Interference Theory

What is forgetting?

• Forgetting can be defined as a failure to retrieve memories from the long-term store 

• This may be due interference or retrieval failure 

What is proavtive interference?

• When old information disrupts learning and retention of new information 

What is retroactive interference?

• When new information disrupts the retention of old information 

What is interference?

• Interference occurs when one set of information competes with another, causing it to be ‘overwritten’ or physically destroyed

What is the effect of similarity?

• Interference is more likely when two lots of information similar

• For example, if we are given the list ‘big, large’ and ‘huge’ to remember, interference would be more likely to occur if this is followed by a list of words with the same meaning such as ‘giant’ ‘massive’ and ‘vast’ compared to if was followed by unrelated words

Evidence of retroactive interference Postman (A01)

• Method

  • Two groups have to learn a list of paired words (e.g. cat-tree, jelly-moss).

  • The experimental group had to learn another list of words where the second paired word is different such as cat-glass and jelly-time.

  • The control group were not given a second list

• Findings

  • Recall of the findings was higher in the control group in comparison to the experimental group

• Conclusion

  • This shows retroactive interference as the new information disrupts the learning and retention of old information

Strength: Support for the role of similarity

• A strength of the interference theory is that there is supporting evidence for the role of similarity

• McGeoch and McDonald (1931) had different groups of participants learn two lists of words.

• For one group of participants, the second list of words consisted of synonyms of the first list of words

• Whereas for another group the second list consisted of nonsense syllables (e.g. GVX, HRE…etc)

• They found that recall of the first list was higher in the group where the second list consisted of nonsense syllables (26%) in comparison to the group where the second list of words consisted of synonyms of the first list of words (12%)

• This shows that (retroactive) interference is more likley when two sets of information are similar 

• Therefore increases validty of theory 

Strength: Supporting evidence

• Strength - supporting evidence for interference 

• Burke and Skrull presented a series of magazine adverts to participants, who were asked to recall details of what they had seen (e.g. a brand name)

• They found  that some participants had more difficulty in recalling earlier adverts whilst others had problems in recalling later ones 

• The effect was greater when the adverts were similar (for example identical products but different brands) 

• This shows foregtting occurs due to retroactive interference (when they failed to recall earlier adverts) and proactive interference (when they failed to recall later adverts) 

• Also interference is shown through everyday material (magazines in this case) rather than just artificial lists which increases the ecological validity 

• This therefore increases the validty of the interfenece theory.

Limitation: Artificiality

• One limitation of the interference theory is that it is derived from artificial lab experiments

• Much of the research evidence for the interference theory has come from artificial laboratory experiments

• Interference requires special conditions e.g. word pair stimuli are generated for the purpose of the experiment

• These conditions are very rare in day-to-day everyday real life

• Therefore, the research appears to have little relevance to everyday situations

• For example in real life information is explained to us and also has real life consequences thus people put more effort into recall

• This indicates that interference only accounts for very specific and limited range of instances of forgetting in long term memory

• This limits ecological validity of supporting research for interference theory

• Since the evidence that supports interference can be seen as invalid

• This therefore decreases validity

Limitation: Incomplete 

• One weakness of teh interference theory is that it is an incomplete explaination of forgetting 

• Interference effects may actually be temporary rather than a permanent form of forgetting 

• Ceraso found that if memory was tested again 24 hours later, recognition showed considerbale spontaneous recovery 

• Meaning that participants were now able to recognise words that they seemed to have forgotten when they were first tested 

• This suggest that interference occurs because memories are temporarily not accessible rather than actually being lost 

• Therefore this is not a complete explanation of forgetting as it struggles to explain how memories can be lost permanently

• Thus showing that it is an invalid explanation