How Lack of Sleep Impacts Cognitive Performance and Focus
March 13, 2023
Sleep is an important time for the brain. Levels of brain activity change in each stage of sleep — including both rapid eye movement (REM) and non-REM (NREM) sleep — and evidence increasingly suggests that sleep enhances most types of cognitive function.
Getting enough hours of high-quality sleep fosters attention and concentration, which are a prerequisite for learning. Sleep also supports numerous other aspects of thinking including memory, problem-solving, creativity, emotional processing, and judgement.
For people with sleep deprivation, insomnia, sleep apnoea, or other conditions that prevent getting adequate rest, short-term daytime cognitive impairment is common. In addition, multiple studies have linked poor sleep with longer-term cognitive decline, including the development of dementia and specifically, Alzheimer’s disease.
Thankfully, there is evidence that improving sleep can boost both short- and long-term cognitive performance. Better sleep can promote sharper thinking and may reduce the likelihood of age-related cognitive decline.
What Happens to the Brain During Sleep?
During a typical night of sleep, an individual goes through four to six sleep cycles that range from 70 to 120 minutes in duration. Both the brain and body experience distinct changes during these cycles that correspond to individual stages of sleep.
During NREM stages, brain activity slows overall, but certain pulses of brain waves remain. This pattern of brain waves is most pronounced in stage 3 NREM sleep, which is also known as slow-wave sleep or deep sleep.
In contrast, REM sleep is marked by a sizable uptick in brain activity. In many ways, the brain’s activity during REM sleep is similar to being awake. Unsurprisingly, REM sleep is known to produce more vivid dreams.
It’s normal to cycle through both NREM and REM stages, with REM sleep being more concentrated in the second half of the night. During each part of this process, different chemicals in the brain become activated or deactivated to coordinate rest and recovery.
Experts still aren’t exactly certain why sleep proceeds in this pattern, but it is believed to facilitate mental recovery, which can unlock cognitive benefits related to attention, thinking, and memory.
How Poor Sleep Affects the Brain
Without sleep, the brain struggles to function properly. Because neurons in the brain don’t have time to recuperate, they become overworked and less capable of optimal performance in various types of thinking.
Poor sleep can take many forms, including short sleep duration or fragmented sleep. Both insufficient and interrupted sleep make it difficult to progress through sleep cycles in a normal, healthy way, which makes it more difficult to think straight and process information after a poor night of sleep.
The short-term detriments of poor sleep on the brain and cognition can be the result of simply pulling an all-nighter, while those with chronic sleep problems may see a continuous negative effect on day-to-day tasks. Over the long-term, however, poor sleep may put someone at a higher risk of cognitive decline and dementia.
Article source from sleepfoundation.org.
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