Memory's Gates: Failures of Monitoring

So far in the current series of posts, I have covered how Schacter's "seven sins of memory" can be more parsimoniously explained as arising from three types of system failure. The first, failures of maintenance, roughly map on to his sin of transience. The second, failures of search, explain both suppression related phenomena as well as interference and transfer appropriate processing. But what about the third type of system failure, what I have termed "monitoring failure"?

A particular memory inaccuracy is likely to involve monitoring failure if a memory search has returned results, but these are taken to be valid results of the search cues when in fact they should not. Schacter categorizes this type of failure in three different ways: suggestibility, misattribution, and bias. It is not clear that these are fundamentally different. In fact, as discussed below, all of the evidence Schacter used to exemplify these “sins” can be more parsimoniously interpreted as failure to correctly evaluate the validity of results from a memory search.

For example, source misattribution errors occur when people insist that they saw someone in one context when in fact they saw them in another, or may incorrectly attribute some piece of trivia as coming from a newspaper, when in fact it was provided by the experimenter. These results can clearly be taken as instances of faulty monitoring of memory search results. Similarly, false recall or recognition in the Deese-Roediger-McDermott paradigm can be seen as a kind of monitoring failure, in which the feelings of familiarity are falsely monitored as indicating that the target word was present, when in fact it was not. The “false fame” effect is yet another example, where previously studied names are considered more likely to be famous than new names.

Although Schacter classifies these misattribution inaccuracies as distinct from suggestibility, this distinction may not be necessary. In a strict sense, errors resulting from suggestibility (for example, the subtle influences of question phrasing on the retelling of traffic accidents) can be viewed as misattribution errors, where the emphasis that originates from the question is instead falsely monitored as originating from the content of the memory itself.
Schacter also categorizes memory biases as distinct from both of these, although they too can be considered instances of monitoring failure, as explained below.

For example, humans show a consistency bias when asked how similar their previous attitudes are to their current attitudes, and tend to overestimate the similarity between current and previous attitudes. This might easily result from a memory search returning current as well as past attitudes towards an issue, despite the proper cues being provided to memory. In this case, faulty monitoring of memory search results might allow some current attitudes to “taint” the perception of previous attitudes, and result in the perception of increased similarity.

On the other hand, when people have reason to believe that their skills or opinions have changed substantially, retrospective biases tend to move in the opposite direction, such that people tend to overestimate the amount they may have changed. Interestingly, faulty monitoring may also be the culprit in this case: despite accurately probing memory, the memory search may also return related current attitudes (presumably those that strongly represent the idea that change has occurred). These results may influence the magnitude of perceived difference between current and previous time points, such that failure to exclude the current attitude (with a strong representation of “change”) may exaggerate the differences between current and previous attitudes.

The aforementioned grouping of bias, suggestibility, and misattribution under the umbrella of “monitoring failure” has additional advantages. For example, “faulty monitoring” might also be at work in other phenomena, such as confabulation. This refers to the phenomenon where some patients with frontal damage will unintentionally fabricate stories about their past. This is not a failure of memory search, because it is clear that the patients know the kind of information they should be looking for – autobiographical facts. However, the results of this search are mistakenly regarded as accurate, as opposed to being correctly monitored (and discarded) as inaccurate.

In the next (and final) post in this series, I will give additional evidence on how these categories of memory failure are superior to the "seven sins" (despite not being as catchy!). Furthermore, this framework makes some interesting predictions about how more complicated memory failures - such as déjà vu - may arise as an interaction between multiple systems.

Note: This post is part 5 (part 1, part 2, part 3, part 4) in a series, in which I'll review and revise Schacter's "seven sins of memory" according to a new framework of memory failure, one that is both closer to neuroanatomy and wider in scope.