Download Key Knowledge 2

MEMORY
Year 12 Psychology Unit 3
Area of Study 2
(Chapter 6, Page 286)
Activity: 6.2
Memory

Storage & retrieval of information acquired through
learning:

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Internal record/representation of prior events/experiences.
A collection of complex interconnected systems:
Each serve a different purpose and operate in a very different
way.
 All receive, process and store info for future use.
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Memory is not perfect:
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We often fail to process & store all info we are exposed to or all
info that we need.
When receive sensory info, brain must select what is
attended to, processed and stored in various memory
systems.
:
INFORMATION PROCESSING SYSTEM

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Receives, organises, stores and recovers info.
Like a computer, it does not passively receive and store new
info, rather it actively alters and organises incoming info so
that it can be stored in a way that is easily retrieved.
Considered an information processing system because of three
key processes:
Encoding
• Conversion
of info into
a form that
can be
stored in
memory
Storage
• Retention
of info in
memory
Retrieval
• Recovery of
info from
memory
Encoding
Typed info is
converted into code
the computer
understands
Info/sensation is
converted into a form
that can be stored in
memory
Storage
Retrieval
Info is generally
stored on hard
drives
Pressing keys tells
the computer
which info you
need
Info is held in
the informationprocessing
system
Info is retrieved
so that we are
consciously
aware of it
Stages of Memory
Internal
stimulus
(thoughts)
External
stimulus
Rehearsal
Attentio
n
Sensory
Memory
Storage
Short-term
Memory
Forgetting
Long-term
Memory
Retrieval
Forgetting
Response
Forgetting
STAGES OF MEMORY:
SENSORY MEMORY

Function - receives sensory info from environment.

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Capacity - unlimited.

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Entry point for new info which is retained in original
sensory form (held as exact copies and not encoded).
Can store all sensory experiences (briefly).
Duration - 0.2sec-4sec.
Sensory impressions stored just long enough to
slightly overlap (so we perceive the world as
continuous, rather than disconnected sensations).
 Sensory info remains long enough for us to attend to
and select the info to be transferred to STM.

STAGES OF MEMORY:
SENSORY MEMORY
Not consciously aware of the majority of info
entering. Only become aware when attention is
directed to toward it in the process of
transferring it to STM.
 Any stimulus that is registered is available to be
selected for attention and for processing in STM.
 If sensory info is not attended to is it lost quickly
(within seconds at most) & completely.
 Info that is attended to is transferred to STM.

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Sensory info is stored in sub-systems called
sensory registers (e.g. iconic memory & echoic
memory).
SENSORY MEMORY:
ICONIC MEMORY

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From Greek word ‘icon’, meaning ‘image’.
Visual sensory memory or the memory of visual
sensory info

Stored in their original sensory form.

Unlimited capacity, brief duration (1/3 of a sec).

Info is held long enough for overlap with the next.

Example: movies- a series of individual frames is viewed as
a continuously moving image.
SENSORY MEMORY:
ICONIC MEMORY (STUDY)

George Sperling (1960): used a tachistoscope projector to
display sets of 12 letters for one twentieth of a sec.
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Could only recall 4-5 letters.
Reported that they had retained an image of all letters for an
instant. However, by the time they had written down 4-5 letters
the remaining letters had faded from memory.
To test whether all letters were actually retained in iconic
memory, sounded a tone just after the letters were flashed.
High tone – recall top row; Medium tone – recall middle; Low tone
– recall bottom.
Results indicate that all the letters were stored in iconic memory
(could remember that row with perfect accuracy).
Delaying the tone found out how quickly images fade in iconic
memory.

Typical duration = 0.2-0.4sec.
SENSORY MEMORY:
ECHOIC MEMORY

Auditory sensory memory or the memory of
auditory sensory information.
Processes all sounds.
 Stores sounds in original sensory form.
 Holds info for 3-4sec.
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This relatively longer holding time is important for
understanding speech:
We hear words as syllables (individual sounds)
 Cannot identify word until all sounds have been heard, so they
need to be stored long enough for all the sounds to be received
and then combined.

