Memory - Forgetting

Question 1

What is interference?

Answer 1

Interference is when two pieces of information are in conflict. Forgetting occurs in LTM because we can’t get access to memories even though they are available.

Question 2

What is proactive interference?

Answer 2

Proactive interference occurs when an older memory disrupts a newer one.

Question 3

What is retroactive interference?

Answer 3

Retroactive interference happens when a newer memory disrupts an older one.

Question 4

Why is interference worse when memories are similar?

Answer 4

• in proactive interference, previously stored information makes new information more difficult to store
• in retroactive interference, new information overwrites previous memories which are similar

Question 5

Procedure

McGeoch and McDonald (1931) Effects of Similarity

Answer 5

Participants were asked to learn a list of words to 100% accuracy (i.e. could recall them perfectly).

Then they were given a new list to learn. The new material varied in the degree to which it was similar to the old:

• Group 1: synonyms (words had the same meanings as the originals)
• Group 2: antonyms (words had opposite meanings to the originals)
• Group 3: unrelated (words unrelated to the original ones)
• Group 4: consonant syllables
• Group 5: three-digit numbers
• Group 6: no new list (control condition, participants just rested)

Question 6

Findings and Conclusions

McGeoch and McDonald (1931) Effects of Similarity

Answer 6

Performance depended on the nature of the second list. The most similar material (synonyms) produced the worst recall. When the participants were given very different material, such as three-digit numbers, the mean number of items recalled increased.

This shows that interference is strongest when the memories are similar. In Group 1, it is likely that the words with the same meanings as the original list blocked access or that the new material became confused with the old material.

Question 7

What are the strengths of interference as an explanation for forgetting?

Answer 7

• evidence from lab studies consistently demonstrates interference in memory
• real-life studies have supported the interference explanation

Question 8

What are the weaknesses of interference as an explanation for forgetting?

Answer 8

• use of artificial materials
• the time allowed between learning
• interference effects may be overcome using cues

Question 9

Why is the use of lab studies a strength?

Answer 9

Many lab experiments have been carried out into interference, (e.g. McGeoch and McDonald’s research on the effects of similarity).

Most of these studies show that both types of interference are very likely causes of forgetting from LTM.

Lab experiments control the effects of extraneous variables and so give us confidence that interference is a valid explanation.

Question 10

What real-life studies have supported the interference explanation?

Answer 10

Baddeley and Hitch (1977) asked rugby players to recall the names of teams they had played so far in that season, week by week.

Accurate recall did not depend on how long ago the match took place. More important was the number of games played in the meantime.

This study shows that interference explanations can apply to at least some everyday situations.

Question 11

Why is the use of artificial materials a limitation?

Answer 11

The stimulus material used is often word lists. This is more realistic than consonant syllables but is still quite different from things we remember in everyday life.

For example, in everyday life, we remember people’s faces, their birthdays, the ingredients of our favourite pizza, etc.

The use of artificial materials makes interference much more likely in the lab. It may not be a likely cause of ‘everyday’ forgetting.

Question 12

Why is the time allowed between learning a weakness?

Answer 12

Time periods between learning lists of words and recalling them are quite short in lab studies. A participant might learn two lists within 20 minutes.

Research reduces the whole experience of learning into a short time period which does not reflect how we learn and remember most information in real life.

So the conclusions generated from research into forgetting in LTM may not generalise outside the lab. The role of interference may be exaggerated.

Question 13

How can interference effects be overcome using cues?

Answer 13

Tulving and Psotka (1971) gave participants five lists of 24 words, each organised into six categories. Categories were not explicit but it was assumed they would be obvious when presented.

Recall was about 70% for the first list, but this fell as each additional list was learned, presumably due to interference. However, when given a cued recall test (told the names of the categories) recall rose again to about 70%.

The memories of the words were stored in LTM but interference prevented access to them. When given a cue, it was easier to access the forgotten words.

Question 14

What is retrieval failure?

Answer 14

When information is initially placed in memory, associated cues are stored at the same time.

If these cues are not available at the time of recall, you might not be able to access memories that are actually there.

Question 15

What is the encoding specificity principle?

