coding capacity duration Flashcards
What is coding?
The format in which memory is stored
What lists did Baddeley give to participants?
Acoustically similar
Acoustically dissimilar
Semantically similar
Semantically dissimilar
Baddeley’s coding experiment - procedure and findings
Asked to recall words in correct order
Did worse with acoustically similar words - immediate recall
Did worse with semantically similar words - after 20 minutes
How is STM coded?
Acoustic
How is LTM coded?
Semantic
Evaluate research on coding
Artificial stimuli - cannot generalise, people usually use semantic coding
Who researched coding?
Baddeley
Who research capacity - digit span?
Jacobs
Describe research on digit span
Pp must recall digits in order
Increase digit number until they cannot recall
What is our digit span?
Mean span for digits is 9.3 items
Mean span for letters is 7.3
Who researched capacity - chunking and memory span?
Miller
Describe research on memory span
Things come in 7s - days, sins, notes on musical scale
Suggests span of STM is 7 +/-2
Describe research on chunking
Noted people can recall 5 words as well as 5 letters
Do this by chunking
What is STM capacity?
7+/-2
What is LTM capacity?
Unlimited
Evaluate Jacobs’ research on capacity
Lacking validity - long time ago so lacked control, pps may have been distracted, confounding variables
Evaluate Miller’s research on capacity
Not so many chunks - overestimated STM capacity, Cowan found 4 chunks
Who research STM duration?
Peterson and Peterson
Describe research on STM duration
24 undergrad students
8 trials
Given a consonant syllable and a 3 digit number on each trial
Count backwards from that number until told to stop
Prevented rehearsal of syllable
Told to stop after a diff amount of time on each trial - 3,6,9,12,15,18 seconds - retention interval
Higher retention interval = lower % of correct responses
What is the duration of STM?
About 18 seconds
Who researched LTM duration?
Bahrick
Describe research on LTM duration
392 Americans aged 17 to 74 Looked at high school yearbooks Photo recognition test Free recall where pps recalled names of their graduating class Pps tested within 15 years of graduation = 90% accurate photo recognition After 48 years recall declined to 70% Free recall 15 years - 60% accurate Free recall 48 - 30%
What is LTM duration?
Up to a lifetime
Evaluate Peterson and Peterson’s research on duration
Meaningless stimuli - lacks external validity
Lacks internal validity - we forget STM because it is displaced by consonant syllables, they were investigating capacity not duration
Evaluate Bahrick’s research on duration
Higher external validity - real life memories
