explanations for forgetting: interference

• forgetting occurs in LTM because we can’t get access to memories even though they are available
• proactive interference occurs when an older memory disrupts a newer one. For example, a teacher learns many names in the past and can’t remember names of her current class
• retroactive interference occurs when a newer memory disrupts an older one. For example, a teacher learns many new names this year and can’t remember the names of her previous students
• interference is worse when memories are similar because:

  • in proactive interference previously stored information makes new information more difficult to store
  • in retroactive interference new information overwrites previous memories which are similar
• Mcgeoch and McDonald study on effects of similarity procedure: participants were asked to learn a list of words to 100% accuracy (if they could recall them perfectly). Then they were given a new list to learn. The new material varied in the degree to which it was similar to the old. Group 1- synonyms, group 2- antonyms, group 3- unrelated words, group 4- consonant syllables, group 5- three digit number, group 6- now new lists (control group)
• Findings and conclusion of McGeoch and McDonald study on effects of similarity: performance depended on the nature of the second list. The most similar material (synonyms) produced the worst recall. This shows that interference is strongest when the memories are similar
• One strength of interference is support in real world situations. Baddeley and Hitch asked rugby players to recall the names of teams they had played against during a rugby season. Players didn’t play the same number of games due to injuries. Those who played most had more interference had poorest recall. This shows that interference operates in some everyday situations, increasing the validity of the theory
• One limitation of interference is that effects may be overcome using cues. Tulving and Psotka gave participants lists of words organised into categories (not told what they were). Recall of first list was 70% but fell with each new list (interference). When given a cued recall test (names of categories) recall rose again to 70%. This shows that interference causes just a temporary loss f access to material still in long term memory which is not predicted by the theory