Sleep and memory are closely connected, so how does a lack of sleep impact your ability to retain information?
The link between memory and sleep has been widely explored by scientists for decades, with countless studies concluding that sleep is essential for helping us consolidate memories and discard excessive information. This takes place during both non-rapid eye movement (NREM) and rapid eye movement (REM) sleep stages.
And because sleep is so important for our memory, sleep deprivation can have a serious impact on our ability to retain information. We’re going to take a closer look at the relationship between memory and sleep, exploring just how damaging poor sleep can be when it comes to your remembering.
The link between sleep and memory
Getting enough rest is essential for helping you process new information, turning things you have learned into stored memories. A healthy sleep cycle consists of four distinct stages: two stages of light NREM sleep, one stage of deep NREM sleep, and REM sleep. NREM sleep stages are essential for preparing your brain to learn new information the following day, as not getting enough sleep can reduce your learning abilities by as much as 40%, according to the Sleep Foundation.
During these stages, your brain also sorts through your memories from the previous day, filtering out the important memories for storage and eliminating other information. These selected memories then become more concrete during deep NREM sleep, while more emotional memories are processed during REM sleep. This can help you make sense of difficult or even traumatic experiences.
Sleep deprivation, brain function and memory
When we don’t get the sleep we need, remembering things becomes significantly more difficult. Memory problems are a common symptoms of sleep deprivation, since the brain doesn’t have enough time to create new pathways for the information you’ve learned recently. This can lead to other issues, such as difficulty learning and focussing, poor emotional control, and finding it hard to make decisions.
Adults and children alike require sleep for memory consolidation. For children, missing out on sleep can make it significantly harder to concentrate at school and remember the things that have been taught that day. For adults, poor quality sleep can reduce productivity, slow reaction times and impact on attention spans.
The amount of sleep you need varies with age, of course. While newborns, infants and toddlers need anywhere between 11 and 17 hours of sleep per day, school children and teenagers need nine to 11 hours, and adults require seven to nine hours of sleep per night.
Sleep disorders and memory loss
Because sleep is so crucial for memory, certain sleep disorders have been associated with memory problems. Insomnia, which is defined as long term sleep deprivation, can lead to daytime cognitive impairments that include reduced memory functioning. Meanwhile, disorders that result in excessive daytime sleepiness, like narcolepsy, can lead to lapses in memory.
Conditions like sleep apnoea can also lead to memory problems. Sleep apnoea impacts over 900 million people across the globe, and is characterised by temporary airway restriction during sleep that can lead to difficulty breathing, increased snoring, and frequently waking up. Because sleep apnoea can result in very fragmented sleep, people living with this condition can struggle to consolidate memories effectively overnight.
By taking steps to prioritise healthy sleep, you can improve your memory and cognitive function in the long run.