Answer 15

Tulving (1983) suggested that cues help retrieval if the same cues are present at encoding (i.e. ‘coding’, when we learn the material) and at retrieval (when we are recalling it).

The closer the retrieval cue to the original cue, the better the cue works.

Question 16

What cues have meaning linked to the memory?

Answer 16

Some cues are linked to the material-to-be-remembered in a meaningful way.

Question 17

What cues don’t have a meaningful link to memory?

Answer 17

Other cues are also encoded at the time of learning but not in a meaningful way:

• Context-dependent forgetting - when memory retrieval is dependent on an external/environmental cue (e.g. the weather or a place).
• State-dependent forgetting - when memory retrieval is dependent on an internal cue, state of mind.

Question 18

Procedure

Godden and Baddeley (1975) Context-Dependent Forgetting

Answer 18

Cues were the contexts where learning and recall took place - on land or underwater.

Deep-sea divers learned word lists and were later asked to recall them:

• Group 1: learn on land - recall on land
• Group 2: learn on land - recall underwater
• Group 3: learn underwater - recall on land
• Group 4: learn underwater - recall underwater

Question 19

Findings and Conclusions

Godden and Baddeley (1975) Context-Dependent Forgetting

Answer 19

When the environmental contexts of learning and recall did not match (i.e. conditions 2 and 3) accurate recall was 40% lower than when they did match (i.e. conditions 1 and 4).

When the external cues available at learning were different from the ones at recall, this led to retrieval failure due to lack of cues.

This study demonstrates context-dependent forgetting because information was not accessible (i.e. was forgotten) when context at recall did not match context at learning.

Question 20

What are the strengths of retrieval failure as an explanation for forgetting?

Answer 20

• an impressive range of evidence supports this explanation of forgetting
• context-related cues have useful everyday applications

Question 21

What are the weaknesses of retrieval failure as an explanation for forgetting?

Answer 21

• context effects are actually not very strong in real life
• context effects only occur when memory is tested in certain ways
• encoding specificity principle cannot be tested and leads to circular reasoning

Question 22

What evidence supports retrieval failure as an explanation of forgetting?

Answer 22

For example, Godden and Baddeley’s research with deep sea divers.

In fact, Eysenck (2010) goes so far as to argue that retrieval failure is perhaps the main reason for forgetting in LTM.

Supporting evidence increases the validity of an explanation, especially when conducted in real-life situations as well as the highly controlled conditions of the lab.

Question 23

What useful everyday applications do context-related cues have?

Answer 23

People often report these experiences: they were upstairs and went downstairs to get an item but forgot what they came downstairs for. But when they go back upstairs, they remember them again.

The application is that when we have trouble remembering something, it is probably worth taking the effort to revisit the environment in which you first experienced it.

This is a basic principle of the cognitive interview, a method of getting eyewitnesses to recall more information about crimes by using a technique called ‘context reinstatement’.

Question 24

How are context effects not very strong in real life?

Answer 24

Baddeley (1966) argued that different contexts have to be very different indeed before an effect is seen (e.g. on land versus underwater).

Learning something in one room and recalling it in another is unlikely to result in much forgetting because the environments are not different enough.

So the real-life applications of retrieval failure due to contextual cues don’t actually explain much forgetting.

Question 25

How do context effects only occur when memory is tested in certain ways?

Answer 25

Godden and Baddeley (1980) replicated their underwater experiment using a recognition test instead of recall.

There was no context-dependent effect. Performance was the same in all four conditions whether the environmental contexts for learning and recall matched or not.

This limits retrieval failure as an explanation for forgetting because the presence or absence of cues only affects memory when you test recall rather than recognition.

Question 26

Why can’t encoding specificity principle be tested and how does it lead to circular reasoning?

Answer 26

When a cue produced successful recall of a word, we assume the cue must have been present at the time of learning.

If a cue does not result in successful recall, then we assume that the cue was not encoded at the time of learning.

But there is no way to independently establish whether or not the cue has really been encoded.

Question 27

What are the five forgetting theories?

Answer 27

• interference theory
• retrieval failure
• decay
• displacement
• repression