CNN Correspondent: The study found that people who had regular naps saw an 6objective difference in brain size 7compared to those who didn't. We know that as we age, our brains 8shrink, and that can be 9associated with cognitive decline. And what she's 10fundamentally saying is that people who napped regularly in many ways had younger brains than those who didn't.
Dr. Sanjay Gupta, CNN Chief Medical Correspondent: Is there a right 11length of a nap, and is it possible to sleep or nap too much?
Victoria Garfield: One of the issues that people say often, if you sleep for too long in the day is you wake up feeling 12groggy, you wake up feeling worse, and that's because you've gone into deep sleep. Your brain is preparing in 13mimicking that sleep at night and thinks you're now ready to sleep for the rest of the day. So, in order to 14avoid that, we've been quite 15conservative and said, well, maybe something up to about 30 minutes.