The ever tightening link between sleep, learning, and memory

It’s been a while since my last post on sleep and learning. During that time, evidence suggesting the critical connection between sleep, learning, and memory has continued to accumulate. For a poor sleeper like me, it has also become more disturbing in some ways. Here’s a quick run down on some of the recent research.

Sleep may double our chance of remembering

One impact of sleep that we have known about for quite a while is that it helps us to solidify and preserve memory. That is, it helps prevent forgetting. A study published in Cortex, however, suggests that sleep may more do than just preserve memories: it may make them much more accessible to us, ensuring that we are actually able to remember when we need to.

To reach this conclusion, the study’s author, Nicolas Dumay of the University of Exeter, re-analyzed data from two previous studies to compare the impact of a period of overnight sleep to a similar period of daytime wakefulness on the ability of study participants to remember a list of made-up words. The differences in memory were significant.

“Sleep almost doubles our chances of remembering previously un-recalled material,” said Dumay. “The post-sleep boost in memory accessibility may indicate that some memories are sharpened overnight. This supports the notion that, while asleep, we actively rehearse information flagged as important.”

Sleep can help combat biases

As positive as improving our ability to preserve and access our memories may sound, it’s important to remember that there can be downsides. Namely, there is no guarantee that the memories we solidify during sleep are valid or desirable. We may, in fact, wind up more deeply learning and remembering information that is flat our wrong or significantly biased.

Fortunately, a study out of Northwestern University suggests that we can take advantage of the way sleep operates on memory to unlearn biases. Xiaoqing Hu, one of the study’s author’s writes about it in much more detail in Can we unlearn social biases while we sleep?  The quick answer to the question, though, is yes. The study assessed 40 participants on their implicit biases related to race and gender. Then, following a session of counter-bias training, participants took a 90-minute nap during which sound “cues” from the training were played repeatedly, but without waking the participants.

The results were striking. Hu writes that:

the biases were reduced by at least 50% relative to the pre-sleep bias level. But we were also surprised at how long the effect lasted. At the one-week follow-up test, the sleep-based intervention was still effective: bias reduction was stabilized and was significantly smaller (approximately 20%) than its baseline level established at the beginning of the experiment.

The results of the one-week follow-up were particularly promising. In many cases, the impact of interventions like this fades away entirely within hours or days. Using sleep as a tool, though, appears to have some staying power. (You may also want to read about meditation as a way to combat bias.)

Lack of sleep linked to Alzheimers

Finally, if the above items don’t motivate you to develop better sleep habits, this final one may scare you into. A study out of Berkeley suggests that a deficit of sleep can lead to a build up of the proteins that many scientist feel are responsible for Alzheimer’s disease. Getting full, restorative sleep has an opposite effective. As Matthew Walker, a Berkeley neuroscience professor and one of the study’s authors put it “Sleep is helping wash away toxic proteins at night, preventing them from building up and from potentially destroying brain cells. It’s providing a power cleanse for the brain.”

It’s important to note that, unlike most studies conducted previously in this area, the Berkeley study was conducted with human rather than animal subjects. Specifically, the participants were “26 older adults, between the ages of 65 and 81, who showed no existing evidence of dementia or other neurodegenerative, sleep or psychiatric disorders.” Also worth emphasizing is the fact that sleep is both a preventative and a therapeutic “treatment” that is well within the reach of all of us.

To help you rest easier …

Of course, I know from my own experience that understanding that sleep is important and actually being able to sleep well consistently are two very different things. To that point, I do plan to pull together a post on the sleep tips that seem to have the most basis in scientific evidence. In the mean time, you may be able to take some solace from a study that suggests we may in fact be getting more sleep than we think we are.



  • A recent large-scale study showed “cognitive performance, measured using a set of 12 well-established tests, is impaired in people who reported typically sleeping less, or more, than 7–8 hours per night.” Access the study >>


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4 thoughts on “The ever tightening link between sleep, learning, and memory”

  1. Sleep is pretty much the magic potion for everything. It makes so much better. It’s also one of the ‘big five’ (along with hydration, diet, exercise an lifestyle factors) that shows up in the ‘how to ease the symptoms of …..’ pages all the time.

  2. I enjoyed this article on the importance of sleep. As a teacher, I see students come to school every day barley able to keep their eyes open. The point about information being able to be recalled after sleep is definitely an interesting concept to consider as a teacher. Sleep or lack of it also plays a role in how much students are able to pay attention during the day. The most interesting thing I took away from this article is the potential link between lack of sleep and alzheimers.

  3. Daniel Delaney

    What a great article. Today many adults and even children are experiencing wakefulness. I believe technology has contributed to this phenomena. Sleep Deprivation impairs attention and working memory, but it also affects other functions, such as long-term memory and decision-making. I wonder how this phenomenon will impact the cognitive development of children. Though the research is about the brain is still in its infancy it is clear that sleep plays a vital role in the cognition and overall functioning of the brain.

  4. Schweinsburg Project 6

    I really enjoyed reading through your blog post about sleep and how it can affect learning and memory. I can attest to some of the same results that were found from the studies. I, too, struggle to recall information if I had trouble sleeping the night before. In fact, I struggle to do many things when I’m working off of little sleep. I have trouble focusing, staying on task, and working efficiently. A lack of sleep usually leads to me making more mistakes and low quality in my performance. I found it interesting that there were connections between sleep and Alzheimers. I did not know that sleeping helps to “wash away” toxic proteins. I can understand how these toxic proteins would have a negative impact on your brain. It is obvious that even just one night without sleep slows your capabilities. I can imagine that many nights without sleep could have a lasting impact on your body. Sufficient sleep could really help students perform better in the classroom. I often tell my students that they need to be getting a full night’s rest. It is easy to recognize students that slept a full 8 hours compared to students that might have only had 3-4 hours of sleep. Students that get a full night of sleep normally perform better in class. This may be something I need to highlight with my students again! Thank you for the post.

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