Night Shift: The Brain’s Extraordinary Work While Asleep

Night Shift: The Brain’s Extraordinary Work While Asleep

Richard W. Stevens

Conscious thinking means our brains, our minds, are sensing, observing, memorizing, recalling, decoding, analyzing, calculating, interrelating, cross-referencing, rearranging, expanding, generalizing, communicating, and even creating. Those coordinated operations, part of cognition, require real work.

After all that brain work, it should be time for a rest, right? Nope. When a supermarket closes, the workers don’t just switch off the lights and go home. Overnight the workers clean, restock, organize, repair, and get the store ready for the next day. It’s the same for the brain. Lie down, close your eyes, lose consciousness, and the brain undertakes the heavy lifting that sleep demands.

Revealing the how and why of sleep, Matthew Walker, professor of neuroscience and psychology at UC Berkeley, has written Why We Sleep: Unlocking the Power of Sleep and Dreams. Sleep is not just an annoying state of rest that wastes valuable time. As Walker describes:

Sleep is not the absence of wakefulness. It is far more than that. [O]ur nighttime sleep is an exquisitely complex, metabolically active, and deliberately ordered series of unique stages.

Drawing from observed behaviors, self-reports, three-dimensional brain scans, and experiments upon humans and animals, scientists have uncovered much about what goes on during the brain’s night shift...