STM & LTM Flashcards Preview

Memory AS Level > STM & LTM > Flashcards

Flashcards in STM & LTM Deck (9)
Loading flashcards...

What 3 things are the STM and LTM distinguished by?

capacity, duration, coding


The capacity of short-term memory

• Miller (7+-2) - average span for STM is 7 items of info, but can be a little more or less

The capacity can differ depending on what we are remembering:

• Jacobs - digits are recalled better than letters (perhaps because there arE only 9 digits but 26 letters)


Criticisms of research on the STM and LTM capacity

• Cowan: believes STM is limited to 4 chunks, rather than 7, based on review of other studies. Vogel at al agreed with Cowan, particularly with visual information
• Simon (1974) found that the size of the chunk impacts how many chunks you can remember (larger chunk=shorter memory) '7 chunks of info' is too vague
• Jacobs also found that individual differences affect the STM, as age increases so does the capacity of our STM


What was Peterson and Peterson's study testing the duration of the STM?

• Participants were given 3 letters and asked to recall them after intervals that varied in length of time. During this interval they were asked to count backwards
• Lloyd and Peterson found that after 3 second intervals participants remembered 90% accurately, but by 9 seconds it was 20%, and by 18 seconds it was less than 2%


What was Bahrick et al's study testing the duration of the LTM?

2 groups
• Group 1: Participants were shown pictures and some were of their old yearbook. asked to recall as many names of classmates as they could
• Group 2: free recall, no pictures. Asked to name as many classmates as they could
• 15 years since graduating, accurate recall with pictures was at 90%. But by 48 years it was 70%
• free-recall group remembered less after 15 years at only 60%, and then 48 years=30%


Evaluation of research on the duration of STM and LTM

• (-) the research is artificial - low mundane realism. people do not try and remember this way or do they try and remember random consonant syllables. (+) However, we do sometimes try and remember meaningless letters and numbers e.g phone numbers and postcodes, so does reflect real like a little bit
• peterson & peterson's results could be due to displacement rather than decay


What 3 types of coding are there?

• acoustic coding
• visual coding
• semantic coding


What was Baddeley's study on semantic and acoustic coding?

• gave participants word lists. STM tested by immediate recall LTM tested by waiting 20 minutes for recall
• used semantically similar words (big, large, great, huge) and used acoustically similar words (mad, max, man, map)
• they showed more difficultly remembering acoustically similar words in STM rather than LTM, but more difficulty remembering semantically similar words in LTM rather than STM
• suggests STM is largely encoded acoustically but LTM is largely encoded semantically


Evaluation of coding research on STM and LTM

• (-) waiting 20 minutes before recall when testing LTM may have been too short of a time for it to be truly testing the LTM. May still be in short term
• LTM may not be entirely semantically coded, could have visual coding (Frost 1972) and even some acoustic (Rothbart 1972)