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Read more: “Instant Expert: Memory“
All too often, our memory can fail us. We all forget important facts from time to time, but in the most serious forms of amnesia people may have no concept of their recent past whatsoever. Understanding memory failings can help researchers work out how we form and retain memories.
Why do we forget?
Any effective memory device needs to do three things well: encode information in a storable form, retain that information faithfully and enable it to be accessed at a later point. A failure in any of these components leads us to forget.
Distraction or reduced attention can cause a memory failure at the encoding stage, while a problem in storage – following brain injury, for example – can cause us to lose the encoded information. Memories can also “fade” and become less distinctive if the storage of other memories interferes with them, perhaps because they are stored in overlapping neural assemblies.
Often, memory failures occur when we try to retrieve information, leading to the feeling that a fact is “on the tip of my tongue”. For example, it can be intensely frustrating to forget someone’s name at a party, only to remember it a few hours later. This problem might be because the brain’s search algorithms aren’t perfect, and it may sometimes have trouble distinguishing the right signals from other neural noise.
Despite its drawbacks, forgetting can also be useful and adaptive. Other things being equal, we tend to remember things that are salient and non-trivial; for example, information that is potentially rewarding or threatening.
Amnesia
The “amnesic syndrome” (also known as classical amnesia) is one of…
