When our heads hit the pillow every night, we tend to think we’re surrendering. Not just to exhaustion, though there is that. We’re also surrendering our mind, taking leave of our focus on sensory cues, like noise and smell and blinking lights. It’s as if we’re powering ourselves down like we do the electronics at our bedside–going idle for a while, only to spring back into action when the alarm blasts hours later.

That’s what we think is happening. But as scientists are now revealing, that couldn’t be further from the truth.

In fact, when the lights go out, our brains start working–but in an altogether different way than when we’re awake. At night, a legion of neurons springs into action, and like any well-trained platoon, the cells work in perfect synchrony, pulsing with electrical signals that wash over the brain with a soothing, hypnotic flow. Meanwhile, data processors sort…