Does your brain sleep?

I always knew that a heart never stops...it beats 24/7. However, I never knew that a brain never sleeps. I guess I just didn't really think about it until my youngest daughter had to have a brain scan [EEG]. She had to stay up all night...and believe me it was tough! The Doctor wanted her to be tired when she went in for the test. Well, I can't remember how we made it through the night without falling asleep, but we did. The next morning we were taken into a small room with a single bed. The technician placed tiny electrodes all over her head.

I was asked to sit in a chair just behind the technician. I could see her brain waves as they ran across the computer monitor. As her brain was being scanned she was asked to do several things; move her arm, blink her eyes, etc. Every time she did something the brain reacted on the screen. It was completely fascinating. Then she was told she could go to sleep and because she was so tired within a couple of minutes she was sound asleep. The brain waves slowed down. When technician turned and whispered to me, "will you switch off the light," the brain acknowledged her whisper. The brain also reacted to the click of the light switch being turned off. It was the strangest thing I'd ever witnessed - almost eerie. The brain knows or reacts to sounds even when your asleep....