Transcript working memory

Memory
Short-Term Memory & Working Memory
THE MULTI-STORE MODEL OF MEMORY

Sensory store
Holds sensory information for a very brief time
 Information not attended to is lost
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Short-term memory (STM)
Holds information for limited time
 7-9 items capacity
 Information not rehearsed is displaced
 Once rehearsed information is transfered to LTM
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Long-term memory (LTM)
Permenant memory store
 Unlimited
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ATKINSON & SHIFFIN MODEL
SENSORY MEMORY
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Iconic store
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Visual information is stored
Echoic store
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Auditory information is stored
SHORT-TERM STORE
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Example: To remember a telephone number
Limited capacity and fragile storage
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Any distraction causes forgetting
The recency effect:
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Last few items in a list are better remembered that the first or middle
words.
The primacy effect:
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First few words remembered better than the middle words.
SHORT-TERM STORE-Duration
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Peterson and Peterson (1959)
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Task of remembering three letters while counting backwards by threes.
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The ability to remember the three letters declined to 50% after 6
seconds.
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This indicates that information is lost from short-term memory rapidly.
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This may be because counting backwards results in interference or
diverts attention away from STM.
SHORT-TERM STORE: Rehearsal
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Rehearsal maintains information in short-term memory.
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Words that are shorter and can be rehearsed rapidly should
remain in STM.
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Words that take longer to reheasre will decay from STM.
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Some evidence supports this while others do not.
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Studies which do not support it cast doubt on the fact that short-term
memory depends on rehearsal.
SHORT-TERM STORE: Forgetting
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Forgetting from STM:
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Decay
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Proactive Interference (disruption of current learning by previous learnt
material).
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Example: Trying to study cognitive psychology after studying for
neuropsychology.
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Neuropsychology inteferes with cognitive psychology learning.
WORKING MEMORY
Baddeley and Hitch (1974) and Baddeley (1986)
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Central Executive
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Resembles attention
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Controlling unit
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Phonological Loop
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Stores speech-based information
Visuo-spatial sketchpad
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Limited capacity
Stores visual-based information
Episodic buffer
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Integrates information from the Visuo-spatial sketchpad and Phonological
loop. Controlled by the Central Executive
WORKING MEMORY
WORKING MEMORY
WORKING MEMORY
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Assumptions
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If two tasks use the same componet, they cannot be performed
successfully together.
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If two tasks use different components, it should be possible to
perform them well together.
WORKING MEMORY
PHONOLOGICAL LOOP
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Phonological Similarity Effect
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Recall of words is better when words sound different than when they
sound the same.
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Example: Recall is better for words such as UP and ODD, than HE
and KNEE
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Speech based reherasal within the phonological loop
WORKING MEMORY
PHONOLOGICAL LOOP
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Word Length Effect
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Better recall of shorter words than longer words.
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Takes longer time to rehearse the longer words which causes greater
levels of decay.
WORKING MEMORY
PHONOLOGICAL LOOP
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A passive phonological store directly concerned with speech
production
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An articulatory process linked to speech production that gives access
to the phonological loop
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Auditory presentation of words gain direct access to the phonological store
Words presented visually need to be articulated then gain access to the
phonological store – access is therefore indirect
Word length effect therefore is dependent on articulatory rehearsal
PHONOLOGICAL LOOP
VISUO-SPATIAL SKETCHPAD
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Temporary storage and manipulation of spatial and visual
information.
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Two components:
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The visual cache
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Stores information about visual form and colour.
The inner scribe
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Deals wıth spatial and movement information.
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Rehearses information in the visual cache.
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Tranfers information from the visual cache to the central executive.
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Involved in the planning and execution of body and limb movements.
CENTRAL EXECUTIVE
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Most important component of working memory.
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Damage to the frontal lobes can cause impairements to the
central executive.
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Functions:
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Switching attention between tasks.
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Planning subgoals to achieve goals.
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Selective attention and inhibition.
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Updating and checking the contents of working memory.
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Coding representations in working memory for time and place of
appearance.
CENTRAL EXECUTIVE
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Single or multiple central executive functions?
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Evidence favours the latter (i.e., multiple)
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Three central executive functions:
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Shifting attention
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Updating information
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Response inhibition
All share common processes (e.g., attention) but also function
independently.
EPISODIC BUFFER
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Stores and intergrates information from both the phonological
loop and visuo-spatial sketchpad.
MEMORY PROCESSES
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Encoding
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Storage
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Retrieval
TESTS OF MEMORY
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Free recall
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Hardest type of recall
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Least environmental support
Cued recall
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Second hardest type of recall
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Provides some environmental support
Recognition
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Easiest type of recall
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Memory best under recognition
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Provides environmental support
TEST OF MEMORY
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Explicit Memory
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Conscious and deliberate retrieval of past events
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Exam
Implicit Memory
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Memory not involving consious recollection
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Word stem completion
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Complete the word ‘Ten___’
LEVELS OF PROCESSING
Craik and Lockhart (1972)
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Attentional processes at learning determine what information is
stored in long-term memory.
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Various levels of processing
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Shallow processing:
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Physical analysis of stimuli.
Deep or semantic processing:
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Analysis of meaning.
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Deep or semantic processing produce more elaboration, longer lasting and
stronger memory traces than shallow processing.
LEVELS OF PROCESSING
Craik and Lockhart (1972)
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Two types of rehearsal:
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Maintenance rehearsal
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Repeating information to remember it.
Elaborative rehearsal
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Involves semantic-meaning processing.
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Information which is sematically processed will be trasnfered to long term
memory.
ELABORATION
Craik and Tulving (1975)
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Elaboration of processing is important
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Aids LTM
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The kind and amount of elaboration is critical for recall
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Precise semantic encodings are better
DISTINCTIVENESS
Eysenck (1979)
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Distinctive or unique memory traces are recalled more than non
distinctive memory traces.
THEORIES OF FORGETTING
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Ebbinghause studied forgetting with himself being the only
participant.
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He learned and recalled a list of nonsense syllables which had
no meaning over several trials.
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Forgetting was very rapaid over the first hour after learning
which slowed down thereafter.
REPRESSION
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Freud argued that anxiety provoking material is often unable to
gain access to conscious awareness, known as repression.
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Adaptive function to maintain psychological well-being.
INTERFERENCE THEORY
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Dominant approach
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Ability to remember currently learned information can be
disrupted with previously learnt material or what we learn in the
future.
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Proactive Interference
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Previous learning interferes.
Retroactive Interference
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Later learning disrupts earlier learning.
CUE-DEPENDENT FORGETTING
Tulving (1974)
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Trace-Dependent Forgetting
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Information is no longer stored in memory
Cue-Dependent Forgetting
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Information is stored in memory but cannot be accessed
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Cue-dependent forgetting associated with external cues (categories)
and internal cues (mood)
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If the mood of retrieval is different from learning information will be
blocked
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The mood effect is stronger for positive than negative moods and for
personal events
CONSOLIDATION
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Is a process lasting for several hours or even days which fixes
information in LTM.
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‘New memories are clear but fragile and old ones are faded but
robust’ (Wixted, 2004, p.265).
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Consolidation process for one memory can be distrupted by
other memories, so better consolidation will take place during
sleep than awake as fewer memories are being formed.
CONSOLIDATION
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Sleep will aid the consolidation period early in the retention
interval, as, thats when memories are vulnerable to disruption.
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Those who slept after learning remembered 81% than those who
slept later 66%.