memory

• who researched memory coding


  Alan Baddeley
• memory coding experiment


  * alan baddeley gave four different lists of words to four groups of pp

  1 ) acoustically similar

  2 ) acoustically dissimilar

  3 ) semantically similar

  4 ) semantically dissimilar

  * pp had to recall the words in the correct order
• memory coding findings


  * stm (immediately) - did worse when recalling acoustically similar words.

  this suggests stm is coded acoustically.

  the brain gets confused as the memory trace of each word is stored in a similar way and place.

  
  

  * ltm (time interval of 20 mins) - did worse when recalling semantically similar words.

  this suggests ltm is coded semantically.

  more confusion when words have a similar meaning because they have a similar memory trace and and would be activating a common schema.
• who researched the stm capacity

  Joseph Jacobs
• what did jacobs measure to find out what stm capacity is

  digit span
• digit span experiment method

  1 ) researcher read four number digits to participants and they had to repeat them in the same order

  2 ) repeated this with more number digits until the pp couldn’t recall the correct order

  3 ) repeated this with letters
• digit span experiment results

  * mean span for number digits = 9.3 items

  * mean span for letters = 7.3 items
• advantages with jacobs experiment

  * can be standardised (repeated) meaning it has a high replicability
• who observed the span of memory and chunking

  George Miller
• what is believed to be the span of stm


  7 items, plus or minus 2
• what is chunking


  grouping sets of letters or numbers into chunks/groups
• how are words made

  via chunking
• how can we increase what is recalled from our stm


  activate ltm to attribute meaning to items
• who discovered the duration of stm


  Peterson and Peterson
• what is thought to be the maximum duration of stm


  30 seconds
• how did Peterson and Peterson discover the duration of stm


  1 ) give a nonsense consonant syllable to Pp (eg : YCG)

  2 ) afterward give the Pp a three digit number in which they have to count back in threes (interference task)

  3 ) on each trial they were stopped at various times (3, 6, 9, 12, 15, 18 seconds)

  4 ) the Pp had to recall the consonant syllable
• what was the point of the interference task in the Petersons’ experiment


  to stop any mental rehearsal of the consonant syllable
• results of the duration of stm study


  * after 3 seconds - average recall was 80%

  * after 18 seconds - average recall was 3%

  * stm duration is around 18 seconds, unless information is repeated (rehearsal)
• why is rehearsal needed to keep information in stm for longer than 30 seconds


  otherwise displacement in stm will occur due to the store having a limited capacity, so forgetting occurs
• who studied the duration of ltm

  Henry Bahrick
• how did bahrick test the duration of ltm


  1 ) collected 392 american participants (aged 17-74) and their high school year books

  2 ) gave two tests : photo-recognition, free recall (name everyone in graduation class)
• what are the IVs in duration of ltm experiment


  1 ) photo-recognition test

  2 ) free recall test

  3 ) within 15 years of graduation

  4 ) after 48 years of graduation
• results of duration of ltm study


  1 ) Pp within 15 years of graduating

  * photo-recognition = 90% accuracy

  * free recall = 60% accuracy

  2 ) Pp after 48 years of graduating

  * photo-recognition = 70% accuracy

  * free recall = 30% accuracy

  * some ltm lasts up to a lifetime
• advantages of Bahricks study

  1 ) high in mundane realism = real life event (not an artificial setting)

  2 ) large sample = representative so can be generalised to some extent
• disadvantages of Bahricks study


  culturally biased as all Pp are american
• strength of Baddeley’s study


  shows a clear difference between memory stores
• limitation of Baddeley’s study


  stimuli was artificial, not meaningful information so has a low mundane realism
• problem with millers study

  may have overestimated the capacity of stm, the lower end may be more appropiate
• disadvantage to Petersons study


  lacked external validity
• advantages of Bahrick’s study


  high external validity as he investigated meaningful memories
• memory processes


  encoding input

  capacity processing

  retrieval / cognitive output
• what information passes into the sensory register

  stimuli from the environment
• what process allows info to pass into stm


  attention
• what process keeps information in stm


  maintenance rehearsal
• what process lets information out of stm


  response (remembering)
• what process passes info from stm to ltm


  prolonged rehearsal
• what process passes info from ltm to stm


  retrieval
• what may happen in prolonged rehearsal that leads to forgetting


  decay
• what is the duration of the sensory register


  0.5 seconds
• in what way does info pass from store to store

  linear