P1: Explanation in STM - Displacement
- Since STM has a limited capacity, info that is in STM can be overwritten & lost through displacement.
- Waugh & Norman used the serial probe technique to show that participants were more able to remember a digit that came towards the end of a 16 digit list, than if it came at the beginning.
- Suggests that digits at the beginning of the list were displaced by the digits that followed them but the items at the end were still in STM.
- This supports the idea that forgetting can occur in STM due to displacement.
- However, the problem is that a faster rate of presentation produces better recall. This could be explained in terms of decay, but is more difficult to explain in terms of displacement.
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P2: Forgetting due to decay:
- Forgetting because of decay is due to the passage of time.
- This memory is fragile, and if not rehearsed, these structural changes are reversed and the memory decays - but rehearsal may cause this change to become permanent - the memory trace is then laid down in LTM.
- Evidence of STM which supports decay as an EOF comes from research which has found that if rehearsal is prevented, info in ST disappears after 18 seconds.
- However, decay theory is reductionist - ignores the fact that we are less likely to forget things that are funny, interesting or distinctive.
- Emotional factors are clearly important in forgetting - e.g. repression and flashbulb memories but a biological explanation does not account for this.
- McKenna & Glendon (1985) studied volunteers who had learnt cardiac resuscitation: found that performance (if not rehearsed) dropped sharply after 3 months - suggests that the skills required need frequent refreshing or will decay.
- Therefore, decay can also explain forgetting in LTM. However, some skills such as riding a bike do not seem to be forgetten - there is research which has been carried out to support this which is known as "Implicit memory" which is a type of memory in which previous experiences aid the performance of a task without conscious awareness of these previous experiences.
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P3: LTM: Retrieval cue failure:
- Another explanation of forgetting in LTM is retrieval cue failure. This is where items in LTM cannot be accessed due to a lack of retrieval cues.
- This is when the information is still available in memory but is not readily accessible.
- Godden & Baddeley (1975) found that divers who learnt a list of words when on land recalled roughly twice as many when tested on land compared with underwater.
- These findings show that information is easiest to recall under the same conditions in which it was learnt & suggests that the extrinsic context in which the information was provided offers cues which help with recall.
- Therefore, some forgetting may occur due to the absence of extrinsic retrieval cues. Other research suggests that physiological or emotional state may also offer cues which help with recall - therefore forgetting may also be dependent on intrinsic state.
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P4: Freud - Repression:
- Freud proposed that the unconscious mind repressed painful, unacceptable memories back into the unconscious to prevent further anxiety.
- Involves the ego defence mechanisms & its purpose to protect the ego.
- Repression can be used to explain forgetting where there is no known damage and this usually involves a loss of personal memories.
- E.G. Irene - Hunter - which seem to suggest that highly traumatic events can cause the forgetting of such events.
- However, these case studies are open to bias and the findings are difficult to generalise or replicate, reducing the validity of repression as an EOF.
- Williams found that 1/3 of girls who had been sexually abused did not show any recall, although some of those did 'recover' these memories - however critics believe these may be fasle.
- If this is the case, it would weaken evidence for repression as an EOF - we forget such events because our emotional state at the time of encoding is completely different to our emotional state at recall.
- Therefore repression may not be a necessary EOF because it would be possible to explain forgetting of highly traumatic events in terms of state dependent learning.
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- In conclusion, there may be a number of explanations for forgetting. The best explanation depend on the nature of the material to be remembered, the context and whether the information is stored in STM or LTM.
- A problem is that much of the evidence for theories of forgetting have come from laboratory experiments (using artificial sitatuions) which lower the ecological validity, so they may not be providing evidence of why we forget in situations like everyday life.
- However, a strength of such research (i.e. lab) is that it is easy to replicate and the findings have been found to be highly reliable.
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