I just finished watching the latest episode of Horizon, Is seeing believing? It had lots of cool material on recent research into our perceptual systems and how some unique individuals (see bat man and synaesthesia) are providing clues into the degree of plasticity our brain is capable of. I think this developmental flexibility has important implications for how we view the evolution of language, which certainly chimes with Deacon’s latest explanations. Another segment of the episode focused on a famous linguistic perceptual trick, known as the McGurk effect, demonstrating the interaction between hearing and vision in speech perception. Here is the first video I found on the subject (although I thought the Horizon episode provided a better visual explanation of it):