Memory Flashcards
Define coding, capacity and duration
Coding - how info is stored
Capacity - amount of info that can be stored
Duration - length of time info can be stored for
Outline the multi-store model of memory
- Atkinson and Shiffrin (1968)
Info enters from environment - enters sensory register
Info passed from SR to STM via attention
Info passed from STM to LTM via prolonged rehearsal
Info transferred from LTM back to STM via retrieval
In STM: maintenance rehearsal keeps info in for longer, info is used, or info lost via decay/ displacement
In LTM: info lost via decay
Define:
‘maintenance rehearsal’
‘decay’
‘displacement’
Maintenance rehearsal - repetition of info without thinking about its meaning to keep it in STM for longer
Decay - info lost due to it not being used often enough
Displacement - info lost due to too much info already stored in memory store
Outline the features of sensory register
(coding, capacity, duration)
CODING
- Sensory info coded into sub-stores
- E.g. visual info in iconic store, auditory info in echoic
- Crowder (1993) - iconic store holds info for few milliseconds, echoic store for 2-3 seconds
- Suggests that different sensory info must be coded into different sensory stores
CAPACITY
- Large
- Sperling (1960)
- Flashed grid of letters to ppts for 1/20th second - told to memorise grid
- Tone (pitch: high, med, low) would sound to indicate which row (1st, 2nd, 3rd) ppts should recall
- Found that recall of row was high - suggests that info already in SR, so it has large capacity
DURATION
- Very short
- Crowder (1993) - suggests that each sub-store has different duration, but overall SR duration is short
- Treisman (1964) - presented two identical auditory messages to ppts - one each ear - with delay between sounds - found when delay was 2 secs or less, ppts could identify messages as similar, when delay over 2 secs they got confused - suggests echoic tore has duration of around 2 secs
JJ
JJ
Outline the features of STM : coding
CODING
- mainly acoustically
- Baddeley (1966)
- 75 ppts given 1/4 word lists:
(a) acoustically similar, (b) acoustically dissimilar, (c)
semantically similar, (d) semantically dissimilar - Ppts given list of words in wrong order and asked to put into correct order
- Found that ppts given list A performed worst - 10% recall
- Suggests that STM codes info acoustically, so when words sound similar, we struggle to remember them as distinct, separate words
Outline the features of STM : capacity
CAPACITY
- 5-9 units
- Jacobs (1887)
- Serial span method
- Ppts presented with increasingly long list of numbers or letters - asked to recall in correct order
- Ppts reached full capacity when fail on 50% tasks
- Findings: capacity of letters = 7
capacity of numbers = 9
Outline the features of STM : duration
DURATION
- 19-30 seconds
- Peterson + Peterson (1959)
- Set of trigrams read to ppts whilst ppts counted down from a number in threes - then ppts asked to recall trigrams
- Found that correct recall of trigrams was 90% after 3 seconds - dropped to 5% after 19 seconds
LTM CODING
CODING
- Mainly semantically
- Baddeley (1966)
LTM CAPACITY
CAPACITY
- Unlimited
- Wagenaar (1986)
- Kept diary over course of 6 years, included 2,400 events
- Tested himself on recall of events rather than recall of dates of events
- Found he had very high recall of events
- Suggests LTM has extremely large capacity
LTM DURATION
DURATION
- Unlimited
- Bahrick et al
- 400 ppts aged 17-74 years
- Shown set of photos of people and names - asked to identify ex school
- Found: ppts who left high school in last 15 years had 90% recall of names and faces
ppts who left high school in last 48 years had 70% recall of faces and 80% recall of names - Suggests LTM has very large duration
Identify and define the three types of LTM
Episodic -
Semantic -
Procedural -
