http://www.ted.com/index.php/talks/view/id/102
He tried to show that our brains could fool us by some optical illusions. But we already knew for a long time that our organs are not perfect, which is exactly why we need science and mathematics. If we trust our organs, why do we need experiments and reasoning? When you studied geometry, did not you ever ask why we need a poof at all? Because we cannot trust our eyes. Some elementary geometry text books even show you two illusive lines one of which seems longer than the other, but a poof shows that the latter is acturally longer. Our feeling tells that the earth is static, but a Foucault pendulum shows that it is in motion. Consciousness is not constrained by its dwelling brain.