley and Hitch’s model of working memory

Baddeley and Hitch believed previous research didn’t
adequately describe or explain what working memory
was or how it functioned.

They felt previous models of memory were more
concerned with basic roles of STM (e.g. storage and role
of rehearsal) rather than it’s role as a system that
supports and enables complex and important cognitive
activities which is what they were interested in.

Example of counting doors in house – requires visual
image of house (visual and spatial sub-system), counting
doors verbally (using sub-system specialised for verbal
information) and a need for the central executive to
select the strategy to complete the task, to manage the
activities of the other 2 sub-systems and to control the
whole process.
Phonological loop







Also called “verbal working memory”.
Encodes and stores auditory info
Active whenever you read, listen, speak or repeat words to
yourself to remember
Temporarily stores a limited amount of verbal speech-like
information (e.g. Phonemes – sounds of words) for a brief
period of time.
Assumed you hold onto the info by using sub-vocal
maintenance rehearsal (repeating over and over internally
like a “loop” of recording tape.
Without rehearsing people can hold only about 2 seconds
worth of information in their phonological memory system.
Because of this people with slow speech but normal
intelligence perform worse on short-term verbal memory
tasks than those with speech at normal rate.
Internal rehearsal is crucial to the phonological loop and
without it if disrupted or eliminated then phonological storage
cannot occur.
Word-length effect

See example on p. 317

As length of words increase, the number
of words able to be remembered
declines. Shorter words are easier to
rehearse in the phonological loop of
working memory than long multi-syllable
words. (e.g. Burma and Greece easier
than Afghanistan and Switzerland).
Visuo-Spatial Sketchpad

Also called “visual working memory”.
Temporarily stores a limited amount of visual and spatial
information for a brief time.
 Visual information is anything you can see or visualise
including all features of the image.
 Spatial information is the visual location of objects in
space.
e.g. Pouring a drink on the kitchen bench or seeing a dog
while jogging

The visuo-spatial sketchpad is a mental workspace for
storing and manipulating visual and spatial information.
See example on p. 317 that requires use of the visuo-spatial
sketchpad.
Visuo-Spatial Sketchpad
Has a limited storage capacity.
 The capacity of both components are
independent of one another as
evidenced in “dual task” experiments.

 E.g. Tasks that require use of visuo-spatial
sketchpad and phonological loop task
simultaneously.
Central Executive
Controls attention
 Integrates information from the
phonological loop and visuo-spatial
sketchpad as well as information
retrieved from LTM; and co-ordinates
the flow of information between the
working memory system and LTM.


Central executive is the “working”
component of working memory.
Central Executive






It directs your attention to activities you are currently
undertaking
Filters essential from non-essential information
Combines information from the other 2 components
Selects, deletes and reorders information
Add information when required from LTM to guide mental
processes and behaviour.
When info no longer needed, it directs its flow to LTM.
Almost everything you think, feel and do in NWC is controlled and
managed by the central executive.
e.g. Planning, goal-setting, changing your mind about what to do.
Has a limited ability to perform more than one task at a time, it
can’t make numerous decisions simultaneously.
Problems with the model

Baddeley (2009) stated it does not
explain how working memory actually
links with LTM.

SO....

In 2000, Baddeley added a 4th.
component known as the “episodic
buffer”.
Episodic Buffer

It is a sub-system of working memory that enables the different
components of working memory to interact with LTM.

Still not yet fully described.

Assumed to be a limited capacity temporary storage system
that holds about FOUR chunks of information.

Capable of holding information in any form, thus can combine
auditory info from phonological loop and visual info from visuospatial sketchpad. It also connects these sub-systems with
LTM.

Episodic buffer is under the control of the central executive.

It is separate from LTM and has it’s own storage space and
processes for storing information.
Episodic Buffer

Called “episodic” because this sub-system can
“pull together” separate streams of information
from elsewhere in working memory and from
LTM, then combine them into scenes or
episodes like memories of a story or a movie
scene.

