Search source
hopkinsmedicine.org
The Science of Sleep: Understanding What Happens When You Sleep | Johns Hopkins Medicine
The third and fourth stages are deep sleep. Though REM sleep was previously believed to be the most important sleep phase for learning and memory, newer data suggests that non-REM sleep is more important for these tasks, as well as being the more restful and restorative phase of sleep.
This page saves a medical search source so citations open as regular web pages. It is not a clinical recommendation.