Related to what you're after, people prepare movement before they consciously decide to act. I read about this in "The User Illusion" by Tor Nørretranders. He c

Related to what you're after, people prepare movement before they consciously decide to act. I read about this in "The User Illusion" by Tor Nørretranders. He cites Deecke, L., Grözinger, B. & Kornhuber, H.H. Voluntary finger movement in man: Cerebral potentials and theory. Biol. Cybernetics 23, 99–119 (1976).