Quite interesting. So epileptic brains are re-using a mechanism from the sleep cycle to defend against daytime seizures [potentially].... But at a cost of cognitive ability. I like how the brain can adaptively rewire stuff to defend itself. Just an anecdote, I find that my epilepsy causes me to drastically fall off a cognitive cliff at a certain point during e.g. a long meeting, and I guess this is a kind of gentle defence mechanism which I tend to call an 'aura' or precursor to a seizure. I like that the brain can give you notice of such a thing, enabling you to escape a bad situation.