Thread: Study finds that "Dreaming is [indeed] perception unconstrained by sensory input."

I think a useful experiment would be to test how smoothly the eyes can traverse closed versus open. That might be the main difference. I mean they can obviously track something quite smoothly when there's a moving object to focus on, but if there isn't and you're trying to move them across a visual field with all kinds of stuff in it (background objects etc) they have nothing to follow and they keep getting 'stuck' on background points. But if closed my eyes seem to be able to track pretty smoothy in comparison. Of course that said, I don't really know the parameters of the experiment or even precisely what some of the terminology means. But I think it would be the next logical step (if they haven't already tested for that).

I would also add that imagination tends not to be persistent. Meaning I imagine something, say a moving figure or a car, and it doesn't keep moving smoothly across my field of vision like a real object would. Maybe I can't even sustain an image of a car, or it sort of leaps ahead or I lose sight of it for a second and then it's over there. I think there's even a tendency if you're imagining something moving -- if it gets near the edge of your field of perception you tend to center it again, a sort of 'reset'. These are several things that can explain the difference, and there may well be more.