This is a good overview. I have been thinking a lot about brain aging recently, as I know two people who have undergone neuro-cognitive testing, apparently an extensive four-hour process. One is my cousin who is the healthiest 70+ year-old I've ever known. (She is now weeks away from her trip to hike the Appalachian Trail for three months. So THAT healthy.) She got her results and was found to be on the high end of normal for her age.

Then just a few days ago my best friend who is 63 and has long-since been worried about her memory and her ability to retrieve words was tested. No results yet.

I get curious about the extent to which anxiety about getting older might contribute to things like having trouble finding the right word to say what you mean. Since I've been in my 50's I've found that when I struggle to remember something I've just been told, get muddled transcribing a phone number, or when the word I'm looking for slips away from my mind, I feel an underlying tension that says, "I'm getting older... Maybe I'm slipping." And I'm positive that that jolt of anxiety makes it even harder than it would have been to think clearly and have good recall.

One thing I don't think you mentioned that I've been hearing a lot about lately is the impact of untreated hearing loss on accelerating dementia. I know several people whose elderly parents refuse to get hearing aids, and they have seen mental decline going right along with that. And sure enough there is science to back that up. I was in the hearing aid center at Costco a while back and saw an info sheet that listed multiple specific ways the brain deteriorates when hearing loss is not corrected.

Anyway, thank you for asking me to comment on this story; it's a fascinating topic.