What actually happens in our brains when we sleep?
(not a test or homework question but I'm curious)
I know about the different brain waves like delta/alpha/etc and sleep cycles, but I remember a friend telling me that when we dream our brain acts physiologically as though we are awake...I don't believe that is correct, but thinking about it I'm really not sure how to compare the REM-stage sleeping brain to the awake brain! Thanks :)

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