Declarative Memory - What Is Memory: Improving Memory Understanding Age Related Memory Loss

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Declarative memory

Also known as explicit memory, declarative memory is information that requires a conscious effort to recall. There are two types of declarative memory: semantic memory and episodic memory. Semantic memory is factual knowledge, such as the names of the continents, the color of your spouse's eyes, or what winter is. Much of the basic information you acquired during your school days falls into this category. In addition to being factual, semantic memory has another key characteristic: It is not bound to a specific point in time. You can't point to the moment in time when you learned your mother's name, for example. And even if you can remember the specific day when you learned the multiplication tables or other facts in school, the timing isn't important to your knowledge of them.

By contrast, episodic memory contains the images and details of experiences you have had. Episodic memories are personal memories tied to specific times and places. The party you attended last weekend, the vacation you took last summer, your children's birthday celebrations (and their births), and your wedding day are all episodic memories (see "Flashbulb memory," below).

Declarative memory is the type of memory that people have trouble with as they age because it is processed through the hippocampus, a brain structure that changes as the years pass and that is particularly vulnerable to degenerative disorders such as Alzheimer's disease. An episodic memory is more fragile than a semantic memory because it is more specific; it occupies less space in your brain and has a smaller associative network. Although patients with Alzheimer's are frequently able to recall episodes from many years ago, they have profound difficulty acquiring new episodic memories.

Last updated:	January 23, 2007