How does our brain strengthen memories? It is long known that while we sleep, our brain reactivates previously learnt information and solidifies memories in the neocortical long-term stores. A new study has now shown an intricate interplay of brain activities that enables this reactivation. They noted that two patterns (slow oscillations, sleep spindles) that occur during our non-rapid eye movement sleep play an important role.
Researchers believe that sleep affects learning and memory in two ways: Lack of sleep impairs a person’s ability to focus and learn efficiently. Sleep is necessary to consolidate a memory (make it stick) so that it can be recalled in the future.
Scientists don’t know exactly how sleep enhances memory, but it appears to involve the brain’s hippocampus and neocortex — the part of the brain where long-term memories are stored. It is thought that during sleep, the hippocampus replays the events of the day for the neocortex, where it reviews and processes memories, helping them to last for the long term.
Researchers continue to investigate the stages of sleep involved in making certain types of memories. Some studies have shown that certain kinds of memories become stable during rapid eye movement (REM) sleep — the time when you dream. Other studies have found that some types of memories are most often secured during slow-wave, deep sleep. Scientists are getting closer to understanding what sleep does to our brain, but there are still many questions to be answered.
What’s certain is that sleep is a biological necessity — we need it to survive. Unfortunately, in this day and age, few of us are able to get the sleep we need to function our best. Experts recommend adults get seven to nine hours of sleep each night. Although this may not be attainable every night, it should be the goal.