Can Lack of Sleep Hurt Your Brain?

Smarter? Happier? Less anxious? Discover the complex relationship between sleep & your brain 

Many people think of sleep as a time when the body shuts down and takes the night off. That assumption couldn’t be more wrong when it comes to the brain.

For millennia, the purpose of sleep has been a mystery but, thanks to research in the last 50 years, we’re beginning to understand our shutdown time a little better. Researchers conducting experiments in the 1950s found that brain waves vary throughout sleep, from deep sleep to rapid eye movement (REM) stages. Not so long ago no one knew anything about REM sleep, a deep, restorative phase of our nightly rest. What scientists are beginning to understand is that sleep plays a critical role in every aspect of health, from regulating appetite to impacting our ability to create memories and learn.

While you’re dreaming, your brain is kicking into high gear to do a system-wide maintenance check and conduct repairs. And just like your vehicle needs to be turned off to fix it, your brain needs you in the same state for maintenance and repair.

If you’re feeling down in the dumps, irritable, or can’t concentrate, your brain may be sending you signals that it’s sleep deprived. It’s the boss when it comes to mood regulation, so treat it nicely with an adequate amount of slumber. As Dr. Lynelle Schneeberg, a clinical psychologist and fellow, American Academy of Sleep Medicine, says, “A well-rested brain results in a person with better coping skills, improved learning and attention and better immune function. If a person has obtained adequate sleep, he or she will feel alert and in a good mood shortly after arising.” Otherwise, expect moodiness, a more depressed state and increased anxiety. 

She also points out that a tired brain puts you at higher risk of suicide and risk-taking behaviors are more common. Also, complex tasks are much more difficult when short on sleep.

While you were sleeping…

In case you haven’t gotten the message yet, your brain never takes a break. It’s busy 24-7 serving as the body’s master regulator. At night, your brain shifts its attention from daytime task processing to cleaning up and fixing issues accrued throughout the day. Among its to-do list during sleep, the brain prunes away unnecessary information it has gathered during the day. It also repairs damaged tissues, secretes important hormones and lays down new pathways that help us learn new things as well as categorize and remember what we’ve already learned. 

What happens to your brain when your sleep cycle is disrupted? The quick answer is that it isn’t anything good at all.

In 1896, the first evidence of the negative effects on sleeplessness were published. In the decades that followed, data from a large number of studies has piled up, underscoring the fact that sleep deprivation impairs important cognitive functions and behaviors. 

In studies, sleep deprived participants were quick to anger and experienced greater stress when asked to do cognitive tests. Scientists say the amygdala, the emotion control center located deep in the brain, is affected most when sleep is reduced. Activity levels were as much as 60% higher than that of subjects who were well rested. Sleep deprivation seems to cause the amygdala to disconnect from areas in the brain that normally moderate its response, instead of overreacting to negative stimuli. In other words, your brain prioritizes what it needs to do to keep you alive over emotional response to challenges. Alive and grumpy is better than dead to your brain.

Impact of sleeplessness on the brain

Data also shows that being overly tired causes people to make riskier decisions. A Duke University study put that idea to the test by looking at participants’ behavior in a gambling environment. They found that increased fatigue caused them to make fewer decisions that prevented loss. They took more chances. If you go into any casino, you see how the environment stops you – the bright lights, the noise, a lack of windows and absence of clocks – from noticing the passage of time and tiredness cues.

And, if you want to be smarter and maximize your ability to learn, you’ll need to be well rested. The hippocampus, the region of the brain critical for storing new memories, struggles to keep up when it’s sleep-deprived. With just one night of lost sleep, its ability to retain new information drops dramatically. A lack of sleep also hampers the hippocampus’s storage function. While you snooze, new data is shuffled off into other parts of the brain. Without sleep, storage capacity fills up quickly and all that information you learned from that cool, new documentary is lost and you certainly won’t remember all those verbs from your class on how to speak Spanish.

When you boil down to the core take-away message, it’s this: get adequate sleep to keep your brain humming along and functioning.

Rest well & wake up ready to go!

Better sleep gives rise to better mornings, bringing your goals into focus and dreams within reach. Hungry for more sleep info? Dig into these posts:

• Expert tips for getting better sleep, starting tonight
• Back to school, back to sleep – making sleep a priority this fall
• 11 reasons why you wake in the middle of the night and what to do about it