Interference

• what is interference concerned with?

  what occurs before, during and after learning.
• what can interference do in the STM?

  can stop new info from passing from STM into LTM.
• what can interference do in the LTM?

  • as your knowledge store grows, info competes w/ each other and therefore may interfere with each other during recall.
• what is proactive interference?

  • when an older memory disrupts with a new one and later learning.
• what is retroactive interference?

  when a newer memory disrupts memory of an older one and earlier learning.
• PORN?

  P- proactive interference

  O- old disrupting retaining new info

  R- retroactive interference

  N- new disrupting old info
• what did underwood & postman (1960) do? (evidence for interference theory)

  • used paired associate learning task to test effect of interference.
  • p's asked to learn series of word pairs so that they can be presented w/ the 1st word (stimulus word= list a) and recall its paried word (response word= list b).
  • then given another list of word pairs to learn, which have the same stimulus word (from list a) but diff response word (from list c).
  • then asked to recall corresponding word from either list b (retroactive) or list c (proactive)- control condition recall w/ no interference.
• what did underwood & postman (1960) find? (evidence for interference theory)

  • if retroactive interference occurs, p's would tend to recall 2nd set of pairs rather than the 1st.
  • if proactive interference occurs, p's would tend to recall the 1st set of pairs rather than the 2nd.
  • recall of the response words was poorer, affected by both proactive & retroactive. however, effect only present when the same stimulus words are used in both lists.
  • shows that if stimuli is similar then we are more likely to forget.
• what is the main criticism of interference?

  • it only really explains forgetting when two sets of info are similar.
  • this doesn't happen very often and so interference can't explain forgetting in the majority of real life settings.
• what did mcgeoch and mcdonald (1931) do? (evidence for interference/effects of similarity)

  • studied retroactive interference by changing the amount of similarity between two sets of materials.
  • p's had to learn a list of words until they could remember them 100% accurately. they then learned a new list.
  • there were 6 groups of p's who had to learn diff types of lists: group 1= synonyms, group 2= antonyms, group 3= unrelated to original, group 4= nonsense syllables, group 5= 3 digit numbers, group 6= no new list- p's just rested.
• what did mcgeoch and mcdonald (1931) find? (evidence for interference/effects of similarity)

  • the group who only had one task showed the least interference whereas the other groups who had to learn another stimulus showed higher rates of interference.
  • retroactive interference was highest in group 1 (synonyms).
  • this study suggests that the higher the levels of similarity between diff subjects to remember, the lower the recall and the higher the interference is.
• evidence from lab studies (strength of interference theory)

  • thousands of lab studies carried out to test interference as an explanation for forgetting.
  • most studies show that both types of interference are very likely to be the common ways we forget info from LTM.
• why is evidence from lab studies a strength of the interference theory?

  • lab exps are highly controlled due to being based in artificial settings, this means extraneous variables are controlled, leading to the ability to show cause & effect.
  • this provides empirical evidence that can be replicated and is therefore reliable.
  • this strengthens the support for this theory as a valid explanation of forgetting.
• why is using artificial materials a limitation for interference theory? (weakness of interference theory)

  • they lack ecological validity. remembering lists of words are not tasks completed in every day life.
  • findings can't be generalised to why we forget in real life.
• real life studies (evidence for interference theory)

  baddeley & hitch (1977):

  • wanted to find out if interference was a better explanation than just the passing of time.
  • asked rugby players to try and remember the names of the teams they had play so far in the season, week by week.
  • because most players had missed some games, for some the 'last team' they played might have been several weeks ago.
• what were the findings of baddeley & hitch (1977)? (evidence for interference theory)

  • results showed that accurate recall didn't depend on how long ago the matches took place.
  • more important was the no. of games they had played in the meantime.
  • so a player's recall of a team from weks ago was better if they had played no matches since then- playing a lot would interfere with their recall.
• how do the results of baddeley & hitch (1977) provide evidence for the interference theory?

  • provided support for retroactive interference.
  • player's recall was worse of past games if they had played more games inbetween (new games interferred w/ their knowledge of old games).
  • this is better than lab studies- looks at the level of forgetting in p's everyday activity.
  • HOWEVER, lacks generalisability as not all people play rugby- so only applicable to rugby/sports players.
• accessibility vs availability (weakness of interference theory)

  researchers have often questioned whether interference effects actually cause a memory to disappear or if effects are temporary.

  ceraso (1967):

  • found that if memory was tested again after 24 hours, recognition (accessibility) showed considerable spontaneous recovery, whereas recall (availability) remained the same.

  this suggests that interference occurs because memories are temporarily not accessible rather than having been lost (unavailable).
• individual differences (weakness of interference theory)

  evidence that some people are less affected by proactive interference than others.

  kane and engle (2000):

  • found that people with a greater working memory span were less susceptible to proactive interference.
  • tested p's by giving three word lists to learn.
  • p's with low working memory spans showed greater proactive interference when recalling 2nd and 3rd lists than p's with higher spans.
• real-world application to advertising (strength of interference theory)

  considerable amounts of research into effects of interference when people are exposed to ads from competing brands within a short time period.

  danaher et al. (2008):

  • found that recall and recognition of an advertiser's message were impaired when p's were exposed to two ads for competing brands within a week.