Forgetting: Interference

• Forgetting occurs in LTM when we cannot get access to memories even though they are available - interference occurs when two pieces of information disrupt each other
• Proactive interference is when an old memory interferes with a new one
• Retroactive interference is when a new memory interferes with an old one
• Interference is made worse when memories are similar - in proactive interference the new information is harder to store whilst in retroactive interference the new information overwrites the old
• McGeoch and McDonald asked participants to learn a list of words to 100% accuracy

  The participants were then given a new list to learn which varied in it's degree of similarity to the first list
• Performance depended on the degree of similarity between the lists with the most similar material (synonyms) producing the worst recall - interference is strongest when the memories are similar
• Strength of interference theory - real world application

  Baddeley and Hitch asked rugby players to recall the names of opposing teams they had played during a season

  Players did not all play the same number of games and it was found that those who played most had more interference and the poorest recall - shows that interference can be found in everyday situations so has high validity
• COUNTERPOINT of interference theory - confounding variables

  The study did not take into account confounding variables like head injuries that may have affected players memory which means it lacks validity
• Limitation of interference theory - interference may be overcome using cues

  Tulving gave participants lists of words organised into categories (unknown to particpants)

  Recall at first was 70%, falling with each new list (proactive interference) but when participants were given a cued recall test, recall rose back to 70%

  This shows that interference causes only a temporary loss of access to memories which was not predicted by the theory
• Strength of interference theory - support from drug studies

  Material learned before taking a drug was recalled better than a placebo group a week later as the drug stopped new information entering the brain areas that process memories, meaning there was no retroactive interference

  This shows that forgetting is due to interference and reducing it also reduces forgetting