4.1.2 Interference Flashcards
Research on the effects of similarity
Supporting evidence from lab studies that PI and RI interference is worse if the memories are similar.
MCGEOCH and MCDONALD (1931) studies RI by changing the amount of similarity between two sets of materials (lists of words)
Participants each had a list of the same 10 words to recall until they were 100% accurate
They were then given a new list to learn
Once they had learnt the new list, they were then required to recall the original list
Research on the effects of similarity - different groups
The new material varied in the degree to which it was similar to the old:
Group one – words had same meanings as the originals
Group two – words had opposite meanings to the originals
Group three – words unrelated to the original ones
Group four – nonsense syllables
Group five – three-digit numbers
Group six – no new list (so given original list again)
Similarity study - strength
A strength is that there is supporting evidence from lab studies:
Performance depended on the nature of the second list.
The most similar material (synonyms) produced the worse recall.
When the participants were given very different material (e.g. three-digit numbers) the mean number of items recalled increased.
Similarity study - strength in real life
However, a strength is that there is further supporting evidence from real life studies:
BADDELEY AND HITCH (1977) asked rugby players to recall the names and teams they had played so far in that season week by week
The number of intervening games varied as some players had missed games due to injury
Accurate recall did not depend on how long ago the match took place. More important was the number of games played in the meantime
Players who played the most games (most interference for memory) had the poorest recall
Validity of the theory is increased
Retroactive interference - study
Schmidt et al (2000)
Schmidt et al - aim
to assess the influence of retroactive interference upon the memory of street names learned during childhood
Schmidt et al - procedure
700 names were randomly selected from a database of 1700 former students at a Deutsch elementary school. Participants were sent a questionnaire to complete and 211 participants responded ranging in age from 11 to 79 years old. As part of the questionnaire, participants were given a map of the Molenberg neighbourhood with all 48 street names replaced with numbers. Participants were asked to remember as many of the street names as possible. They collected other personal details such as how many times they had moved house, where they had lived and for how long, how often they had visited Molenberg. The amount of retroactive interference experienced was assessed by the number of times the individual had moved to another neighbourhood or city (thus learning new sets of street names)
Schmidt et al - variables
Independent variable: how many times they moved house
Dependent variable: how many street names the participants can recall
Schmidt et al - findings + conclusion
Findings: those that moved away and moved house more forgot the older patterns (RI)
Conclusion: the findings suggest that learning new patterns of street names when moving house makes remembering old patterns of street names harder to do. Retroactive interference does seem able to explain forgetting in some real-life situations
Interference + cues - study
Tulving and Psotka
1971
Interference - limitation
One limitation is that interference is temporary and can be overcome with cues (hints/clues to help us remember).
TULVING and PSOTKA (1971)
Gave participants lists of words organised into categories, one list at a time (they didn’t know that the categories were).
Recall average was 70% for the first list
This became progressively worse as more lists were learnt (PI)
At the end of the procedure, the participants were given a cued recall test – they were told the names of the categories
Recall then rose again to about 70%
This shows that interference causes a temporary loss of accessibility to material that is still in the LTM – this was a finding not predicted by the interference theory
Support from drug studies
Retrograde facilitation:
COENEN and VAN LUIJTELAAR (1977) gave participants lists of words and later asked them to recall them.
The intervening experience in between would act as interference.
Those under the influence of diazepam – recall one week later was poor (compared with a placebo control group).
But when the list was learnt before the drug was taken, later recall was better than the placebo group.
The drug facilitated (actually improved) recall material learned beforehand
JOHN WIXTED (2004) suggests that the drug prevents new information (experiences after taking the drug) reaching parts of the brain involved in processing memories
Therefore, it cannot interfere retroactivity with information already stored
Support from drug studies - strength
However, a strength is that this research has real-life applications
DANAHER ET AL (2008) found that recall and recognition of an advertiser’s message were impaired when participants were exposed to two advertisements for competing brands within a week.
This is a serious problem when so much money is spent on advertising.
Danaher et al suggest an application of this research is that such effects can be overcome by running the advert multiple times on one day to reduce interference effects.
