Memory 3 STM Flashcards
sensory memory,
give an example which psychologists use to describe sensory memory.
Persistence of vision: frames in film
Lingering of visual stimulus
Sperling (1960):
Sperling (1960): measuring capacity and duration of iconic (visual sensory) memory
Participants presented with an array of 12 letters for 50 milliseconds (i.e., 1/20 of a second)
Asked to recall as many letters as possible
Whole report method: 4.5 (out of 12) letters recalled
Sperling (1960): measuring capacity and duration of iconic (visual sensory) memory
Under-estimation of capacity OR ICONIC MEMORY
WHY?
Sperling (1960): measuring capacity and duration of iconic (visual sensory) memory
Under-estimation of capacity of iconic memory under whole report method: memory may have FADED AWAY by time of recall
FADED AWAY AS THEY ARE ACTUALLY RECITING THE LETTERS THEY REMEMBER
Partial report method: Row to be recalled indicated by high-/medium-/low-pitched tone after presentation of letter array
Full capacity of iconic memory (Y, out of 12) to be extrapolated from partial report result (Z, out of 4)
Y = Z * (12 ÷ 4) = Z * 3
capacity for visual memory was found to be more than twice the original estimate when it was studied by Sperling in 1960 using the partial report method .
what happened?
Participants were asked to report back only only letters from a particular row. When they were told which row to recite (using a high, medium or low tone to indicate which row). when this tone sounded immediately they could remember an average of 3.2 out of 4 letters. when the sounding of the tone was delayed by increments of 100m/secs the recall rate dropped off sharply. Indicating that the capacity for visual memory recall is very high (9.6 out of 12 i.e. 3.2 x 3 ) but the duration is very low 0.5 - 1 m/second.
Peterson & Peterson (1959):
Peterson & Peterson (1959): measuring duration of short-term memory
REHEARSAL
Also known as the Brown-Peterson task
Participants received three letters to remember + a number (e.g., Y N F 37)
Began counting backwards by 3s from given number (e.g., 37, 34, 31, 28, ….) – to prevent rehearsal of letters
After counting for various amounts of time, stopped counting and tried to recall letters
Original conclusion: without rehearsal, information can be held in STM for only a few seconds, and it decays almost completely after 18 seconds.
Keppel & Underwood (1962)
questioned the analysis of average performance over many trials in the Peterson and Peterson trials.
– there was interference across trials
participants were getting confused .
Keppel & Underwood (1962) analysed performance on participants’ FIRST TRIALS ONLY
Conclusion: without rehearsal, information can be held in STM for up to 18 seconds.
Miller (1956):
Miller (1956): measuring CAPACITY of short-term memory
DIGIT SPAN TEST
Digit span = length of longest string of digits that can be recalled in the right sequence without error
Classic view (e.g., Miller, 1956): Magical Number 7 ± 2 Modern view (e.g., Cowan, 2001): only 4 items
problem with the digit span test;
chunking
people can recognise groups they know from before, i.e. area code 0207 or seemingly random groups of letters which are intact acronyms like bbc or kgb
think about CHASE and SIMON 1973 chess study
Conrad (1964):
Conrad (1964): auditory/phonological coding in STM
STM IS MAINLY SOUND BASED
Participants saw brief presentation of a number of letters and then recalled, by writing, the letters in the order they had been presented
Errors in recall were analysed
Letter more likely to be mis-recalled as a similar-sounding letter than as a dissimilar-sounding letter: for example, B more likely to be mis-recalled as P or V than as S
EVEN though the presentation and recall were visual ……
Participants used a speech based STM to handle the task
Della Sala et al. (1999): visual coding in STM
Visual Patterns Test (VPT)
Saw test pattern (always half filled, half unfilled) for three seconds
Attempted to re-produce pattern (‘visual recall’)
Average performance - recall of positions of 9 filled cells
researchers took care to not let any of the shapes be recognisable and thus CHUNKABLE
FILLED HALF AND HALF. SEEN FOR THREE SECONDS. 9 CELLS IS AVERAGE MAX RECALL
THREE components of BADDELELY AND HITCH’S working memory theory.
when?? and what
1974
1) the PHONOLOGICAL LOOP processes VERBAL and AUDITORY information
2) the VISUAL-SPATIAL SKETCHPAD
3) While the CENTRAL EXECUTIVE coordinates the two while focusing attention on relevant information
eg person driving a car while talking to a person giving directions, will tune out the radio to listen to the passenger.
PHONOLOGICAL LOOP
Phonological loop =
phonological store (SOUND BASED INFO IS STORED)
+ articulatory rehearsal process (INFO IS REFRESHED AND KEPT “ALIVE”)
Evidence for phonological loop
- Phonological similarity effect (Conrad, 1964)
- WORD LENGTH EFFECT. (e.g., Baddeley et al., 1975): number of items that one can recall in short-term serial recall (as in digit span task) = number of items that one can say aloud within two seconds.
It depends on one’s speech rate and the lengths of the words to be recalled.
Evidence for the Phonological Loop
Evidence for phonological loop
ARTICULATORY SUPPRESSION effect (Baddeley et al., 1984): repeating an irrelevant sound disrupts operation of phonological loop
REDUCES THE REHEARSAL ADVANTAGE FOR SHORT WORDS
BADDELEY et al 1984 wh wh wh wh wh what did he and his mates do?
Evidence for phonological loop
ARTICULATORY SUPPRESSION effect (Baddeley et al., 1984): repeating an irrelevant sound disrupts operation of phonological loop
REDUCES THE REHEARSAL ADVANTAGE FOR SHORT WORDS
