" Because the observer's only freedom is the choice of which question to pose (Shall I look up at the sky?), it is here that the mind of the observer has a chance to affect the dynamics of the brain. An examination of the mathematics, Stapp argued, shows that "the conscious intentions of a human being [reflected in the choices he makes about what question to put to nature] can influence the activities of his brain....Each conscious event picks out from the multitude of...possibilities that comprise the quantum brain the subensemble that is compatible with the conscious experience." The physical event reduces the state of the brain to that branch of it that is compatible with the particular experience or observation. "

― Jeffrey M. Schwartz , The Mind and the Brain: Neuroplasticity and the Power of Mental Force