INTERFERENCE: EXPLANATIONS FOR FORGETTING

INTERFERENCE → where two lots of information become confused in memory, or when one memory blocks another. This can result in forgetting or distorting one of the memories or both.

~TYPES OF INTERFERENCE~

Proactive Interference - where previously learnt information interferes with new information (old interferes with new) - ‘can’t remember the new’

Retroactive Interference - where a new memory interferes with an older one (new interferes with old) - ‘can’t remember the old’

PROCEDURE:

Psychologists did a study where participants learned a list of 10 words until they had 100% accuracy. They then learnt a new list. These were:

  • synonyms - words with same meanings to the original list

  • antonyms - words with opposite meanings to the original list

  • words unrelated to the original ones

  • consonant syllables

  • three digit numbers

  • no new list - participants just rested

FINDINGS:

  • When the participants were asked to recall the original list of words, the most similar materials (synonyms) produced the worst recall.

CONCLUSION:

  • This suggests that interference is most prominent when memories are similar.

EVALUATION

Research Support

→ REAL-WORLD INTERFERENCE

  • One strength is that there is evidence of interference effects in more everyday situations.

  • Baddeley & Hitch asked rugby players to recall the names of the teams they had played against during a rugby season.. The players all played for the same time interval, but the number of intervening games varied because some players missed matches due to injury.

  • Players who played the most matches (most interference for memory) had the poorest recall.

  • This study shows that interference can operate in at least some real-world situations, increasing the validity of the theory.

  • However, the conditions necessary for interference are relatively rare.

  • This is very unlike lab studies, where the high degree of control means a researcher can create ideal conditions for interference.

  • The conditions for interference may occur occasionally in everyday life, but not often.

  • This suggests that most forgetting may be better explained by other theories such as retrieval failure due to a lack of cues.

→ SUPPORT FROM DRUG STUDIES

  • Another strength comes from evidence of retrograde facilitation.

  • Psychologists gave participants a list of words and later asked them to recall the list, assuming the intervening experiences would act as interference. They found that when a list of words was learned under the drug diazepam, recall one week later was poor (compared with a placebo control group).

  • But when a list was learned before the drug was taken, later recall was better than placebo. So the drug actually improved recall of material learned beforehand. A psychologist suggest that the drug prevents new information reaching parts of the brain involved in processing memories, so it cannot interfere retroactively with information already stored.

  • This finding shows that forgetting can be due to interference - reduce the interference and you reduce the forgetting.

Conflicting Evidence:

→ INTERFERENCE AND CUES

  • One limitation is that interference is temporary and can be overcome by using cues.

  • Psychologists gave participants a list of words organised into categories, one list at a time. Recall averaged about 70% for the first list, but became progressively worse as participants learned each additional list.

  • At the end of the procedure, the participants were given a cued recall test - they were told the names of the categories. Recall rose again to 70%.

  • This shows that interference causes a temporary loss of accessibility to material that is still in LTM, a finding not predicted by interference theory.