Will there come a time when we don’t need to sleep?

Non-REM sleep, which accounts for roughly 80% of an adult human’s slumber, helps the brain consolidate memories by strengthening key neural connections and weakening less useful ones (scroll to visualize the anatomy of sleep). In the study, researchers used light pulses to switch targeted neurons on and off in the sleep-deprived mice’s brains for 30-minute intervals, recreating the firing pattern observed during sleep. Treated mice performed memory tasks similarly to well-rested mice, indicating the specific pattern of neural activity matters more than unconsciousness.

In nature, dolphins can shut down one half of their brain at a time, allowing them to keep swimming and surface for air. Migratory birds also appear to do something similar in flight. Watch how it works.