- Created by: Emma Goddard
- Created on: 20-05-15 17:18
One explanation of forgetting in short-term memory (STM) is displacement. Since STM has a limited capacity, information that is in STM can be overwritten and is lost through displacement. Waugh and Norman (1965) 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 the digit came at the beginning of the list. This suggests that digits at the beginning of the list were displaced by the digits that followed them, but items at the end of the list were still available 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.
Forgetting because of decay is due to the passage of time. OPTIONAL - It may be that some kind of structural change occurs in the brain's nerve cells when a memory is laid down in STM. 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 explanation of forgetting comes from research which has found that, if rehearsal is prevented, information in STM dissappears after 18 seconds. However, decay theory is reductionist as it 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: performance (if not rehearsed or repeated) dropped sharply after 3 months. This suggests that the skills required for cardiac resucitation need frequent refreshing or they will decay with time. Therefore, decay can also explain…