Short term memory Flashcards
what is the capacity of STM?
limited
7+/-2
what is the duration of STM?
limited
18-30 seconds
how is STM encoded?
acoustically
what did Miller (1956) do?
concluded stm can only hold 7+/-2 items at any one time
what did Jacobs (1887) study?
digit span technique
participants repeated an increasing string of numbers until they couldn’t anymore
found an average of 7.3 letters and 9.3 words
what is chunking?
stm can be enhanced by grouping together sets of digits or letters into meaningful units or chunks
what did Peterson and Peterson (1959) study?
asked participants to recall a set of trigrams after a delay of 3, 6, 9, 12, 15, or 18 seconds, during which they would do a distraction task
what did Peterson and Peterson (1959) find?
80% recall after 3 seconds
50% recall after 6 seconds
10% recall after 18 seconds
demonstrates how STM lasts no longer than 18-30 seconds
what did Baddeley (1966) study?
gave participants a list of words either acoustically similar or dissimilar, and words either semantically similar or dissimilar
what did Baddeley (1966) find?
when testing STM, participants had trouble remembering acoustically similar word lists, but could recall semantically similar word lists
when testing LTM, participants became muddled when recalling semantically similar words, but could recall acoustically similar word lists
suggests STM uses acoustic coding and LTM uses semantic coding
what did Conrad (1964) study?
participants shown 6 consonants shown rapidly on a screen (0.75 seconds)
condition 1: letters were acoustically similar (B, G, C, T)
condition 2 : letters were acousticaly dissimilar (F, J, X, M)
participants were told to write down the letters in the correct order.
Found more errors were made when recalling acoustically similar letters.
Concluded even though letter were displayed visually, they were encoded acoustically
