How you can boost your cognitive performance by sleeping better.

Modern life asks a lot from our brain. Many of us must learn and synthesise new information, solve complex problems, and make tough decisions every day. It's no wonder entire industries have sprung-up around products—such as nootropics and brain training apps— which claim to improve mental performance. But what if there were a natural, scientifically-backed way to help your brain function at its peak? What if it was not merely side-effect free, but actually improved other aspects of your mental and physical health? What if I told you it cost nothing and was widely-available? If you haven't guessed already, the wonder-drug I'm talking about is sleep.

What is cognitive performance?

High cognitive performance is when you’re able to use your brainpower to its full potential. On the other hand, low cognitive performance feels like a dense layer of fog has descended upon your mind. Even simple tasks, such as recalling a word, seem to be restricted to dial-up internet speed. These two different states couldn’t feel more different but measuring this difference scientifically can prove challenging. This article will focus on three objective aspects of cognitive performance; reaction time, emotional reactivity, and the ability to form and recall memories.


Reaction Time

Reaction time measures how long it takes to respond to a given stimulus, such as the time it takes for one to brakeupon seeing a hazard on the road. Unsurprisingly, slow reaction time increases the risk of traffic accidents. The right quality and quantity of sleep have consistently been shown to improve reaction time. On the other hand, insufficient, or poor quality sleep can drastically slow reaction time. In fact, according to a study by the AAA Foundation for Traffic Safety, people who sleep six to seven hours a night are twice as likely to be involved in a crash as those sleeping 8 hours or more.

Emotional Reactivity

When tough decisions must be made, you probably want your emotional, knee-jerk reactions to be moderated by rational thought. This relies on a balance between the regions of the brain known as the prefrontal cortex and the amygdala. The prefrontal cortex, which is responsible for reason, problem-solving and decision making, is larger in humans relative to other primates. The amygdala is a brain region associated with the fight or flight response. Research using MRI scans of the brain has revealed that the careful balance between the prefrontal cortex and amygdala hinges on adequate sleep. As neuroscientist and author Mathew Walker writes in his book 'Why We Sleep',

"With a full night of plentiful sleep, we have a balanced mix between our emotional gas pedal (amygdala) and brake (prefrontal cortex)." (p. 147)

This is why you are better poised to make decisions and perform under pressure when well-rested. Take away the foundation of sleep, however, and this relationship becomes unstable. The result is a brain that can rapidly flick between heightened emotional states.


Each night while we're asleep, our brain performs processes crucial to memory consolidation. Fresh information is transferred to long term memory, which in turn, frees up our inbox, ensuring our brain is ready to learn new information the following day. Therefore, to say sleep boosts memory would be to understate its importance. Sleep is integral to the process of memory formation itself. Research indicates that even a 90-minute nap following new information can boost memory by 20% when compared to staying awake. What happens to memory when you are sleep deprived? Losing a single night of sleep can create a memory deficit of 40%.


The consequences of poor sleep might sound alarming, but we believe they represent an opportunity. Data indicates that increased blue light exposure at night, and a decline in exposure to natural light are causing people to go to bed later and sleep less than they once did. That means, for most of us, making a few small changes to our light diet could have benefits for our cognitive performance and other aspects of our wellbeing. That is our goal at OSIN; to empower people to live a healthier, more fulfilling life by providing lighting solutions that support natural sleep.

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