If you're interested in the health of your brain, it's likely that you've read a study or two about the cognitive benefits of sleep.
Yet a new study published in Perspectives on Psychological Science suggests that we may not reap the wonderfully cleansing and rejuvenating rewards of sleep in old age.
Many sleep studies are conducted on younger people who need a lot of sleep, in part, because their brains are developing in many different ways. For example, when we are young, we're forming ideas of who we are.
We're also trying to remember and learn all sorts of different things about the world and our place in it. Our brains are working really hard and sleep helps to consolidate memories and clean out the detritus that lingers between the cells in our brains.
In middle age it is very important that we sleep well and maintain healthy sleep patterns also, because this helps to protect our brains in old age. If we don't get enough sleep in this stage of life, Markman says, by old age there's broken windows and graffiti all over your brain.
As we reach old age there is less "creation of self" going on in our brains, and our brains don't need as much recovery time. In fact, if we need more sleep in old age, it is likely because we're sick. So, in some studies, we see a reversal between the amount of sleep people are getting and cognitive functioning.
Healthy older adults just don't need a lot of sleep – and that's okay.