Explanations for Forgetting - Interference

• forgetting occurs because memories stored at different times in LTM disrupt each other
• interference

  two lots of information become confused in memory - one memory blocks another, causing one or both of the memories to be forgotten or distorted
• forgetting is likely because we can't access the memories even though they are permanently available, interference means they are harder to locate and we experience this as forgetting
• proactive interference

  old memories/learning affect the recall of new information
• retroactive interference

  where new learning/memories affect the recall of old information
• Muller (1900)

  • gave participants a list of nonsense syllables to learn for 6 minutes and after a retention interval, asked participants to recall the list
  • in some cases, participants had been given an intervening task between initial learning and recall
  • this produced retroactive interference because describing in the pictures interfered with previous learning of the word list
• Underwood (1957)

  • analysed findings from a collection of studies (meta-analysis) where participants were asked to learn a series of word lists
  • participants learn earlier word lists better than later word lists
  • if participants memorised 10 or more lists, then after 24 hours, they would remember 20% of what they had learned, if they only learnt 1 list, recall was 70%
  • the more lists they learned prior to the new one, the worse the newer lists were recalled
  • each list makes in harder to learn the subsequent one
  • proactive interference
• McGeoch and MCDonald (1931)

  • looked at retroactive interference by changing the amount of similarity between two sets of materials
  • participants learned a list of 10 words until they remembered them with 100% accuracy
  • they learned a new list depending one what group they were in
  • group 1 - synonyms
  • group 2 - antonyms
  • group 3 - unrelated
  • group 4 - nonsense
  • group 5 - three digit numbers
  • group 6 - no new numbers
• Baddeley and Hitch (1977)

  • asked rugby players to try and remember the names of the teams they had played so far in the season week by week - the duration was the same for every player
  • they found that the accurate recall didn't depend on how long ago the matches took place but the number of games they had played in the meantime
  • retroactive interference