Interference

Interference

1. Muller and Pilzecker (1900)

   • Retroactive interference
     • Current attempts to learn something interfere with past learniing
     • They gave participants a list of nonsense syllables to learn for 6 minutes and then, after a retention interval, asked to recall the lists
     • Performance was less good if participants had been given an intervening task between initial learning and recall
     • The intervening task produced a retroactive interference because the later task interfered with what had previously been learned
   • Proactive interference
     • Underwood (1957)
       • Analysed the findings from a number of studies and concluded that when participants have to learn a series of word lists they do not learn the lists of words encountered later on in the sequence as well as lists of words encounted earlier on
       • Overall, found that if participants memorised 10 or more lists the after 24 hours they remembered about 20% of what they learnt
         • However, if they learnt only one list recall was over 70%

2. McGeoch and Mcdonald (1931)

   • Experimented with the effects of similarity of materials
   • They gave participants a list of 10 adjectives
     • Once these were learned there was then a resting interval of 10 minutes during which they learnt List B followed by recall
   • If list B was a list of synonyms of list A, recall was poor (12%)
   • If list B was nonsense syllabus this had less effect (26%)
   • If list B was numbers this had the least effect (37%)
   • This shows that interference is strongest the more similar the items used

3. A real world study

   • Baddeley and Hitch (1977)
     • Investigated interference effects in everyday setting of rugby players recalling the names of the teams they had played against over a season
       • Some players played in all games in the season whereas others missed some games because of injury
         • The time interval from start to end of the season was the same for all players but the number of intervening games was different for each player because of missed games
           • If decay theory is correct then all players should recall a similar percetage of the games played because time alone should cause forgetting.
           • If the interference theory is correct then those players who played most games should forget proportionately more because of interference, which is what Baddeley and Hitch found

4. Individual differences

   • Kane and Engle (2000)
     • Demonstrated that individuals with a greater working memory span were less suscepitile to proactive interference
     • Giving participants three word lists to learn, those participants with low working memory span showed greater proactive interference when recalling the second and third lists that did participants with higher spans

5. Research is quite artificial

   • Most of this research is lab based and often used rather artifical lists of words and nonsense syllables
   • May not be relate to everyday usues of memory as it doesnt tend to involve lists of words
   • Lead to participants lacking motivation to remember the links in such studies and this may allow intereference effects to appear stronger than they really are
   • Low ecological validity

6. Intereference only explains some situations of forgetting

   • Anderson (2000) concludes that there is no doubt that interence plays a role in forgetting but how much forgetting can be attributed to intereference remains unclear