Explanations for forgetting

Question 1

What is forgetting?

Answer 1

A person’s loss of the ability to recall or recognise something that they have previously learned

Question 2

What is the interference theory?

Answer 2

This occurs when two pieces of information conflict with each other, resulting in forgetting of one or both, or in some distortion of memory.
Interference has been proposed mainly as an explanation for forgetting in LTM. Once information has reached LTM it is more or less permanent. Therefore, any forgetting of LTMs is most likely because we can’t get access to them even though they are available. Interference between memories makes it harder for us to locate them; this is experienced as forgetting.

Question 3

What are the two types of interference?

Answer 3

Proactive interference and retroactive interference

Question 4

What is proactive interference?

Answer 4

This occurs when an older memory interferes with a newer one

Question 5

What is an example of proactive interference?

Answer 5

Teacher has learned so many names in the past she has difficulty remembering the names of her current class

Question 6

What is retroactive interference?

Answer 6

When a newer memory interferes with an older one

Question 7

What is an example of retroactive interference?

Answer 7

Teacher has learned so many new names this year she has difficulty remembering the names of her students last year

Question 8

Evidence for proactive interference

Answer 8

Underwood (1957) – participants required to learn a series of word lists do not learn the lists of words encountered later on in the sequence as well as lists of words encountered earlier on.
Underwood found that if participants memorised 10 or more lists, then, after 24 hours, they remembered about 20% of what they learned. If they only learned one list, recall was over 70%. This provides evidence for proactive interference because it shows how when there is more lists to remember, participants did not do as well because they do not learn the list encountered later on as well. However, when only one list is learned, recall was over 70% as there is no interference.

Question 9

Evidence for retroactive interference

Answer 9

Muller (1900) – gave participants a list of nonsense syllables to learn for six minutes and then asked participants to recall the list. Performance was worse if participants had been given an intervening task (to describe a painting) between initial learning and recall. Because performance decreased when participants were interfered with a new task, therefore a new memory which interfered with their ability to remember the list of nonsense syllables.

Question 10

What is a similarity between proactive interference and retroactive interference?

Answer 10

Interference is worse when the memories or learning are similar

Question 11

Research on effects of similarity

Answer 11

McGeoch and McDonald (1931) experimented with the effects of similarity of materials. They gave participants a list of 10 adjectives (List A). Once these were learned there was then a resting interval of 10 minutes during which they learned List B, followed by recall. If List B was a list of synonyms of List A, recall was poor (12%). If List B was nonsense syllables this had less effect (26% recall). If List B was numbers this had the least effect (37% recall). This shows that interference is strongest the more similar the items are.

Question 12

Why does similarity affect recall?

Answer 12

It could be due to proactive interference - previously stored information makes new similar information more difficult to store. Or it could be due to retroactive interference - new information overwrites previous similar memories because of the similarity.

Question 13

Evaluation interference - real world

Answer 13

One strength is that there is evidence of interference effects in more everyday situations. Baddeley and Hitch (1977) investigated interference effects in rugby players recalling the names of the teams they had played against over a rugby season. Some players played in all of the games in the season whereas others missed some games because of injury. The time interval from start to end of the season was the same for all players but the number of intervening games was different for each player because of missed games. Baddeley and Hitch found that those players who played most games forgot proportionally more games played because of interference. This shows that interference can operate in at leas some real-world situations, increasing the validity of the theory.

Question 14

Evaluation interference - cues

Answer 14

One limitation is that interference is temporary and can be overcome using cues. Researchers gave participants lists of words organised into categories, one list at a time, not being told what the categories were. Recall averaged about 70% for the first list, but became progressively worse as participants learned each additional list, an example of proactive interference. However it is difficult to say whether the words really disappeared from LTM or if they were still available as at the end of the procedure the participants were given a cued recall test, being told the names of the categories. Recall rose again to about 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.

Question 15

Evaluation interference - drugs

Answer 15

Another strength comes from evidence of retrogade facilitation. Researchers 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 influence of the drug diazepam, recall one week later was poor compared to 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. This suggests 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, reduced interference means reduced forgetting.

