Memory psychology Flashcards
What is the capacity of memory ?
How much data is held in each memory store
What does duration of memory refer to ?
A measure of how long a memory lasts before it is no longer available
What is coding in memory ?
The way information is changed so that it can be stored in memory ie can be stored visually, acoustically or semantically
How was capacity of STM assessed ?
- assessed in 1887 by Joseph Jacobs
- this was done using digit span technique which involved a participant having to immediately recall a sequence of letters or numbers which increased by one letter or number with each trial.
- found that average span was 9.3 for digits and 7.3 for letters
What is Miller’s magic number ?
- Miler reviewed psychological research in 1956 and concluded that span of short term memory was 7 items +- 2.
What are some evaluation points related to STm capacity research ?
- Miller’s OG findings have not been replicated. Cowan ( 2001) reviewed many studies, concluded that STM capacity is limited to 4 chunks.
- Simon ( 1974) found people had a short memory span for larger chunks
- Jacobs found that recall ( digit span method) increased with age. 8 year olds on average were able to remember less digits ( 6.6 digits) compared to 19 year olds ( 8.6 digits)
This shows capacity of STM isn’t fixed, individual differences play a role
How did Bahrick investigate the duration of LTM ?
Participants ( 400 people aged 17-74) were shown photos from high school year book to see how many classmates they could recognise. After 15 years of graduation, participants were 90% accurate in identifying faces, after 48 years this decreased to 70%.
Free recall condition ( had to list names) accuracy dropped from 60 -30% betw 15 and 48 years.
Who developed the multi store model of memory ?
Atkinson and Shiffrin, 1968
Describe the multi store model of memory
Sensory register - takes in sensory information through your sense organs. Very large capacity but very brief duration
If a person pays attention, focusing on one of the sensory stores, data is transferred to short term memory
Maintenance rehearsal to keep info in STM and to transfer it to LTM
Info disappears from STM if new information enters displacing the OG info. This is due to limited capacity of STM
How was the duration of STM studied ?
Studied by Loyd and Margaret Peterson ( 1959)
Participants were given a consonant syllable and a 3 digit number each trial ( 8 trials) ie THX 512
They had to try and recall consonant syllables after a retention interval of 3,6,9,15 or 18 secs.
During retention interval had to continuously count backwards from 3 digit number
What were the findings of Loyd and Peterson’s study ?
Participants on average were 90% correct after 3 seconds, 20% correct after 9 seconds and only 2% correct after 18 seconds. Shows the very short duration of STM (duration- under 18 seconds) without verbal rehearsal
What are some negative aspects of Peterson’s study ?
- experiment was artificial, lacking ecological validity as trying to memories consonant syllables - meaningless. Doesn’t reflect everyday memory activities
- STM results may have been due to displacement. Participants had to count backwards in retention intervals, may have “overwritten” syllables to be remembered.
What was Baddley’s study into coding in memory ?
Found that by testing STM recall and LTM memory recall of (acoustically similar , semantically different words) and (semantically similar, acoustically different words) that participants had difficulty in remembering acoustically similar word lists in STM but not in LTM. Also found that semantically similar word are easier to remember in STM, not LTM.
Backs up idea that STM is encoded acoustically and LTM is mostly coded semantically
Baddley’s coding study evaluation points
- in his study LTM was tested by waiting only 20 mins. Does this really test long term memory ?
- Nelson and Rothbart found evidence of acoustic coding in LTM - 1972
- Wickers et al found that STM sometimes uses semantic coding - 1976
Who developed the working model of memory ?
Baddley and Hitch ( 1974).
What store does the WMM address and what are the components ?
- addresses the STM store
- made up of central executive, episodic buffer, phonological loop and visuospatial sketchpad
Phonological loop
- processes auditory information and preserves the order of the information
- made up of the phonological store ( inner ear - holds onto the words you hear) and articulatory control process ( inner voice - holds info in your head through silent looping)
Central executive
controls attention and receives information from senses. Filters this before passing it onto the subsystems.
What is the capacity of the central executive ?
limited, only holds one type of info at a time. can switch very quickly though
What is the capacity of the PL ?
what can be said in around 2 seconds
What criticisms of the MSM led to development of WMM ?
- too reductionist. Baddley and Hitch believed the STM must be more complex than just a single unitary store
- too passive. Believed that STM was an active processor, not just a stopping-off station for transfer of info to LTM.
Visuospatial sketchpad
- used when you have to plan a spatial tasks ie getting from one room to another
- stores visual and spatial information
What are the two components of the VS ?
- Logie suggested that it can be divided into a visual cache and inner scribe
- visual cache - stores visual info ie form and colour of objects
- inner scribe - stores arrangement of objects in space
Episodic buffer
- added by Baddley ( 2000) realised that model needed a more general store
- integrates info from CE, PL and VS
- maintains a sense of time sequencing
Dual task performance studies, how do they support WMM ?
- dual task performance studies back up WMM.
- Baddley ( 1975) found that if you perform two visual tasks at same time, you perform them less well than separately
- if one of the tasks involves sound and the other is visual, no interference
- suggests that there are separate stores for visual and sound processing
weakness of dual task performance studies
- artificial tasks used challenge external validity
Case study support for WMM
- study of KF by Shallice and Warrington ( 1970)
- following brain injury from motorcycle accident, KF able to process letters and numbers but not auditory info ie meaningful sounds like ringing phone
- suggests that there are separate stores for visual and sound processing, and that in this case his brain damage restricted to PL.
Word length effect ( support for WMM)
- Baddley ( 1975) gave participants a list of long and short words. recalled more short than long words.
- this provides supporting evidence for the phonological loop having a limited capacity
Central executive as a unitary store is wrong
- Eshingger and Damasio 1985 studied EVR, who had cerebral tumour removed.
- performed very well on tests requiring reasoning, suggesting his CE was intact initially
- but his poor decision making skills suggests that his CE was not wholly intact
- may suggest that the CE is made of multiple components
What is a problem of using case studies of brain damaged patients to support WMM ?
-process of brain injury is traumatic so it may be this trauma rather than different parts of the brain being damaged causing the behaviour changes
- also case studies are unique, cannot be generalised to entire population
What is the encoding specificity principle and who was it proposed by ?
- proposed by Tulving and Thomson (1973)
- stated that memory is most effective if info present at coding is also present at time of retrieval
- also states that cues don’t have to be exactly right, but the closer to the OG cue, the more effective
What was Tulving and Pearlstone’s study in 1966 ?
- participants had to learn 48 words present in 12 categories. each word was presented as a category + word eg fruit - apple.
- free recall:approx 40% of the words recalled while 60% for cued recall
- provides evidence of encoding specificity principle + effectiveness of cues.
What is context-dependent forgetting ?
environmental cues present at encoding not present at retrieval
What was Godden and Baddley’s study on context dependent forgetting ?
- partcipants were scuba divers. had to learn a set of words either on land or under water. then tested either on land or under water.
- results showed that highest recall occurred when learning and recall environment matched.
What is state dependent forgetting ?
if mental state ie sadness or drunkenness present at encoding isn’t present at retrieval this results in forgetting
What was Goodwin et Al’s experiment ( 1969)?
- asked male volunteers to remember a list of words either when drunk or sober ( those in drunk condition drunk 3 times the UK driving limit)
- participants then asked to recall list, some drunk and some sober
- results showed that the information learned when drunk was recalled most effectively when in the same state ( drunken )