SENSORY MEMORY:
ECHOIC MEMORY (STUDY)

Activity: 6.6
Cowan et al. (2000): participants focused on
reading a story & ignored the numbers they heard
being spoken.
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Signal sounded at random times during their reading.
Participants then had to repeat the last few numbers
heard.
Could accurately repeat if the signal was presented
immediately after the last spoken number.
Recall diminished when time between last number and the
signal was delayed up to about 10sec.
Participants reported being only vaguely aware of the
spoken numbers while they were reading, but when the
signal sounded they could still ‘hear’ the last few numbers,
could shift their attention to those numbers and could
therefore repeat them.
SENSORY MEMORY:
STORING & FILTERING

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Can store virtually all the info provided by sensory
receptors but the info fades rapidly (rate varies among
the different senses).
Info is lost & replaced so rapidly that we are rarely
aware of our capability to store sensory info.
Acts as a filter to keep out irrelevant and unimportant
information that could clutter our sensory stores.
Would be frustrating, confusing, dangerous & inefficient to
process EVERYTHING that reached sensory memory or
attend to all the sensory info that our receptors detect.
 E.g. if out walking & hear car brakes screeching, will attend
to & act on that incoming sensory info for your safety. In
doing so, you ignore all other incoming info (other sounds,
smells, etc.).

SHORT TERM MEMORY

Temporarily holds all info you are
consciously thinking about at any one moment.
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Receives info from SM and/or LTM.
Limited storage capacity for brief periods (longer
than SM), unless info is renewed in some way:
Consciously repeating/rehearsing it;
 Using the information.

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Info is encoded (unlike sensory memory).
SHORT TERM MEMORY

SO, once info reaches STM there are
three options:

Info can be retained in STM:
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Info can be discarded:
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By working on (attending to/using) or rehearsing the
information.
If it is not encoded, used or consciously rehearsed.
Info can be sent to LTM for storage:

Requires further encoding.
SHORT TERM MEMORY
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SO, once info reaches STM there are
three options:
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Info can be retained in STM:
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Info can be discarded:
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By working on (attending to/using) or rehearsing the
information.
If it is not encoded, used or consciously rehearsed.
Info can be sent to LTM for storage:

Requires further encoding.
SHORT TERM MEMORY:
AKA

STM also known as ‘working memory’ because it is
the part of memory where info you are consciously
aware of is actively ‘worked on’:
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Processing info from sensory memory;
Using/manipulating info from LTM.
Info only remains while we consciously process,
examine or manipulate it.
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‘WORKING MEMORY’
Like a mental ‘workspace’ (temporary storage facility) for
info used in conscious cognitive activity.
Computer: process new info from keyboard (sensory)
& retrieve stored info from hard disk (LTM).
SHORT TERM MEMORY:
DURATION
Info can be held for a short period (18-20secs).
 Info can be kept in STM for longer than the normal
18-20sec by maintenance rehearsal (see slide
further on).
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Margaret and Lloyd Peterson (1959): use of
trigrams to demonstrate duration of STM.
Memorise meaningless groups of 3 letters;
 Given a distractor (e.g. count backwards by threes);
 After 3-18sec interval, recall trigrams.
 Longer interval = less recall.

