The importance of a good night’s sleep is widely accepted, but what actually goes on in our brains while we’re sleeping remains shrouded in mystery. While students debate whether to pull an all-nighter or hit the hay before a final exam, scientific investigators are debating the link between sleep and memory.
In a recent study published in PLOS ONE, award winning sleep investigator Stuart Fogel, Professor at the University of Ottawa’s School of Psychology, sheds light on the how sleep enhances memory.
Researchers have provided the first evidence that the same areas of the brain active during learning reactivate while we’re asleep. Furthermore, the team determined that the overnight sleep-related boost in brain activity during reactivation was related to not only the subsequent strengthening of the original memory, but also a transformation to a more consolidated state.
"We found, for the first time, that the memory trace activated during motor skill learning, for example, learning to play a short piano piece was reactivated during sleep. We also found that the greater the reactivation, the greater people improved their performance,” said Stuart Fogel, member of the University of Ottawa Brain and Mind Research Institute and Director of Sleep Neuroscience at The Royal's Institute of Mental Health Research.
Technological advancements allowed the research team to simultaneously record electrical brain waves (EEG) and functional brain imaging (MRI) during sleep, demonstrating how the brain processes newly formed memories. Brain regions, particularly reward centres and those involved in motor skills, are reactivated during sleep spindles, which are short bursts of electrical activity thought to be involved in memory processing.
Motor skill performance may improve rapidly with practice, but skills can improve further during rest periods without practice, a phenomena known as “offline gains”. Sleep allows the brain to transform memory from a fragile state, which is susceptible to forgetting and interference; to a strengthened, more accessible and enduring memory.
“Our findings revealed that newly formed memories need to be strengthened in order to be permanently stored. Our brains perform this work during sleep, through the process of reactivation,” said Fogel.
The expert verdict? Skip the Red Bull and go to sleep so you can make the most of memory gains and ace your final exams.
Read the PLOS ONE paper: Reactivation or transformation? Motor memory consolidation associated with cerebral activation time-locked to sleep spindles.
Dr. Stuart Fogel is an Assistant Professor in the School of Psychology at the University of Ottawa, Director of Sleep Neuroscience at The Royal's Institute of Mental Health Research, a member of the University of Ottawa Brain and Mind Research Institute, and an Adjunct Professor in the Department of Psychology at Western University. He was the first to discover that bursts of brain activity during sleep, called “sleep spindles”, are involved in the overnight enhancement of newly formed memories, and are a biological marker of human intelligence. Fogel recently earned the Canadian Sleep Society Roger Broughton Young Investigator Award for his contributions to sleep research and his work advocating for the importance of sleep to support good physical and mental health.
University of Ottawa Brain and Mind Research Institute (uOBMRI)
uOBMRI is Ottawa’s largest collection of basic researchers and clinician scientists that are focused on brain and mind related health. The uOBMRI helps orchestrate research in a collaborative and innovative fashion by overcoming the barriers that exist between research at the basic and clinical levels. It does so by helping to coordinate research efforts of its research members at the various uOttawa faculties, resident hospitals, affiliated networks and local research institutes. The uOBMRI supports its members by enhancing the research environment, facilitating access to resources and expanding programs in order to attract the best candidates. We are working together to promote awareness and education of brain and mind related health in the community.
The Royal is one of Canada’s foremost mental health care, teaching and research hospitals. Its mandate is simple: to help more people living with mental illness into recovery faster. The Royal combines the delivery of specialized mental health care, advocacy, research and education to transform the lives of people with complex and treatment-resistant mental illness. The Royal’s Institute of Mental Health Research is affiliated with the University of Ottawa and a member partner of the uOBMRI.
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