Coding, Capacity and duration of memory Flashcards
(17 cards)
What is coding?
-The process of converting information between different forms as memory is stored in different formats
How did Baddeley test coding?
-gave different lists of words to four groups of participants to remember
-Asked to recall the words in the correct order, either immediately or after 20 minutes
What groups of words did Baddeley use to test coding
-Group 1: acoustically similar (sound similar)- cat, cab,can
-Group 2: Acoustically dissimilar (sound different)
-Group 3:Semantically similar (similar meanings- large,big
-Group 4: semantically dissimilar (different meanings)- good huge biug
a)What were the results of the memory and b) what were Baddeley’s conclusions?
a)Found that if they did it immediately (STM) they did worse with acoustically similar words
-After 20 minutes (LTM) they did worst with semantically similar words
b)This suggests that information is coded acoustically STM and semantically in LTM
What is the evaluation of Baddeley’s research into coding?
S- Separate memory stores: Baddeley identified a clear difference between two memory stores. Baddely’s findings that STM = acoustic and LTM = semantic are largely supported. This finding had led to the multi-store model so was important in understanding memory.
L- Artificial stimuli: Baddeley used artificial stimuli rather than meaningful material. The word lists had no significance to the participants so may not be revealing about coding in different kinds of memory tasks, especially everyday life. Therefore, if it had been more meaningful information, people may use semantic coding for STM tasks. Therefore findings may have limited application for memory IRL.
What is capacity in memory?
-The amount of information that can be held in a memory store
What Joseph Jacobs digit span?
-Jacobs would read out 4 digits and if the participant recalled correctly he would add another digit to the list
What was Jacobs findings for digit span?
-mean span for digits= 9.3 items
-mean span for letters = 7.3
What did George Miller think the capacity of STM was?
7+-2 (5-9)
What did Miller believe was the reason people can remember 5 digits as easy as 5 letters?
-Proposed that humans do this by chunking: grouping sets of digits or letters into chunks
What is the evaluation for capacity in memory?
-S: A valid study: Jacobs’s study has been replicated. Jacobs’ study was old and lacked adequate controls as participants were distracted (CV). Jacobs findings have been confirmed by better controlled studies -Bopp and Verhaeghen (2005). Jacob’s study is a valid test of digit span in STM
-L: Not so many chunks: Miller’s research may have overestimated STM capacity. Cowan reviewed other research and concluded that the capacity of STM is only about 4+-1 (3-5) and therefore lower than Miller’s estimate of 7+-2.
What is the duration in memory?
- The length of time information can be held in memory
How did Margaret and Lloyd Peterson test duration STM?
-tested 24 students in eight trials
-Each trial a student was given a consonant syllable (e.g. YCG) to remember. Also given a 3 digit number which they counted backwards from this number until told to stop to prevent any mental rehearsal of the syllable.
-On each trial they were told to stop after varying periods of time - 3,6,9,12,15 or 18
a)What were the findings of Margaret and Lloyd Peterson’s research on the duration of STM and b) what were their conclusons ?
a)After 3 seconds, average recall = 80%
-After 18 seconds = 3%
b)
-Peterson and Peterson findings suggested that STM duration = 18 seconds, unless we repeat the information over and over
What was Bahrick’s research on duration of LTM?
-studies 392 Americans aged 17-74
Recall was tested:
1)Photo-recognition test consisting of 40 photos from participants high school yearbooks
2)free recall test where participants recalled the names of the class
a)What were findings Bahrick’s research on duration of LTM and b) Bahrick’s conclusions?
a)Photo recognition:
15 years after graduation = 90% from photo recognition
48 Years after graduation = 70%
Free recall:
15 years after graduation = 60%
48 years after graduation = 30%
b) This shows that LTM may last up to a lifetime for some material
What is the evaluation for duration of memory
S: High external validity (Bahrick): Research investigated meaningful memories - old friends names and faces. When studies on LTM were conducted with meaningless pictures to be remembered, recall rates were lower (Shepard). Therefore Bahrick’s findings reflect a more “real” estimate of the duration of LTM.
However, Bahrick’s study may have confounding variables as it is unknown how recently the participants had looked back on their yearbooks and would have recalled names, which would mean it may not have been in LTM. Therefore, Bahrick’s study may not be completely valid
L: Meaningless stimuli in STM study: Petersons’ study used artificial stimulus. Consonant syllables do not reflect everyday memory activities so limited application.
