What a marvellous article. One thing I’ve never quite appreciated in neuroscience is how useful physical movement is as a debugging layer. During a task, in observing gaits, tremors, speed, accuracy, etc., you’re able to gain a deeper understanding of how cognition works for non-movement tasks. I guess cognition is, after all, still just movement, but through a conceptual plane instead of a physical one.
It's been argued that most, maybe all, of human cognition is based on a sort of folk-physics mental model with objects. We throw ideas into the ring to be chewed on and distilled and maybe brought in to practice or thrown out as useless. The linguistic metaphors we use, at least, to talk about ideas and abstractions, are never more than one, maybe two, steps away from a hand moving or rearranging something.