Do "undecided" voters actually make their choices before they realize?
That is a question University of Virginia psychology professor Brian Nosek and his colleagues are trying to answer.
"Many people, especially early in the political process, declare themselves as undecided," Nosek said. "But while they have consciously said that they are undecided, they unconsciously may have already made a choice."
And in a close election, undecided voters may determine the outcome the moment they make their decisions known on Election Day.