Take a deep breath. That’s routine advice for how to calm down or slow down. Yoga instructors, therapists, parents, and even elementary school teachers use long, slow breathing exercises to instill tranquility or reduce anxiety. Now, researchers at Stanford University School of Medicine are giving the same advice, with brand-new neuroscience to back it up. In a recent study, they and their colleagues have uncovered a direct and powerful connection in the brain between breathing and states of mind.