7.2: Stages in Memory

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Most people think of memory as a storage device. It’s like an information bank: we perceive something, store the information away in memory, and withdraw it later. We sometimes forget, to be sure, but when we don’t forget, our memories are pretty reliable. On this view memory is passive; it is a record of things we experienced or learned. But this view is wrong. Perception, as we saw earlier, doesn’t work like a video camera. And memory doesn’t work like a video tape. Memory is active, and it involves reconstruction on our part. What we remember is jointly determined by the information that does get stored in our brains and by our reconstruction of it when we remember something.

Screenshot (15).png — Figure \(\PageIndex{1}\): Which Penny is Right?

Memory is not a single, unitary process or system. In the 1960s, psychologists thought that memory consisted of short-term memory, which fades very rapidly, and long-term memory, which is more permanent.

Nowadays, they more frequently draw a distinction between working memory, which holds a small amount of information for a short period of time (like the phone number we keep repeating to ourselves as we scramble for the phone), and long-term memory. But there are increasing signs that working memory and long-term memory each consists of further subsystems. We don’t need to worry much about this, however, and a simple three-part division will serve our purposes here.

We can think of memory as involving the following three stages:

Encoding: occurs when we perceive something
Storage: which often involves
1. Elaboration (adding information to the memory)
2. Revision (“rewriting” the memory)
Retrieval: when we access/use our memories
1. Recall
2. Recognition

Screenshot (16).png — Figure \(\PageIndex{2}\): Stages in Memory

Where Things Can Go Wrong

The output of memory—the thing we think we remember—is often different, sometimes dramatically different, from the input, and errors can creep in at all three stages in the process. This isn’t to say that our memories are wildly inaccurate. Creatures with extremely unreliable memories couldn’t survive for long. Still, important errors often occur.

This is easy to overlook, because we often fail to notice when our memories are inaccurate. After all, our memories usually do seem very accurate to us. Moreover, the details often don’t much matter, so we don’t notice when they are wrong. Finally, it is often difficult, or even impossible, to check a memory against what really happened.