memory Flashcards
what is coding?
The format in which information is stored in the various memory stores
what is capacity?
The amount of information that can be stored in a memory store
What is duration?
The length of time information can be held in memory
what was Baddeley’s research on coding?
1966
each group had a different list of words
group 1 – acoustically similar words group 2 – acoustically dissimilar words group 3 – semantically similar
group 4 – semantically dissimilar
immediate recall was worse with acoustically similar words (STM is acoustic)
recall after 20 minutes was worse with semantically similar words (LTM semantic)
What was Jacobs research on capacity?
1887
research have read four digits and increases until the participant cannot recall the order correctly
on average participants could repeat back 9.3 numbers and 7.3 letters
What was Miller’s research on capacity?
1956
observed every day practice
noticed things came in sevens e.g. days of the week
suggests the span of STM is 7+-2
increased by chunking – grouping sets of digits/letters into meaningful units
What was Peterson and Peterson research on duration of STM?
1959
24 students given a consonant syllable to recall and a three digit number to count backwards from
retention interval varied from 3, 6, 9, 12, 15, 18
after three seconds average recall was 80%
after 18 seconds average recall was 3%
STM duration is up to 18 seconds
What was Bahrick et al research on duration of LTM?
1975
392 American participants between 17 and 74
Recognition test – 50 photos from high school yearbook
free recall test – listing names of their graduating class
Recognition test – 90% accurate after 15 years 70% accurate after 48 years
free recall test - 60% recall after 15 years 30% after 48 years
Evaluation
coding capacity and duration
strength: baddeley identified to memory stores
later research showed their exception to Badeleys findings
however STM is mostly acoustic and LTM is mostly semantic
lead to the development of the multi store model
evaluation
coding capacity and duration limitation: baddeley used artificial stimuli
Words had no personal meaning so tell us a little about coding for every day memory tasks
when processing more meaningful info people use semantic coding
findings have limited application
Evaluation
coding capacity and duration
strength: Jacobs study has been replicated
Old study that may have lacked control over variables
findings have been confirmed in later control studies
Shows Jacob study is a valid measure of STM digit span
Evaluation
coding capacity and duration limitation: Miller’s research overestimates STM capacity
Cowan (2002) – reviewed other research
concluded that the capacity of STM was only 4+-1 chunks
Suggest Miller overestimated STM capacity
Evaluation
coding capacity and duration limitation: Peterson and Peterson used meaningless stimuli
recall of consonant syllables does not reflect meaning for every day memory tasks
Study lacks external validity
evaluation
coding capacity duration
strength: Bahrick et al had high external validity
every day meaningful memories were studied
findings reflect a more real estimate of the duration of LTM
what is the MSM?
Multi store model
Atkinson and Shiffrin 1968
describes how info flows through the memory system
