Short and Long term memory Flashcards
give a history of memory:
Hint (Plato, Freud and James)
First idea of STM: Plato (424-348bc) (wax model)
Distinctions between 2 types of memory:
Late 19th century
Freud: Surface ( transitory, temporary) and Deep (Permanent)
William James: Primary (stream of consciousness) and Secondary ( Memory)
Outline the three memory systems
Sensory memory
Stm (working memory)
Ltm `
Outine sensory memory
A large capacity, literal record of perceptual experience
Lost very quickly (transient)
Sensory memory: Visual and auditory
• Iconic memory (or ‘Visual sensory register’) – Holds visual input for 50 msec – Representation is pre-categorical (literal record of percept)
• Echoic memory (or ‘Auditory sensory register’) – Holds auditory input for 2-3 seconds
give a piece of research conducted to study iconic element of sensory memory
Sperling’s (1960) Iconic Memory Research
Whole report procedure – Flash a matrix of letters and digits for 50 milliseconds
– Identify as many items as possible
– Participants typically remembered 4 items
• Partial Report Procedure
– Flash a matrix of letters and digits for 50 milliseconds – Participants are told to report items in just one row – Participants were able to report any row requested
Outline the model fo free recall
serial position curve
first few items recall high…reall then drops on next few items before rising again for last
excellent recall on kst few items= recency effect
excellent recall on first few items= primacy effect
-less pronounced than recency effect
if recall delayed by additional task- no recency effect seen
Glanzer and Cunitz (1966)
first few items held in LTM
last few held in STM
-extra attentional tasks eliminate STM contribution so recency disappears
What is the capacity
code
duration
of STM?
capacity: digit span: digit span- 7+/- 2 (Miller, 1956) items - can be improved via chunking Cowan 2000- 7 is an over-estimate (more like 4 +/-1)
Code: Short-term memory thought to be based on a verbal (“phonological”) code
duration: short (around 30 seconds)
Evidence for phonological coding in short-term memory
• Phonological similarity effect – words that ‘sound’ alike more poorly recalled than dissimilar sounding words (Baddeley (1966a, cited in Baddeley, 1990))
what is the evidence for phonologica lencoding in memory
Word length effect: recall of words is worse for longer words than for shorter words
• The word-length effect is eliminated if phonological coding is prevented through ‘articulatory suppression’ (e.g., counting or repeating an Irrelevant word, “the, the, the…”)
Outline the multistore model of memory
stimuli –> sensory store –> STM (maintance) –> rehersal–> LTM
Maintenace rehearsal
Then transferred from STM to LTM by rehearsal
To be recalled has to be transferred back to STM
(Attkinson and shiffrin image)
Outline baddeleys working memory model
model of STM
imput -> sensory memory -> attention–> central exec–>VSS/phonological loop(artiulary control and phonoligcal store) –> episodic buffer –>LTM
Characteristics of Ltm?
Duration
Capacity
Code?
Duration: decreases rapidly at first but slows down after 3 years
capacity: Standing (1973): “Learning 10,000 Pictures”
- Participants could recognise 133/160 pictures selected randomly from about 10,000 pictures studied earlier - Must have had a long-term memory trace of ~6,600 of the pictures
- “The capacity of recognition memory for pictures is almost limitless.” - Pictures better recognised than words. Why…?
Because of dual coding (Paivio, 1969)- seeing an image and describing it yourself
Outline the dual coding hyptohesis
Paivio, 1969
- seeing an image and describing it yourself
- 2 methods of encoding
- 2 routes of retreival (visual and verbal)
- theroefore easier
Outline the differences between implicit and explicit memory
• Explicit memory – when retrieval of a memory is deliberate/requires conscious recollection. Also called declarative memory
- note that short-term remembering is also typically ‘explicit’
• Implicit memory – when behaviour indicates that memories are being retrieved in the absence of a deliberate, conscious, attempt to retrieve them
E.g., - procedural memory
- much of recognition memory is implicit (e.g., for very familiar faces; the meaning of common words)
What are the sub-types of explicit memory:
Explicit memories typically divided into two types (Tulving, 1983):
– Semantic memories (general knowledge about the world)
– Episodic memories (memories for experiences/events)
what are the differences between episodic and semnatic memory types?
source of info: snesory experience (episodic) comprehension (semantic)
units of info: events (epsiodic) Knowledge (semantic)
orgnanisational: time-related (episodic) conceptual(semantic)
emotional content of memory: more important (episodic) less importnat (semantic)
liklihood of forgetting great (episodic) small (semantic)
time reuqired to remember great (episodic) small (semantic)
how is semantic memory organised?
Collins, A. & Quillian, M. (1969). Retrieval time from semantic memory. Journal of Verbal Learning and Verbal Behavior, 8, 240-247
semantic knowledge organised like a Hierarchy- reaction times slower –> takes a while to get down the pathway.
)
tested using facts of association and reaction times e.g. should be easy to decide “cananry is yellow” because they’re stored on same leel of hierarchy however “cananry” can fly” two nodes stored seperately so should take longer
-found prediction correct
However, Conrad found that when you controlled for familiarity in this study, the effect disappears
