The strange science of life, death, and consciousness
The paper appeared in Nature, and the scientists were careful to say that only bits of the brains had come back online, not enough to equal consciousness. All the same, the findings were paradigm-shattering. It means, for one thing, we don’t die all at once.
Your brain — three pounds of gelatinous convolutions and a hundred billion nerves, invisible in its machinations but responsible for all we think, all we do, and all we are — is a greedy little organ. Thirty seconds without oxygenated blood, and you lose consciousness; one minute, and brain cells die; three minutes brings permanent brain damage; and after five, death is imminent.
Or so we’ve always assumed.
What the new study showed, by contrast, is that cell death is a “gradual, stepwise process.” Prof Nenad Sestan, a professor of neuroscience at Yale University, explained that we might have a longer time window after death than we previously thought — and some of those processes can even be “postponed, preserved or even reversed.”
Brain Time: Image credit/creation by Brandy Schillace
The changes were only witnessed at the level of cells and neurons. No brain-wide electrical activity turned up in an electroencephalogram (EEG brain scan), no sense that the pig heads had awareness or perception. They were, basically, still dead brains (and 10 hours after decapitation, it’s no wonder).
The point of this experiment wasn’t to create zombie pigs; the scientists were looking for ways to repair a brain after loss of blood flow and oxygen — such as after a stroke, or when suffering diseases like Alzheimer’s. But the exercise raises some interesting questions about the nature of brains, awareness, and where the ‘self’ resides among the tangled cells of gray matter.
We’ve just been talking about mammals, and intelligent mammals, at that (pigs are quite brainy). But for a moment, let’s look at a simpler structure: butterfly brains. Called the subesophagael ganglion, this brain…