I will be talking about trace decay and showing experiments to support the theory. In the study by Peterson and Peterson it was found that recall dropped from 80% after 3 second recall to fewer than 20% when the retention interval was 18 seconds. They believe the cause of this drop was due to one possibility which is that the memory trace simply disappears if it is not rehearsed. In the brown Peterson technique, participants were required to count backwards in threes to prevent rehearsal.
This is called trace decay theory and is based on the idea that memories have a physical basis (a trace) and that this will decay in time unless the trace is passed to long term memory. The trace disappears just like a photographic image that is not fixed with chemicals. Information in short term memory certainly does disappear but it may not be because of spontaneous decay but it may be the result of interference. Another possible explanation for the Peterson and Peterson findings is that the interference task caused retroactive interference.
This occurs when a second set of information pushes out earlier material from the memory store. It is most likely to happen when the two sets of information are sufficiently similar. Evidence supporting that point of view was reported by Reitman. The participants carried out either a syllable detection task or a tone detection task during the retention interval. Those who performed the syllable detection task had much lower recall than those who performed the tone detection task, presumably because syllables interfered much more than tones.
Evidence on the effects of interference is considered again later. Evaluation includes the fact that it has little mundane realism and therefore lacks generalisation to real life. It is really a product of the artificial tasks conducted in the laboratory as it is rare in real life that two responses are attached to the excellent criticism. It showed that when asked to recall a word list, different items are recalled each time. This suggests forgetting occurs due to lack of accessibility rather than interference, which causes a lack of availability, meaning the same items should be recalled each time.
Also when given cues, the effect of retroactive interference disappeared. Thus, cue dependent forgetting is perhaps a better alternative to interference theory. Endel Tulving conducted a number of studies on cue dependent forgetting. In one study Tulving and Psotka compared the cue dependent explanation of forgetting with the interference theory of forgetting. In this experiment participants were given word lists. There were six different word lists, each with 24 words. Each set of words was divided was divided into six different categories.
Cue dependent forgetting is a classic example of forgetting because of lack of accessibility. The information is in memory, but just cannot be accessed until an appropriate cue is given and suddenly it is found. Such information is said to be available but not accessible. Cue dependent forgetting probably offers more insights and has more real- world validity than interference theory, but it does depend on whether the memory failure is due to availability or accessibility.