Memory - Explanations of Forgetting; Interference Theory and Retrieval Failure Flashcards
What is interference theory?
- Interference is where two lots of information become confused in memory. One memory blocks another, causing one or both of the memories to be forgotten or distorted. It is mainly an explanation of forgetting in LTM.
- Forgetting is likely because we can’t access the memories even though they are available (as they are more or less permanent). Interference between memories makes it harder for us to locate them, and we experience this as forgetting.
Retroactive interference
- This works backwards in time, occurring when coding new information causes old information to be disrupted and it is a struggle to recall it - the new interferes the old
- An example of this is changing one’s email address and forgetting the old one
Proactive interference
- This works forwards in time, occurring when previously stored information interferes with new information recall -> past memories inhibit the ability of an individual to retain new memories
- The old interferes with the new
- An example of this is writing down an old address despite moving to a new one for an extended period when the addresses are similar
Mcgeoch and and McDonald (1931) - Retroactive interference
- They studied retroactive interference by changing the amount of similarity between two sets of materials - participants had to learn a list of 10 words until they could remember them with 100% accuracy
- They then had to learn a new list, with 6 groups of participants with the following conditions
1) Group 1 - synonyms with the first list
2) Group 2 - antonyms with the first list
3) Group 3 - Words unrelated to the original list
4) Group 4 - nonsense syllables
5) Group 5 - 3-digit numbers
6) No new list - these participants just retested - When participants then recalled the original list of words, their performance depended on the nature of the second list - the most similar material (synonyms) produced the worst recall
- This suggests that interference is strongest when memories are similar
- Evaluation - lab experiment may cause a lack of ecological validity, and confounding variables; would be better to match
Evaluation of interference theory - Supporting evidence
1) Mcgeoch and McDonald’s study (1931) - this supports and provides external validity for the theory of retroactive interference as similar words were confused most, supporting that similar coding is confused
2) There have been thousands of lab experiments carried out on this explanation of forgetting e.g. McGeoch and McDonald’s study; most of these studies support that both types of interference are very likely to be common ways that we forget LTM information
- This is a strength of the supporting evidence as it provides external reliability for both areas of the theory, strengthening interference theory
Evaluation of interference theory - supporting evidence cont.
3) Baddeley and Hitch (1977) asked rugby players to try to remember the names of the teams they had played so far in that season every week. As most of the players missed games, for some ‘last team’ they played might have been two weeks ago or three weeks ago or more
- They found that accurate recall did not depend on how long ago the matches took place; much more important was the number of games they had played in the meantime, and so a player’s recall of matches was better if they had played no matches since then
- This provides external validity for retroactive interference as the more new information that was provided, the more interference there was with old information, the less accurate the recall of it was
Evaluation of interference theory - undermining the evidence
1) There is a much greater chance that interference will be demonstrated in the lab than in real-life situations - the stimulus materials used in most studies are lists of words and the task facing participants is to learn these lists
- This is more realistic than random syllables, but its still some way from the things we learn and try to remember in everyday life such as people’s face, their birthdays and other meaningful information.
- Due to the lab environment of the studies, the evidence provides little ecological validity to interference theories as it is not entirely generalisable to everyday situations
What is retrieval failure theory?
- This theory argues that forgetting occurs in the absence of appropriate cues (a cue is a ‘trigger’ of information that allows us to access a memory).
- The encoding specificity principle argues that, for a cue to be helpful for recall, it has to be present when the memory is encoded and when it is retrieved.
- If the cues at encoding and retrieval are different, or the cues are absent at retrieval, there will be some forgetting.
- It may appear as though we have forgotten the information, but it is really retrieval failure – the memory is inaccessible due to the lack of cues, but the memories are available.
What is the encoding specificity principle?
Tulving and Thomson - The encoding specificity principle argues that there are two types of forgetting due to the absence of cues:
- Context-dependent forgetting - being in a different place when you try to recall memory.
- The external cues available at learning (encoding) are different from those at recall. This leads to retrieval failure. E.g. classroom vs exam hall. - State-dependent forgetting - being in a different mood/state of arousal when you try to recall memory.
