Mind & Brain The Limits of Breath Holding It's logical to think that the brain's need for oxygen is what limits how long people can hold their breath. Logical, but not the whole story By Michael J. Parkes THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already have an account? Sign In Matthew Lane Take a deep breath and hold it. You are now engaging in a surprisingly mysterious activity. On average, we humans breathe automatically about 12 times per minute, and this respiratory cycle, along with the beating of our heart, is one of our two vital biological rhythms. The brain adjusts the cadence of breathing to our body’s needs without our conscious effort. Nevertheless, all of us also have the voluntary ability to deliberately hold our breath for short periods. This skill is advantageous when preventing water or dust from entering our lungs, when stabilizing our chests before muscular exertion and when extending how long we can speak without pause. We hold our breath so naturally and casually that it may come as a surprise to learn that fundamental understanding of this ability still eludes science. (Feel free to exhale now, if you haven’t already.) THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already have an account? Sign In Digital Issue $7.99 Add To Cart Digital Issue + Subscription $39.99 Subscribe ADVERTISEMENT Scientific American is a trademark of Scientific American, Inc., used with permission © 2015 Scientific American, a Division of Nature America, Inc. All Rights Reserved.