VIDEO: How sleep effects your emotions -

It's not just your imagination -- you're more irritable when you're low on zzzzs. Sleep scientist Matt Walker explains how our nightly slumber affects the emotional centers in our brains, and why we can think of sleep as first aid for our feelings.

By Matt Walker:

Matt is a brain scientist trying to understand why we sleep. Matt Walker's research examines the impact of sleep on human health and disease. He got his PhD from the Medical Research Council in London, UK, and subsequently became a Professor of Psychiatry at Harvard Medical School. He's currently a Professor of Neuroscience and Psychology at the University of California, Berkeley, and Director of the Center for Human Sleep Science.