Further to my last entry, on the subject of exercise, here's another report, this time saying that light exercise, such as a more leisurely walk, can be of benefit -- in this case, it appears to cut the risk of type 2 diabetes. But it's worth noting that the benefit increased the more walking was done.

And while we're on the subject of factors that benefit cognition, New York Magazine has a good article on sleep deprivation in kids. Some worrisome stats: in surveys, 90% of American parents think their child is getting enough sleep, but 60% of high schoolers report extreme daytime sleepiness, 25% admit their grades have dropped because of it, and over 25% fall asleep in class at least once a week. Studies indicate 50% of American adolescents get less than seven hours of sleep on weeknights, and only 5% of high-school seniors get the recommended average eight hours. And why are these figures so worrying? Because research has shown dramatic differences in academic performance in children who get less sleep. One study found the performance difference between getting 30 minutes less sleep each night or 30 minutes more, was equivalent to two years' maturity, after only 3 nights. Another found that just being allowed to stay up late on Friday and Saturday nights caused elementary school children's test scores to drop 7 points. And two very large studies have shown there's a consistent average 15 minute sleep difference between A students, B students, and C students. I could go on and on, but read the article!

And, nothing (probably) to do with cognition, but while we're on the subject of sleep, Scientific American has an interesting article telling about how we dream more, and more intensely, if we're short of sleep.