Your brain on dreams

The Disney Channel's perky PSA showed an assortment of animals and people deep in slumber. The energetic voiceover: "Sleep is how your body rests!" followed by an exhortation to get proper rest.

I was folding clothes nearby when this caught my attention. "Hm," I thought out loud, "I would have said, 'Sleep is how your brain rests.'" I was about to go on that it's perfectly possible to lie down and rest your body without being asleep; that the change in brain state is what makes the difference between sleep and wakefulness.

"No!" said Ulysses, forcefully. "Sleep is how your body rests."

"Sleep is how your brain rests," I repeated, "because your brain waves..."

Ulysses cut me off. "Sleep is how your body rests."

"Sleep is how your brain rests," I said, unhelpfully.

"Sleep is how your body rests."

"Sleep is how your brain rests."

"Sleep is how your body rests."

"OK, OK, whatever," I said.

* * *

At bedtime, I tucked Ulysses in and said, "Now it's sleep time. Shut your eyes and go to sleep."

"Sleep is how your body rests," he reminded me.

"Sleep is how your brain rests," I said.

"No! Your brain has to stay awake."

"Why do you say that?" I asked.

"Your brain has to stay awake, so it can dream."

He kinda had me there.