Forgetting: Interference

• Interference - Is an explanation for forgetting in the long-term memory, which states that forgetting occurs because memories interfere with and disrupt one another; in other words, forgetting occurs because of interference from other memories (Old and New)
• Interference

  The multi store model of memory states that LTM has an unlimited capacity, and memories have a duration of potentially a lifetime. However, we know by experience that we forget information stored in the LTM.
• Interference

  • Forgetting is due to interference – when two pieces of information conflict with each other, resulting in the forgetting of one or both OR some distortion in the memory.

  Interference theory is therefore an accessibility theory of forgetting – the memories are there, we just cannot gain access to them because there is an interference between the memories.
• Interference

  Two types of interference

  1. Proactive interference – looking forward, old to new
  2. Retroactive interference – looking back, new to old
• Who conducted the study on interference in 1931?


  McGeoch and McDonald
• What is the main finding regarding interference in memory?

  Interference is worse if the memories are similar
• What was the purpose of McGeoch and McDonald's study?


  To see if similarity between two activities causes greater interference
• How did McGeoch and McDonald study interference?


  By changing the amount of similarity between two sets of materials
• How many participants were involved in the study?

  12 participants
• What task did participants perform after learning the first list of words?


  They learned a new list of words
• What were the six groups of participants in the study tasked with learning?

  1. Synonyms (same meanings)
  2. Antonyms (opposite meanings)
  3. Unrelated words
  4. Nonsense syllables
  5. Three-digit numbers
  6. No new list (control condition)
• What was the outcome for participants who learned synonyms?


  They produced the worst recall
• What happened when participants were given different material, such as three-digit numbers?


  The mean number of items recalled increased
• What does the study suggest about the nature of interference in memory?


  Interference is strongest when the memories are similar
• Why might synonyms cause worse recall according to the study's findings?


  They likely blocked access to the original list or confused with old material
• (+) Evidence from lab studies - Good validity of results
• (-) Use of artificial material
• (+) Support from real life studies
• (-) Interference effects may be overcome using cues
• (-) Time allowed between learning