Editor's Letter: Quieting the mind

last updated 8 January 2015

Surely you, too, know the feeling. You’ve got a task to do but can’t concentrate. All that noise in your brain—things you should have done in the past, things you shouldn’t have, random diversions, longtime worries and self-doubt—can crescendo into a self-defeating chorus: “I can’t do it!” Journalist Sally Adee recently got a rare chance to clear the clutter (see The last word). She put on an electrode cap, was administered a mild electrical current, and to her astonishment, “everything in my head finally shut up.” Instead of obsessing over the obstacles in her path, she found herself “waiting for a problem to appear so that I could solve it.” What happened? One theory has it that the electrodes reduce activity in the prefrontal cortex, the part of the brain that governs critical thought. Neuroscientists have found a similar explanation for why electric shock therapy helps the severely depressed (see Health & Science): It dampens overactive connections between the mood-regulating and the cognitive parts of the brain, reducing negative, self-limiting thoughts. Psilocybin mushrooms are thought to work much the same way. Even exercise can help.

Connectivity is a watchword of our age. We measure the progress of nations by their broadband capacity, the power of ideas by the links they draw, and the influence of people by the Twitter followers they attract. But the new insights into the human brain, with its 100 billion neurons, remind us that there can be too much of a good thing. There are times when it’s better to disconnect, and quiet all the voices. Maybe for you, like me, a brisk swim, cycle, or run is enough, for at least a while, to take your mind off your mind.