Summoning the Sandman

Ingrid Lekk, Dr Steve Wilson

Groggy? This gray globule may shoulder some blame. Seen here in a zebrafish, the pineal gland — which takes its name and pronunciation from its pinecone-like shape — lives deep in the brain and helps the body tell day from night.

When the sun goes down, the gland floods your system with melatonin, also known as “the vampire hormone ” for its nocturnal schedule. Peaking after midnight and melting away around eight AM, this chemical doesn’t necessarily put you to sleep itself, but it does inform other parts of the brain that it’s time to wrap things up for the day.

Or that’s how the pattern is supposed to go. But light from screens, like cell phones, TVs, and tablets, can trick the pineal gland into thinking it’s still daytime at night, delaying the release of melatonin. Compared with those who read paper books before bed, tablet users tend to fall asleep later, dream less, wake later, and feel sleepier the following morning.

About the Author

Charlie Wood

Charlie Wood is a science writer with a bachelor’s degree in physics from Brown University and a master’s degree in science journalism from New York University. In previous lives he taught physics in Mozambique and English in Japan, but these days he freelances from his home in New York.