MEMORY GAPS, MEMORY ERRORS
The processes we’ve been discussing—acquisition, storage, and retrieval—function extremely well in a huge range of circumstances. As a result, each of us can learn an enormous quantity of information, store that information for a long time, and then swiftly retrieve the information when we need it. But of course there are times when remembering is less successful. Sometimes we try to remember an episode but simply draw a blank. Sometimes we recall something, but with no conviction that we’re cor-rect: “I think it happened on Tuesday, but I’m not sure.” And sometimes our memories fail us in another way: We recall a past episode, but it turns out that our memory is mistaken. Perhaps details of the event were different from the way we recall them; perhaps our memory is altogether wrong, misrepresenting large elements of the original episode. Why, and how often, do these memory failures occur?