If you've ever stayed up all night cramming before a big test at uni, you'll know that sleep is often the first thing we sacrifice when we have a lot to do. While we all know that sleep is important for our health and wellbeing, surely forgoing it every now and then to speed-read through a semester worth of notes is alright? Right?
But new research suggests that you could actually do better on that test if you got your full eight hours of sleep. We're discovering that sleep may play a bigger role in how our brains remember things than first thought.
These studies aren't just important to remind ourselves why we really should get a good night's sleep before a big exam. It's also helping scientists understand degenerative diseases like Alzheimer's and whether sleep can help slow down, or even reverse, the effects.
In a lab at Washington University, St. Louis, rows upon rows of well-rested fruit flies flit about inside test tubes. Neurobiologist Paul Shaw is looking at how the memory function of fruit flies can be improved by sleep.
Fruit flies share 75% of the genes that cause disease in humans, and are pretty low maintenance, making them a good way for researchers to study genetics.
Shaw first tested the memory of regular fruit flies by putting them through some simple experiments. He then genetically modified generations of fruit flies to essentially ‘break' their ability to form memories.
The results? By putting fruit flies to sleep, they could repair this memory defect.
“We make them sleep, and they become normal,” says Shaw. “Sleep is letting the brain solve the problem in the best way possible.”
Importantly, sleep doesn't solve the underlying mutation. They were still ‘broken', but sleep was somehow allowing their brain to create new circuits.
In 2009, Washington University neurologist David Holtzman showed that animals deprived of sleep over time accumulated a protein by-product called beta-amyloid.
With Alzheimer's, beta-amyloid builds up because sufferers have a genetic mutation that causes too much to be made, or not enough of it is cleared. Early research suggests that sleep reduces the amount of beta-amyloid produced in the brain, and could even help clear it.
This research is also backed up by Matthew Walker, a professor of cognitive neuroscience at the University of California, Berkeley, who calls sleep a “power cleanse” for the brain. He has found that people with a high level of beta-amyloid were less likely to remember facts and had the least amount of REM sleep compared to those with less beta-amyloid.
Their research looked at the buildup of beta-amyloid in the prefrontal cortex, which can kickstart Alzheimer's.
“We've been missing a middleman here in the puzzle of Alzheimer's disease, and that missing middleman is sleep degeneration.”
All this research into sleep isn't just helpful for understanding and curing degenerative diseases like Alzheimer's.
It's also helpful for us to improve our own memory and performance.
Did you ever follow the theory that by sleeping with your notes under your pillow, you'd somehow learn what you needed to by osmosis. Okay, so obviously it doesn't work like that.
But there is some method behind the madness. As you sleep your brain is consolidating memories, so if the last thing you read was something you needed to remember, there are suggestions that sleep will help it ‘stick' better in your memory.
Dr. Jack Mellor, a neuroscientist at the University of Bristol, examined the behavior of firing neurons in the rat’s hippocampus, an area of the brain associated with memory. His team measured the ‘reactivations' on rats while they explored a new environment during wakefulness, and then measured it again while they slept.
They found the same brain activity that happened while the rats were awake, also happened while they were asleep, just at a much faster speed. They concluded that activity from the day is replayed while asleep to strengthen connections between nerve cells, which provides a mechanism for consolidating memories.
So the next time you feel like you've got too much on to sleep, consider that sleep may be the best thing for you. As Shaw says “the more your brain has to do, the more you're going to need sleep for it to happen”.
There’s no secret to a good night’s sleep. Just good science. And a really good mattress. Remember we offer a 100-night trial to see if you really can wake up better on a Sleeping Duck. Find out more today.