explanations for forgetting

• Retroactive interference is when new information interferes with recall of previously learnt information.
• Proactive interference is when existing memories interfere with the learning of new information. This usually happens when new information is similar to old information.
• Interference theories suggest that forgetting is caused by competing memories.
• Keppel and Underwood (1962)


  Aim: to investigate the effect of proactive interference on LTM.
• Keppel and Underwood (1962)


  Method: participants were presented with meaningless three-letter consonant trigrams at different intervals. To prevent rehearsal the participants had to count backwards in  threes before recalling. 
• Keppel and Underwood (1962) 


  Results: participants typically remembered the trigrams that were presented first, regardless of the interval length.
• Keppel and Underwood (1962)


  Conclusion: results suggest that proactive interference occurred, as memory for the earlier consonants interfered with the memory of new consonants, due to the similarity of the information.
• Baddeley and Hitch (1977)


  Aim: to investigate retroactive interference in everyday memory.
• Baddeley and Hitch (1977)


  The sample was made up of rugby union players who had played every match in the season and players who had missed some games due to injury.

  Participants were asked to recall the names of teams they had played against earlier in the season.
• Baddeley and Hitch (1977)


  Results: the players who had played the most games forgot proportionally more games than those who had played fewer games due to injury.
• Tulving and Thomson (1973) proposed the encoding specificity principle and argued that memory is most effective when information that was present at the time of coding is also present at the time of retrieval.
• Godden and Baddeley (1975)


  Aim: to investigate the effect of contextual cues on recall.