This discovery fits in with my own observations. I think it was one of the hidden issues between me and my ex-husband. In that context, I once speculated (totally unscientifically) that maybe the brain's internal clock is at fault in some disorders, since depression slows you down and anxiety speeds you up when it doesn't freeze you entirely. He was so anxious he twanged like a bowstring, and he always needed to be doing -- and doing fast. I loathe being hurried.
Also, I suspect that people have different favored speeds for different activities, or for different moods. Then there's the difference between mental and physical speed; my brain is fast but my flesh slow and lumbering -- a contributor to my weight, rather than a cause of it, since I was slow even when I was thin and physically fit.
I also suspect that an uncontrolled or chaotic internal rhythm is one of the big factors in ADHD. God knows I find the iPod a blessing for getting me moving and keeping me in focus; my own internal music (a concept I swiped from Oliver Sacks) doesn't seem up to the job. OTOH, once I am locked into a task I tend to stay locked in; I'm fully capable of sitting with my whole body clenched for six hours at a time as I write or work on a computer problem. That brings up the need for breaks or changes of rhythm.
So what's your rhythm? Slow and steady, a fast staccato, a dreamy waltz? Is your mind a jukebox full of 3-minute songs or a Bayreuth of Wagnerian opera cycles?