I love this article! I've known since I started riding that it helps me mentally but only in the last 5 and a bit years (since the second shoulder op) did I process how/why. It was when I was talking to the psychologist at the rehab centre about meditation - I physically can't meditate.
All that "empty your mind and relax" crap - isn't possible and believe me, over the years I've really really tried (yoga courses/classes, reflexology course etc etc)!! But my brain has two parts I think and if I can calm one part with focus the other bit still chatters away in the background and so stillness doesn't arrive.
It's only after talking to her about meditation and her pointing out that the focus required for motos is like meditation because meditation isn't just emptying your mind, but focusing to clear all of your mind onto one thing.
Since then I've realised the ski touring is the same to me - but mainly because I count my steps and then when I pause to look at the view and catch my breath a bit, I also breathe really deep and slow to get some balance on the breathing. But that actually is essentially 'yoga breathing' and means I concentrate on the view and on the breathing - mind calm !! Skiing too - but I've always equated that with biking, mentally and physically!
I actually used to use a system of breathing to make cornering easier on track, which moved on to road riding too - a little like yoga breathing but it apparently helped some other people avoid arm pump (is that the right phrase?) because it makes you relax without trying!!
I 100% notice the detriment to my brain since I've not been riding all summer for 8 years

Tough times TBH