One form of dualism involves the mysteries of quantum mechanics. Roger Penrose from the University of Oxford argues that consciousness is the link between the quantum world, in which a single object can exist in two places at the same time, and the so-called classical world of familiar objects where this cannot happen. Speculation that quantum mechanics and consciousness are linked is based on the principle that the act of measurement--which ultimately involves a conscious observer--has an effect on quantum events.
Moreover, with Stuart Hameroff of the University of Arizona, he has proposed a theory that the switch from quantum to classical states occurs inside certain proteins call microtubules. The brain's microtubules, they argue, are ideally situated to perform this transformation, producing "occasions of experience" that with the flow of time give rise to stream of consciousness thought.