Yes, I think that is the one. I forget the details on a regular basis, and have to keep looking it up to cite it.That was probably the Basketball Free Throws study. It's mentioned in the Psychology Today article but basically, they had 3 groups. A group that practiced free throws, one that just imagined practicing free throws, and a control that did neither. While the group that actually practiced improved the most, the imagination group improved significantly as well. Control, of course, showed no improvement.
Peace favor your sword,
Kirk