Explanations for Forgetting: Interference

Question 1

Describe the study on retroactive interference (RI)

Answer 1

Muller and Pilzecker (1900) gave participants a list of nonsense syllables to learn for 6 minutes and then, after a retention interval, asked them to recall the lists.
- Performance was worse if they had been given an intervening task between initial learning and recall.
- Intervening task produced RI as the new information has interfered with the old information

Question 2

Describe the study on proactive interference (PI)

Answer 2

• Underwood (1957) analysed findings from several studies and concluded that when participants had to learn a series of word lists, they don’t learn the word lists encountered later in the sequence as well as lists of words earlier on. (old information inteferes with new)
• Overall, he found if they memorised 10 or more lists, after 24 hours, they recalled about 20% of what they learned, but if they learnt one list, recall was over 70%

Question 3

Describe the study on the effect of similarity of test materials

Answer 3

• McGeoch and McDonald (1931) gave participants a list of adjectives (A). Once these were learned there was a resting interval of 10 minutes during which list B was learned, followed by recall
• If list B was synonyms of list A, recall was 12%. If list B was nonsense syllabus, this had less effect (26%), if B was numbers then recall was 37%.
• Shows interference is strongest the more similar the items are. Only interference, not decay, can explain these effects.

Question 4

Describe the real-world study

Answer 4

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

Question 5

Give evaluation for interference theory (1)

Answer 5

• Much of the research it’s based on rather artificial. For example, studies like McGeoch and McDonald’s have tasks that are artificial and don’t reflect memory tasks in everyday life. We don’t have to remember two separate word lists like adjectives and nonsense syllables, suggesting the tasks may lack mundane realism. Furthermore, the nature of the tasks means participants may lack motivation to remember the initial list, as there’s no consequences to forgetting compared to real life. Therefore, forgetting may exaggerated, calling into question the validity of interference theory. However, Baddeley and Hitch’s study on rugby players supports the theory in a more ecologically valid environment.
• In addition, the nature of the experiments and the time between learning may be exaggerating interference effects. For example, in a lab experiment it’s designed for interference to be maximised as the remembering and recalling processes could be done within an hour. Suggesting that the effects of interference found may be greater than in day-to-day life, question the validity of the theory.

Question 6

Give evaluation for interference theory (2)

Answer 6

• Furthermore, the theory only explains some situations of forgetting. For example, rather special conditions are required like the two memories need to be quite similar, so interference may be unimportant in everyday forgetting. Anderson (2003) concluded that there’s no doubt that interference plays a role in forgetting, but how much of forgetting is due to interference remains unclear. This means other theories are needed to provide a complete explanation
• Interference can explain temporary forgetting, rather than permanent forgetting. Research by Tulving and Psotka (1971) gave participants 5 lists of 24 words in 6 categories. The categories weren’t explicit but obvious to participants. Recall for the 1st list was 70% but fell as participants were given each additional lists to learn, presumably due to interference. However when given a cue, name of the category, recall rose to about 70%. Suggesting interference affects temporary availability.