Last week my fellow Phenom Ed Yong wrote a post about what happens to consciousness when animals die. According to the research Ed described, a rat’s brain shows signs of consciousness for at least 30 seconds after its heart stops.

That study got a lot of buzz, understandably, because of what it implies about near-death experiences: namely, that they’re more likely the product of a human mind than of some mystical power.

But Ed’s post also raised some more nuanced — and I think, more profound — questions about the work. For example, coma expert Steven Laureys of the University of Liège pointed out that nobody really knows yet how to determine whether an animal is conscious or unconscious by