Called it “buffer” because it provides
temporary working space where information
can be processed into these episodes and
edited or reordered in an organised and
meaningful way. A “mental workbench” for
cognitive abilities.
Alan Baddeley and Graham Hitch’s model of
working memory
Read example on pg. 319
 Going to party….
- phonological loop stores the directions
- Visio spatial sketchpad visualise route
- Central executive directs the Episodic buffer
to combine info from storage branches
- Episodic buffer also adds info from LTM
- Episodic buffer used as the mental
‘workbench’ to make adjustments

LONG TERM MEMORY

Long term memory (LTM) is the relatively permanent
memory system that holds vast amounts of
information for a long time, possibly indefinitely.

In all models of memory, it is a different memory
system that primarily interacts with STM.

Where info in STM is “active”, information in LTM is
“inactive” and we are not consciously aware of it
unless we retrieve it.

Generally STM and LTM differ in how information is
retrieved, the form in which information is stored, and
the way in which information is forgotten.
RETRIEVAL FROM LTM

We retrieve info from LTM using retrieval
cues similar to call numbers on books in a
library or the “find” function in computer
software.

Retrieval of info from LTM can be
intentional or unintentional.

Usually it takes only a few seconds to
search through vast information in LTM to
find the required information.
RETRIEVAL FROM LTM

Information retrieved from LTM is held in
STM while it is being used. When no
longer required, it can be transferred back
to LTM for continued storage.

Difficulty in retrieval of info from LTM is
usually due to poor organisation of info
during encoding and storage or failure to
use an appropriate retrieval cue. If info is
not properly stored, it is difficult to locate
and retrieve.
LTM DIFFERS FROM STM

The form in which information is stored.

In STM – info usually stored in terms of
physical qualities of the experience (e.g.
What we saw, did, heard, tasted,
touched) especially sounds.

In LTM – info usually stored semantically
(meaning).
LTM DIFFERS FROM STM

The way forgetting occurs.

Info stored in LTM lasts longer and is
actually relatively permanent. Thus
memory is not actually forgotten, but
rather we are unable to retrieve it.
Atkinson-Shiffrin’s multi-store model of memory
Long Term Memory
TWO TYPES OF LTM STORES:
1. Procedural (implicit)– Memory of how to do
something, actions and skills, can be physical
or intellectual (knowing how) learned by
conditioning and practice. E.g. ride a bike, log
onto Internet.

Known as “implicit” as information can be
retrieved through performance rather than
intentional conscious recall or recognition.
Sometimes even difficult to recall when or
where we learned the actions required to do
something. (e.g. daughter of florist flower
arranging).
Atkinson-Shiffrin’s multi-store model of memory
Long Term Memory

Declarative (explicit)– Memory of specific facts or
events (knowing that) that can be explicitly stated or
“declared”. Called explicit as it is open to intentional
retrieval. E.g. name of a flower.
1. Episodic – Memory of specific life
events, personal experiences, autobiographical
(episodes) – often includes details of time, place,
psychological state of person when event occurred.
2. Semantic – Information we have about
the world. Specialised knowledge in areas of
expertise, (e.g. game of chess) academic
knowledge, (e.g. humans are mammals) important
places, rules (“I” before “e” except after “c”) meaning
of words, famous people etc. Facts that do not rely
on specific time or place.
Atkinson-Shiffrin’s multi-store model of memory
Long Term Memory

Tulving (1983) argues that semantic and
episodic systems often work together in
forming new memories.
Thus, the memory that ultimately forms
may consist of both an autobiographical
episode and semantic information.
EXPLICIT MEMORY

Refers to the memory of information that
can be consciously recalled. It is memory
with awareness. E.g. Pin number of debit
card.

Involves a deliberate and conscious
attempt to retrieve previously stored
information.

Tests of explicit memory are often of recall
and recognition.
IMPLICIT MEMORY

Refers to memories that cannot be consciously
recalled, but that affect behaviour and knowledge
involved in performing a particular task.

It is memory without awareness. (e.g. using knife
and fork, writing, swimming)

Testing for implicit memory usually involves some
kind of cognitive task that draws on past experience,
such as filling in the blank letters of a word. The task
may seem unrelated to any previous learning and
thus there is no conscious recall.

Often referred to an “nondeclarative memories”.
LANDMARK EVENTS

Landmark events are key events that are
significant to us and act as landmarks for
our memory. (e.g. driver’s licence test, end
of year formal)

Landmark events can be used to search
backwards and forwards through memory
to locate details about other events that
occurred at about the same time. They act
as retrieval cues (memory prompts) for
other information.
ORGANISATION IN LTM

Months of year example (p. 326) as evidence there
is some organisation to info in LTM (Tulving, 1983).

