Explanations of Forgetting: Interference

• retroactive interference


  when a new memory interferes with an old one

  e.g. you forget your classmates from last year because you've got new one this year
• proactive interference


  when an old memory interferes with a new one

  e.g. when you remember your old phone number than your new one
• effect of similarity


  becomes worse the more similar the memories are
• Strength - research evidence

  McGeoch and McDonald

  procedure: both studied retroactive interference by changing the amount of similarity between 2 sets of materials.

  ppts had to learn a list of 10 words until they could remember them with 100% accuracy

  6 groups:

  1. synonyms

  2. antonyms

  3. words related to original ones

  4. nonsense syllables

  5. 3-digit numbers

  6. no new list - ppts rested

  findings: when ppts recalled the original list of words, their performance depended on the nature of the 2nd list. shows interference is strongest when memories are similar
• Strength - support for retroactive interference

  Underwood and Postman

  aim: investigate how retroactive interference affects learning

  method: a lab experiment was used. ppts were split into 2 groups. both groups had to remember a list of paired words. the experimental groups also had to learn another list of words where the 2nd paired word is different. control group weren't given the 2nd list

  results: recall of the control group was more accurate than that of the experimental group

  conclusion: suggests that learning items in the 2nd list interfered with ppts ability to recall the list
• Weakness - interference theory is commonly tested using lab experiments

  much greater chance that interference will be demonstrated in the lab than in real-life weaknesses

  stimulus materials used in most studies are lists of words. learning lists of words is more realistic than learning lists of consonant syllables

  limitation -> use of artificial tasks makes interference much more likely in the lab. interference may not be as likely an explanation for forgetting in everyday life as it's the lab
• Weakness - alternative theories of forgetting such as trace decay

  trace decay - idea that forgetting occurs due to passage of time, rather than the events that occur between encoding + recall; the memory trace decays

  research from Baddeley + Hitch contradicts this

  they asked rugby players to recall the names of the teams they had played that season. the time interval was the same for all but the number of teams varied between players as some had missed games due to injury

  players who played the most games had the poorest recall -> most interference