Chapter Review Summary

Your memory is usually accurate, but errors do occur and can be quite large. In general, these errors are produced by the connections that link your memories to each other and link memories for specific episodes to other, more general knowledge. These connections help you because they serve as retrieval paths. But the connections can also “knit” separate memories together, making it difficult to keep track of which elements belong in which memory.

Some memory errors are produced by your understanding of an episode. The understanding promotes memory for the episode’s gist but also encourages memory errors. A similar pattern emerges in the DRM procedure, in which a word related to other words on a list is (incorrectly) recalled as being part of the list. Closely related effects arise from schematic knowledge. This knowledge helps you understand an episode, but at the same time, a reliance on schematic knowledge can lead you to remember an episode as being more “regular,” more “normal,” than it actually was.

Memory errors can also arise through the misinformation effect, in which people are exposed to some (false) suggestion about a previous event. Such suggestions can easily change the details of how an event is remembered and can, in some cases, plant memories for entire episodes that never occurred at all.

People seem genuinely unable to tell apart their accurate and inaccurate memories. This is because false memories can be recalled with just as much detail, emotion, and confidence as a historically accurate memory. Nor can we reliably detect false memories by relying on the contrast between whether people say they “remember” the past or whether they say they merely “know” what happened in the past. The absence of a connection between memory accuracy and memory confidence contrasts with the common-sense belief that you should rely on someone’s degree of certainty in assessing their memory. The problem in this common-sense notion lies in the fact that confidence is influenced by factors (such as feedback) that have no impact on accuracy, and this influence undermines the linkage between accuracy and confidence.

While memory errors are easily documented, cases of accurate remembering can also be observed, and they are probably more numerous than cases involving memory error. Memory errors are more likely, though, in recalling distant events rather than recent ones. One reason for this is decay of the relevant memories; another reason is retrieval failure. Retrieval failure can be either complete or partial; the tip-of-your-tongue pattern provides a clear example of partial retrieval failure. Perhaps the most important source of forgetting, though, is interference.

People have sought various means of undoing forgetting, including hypnosis and various drugs. These procedures, however, seem ineffective. Forgetting can be diminished, though, through procedures that provide a rich variety of retrieval cues, and it can be avoided through occasional revisits to the target material.

Although memory errors are troubling, they may simply be the price you pay in order to obtain other advantages. For example, many errors result from the dense network of connections that link your various memories. These connections sometimes make it difficult to recall which elements occurred in which setting, but the same connections serve as retrieval paths, and without the connections you might have great difficulty in locating your memories in long-term storage. Even forgetting may have a positive side, by virtue of trimming details from memory in a fashion that may foster abstract thinking.

Autobiographical memory is influenced by the same principles as any other form of memory, but it is also shaped by its own set of factors. For example, episodes connected to the self are, in general, better remembered—a pattern known as the self-reference effect.

Autobiographical memories are also often emotional, and this has multiple effects on memory. Emotion seems to promote memory consolidation, but it may also produce a pattern of memory narrowing. Some emotional events give rise to very clear, long-lasting memories called flashbulb memories. Despite their subjective clarity, these memories, like memories of any other sort, can contain errors and, in some cases, can be entirely inaccurate. At the extreme of emotion, trauma has mixed effects on memory. Some traumatic events are not remembered, but most traumatic events seem to be remembered for a long time and in great detail.

Some events can be recalled even after many years have passed. In some cases, this is because the knowledge was learned so well that it reached a state of permastore. In other cases, occasional rehearsals preserve a memory for a very long time.