Forgetting interference theory

• Interference occurs when the recall of one memory blocks the recall of another, causing forgetting or distorted perceptions of these memories. Interference can be retroactive or proactive
• Proactive interference: previously learnt information interferes with the new information you are trying to store.
• Retroactive interference: a new memory interferes with older ones
• Retroactive interference was demonstrated by McGeoth and McDonald (1931), who found that when participants were divided into 6 groups to recall different lists of words (synonyms, antonyms, words unrelated to the original list, 3-digit numbers, consonant syllables) or no new list (control group), those who’d learnt the synonyms list experienced an average of 3.1 fewer correct items recalled, compared to the control group.

  • This supports the idea that the extent of forgetting is larger when the two memories or materials are very similar
• One weakness of the interference theory is that artificial stimuli are used in these tasks, such as learning lists of random words with no personal meaning to the participants, which means that the findings of interference studies are likely to have low mundane realism. This is because, in real life, we are likely to learn lists of meaningful information, such as revision topics for psychology, which we draw links upon and also which have personal meaning to us. These factors may also influence the extent of forgetting, rather than influence.
• One strength of the interference theory is that Baddeley and Hitch found that, in a group of rugby players who had to recall their last game and the number of games they’d played that season (which would be different for each player), the number of games they’d played since was more important than the total time they’d been playing for. This can be explained in terms of interference, where the more games each player played, the more likely the memories of these newer games would interfere or block the recall of older games (retroactive interference).
• Another strength of the interference theory is that interference has been consistently demonstrated in several studies, but particularly in lab experiments. This increases the validity of the theory, due to the use of highly-controlled conditions in lab experiments, standardised instructions alongside the removal of the biasing effects of extraneous and confounding variables
• Another weakness of the interference theory is that they are often conducted in very short spaces of time, with participants recalling their words 1 or 2 hours after they have learnt them. This does not reflect the normal passage of time in everyday life, where we often find that several days pass until we need to recall such information e.g. in the case of an exam. Therefore, this suggests that interference is unlikely to be a valid explanation for forgetting from the LTM.