Question 16

What is the suggestion of retrieval failure?

Answer 16

The reason people forget information may be because of insufficient cues. 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, it may make it appear as if you have forgotten the information but, in fact, this is due to retrieval failure – not being able to access memories that are there.

Question 17

What is the encoding specificity principle?

Answer 17

This states that if a cue is to help us recall information it has to be present at encoding (when we learn material) and at retrieval (when we recall it). However, if the cues available at encoding and retrieval are different (or absent at retrieval) there will be some forgetting.

Question 18

What is research to support encoding specificity principle?

Answer 18

Tulving and Pearlstone has participants learn 48 words belonging to 12 categories. Each word was presented as a category and a word, e.g. fruit-apple.
Participants either had to recall as many words as they could (free recall) or given a cue, the category name (cued recall).
- 40% of words recalled in free recall.
- 60% of words recalled in cued recall.

Question 19

What is context-dependent forgetting?

Answer 19

This states that retrieval cues may be based on context (an external cue), i.e. the setting or situation in which information is encoded and retrieved e.g. a particular room, a rainy day etc.

Question 20

Research to support context-dependent forgetting

Answer 20

Godden and Baddeley (1975) studied deep-sea divers who work underwater to see if training on land helped or hindered their work underwater. The divers learned a list of words either underwater or on land and then were asked to recall the words either underwater or on land.

This created four conditions:
1. Learn on land – recall on land
2. Learn on land – recall underwater
3. Learn underwater – recall on land
4. Learn underwater – recall underwater

In two of these conditions the environmental contexts of learning and recall matched, whereas in the other two they did not. Accurate recall was 40% lower in the non-matching conditions. The external cues available at learning were different from the ones available at recall and this led to retrieval failure

Question 21

What is state-dependent forgetting?

Answer 21

This states that retrieval cues may be based on the mental state of the person (internal cue) at the time of learning and recall e.g. feeling upset or being drunk

Question 22

Research to support state-dependent forgetting

Answer 22

Carter and Cassaday gave antihistamine drugs to their participants which made the participants slightly drowsy creating an internal physiological state different from the ‘normal’ state of being awake and alert. The participants had to learn lists of words and passages of prose and then recall the information.

4 conditions:
o Learned on drug – recalled on drug
o Learned on drug – recalled not on drug
o Learned not on drug – recalled on drug
o Learned not on drug – recalled not on drug

In the conditions where there was a mismatch between internal state at learning and recall, performance on the memory test was significantly worse. So when the cues were absent then there is more forgetting.

Question 23

Evaluation RF - real-world

Answer 23

One strength is that retrieval cues can help to overcome some forgetting in everyday situations. Although some cues may not have a very strong effect on forgetting, Baddeley suggests they are still worth paying attention to. For instance, when we are in one room and think to get something in another room, once entering the other room we forget what we wanted. But when we go back to the first room, we remember again. When we have trouble remembering something, it is worth making the effort to recall the environment in which we learned it first. This shows how research can remind us of strategies we use in the real world to improve our recall

Question 24

Evaluation RF - recall vs recognition

Answer 24

One limitation is that context effects may depend substantially on the type of memory being tested. Godden and Baddeley replicated their underwater experiment but used a recognition rest instead of recall - participants had to say whether they recognised a word read to them from a list, instead of retrieving it for themselves. When recognition was tested there was no context-dependent effect, performance was the same in all four conditions. This suggests that retrieval failure is a limited explanation for forgetting because it only applied when a person has to recall information rather than recognise it.

Question 25

Evaluation RF - state-dependent forgetting

Answer 25

One strength is that there is research evidence to support state-dependent forgetting. Goodwin (1969) asked male volunteers to remember a list of words either while drunk or sober. He found that recall was better when they learned drunk and recalled drunk or when they learned sober and recalled sober. This supports the state-dependent memory theory as the performance was best in the participants who learned and recalled the material in the same state