Sleeping is by many measures the most mysterious of human activities, but one thing that is clear is that as we age, we lose some of our ability to stay up late and get up early. Napping is a necessary means of daily rejuvenation.
But now scientists at the University of Massachusetts have announced new findings which may make that nap less enticing to older people: sleep might make your tired bones feel better, but it does not, it turns out, do much for your memory.
Researchers Lauri Kurdziel and Rebecca Spencer had already shown that a good night's sleep left young people with somewhat enhanced memory of how to perform certain tasks. But in their more recent work they gave a group aged 18-30 and a group 50 to 80 years old identical tasks, tested the effect of sleep on learning, and found that only the younger group got a performance boost from their snooze.
Despite all the obvious advantages of wakefulness - vigilance, increased sensory input, more time to play video games - sleep has survived the whole historical and prehistorical arc of human development, and still claims a quarter to a third of every day. It must do something for us besides prolong the life of our light bulbs. Even if it doesn't improve memory for the old, who need all the memory help they can get, we're confident sleep will not lose popularity among people of any age.