Whether you have Alzheimer’s or are of a certain age that you’ve started routinely forgetting where you put your keys, you’re probably hearing a lot about the benefits of “exercising your brain.” We hear this “use it or lose it” philosophy mentioned frequently in sound bytes from medical experts, but what are they really asking us to do? And why? Are they just trying to get us to do lots and lots of crossword puzzles?
Here’s what they mean. Let’s think of the neurons in your head as roads, and let’s say you’re trying to remember a piece of information. Let’s say you’re trying to remember my name: Lisa Genova. When you think, “What is her name?” your brain starts looking for the road that will take it to the answer. You might travel down the road “Author of STILL ALICE” to get to Lisa Genova.
If that’s the only piece of information you know about me, you might have a hard time at first finding that one and only road. And because it hasn’t been well-traveled, the road might be small, unlabelled, maybe not even paved. It might take you a few minutes (or all day!) to remember my name.
But if you loved the book, if it stays with you after you finish the last page, if you talk about the book with friends and at book club, if you travel this particular road over and over, or in other words, if you practice and rehearse this information, “Lisa Genova is the author of STILL ALICE,” then the road becomes stronger. It becomes simple to find with a nicely labeled street sign, and it’s now wider and paved. After many experiences with “Lisa Genova is the author of STILL ALICE,” this road becomes familiar territory, smooth and easy to travel on. You now know my name and can remember it easily.
But what happens if you are in the earliest stages of Alzheimer’s, and amyloid-beta is starting to clog some of your synapses? Imagine amyloid-beta as a roadblock, keeping you from traveling down that road that leads to the information you’re looking for. What if amyloid beta is blocking the “Author of STILL ALICE” road to Lisa Genova. If this is the one and only road to my name, and it is blocked, then you can’t retrieve my name. Now when you ask yourself, “Who is the author of STILL ALICE?” you cannot remember no matter how hard you think. The information is inaccessible. Forgotten.
But let’s say you paved more than one road to my name. Let’s say you also built “Author of LEFT NEGLECTED Street” and “Neuroscientist from Harvard Avenue.” Now you can have a roadblock on “Author of STILL ALICE Road” and still have two other ways to get to my name. These other roads may not be the most direct routes to my name if you haven’t traveled them as much, but they’ll still lead you to Lisa Genova. You can still remember me.
The more connections you make to a piece of information (the more roads you build) and the more you use or rehearse that information (the more you travel those roads), the more able you’ll be to detour clogged connections (amyloid beta road blocks), and remember what you’re trying to remember.
Say you learn ten things about me. You’ve built ten neural roads. And now let’s say you have Alzheimer’s. You can have nine roadblocks, a significant amount of memory loss. But you still have one road left. You can still remember my name.