[burnished]

From the neuroscience side not that I'm aware of. Getting old is basically the process of your body not being able to repair itself anyway.

I think the apparent conflict resolves if you consider that you have learned to be a better problem solver, a better learner, such that a small decrease in some 'raw ability' is completely overshadowed by gains from learning.

For a concrete example I'm much better at close reading now. Even if younger me was 10x as intelligent there are problems he'd bounce off that I wouldn't simple because I now know how to slow down and read thoughtfully.