>In normal aging, Leventhal said, "Grandpa is able to see you at age 90 when you walk into the room, but he can't recognize you."<

From what one hears here, there are regions in the East (Kaukasus) where persons tend to get far over a hundred years old, up to 6 generations living together, and this not being unusual.
I do not recall mentioning that they run around the last decades to debile to recognize people.

As can be observed with various politicians and others,
persons who into high age are having serious responsibilities, seem to remain quite fit often compared to others, who just alike sit around in some "home" for old people and await their death to come while others die around them.

Apart from that, that the mentioned "grandpa" in the quote can see but not recognize, I would have assumed can even to a headblind Westie scientist from their own data tell him it ain't occipital cortex, but other systems to do with such.

One might be short of suggesting the author to in Westie science data read what limbic systems get damages with Alzheimer's.
And also in other context maybe, what sectors Western science names when it comes to facial recognition of humans.