I got in a discussion with a philosophy grad student today, who told me that the question of whether thoughts were "just" patterns of neural flashes, or if there was something epiphenomenal going on, was still a serious open question. I'm really hoping that this is just a description of the current state of affairs in the philosophy world, and not the neuroscience world, but she seemed rather insistent on this point. This isn't actually considered an open question in neurobiology, right?