Why do dementia patients remember some things but not others?


How come patients with dementia remember some things like how to speak but not others like who their daughter is? Does the brain memorize some things in one part of the brain and others in the other parts, and dementia only affects specific parts?

In: Biology

Yeah you’re pretty much exactly right! We have memory for different types of things and those are stored in the different areas of the brain. Memory for how to *do* things that you have had a lot of practice with (like speaking, riding a bike, and tying your shoes) is called **procedural memory,** which is stored in a different part of the brain than memory for things that have happened to you (**episodic memory**) and memory for facts (**semantic memory**). Dementias like Alzheimer’s typically attack a part of the brain called the hippocampus, and its surrounding areas, which are responsible for episodic and semantic (but not procedural) memory.

Episodic and semantic memory loss typically happens in a “backwards” fashion, where you first lose memory for things that happened more recently, and this progresses further and further back in time until you might only remember things that happened to you in your adolescence and younger. This is why people with Alzheimer’s might forget their grandchildren first, then their children, and then even their own spouse – it goes from most recent to least recent.

I hope this is helpful!