- The internal cues at learning (encoding) are different from those at recall, which leads to retrieval failure. E.g. drunk vs sober.
Baddeley and Goddon (1975)
Baddeley and Godden (1975) - carried out a study of deep-sea divers working underwater. In this study, the divers learned a list of words either on land or underwater, and then were asked to recall the words either on land or underwater. This created four conditions: - Learn on land – recall on land - Learn on land – recall underwater - Learn underwater – recall on land - Learn underwater – recall underwater
Finding: Accurate recall was 40% lower in the non-matching context conditions.
Carter and Cassaday (1998)
Gave anti-histamines (that have a slightly sedative or tiring effect) to groups of participants, followed by a recall task. They were compared to a non-sedated control group. See the conditions below:
- Learn on drug – recall on drug – Matched Condition
- Learn on drug – recall without drug – Mismatched Condition
- Learn without drug – recall without drug – Matched Condition
- Learn without drug – recall on drug – Mismatched Condition
Findings: Participants best recalled words when they were in the same state of mind as when they learned the words. If they’d taken anti-histamines during encoding they best recalled them when they were on anti-histamines.
Goodwin et al (1969)
- Asked male volunteers to remember a list of words when they were either drunk or sober
- The participants were then asked to recall the lists after 24 hours when some were sober but others had to get drunk again for experimental purposes and the recall scores suggested that information learned when drunk is more available in the same state later, providing evidence for state-dependent forgetting
Evaluation of retrieval failure - Supporting evidence and real-world application
1) There has been an impressive range of research supporting retrieval failure as an explanation for forgetting. The studies by Godden and Baddeley; Carter and Cassaday are excellent examples of this research. Godden and Baddeley found that accurate recall was 40% lower in the non-matching context conditions. The external cues available at learning were different from those at recall which led to retrieval failure. Carter and Cassaday found that in the conditions where there was a mismatch between internal state at learning and recall, performance on the memory test was significantly worse. The internal cues available at learning were absent at recall, which led to retrieval failure.
- This research supports the validity of the retrieval failure explanation. This is especially true as the evidence suggests that retrieval failure occurs in real-life situations as well as in the highly controlled conditions of the lab.
2) It has been shown that eyewitness testimony can be improved using a technique called the cognitive interview. This technique has a number of stages, one of which is asking the eyewitness to reinstate the context by returning to the original crime scene in their mind, and imagine the environment (such as the weather, what they could see) and their emotions (such as what were their feelings). The cognitive interview has been successful with many studies reporting an increase in correct information after use of the technique. Additionally, we can use the research to improve recall when we need to e.g. when taking exams. It may be unrealistic to learn the information in the exam hall, but research has shown that just thinking of the room where you did the original learning was as effective as actually being in the same room at the time of retrieval
- This is a strength of the explanation because it suggests that knowledge of the explanation is useful in real-life situations, and therefore supports the external validity of the explanation.
Evaluation of retrieval failure - Weakness of supporting evidence
1) Baddeley argues that the context effects are actually not very strong, especially in real life. Different contexts have to be very different indeed before an effect is seen. For example – it would be very hard to find an environment as different from land as underwater. In contrast, learning something in one room and recalling it in another is unlikely to result in much forgetting because they environments are generally not different enough.
- This suggests that retrieval failure due to the absence of contextual cues may not really explain much forgetting. It also means that the study can’t provide very strong support for the retrieval failure theory as the contexts in the study are too different to truly generalise to other situations.
2) The context effect may be related to the kind of memory being tested. Godden and Baddeley (1980) replicated their underwater experiment but used a recognition test instead of recall. Participants had to say whether they recognised a word read to them from the list, instead of having to retrieve it themselves. When recognition was tested there was no context dependent effect; performance was the same in all four conditions.
- This suggests that the study can’t provide very strong support for the retrieval failure theory as the type of memory test may not generalise to all other situations. It also suggests that the presence or absence of cues only affects memory when you test it in a certain way, so the explanation isn’t a completely valid explanation of forgetting.
