I don't know. It just makes sense for me. By the same token, why does closing your eyes demand a more proprioceptive signal from you when moving around?
Well, for me it does not. When you make a point like that it would be good if you had arguments in favor of it, don't you agree?
Also, I don't understand your question. What is a "more proprioceptive signal"? And what does that have to do with our discussion?
I meant "stronger" proprioceptive signal. When you take away one orientation sense (eyesight) the body needs to boost it's proprioceptive ability to determine the position on your limbs/to maintain equillibrium etc.
Try this: stand on one leg and like in a one-leg deadlift touch the floor. Do the same thing with your eyes closed. Which was harder? Or try to balance on a medball or basketball with your eyes open vs. your eyes closed.