Research conducted 65 years ago participants were
asked to recall items from categories learned before
the experiment. They recalled them in bursts of
related items, paused briefly, then recalled another
group of items and so on (Bousfield & Sedgewick,
1944)

See example of Bower and Clark (1969) research on
LTM organisation (page 327) – boy, cap, rag, pram
etc.

L.A. 6.19
Semantic Network Theory

Models and theories have been developed to
describe and explain how the vast amount of
information in LTM is stored and organised.

Semantic Network Theory – first developed by
US psychologist Alan Collins and computer
scientist Ross Quillian in 1969.

The theory emphasises organisation of
information in terms of connections
(“networks”) based on meaning (“semantic”).
Semantic Network Theory

The theory proposes that information in LTM is organised
systematically (structured hierarchically) in the form of
overlapping networks (“grids”) of concepts that are
interconnected and interrelated by meaningful links.

Each concept is called a “node” and is linked with a
number of other nodes.

When we search memory we start by searching a general
area, we then follow the links to find the specific
information we need using the interconnecting nodes.

See Fig. 6.36 on p. 329

The word link game!
Semantic Network Theory

In reality, LTM contains 1000’s of concepts,
each with very many connections. E.g.
Network for animals that includes fish could
overlap with network for proteins that
includes fish, nuts, eggs, cheese, meat etc.

This system of storing information like a
filing system is highly efficient and effective
in retrieving information. It minimises the
duplication in storage of information due to
the multiple network links.
SPREADING ACTIVATION

The retrieval of info from LTM begins with someone
searching a particular “region” of memory and then tracing
associations for links among memories (concepts) in that
region, rather than randomly searching the vast
information stores in LTM.

In 1975, Collins published a revision of the theory with US
colleague, Elizabeth Loftus. This was a less rigid version
of the model and introduced the concept of spreading
activation.
Spreading activation proposes that activating one node
during retrieval increases the likelihood that associated
nodes become activated. The shorter the link between
nodes in the network, the stronger the association
between them and the less time it takes to activate (and
retrieve) related concepts to which they are linked.
Longer = weaker and therefore longer time to retrieve.
 The more nodes activated, the quicker the retrieval of info
from LTM.

SEMANTIC NETWORK THEORY
AND MAPS

Maps can be a useful analogy for understanding
semantic network theory.

Concepts are the “towns” and the links or
associations are the “roads”.

We store new concepts by building new roads
between the towns. Thousands of towns are
interconnected by kilometres of roads (links) to form
a vast interconnected network.

The longer the road connecting two towns the longer
it takes to activate and retrieve a concept.
(Schwarz & Reisberg, 1991)
Semantic Network Theory
Serial Position Effect:
Evidence for separate STM & LTM

The Serial Position Effect is a finding that free recall (recall
in any order) is better for items at the end and beginning of
the list than for items in the middle of the list.

Recall tends to be best for items at the end and then the
beginning and worst for those in the middle of the list.
Retention as a U shaped curve with a strong recency effect.
Primacy effect – superior recall for items at the beginning of
a list
 Recency effect – superior recall for 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.
SERIAL POSITION EFFECT

WHY? – Items at end still in STM so
remembered well because of attention and
rehearsal, Items at start have been transferred
to LTM. Middle items presented too late to be
adequately rehearsed and transferred to LTM,
too early to be held in STM without rehearsal
so more likely to be forgotten (unless
distinctive in some way).

Serial recall is when participants are required
to recall information in the order the items are
presented.
Serial Position Effect:
Evidence for separate STM & LTM
SERIAL POSITION EFFECT

Study conducted by US psychologists, Glanzer and
Cunitz (1966) found that recall of a list of words after a
delay of 30 seconds (beyond the limits of STM) the serial
position effect was not entirely observed. Recall was
better at beginning of list (probably as words were
transferred to LTM) and words at end of list no recency
effect was evident.

The serial position effect enables psychologists to identify
STM and LTM as different components of memory and to
describe STM and LTM as interacting in reference to
their functions in memory.

Findings inform TV advertisers who know that ads placed
at beginning or end of a series of ads during a break are
more likely to be recalled.