In 1964, a San Diego high-school student named Randy Gardner took part in a science fair project and went without sleep for just over 11 days.
On day 2 of the experiment, Gardner experienced memory lapse. By day seven he was experiencing vivid hallucinations, and by day 11 he was incoherent, paranoid and suffering from muscle tremors.
The 17-year-old made a full recovery and didn’t go on to suffer any long-term effects. Nobody has beaten this record since, and the Guinness Book of Records stopped taking entries for sleep deprivation in 1997 due to health risks.
But it doesn’t take 11 days of lack of sleep to experience cognitive decline. Even after a single night of poor sleep, we experience an impairment in function, memory recall and emotional regulation.
Let’s take a look at the science behind the relationship between sleep and brain performance.
What happens to the brain during sleep?
When we are sleeping, the brain undergoes a restorative reset, performing an array of tasks, including its own version of waste removal as the glymphatic system clears out toxins and metabolic waste.
Short-term memories are stored as long-term memories in the neocortex, neural connections are strengthened and REM sleep helps solve problems and regulate emotions.
It’s not all activity, however; there are periods of rest for the brain during non-REM sleep stages 1, 2 and 3. These stages are when the heartbeat slows, muscles relax and brain waves slow, albeit with brief bursts of electrical activity during stage 2, where we spend most of our time during the non-REM sleep cycles.
During REM sleep, brain wave activity heightens, becoming close to that during wakefulness. The amygdala and hippocampus are highly active, helping to process memory and emotion. This stage of dreaming helps support creative thinking when awake.
The brain on a bad night’s sleep
When you experience a lack of sleep, or regular poor sleep quality, brain performance will be affected in several ways.
The prefrontal cortex – the brain’s centre of decision making, problem solving and control – becomes less efficient. You’ll experience poor attention span and reduced cognitive flexibility and limited working memory.
As the amygdala becomes overactive, you may find it more difficult to contextualise information emotionally. Memory consolidation weakens as the process of storing information in the cortex is impaired.
Other short-term effects of poor sleep include:
• Impaired judgement
• Slower reaction time
• Poor risk assessment
When sleep deprivation becomes normal
For those who suffer from chronic sleep disorders, the short-term consequences listed above become embedded as part of the everyday life experience.
Poor sleep can have more serious side effects, too. Based on research done by the National Library of Medicine, the Sleep Foundation reports that there are established links between chronic lack of sleep and Alzheimer’s disease.
“Research shows that sleep helps the brain conduct important housekeeping, such as clearing out potentially dangerous beta amyloid proteins,” reports sleepfoundation.org.
“In Alzheimer’s disease, beta amyloid forms in clusters, called plaques, that worsen cognitive function. Studies have found that even one night of sleep deprivation can increase the amount of beta amyloid in the brain.
"One analysis found a considerably higher risk of Alzheimer’s disease in people with sleep problems, estimating as many as 15% of cases of Alzheimer’s disease were attributable to poor sleep.”
With brain health and cognitive function so reliant on good-quality, regular sleep, it’s wise to understand how to optimise sleep conditions.
Optimising quality sleep
Swedish-based bed manufacturer Hästens understands the importance of a good night’s sleep. Hästens has been handcrafting beds since 1852. Each bed is handmade in the Swedish town of Köping, taking up to 600 hours to craft using only natural materials.
“When you sleep better, you perform better,” says Hästens. “We are living in challenging times and you may think that with the hectic pace of modern-day life, sleep might feel like a luxury you can't afford. However, from a medical perspective, it's absolutely essential to get good sleep if you want to keep your immune system strong and keep your body and brain healthy.”
To see Hästens’ full range of beds and accessories, and to read more about the benefits of a good sleep, head here.
