Why does spinning help to maintain lucidity? I know it works, as I've had much success from its use, and innumerous others have too. It seems to be a cardinal technique; however, I can find no evidence for why this actually works.

I do not believe it to be a placebo effect, for if it were then I would have equal success with random other techniques that I may generate, but I don't.

So what is hypothesised to actually occur in the brain when one engages in such a task?