New Research Shows That Sleep and Memory Go Hand in Hand: Learn How Your Brain Is Active During REM Sleep

Nothing gives you a boost of energy quite like a good night’s rest. But did you know that sleep and memory are also connected? A recent study from Cornell researchers revealed that neurons help “reset” the brain by removing old memories during sleep each night. Keep reading to learn more about the results and how your brain is active even during rapid eye movement (REM) sleep.

How does your memory reset during sleep?

“Memory resetting is the brain's way of clearing out old or unnecessary information to make room for new, more important memories,” says Shelby Harris, PsyD, DBSM, licensed clinical psychologist and director of sleep health at Sleepopolis. 

The study, published in the journal Science, found that at certain points of deep sleep areas of the hippocampus (a key brain area for memory) go silent, allowing the neurons to reset. 

Your hippocampus is divided into three regions: CA1, CA2 and CA3. Regions CA1 and CA3 have been studied multiple times and help encode memories related to time and space. Area CA2, which hasn’t been researched much until this study, deals with memory resets. 

“We realized there are other hippocampal states that happen during sleep where everything is silenced,” said Azahara Oliva, assistant professor of neurobiology and behavior and the paper’s corresponding author regarding the hippocampus regions and functions. “The CA1 and CA3 regions that had been very active were suddenly quiet. It’s a reset of memory, and this state is generated by the middle region, CA2.”

Which parts of the brain are involved during memory reset while sleeping?

As the study mentioned, the hippocampus is part of the memory resetting process. “It’s the brain's key area for creating and organizing new memories, and it plays a central role in resetting memory by clearing out what’s no longer needed,” says Harris. 

Additionally, the prefrontal cortex and the neocortex are important for sleep and memory. The prefrontal cortex supports memory organization and the “neocortex contributes to complex aspects of memory, supporting higher-order brain functions and sensory processing, and works with the hippocampus to provide a place to store and stabilize memories during sleep,” says Sanam Hafeez, PsyD, a clinical neuropsychologist and founder and director of Comprehend the Mind.

Lastly are the amygdala and the thalamus. “The amygdala processes emotional experiences and helps to encode and prioritize emotional memories, especially through REM sleep,” says Hafeez. The thalamus is a relay station that filters sensory information to different parts of the brain and “plays a role in synchronizing neural activity during sleep.”

How are sleep and memory connected?

Getting a good amount of sleep is crucial for memory. “During deep sleep and REM (rapid eye movement) sleep, the brain processes new information you receive and strengthens important memories while removing unnecessary details,” says Harris. “This helps "reset" the brain so it's ready to learn and remember new things the next day.”

Hafeez adds, “Sleep also supports cognition by helping to remove brain toxins that accumulate during waking hours, thus promoting the maintenance of cognitive function. Attention and problem-solving are key for memory formation, but you won’t be able to do this well if you aren’t getting enough rest.” Naturally, sleep deprivation or routinely interrupted rest can have a negative impact on the brain.

Can memory resets help with Alzheimer's or dementia?

Memory problems are common for people with Alzheimer's or dementia. As Harris explains, their brains struggle to remove harmful proteins and keep information organized. Diving deeper into memory resetting could help develop new treatments to get rid of those damaging proteins or “improve how the brain manages memory, potentially slowing down memory loss,” adds Harris.

Currently, it’s unknown whether memory resets will help with these diseases; however, Hafeez says carrying out further research to determine the effectiveness and safety of such interventions for Alzheimer’s and dementia is necessary.

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This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.