7.4: Storage

The chapter on perception shows that we sometimes inaccurately encode information, but once information is stored in the brain it might seem safe. Even here, however, our memories are active, and over time we unconsciously elaborate and revise the information we have stored. Since this occurs outside the realm of consciousness, it is sometimes difficult to determine whether the revisions occur during storage or during retrieval (for our purposes, it won’t usually matter which is involved), but in many of the examples in this section, errors clearly occur during the storage phase.

Editing and Revising

A central theme of this book is that we have a strong need to make sense of our world, to understand why the things that matter to us (including other people and ourselves) behave as they do. This drive for explanation and understanding is so strong that it sometimes leads us to see patterns and reasons even where they don’t exist, and to construct explanations even when we don’t have enough evidence to warrant them. It can lead us to fill in gaps in our memories even when we have little objective basis for doing so. This will be clearer if we consider several examples that illustrate the varied ways we do this.

The Ants

Subjects in an experiment heard a story that contained sentences like:

• The ants ate the jelly.
• The ants were in the kitchen.

Later they were asked to identify the sentences they had heard. Most thought they remembered:

• The ants ate the jelly in the kitchen.

But this sentence wasn’t in the story. What happened?

The subjects had, automatically, filled in gaps based on what they knew made sense. They didn’t store what they had literally heard, but an organized, meaningful version of the story. This filling in of gaps is a type of inductive inference. It is a way of updating the information stored in our heads. In this case, the subjects had some stored information and then inferred things that seemed to follow from it. For example, they inferred that the ants ate the jelly in the kitchen. But this wasn’t a conscious inference; they genuinely thought they remembered hearing the sentence.

The Graduate Student’s Office

In another study, undergraduates were asked to wait in a graduate student’s office. Later they were asked what was in the office, and most of them mentioned books. In fact, there weren’t any books in the office. What happened? The subjects’ memories had added a detail, based on the subjects’ expectations about graduate students’ offices.

The Dictator

In another study, people heard a fictitious story about a dictator. In one version, he was called ‘Gerald Martin’; in another he was called ‘Adolph Hitler’. The story didn’t mention Jews. Many students in the group who heard the Hitler version of the story thought it contained the sentence:

• He hated the Jews.

Students who heard the other version did not. What happened? Students in the first group filled in a detail based on what they knew about Hitler. They drew an inference, unconsciously, based on common knowledge.

The Labels

In yet another study, people were shown several fuzzily drawn figures (figure 7.4.1). Half of the people were shown the figures with one set of labels; the other half were shown the very same figures, but with different labels. For example, a figure that was labeled as a barbell for the first group was labeled as a pair of glasses for the second. The people were later asked to draw the figures they had seen. What do you think happened? As you might have predicted, the pictures they drew were heavily influenced by the labels they had seen. What they remembered seeing was partly determined by the way in which they had labeled or classified it.

Figure \(\PageIndex{1}\): Classification and Memory

The Lecture

A group of people attended a lecture. Some of them later read an inaccurate press report about it. Those who read this report tended to remember the lecture as it was described, even though the description was inaccurate. They unconsciously edited their memories to match the report.

These five examples suggest a moral. Memory is not passive. It involves active reconstruction to make as much sense of the data as we can. This reconstruction is influenced by our expectations and what we know. In the next section, we will see that it can be affected by other factors as well.