Activity: 6.7
Page 305
SHORT TERM MEMORY:
CAPACITY

Limited amount of info can be held at any one
time:
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7 + 2 (regardless of type of info, only 5-9 pieces held).
When STM is full, new items can only be added by
pushing old ones out.
 Space in STM also filled when info is temporarily
brought back form LTM.
 Info in STM is lost through decay (not being used)
and displacement (being pushed out).
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Chunking can be used to manipulate our capacity.
SHORT TERM MEMORY: BADDELEY & HITCH (1974)
MODEL OF WORKING MEMORY
Working memory has 3 sub-systems:
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Verbal Working memory (phonological loop): stores a limited number of sounds
(phonemes), such as words, for a short time.
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Time it takes to pronounce each word impacts on amount you can retain in memory.
Shorter words = can rehearse more in a shorter period.
Many longer words = some info lost from the limited verbal working memory system.
Visual Working memory (visuospatial sketchpad): temporarily stores visual &
spatial information, such as the location of objects in the environment.
Central executive: integrates (does not store) information from the verbal &
visual storage system, as well as information retrieved from LTM.
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Plays important role in working on info held in the two other sub-systems.
Involved in processes such as calculation of mental arithmetic, decision-making.
Functions like an office executive: collects info from assistants (other sub-systems) then
decides what deserves attention (to process into LTM) and what should be ignored (&
consequently lost).
Suppresses irrelevant info from our conscious thought.
Helps you decide what to do next, or what not to do.
Can only perform one task at a time.
SHORT TERM MEMORY: BADDELEY & HITCH (1974)
MODEL OF WORKING MEMORY
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Limitation: Doesn’t explain how working memory actually
links with LTM, SO 4th component added in 2000:
Episodic Buffer: sub-system of working memory that
enables other components to interact with LTM.
Not yet fully described;
 Limited-capacity temporary storage system that holds about 4
chunks of information in any form;
 Can combine auditory & visual-spatial info and connect those
sub-systems with LTM;
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Episodic: ‘Pulls together’ streams of information from elsewhere
(working memory and LTM) then combines them into ‘episodes’ like
movie scenes.
Buffer: Provides space to process information into episodes (edit, reorder
information in an organised and meaningful way).
Also under control of the central executive.
Activity: 6.14
EPISODIC BUFFER
CAN BE SEEN AS A
‘MENTAL
WORKBENCH’
Pages 318 & 319
Models for Explaining Human Memory:
Activity: 6.3
Atkinson-Shiffrin Multi-Store

Memory as three distinguishable components:
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Sensory Register – Entry point for all new
information from the external environment.
Short-Term Store – ‘Temporary working memory’
which holds information we are consciously aware of.
Long-Term Store – Holds information relatively
permanently in a highly organised way (with an
essentially unlimited capacity).
Model played important role in shifting study of
human memory away from idea of a single
system; still a useful framework, although some
of its underlying ideas have since been
challenged or even refuted (see page 295).
If sensory info not
attended to, its
‘memory trace’ (neural
imprint) decays.
Rehearsal is needed to
maintain information
in short-term store.
Info may bypass shortterm store & transfer
directly to long-term
store. BUT model did
not explain how this
occurred.
Considered possibility
that there may be
different sensory
registers for different
types of information
(visual; auditory).
Models for Explaining Human Memory:
Activity: 6.4
Atkinson-Shiffrin Multi-Store Model

Structural Features: Permanent, built-in, fixed
features of memory.
Three different stores;
 Their functions;
 Their storage capacities;
 Their duration (how long information is held).
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Control Processes: Selected and used by each
individual & may vary across situations.
Under conscious ‘control’ of the individual.
 Examples: attention, rehearsal, retrieval.
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SHORT TERM MEMORY:
EFFECTS OF REHEARSAL
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Rehearsal: process of actively manipulating info so
that it can be retained in memory.
Maintenance Rehearsal: repeating info over and
over to retain it in STM.
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Can be verbal or non-verbal;
Can be retained indefinitely in STM, if not interrupted;
Does not always lead to long-term retention;
Does not assist encoding info for transfer to LTM;
Amount of new info that can enter STM is restricted
because of limited storage capacity (7 + 2).
SHORT TERM MEMORY:
Activity: 6.11
EFFECTS OF REHEARSAL
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Elaborative Rehearsal: process of linking new info in a
meaningful way with info already stored in memory (or
with other new info), to aid in its storage and retrieval
from LTM.
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Use of elaborative rehearsal strategies = info more likely to be
stored in LTM.
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The more the info is linked with other experiences the more likely
it will be remembered.
More active than maintenance rehearsal.
 More effective (ensures info is encoded well) & efficient in
storing meaningful info.
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Self-reference effect: relate new info to personal experiences
and our personal situation – encoding is enhanced and
therefore we are more likely to remember it.
SERIAL POSITION EFFECT
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Recall is better for items at the end & beginning of a
list. The graph results in a U-shaped curve. (p.369)
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Primacy Effect: superior recall of items at the beginning.
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Recency Effect: superior recall of items at the end.
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Receive more attention & rehearsal, so transferred to LTM.
Remembered because they are still in STM.
Middle items too late to be adequately rehearsed and
transferred into LTM, but too early to be held in
STM without rehearsal.
Serial position effect only evident if test memory
immediately after learning list of items.
SERIAL POSITION EFFECT
Page 331
SHORT TERM MEMORY: CAPACITY
CHUNKING

