Interference

• Retroactive interference is when recent/new information hinders the recall of old information.

  Proactive interference is when past/old  information hinders the  recall of new information.
• Interference theory states that forgetting occurs because memories interfere with one another and end up disrupting each other which leads to forgetting (Baddeley, 1999).
• McGeoch & McDonald (1931) 


  Studied retroactive interference by varying the amount of similarity between sets of word lists presented to participants. 

  • In their experiment, all participants had to learn a list of 10 words until they could remember them with 100% accuracy.
  • They were then split into six groups and each group was required to learn a new list.
  • The six groups were synonyms , antonyms, words unrelated to List 1, nonsense syllables, 3-digit numbers, and the sixth group got no new list.
• McGeoch and McDonald found that the most similar material (i.e. synonyms) produced the worst recall showing that interference is strongest when memories are similar. 

  Those who had learned synonyms in the second list were significantly impaired, down to 12%.
• Supports


  • When a cue was present participants were able to recall more words. This shows that participants did have the information stored in LTM but similarity between words (interference).
  • Baddeley and Hitch study shows real life application. Found that in a group of rugby players, the number of games they’d played was more important than the total time playing. In terms of interference, the more games played, the more likely the memories of the newer games would interfere or block the recall of older ones (retroactive interference).
• Limitations


  • The artificial stimuli 

  used in these tasks, such as learning lists of random words with no personal meaning to the participants, means that the findings of interference studies are likely to have low mundane realism. This is because in real life, we are likely to learn lists of meaningful information, such as revision topics for psychology, which we draw links upon and also which have personal meaning to us. These factors may also influence the extent of forgetting, rather than influence. 
• Another limitation


  • Short time

  With participants recalling their words only 1 or 2 hours after they have learnt them. This does not reflect the normal passage of time in everyday life, where we often find that several days pass until we need to recall such information e.g. in the case of an exam. Therefore, this suggests that interference is unlikely to be a valid explanation for forgetting from the LTM.