It has been know for a while that sleep is important for learning and long-term memory formation. What is less clear is how exactly this works. Despite much research, this is an issue that was only imperfectly understood. Now it seems that new neuroscientific research may have the answer.
A study by neuroscientists at the University of California, Riverside offers some exciting glimpses into how the brain forms long-term memories as we sleep. Their study, which was recently published in the Journal of Neuroscience offers a mechanistic explanation for how deep sleep, called slow-wave sleep, helps us to consolidate memories.
During normal sleep, brain activity remains high. It alternates between non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. NREM sleep has three stages, including deep sleep. Deep sleep makes up about a fifth of your normal sleep time, but it mostly happens during the first third of the night.
Using a computational model, the researchers found a link between electrical activity in the brain during deep sleep and synaptic connections between neurons. Sleeping brains show electrical activity in the form of sharp-wave ripples in the hippocampus and large-amplitude slow oscillations in the cortex, reflecting alternating periods of active and silent states of cortical neurons during deep sleep. Memories acquired while you were awake are first stored in the hippocampus, then transferred to the cortex as long-term memory during sleep. Think of it as similar to transferring files from a memory stick to a hard drive.
Getting enough sleep is important to your general health and well-being, and a sharp memory will help you perform better at work, college or school. That is certainly a good reason for getting a good night’s rest!