Grouping separate bits of info into a larger single
unit or ‘chunk’ of info.
Increases the amount of info held in STM.
 Improves capacity, however for permanent storage
the info MUST STILL be transferred to LTM.
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Phone number length and layout:
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5-5-7-8-1-9-3 versus 5578 8193
Applying meaning/significance to groups:
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C I A N S W F B I versus CIA NSW FBI
SHORT TERM MEMORY: CRAIK & LOCKHART (1972)
LEVELS OF PROCESSING FRAMEWORK
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‘Depth’ of information processing during learning
determines how well it is stored in LTM.
Memories are encoded, organised & stored in LTM
semantically:
More meaning given to information = better storage.
 Continuum of processing levels: shallow to deep.
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Shallow: Attend to superficial details.
Deep: Apply more meaning to the information.
Limitation: difficult to quantify and measure levels of
processing.
SHORT TERM MEMORY: CRAIK & LOCKHART (1972)
LEVELS OF PROCESSING FRAMEWORK
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Craik & Tulving (1975) experiment.
Words flashed on screen for participants to process:
Semantically (meaning of the word);
 Acoustically (sound of the word);
 Visually (appearance of the word).
 Deeper processing (semantic encoding) led to better memory.
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Page 313
LONG TERM MEMORY
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Holds unlimited amounts of info for a long period of
time (the ‘memory warehouse’).
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Differs to STM in how info is retrieved, the form it is
stored, and the way it can be forgotten.
We retrieve info from LTM using retrieval cues.
Info retrieved from LTM is held in STM while it is being
used.
Once info is used it can be transferred back to LTM for
continued storage.
Info stored in LTM is potentially permanent (excluding
brain injury or complications).
Two storage types: Procedural & Declarative Memory
LONG TERM MEMORY:
PROCEDURAL MEMORY
 Memory
of actions and skills that have been
learned previously and involve knowing ‘how to
do something’.

Also called implicit memories because it’s often hard
to recall when/how we learned to perform them.
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Difficult to put into words or explain how you knew
the information.
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Riding a bike. You just ‘know’ how to do it, even if it’s been a
long time since you rode one. You would find it difficult to
explain every behaviour or movement required.
LONG TERM MEMORY:
DECLARATIVE MEMORY

Memory of specific facts or events that can be brought
consciously to mind and explicitly stated or declared.
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Also called explicit memories (‘knowing that’).
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Episodic Memory: holds info about specific events or personal
experiences.
• Include details of time, place and the psychological/ physiological
state the person was in when the event occurred.
• Like a mental diary, recording episodes we experience.

Semantic Memory: stores info we have about the world.
• Includes our specialised knowledge in areas of expertise,
academic knowledge, rules, everyday general knowledge and the
meaning of words.
• Facts not dependent on place or time.

Both episodic and semantic memory are linked and often
hard to separate.
LONG TERM MEMORY: ORGANISATION
SEMANTIC NETWORK THEORY

Info is organised systematically in overlapping networks of concepts
that are interconnected and interrelated by meaningful links.
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Each concept (called a node) is linked with other nodes.
When we retrieve info the activation of one node causes related nodes to be
activated.
Each concept is organised into a hierarchy, with subcategories.
At each node, certain characteristics of that concept are stored.
LTM contains thousands of concepts.
Effective means of storage, enables efficient and effective retrieval of info.
Minimises duplication.
Retrieval begins by searching a particular region then tracing associations
for links among concepts in that region (operates like a search engine).
Specific retrieval cue activates the relevant node/s (stored memories), which
in turn activate other nodes they are linked to (related memories).
Shorter link = stronger association & less time taken to activate (retrieve).
 Longer link = weaker association & more time taken to activate (retrieve).
 More nodes activate = quicker retrieval of info from LTM.
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Activity: 6.21
Page 329