Macbeth extolled “sleep that knits up the ravell’d sleave of care,” in Shakespeare’s great tragic play of the same name. Soothing rest is not all that shut-eye provides, however. As sleep and cognition researchers Robert Stickgold and Jeffrey M. Ellenbogen explain in their feature article in this issue, the brain is very busy during a night’s slumber. It is processing and sorting all the things we learned during the day, making valuable memories more resilient and tossing away irrelevant details. It finds hidden relations among our recollections and works to solve problems that arose during our waking hours. Read about it in our cover story, “How Snoozing Makes You Smarter.”
While we are catching some zzz’s, the brain preferentially strengthens memories that have important emotional content. A humming emotional-rewards circuit is also key to warding off depression in many of us, as neuroscientist and psychologist Kelly Lambert explains in “Depressingly Easy.” Activities that stir our thinking, motor and pleasure centers—such as gardening, cooking, knitting—engage the brain in ways that make us mentally healthier, Lambert explains. Anticipating the ultimate result as we perform such laborious tasks can be more enjoyable than achieving the end goal itself. The swift ease of modern, push-button conveniences, in contrast, may undercut our brain’s supply of hard-earned rewards, making us more susceptible to depression.
There is nothing like a good yarn to pluck our emotional strings, as Jeremy Hsu writes in “The Secrets of Storytelling”. Stories are one of humanity’s universals—they appear in all cultures—and certain themes arise repeatedly in tales around the world. Why do these narratives have such power over our feelings? The study of stories reveals clues about our evolutionary history and the roots of emotion and empathy. Indeed, as you will learn from Hsu’s article, the stories we tell explain much about ourselves.