1🍓Coding, Capacity & Duration of Memory- Memory PAPER1 Flashcards
Coding
-memory often process where physical ‚trace’ of information about past stored
-the way memory encoded describes format that information is converted to when storing and retrieving such ‚traces’
types of encoding:
-visual
-acoustic
-semantic
-eg may try retain phone number by repeating to self (acoustically) or imagining piece of paper you saw it written on (visually)
Capacity
-maximum amount of information that can be retained in memory
Short term memory (STM)
-Miller (1956) STM research ‚the magical number seven’ concluded adult STL capacity avarage 7(+ or -2)
-said capacity csn be increased through chunking, converting string items into number of large more memorable chunks, 7 chunks of digits instead of 7 digits
Long term memory (LTM)
-assumed to have unlimited capacity, no research able to measure finite number, difficult
Duration
-how long memory ‚trace’ (info about past) can be held for before forgotten
-attending to and rehearsing information helps retain information in STM for duration approximately 30 seconds and consolidate into LTM
-duration of LTM is considered to be anything greater than 30 seconds, maximum duration appears to be unlimited
Research on coding
BADDELEY (1966)
Baddeley (1966) AIM
To test whether LTM encoded acoustically or semantically
Baddeley (1966) METHOD
-four groups shown slideshow including 10 words, displayed for 3 seconds each
-acoustically similar words e.g hat, cap, sack
-acoustically dissimilar words e.g cow, dad, led
-semantically similar words e.g big, large, huge
-semantically dissimilar words e.g hot, pen, men
-learning phase seperatley from testing phase by interference test where participants had to hear and write numbers (recall test)
Baddeley (1966) RESULTS
-acoustically similar words were harder to recall than acoustically dissimilar words
-semantically similar words were harder to recall than semantically dissimilar words
Baddeley (1966) CONCLUSION
-STM is encoded acoustically
-LTM is encoded semantically
Memory span
-longest list of items person csn repeat back in correct order immediately after hearing or seeing them
-known as digital span when numbers are used
Research on capacity
-Jacobs (1887)
-Miller (1956)
Jacobs (1887)
-found that mean number of letters on avarage to be correctly recalled was 7.3
-for numbers 9.3
Miller (1956) AIM
To investigate the capacity of STM
Miller (1956) METHOD
-literature review of published investigations into perception and STM from the 1930s to 1950s
Miller (1956) RESULTS
-existing research suggested organising stimulus input into series chunks enabled STM to cope with about 7 chunks
-this is why more than 7 digits, words and musical notes csn be remembered successfully
-when we try remember phone number we chunk it into groups
Miller (1956) CONCLUSION
-organisation (or encoding) can extend the capacity of STM and enable more information to be stored there
Research on duration
-Peterson & Peterson (1959)
-Bahrick (1975)
Peterson & Peterson (1959) AIM
-to investigate how different short intervals containing an interference task affect the recall of items presented verbally
-to infer the duration of STM
Peterson & Peterson (1959) METHOD
-participants 24 female university students
-verbal items tested for recall were 48 constant nonsense syllables e.g JBW or PDX spelled out
-named trigrams
-researcher spelled syllable out and then immediately said three digit number
-participants had to count down backwards either in 3s or 4s from that number
-this was to prevent repition of trigram by participant
-at end of pre set interval between 3 and 18 secs red light went on participant had to recall trigram
Peterson & Peterson (1959) RESULTS
-longer the interval the less accurate the recall
-at 3 secs 80% of trigrams correctly spelled
-at 18 secs only 10% correctly recalled
Peterson & Peterson (1959) CONCLUSION
-STM has limited duration of approximately 18 secs
-if unable to rehearse information it will not be passed to LTM
-support for multi store model and idea of discrete components
Bahrick (1975) AIM
-to investigate duration of LTM
Bahrick (1975) METHOD
-under 400 american uni graduates shown photographs from high school year book
-for each photograph given group names and asked to select name that matched photographs
Bahrick (1975) RESULTS
-90% participants able to correctly match names and faces 14 years after graduating
-60% participants able to correctly match names and and faces almost 50 years after graduation
Bahrick (1975) CONCLUSION
-people could remember certain types of information such as names and faces for almost a lifetime
-support multi story model and idea that out LTM has lifetime duration (at least 47 years) and is semantically encoded
