This week CrowdScience investigates the information superhighway connecting mind with body. The Vagus nerve is part of our parasympathetic nervous system, delivering information from all our major organs to the brain stem, and stimulating it can help us switch off our fight or flight response and calm us down. But listener Mags wants to know what science says about its impact on our general wellbeing? Marnie Chesterton learns some deep breathing techniques and discovers how the length of our exhale is closely linked to our heart rate, all of which is important for developing something called vagal tone. Cold water immersion also said to stimulate the Vagus, so Marnie braves a freezing shower, only to discover she needs to get her face wet but keep the rest of her body dry, to avoid what scientists called autonomic conflict, which is when your stress response and calming response are both switched on by the same event. Activating both arms of the nervous system in this way can lead to serious heart problems in some people. New research into the gut-brain axis has shown that the Vagus nerve may be responsible for transporting the so-called happy hormone serotonin, which could have important implications for the treatment of depression. And innovations in electrical stimulation of this nerve means implanted devices may soon be used to treat inflammatory conditions like arthritis. Presented by Marnie Chesterton and produced by Marijke Peters for the BBC World Service Contributors: Dr Lucy Kaufmann, Adjunct Professor of Neurology, NYU Mike Tipton, Professor of Human and Applied Physiology, University of Porstmouth Mark Genovese, Emeritus Professor of Medicine, Stanford University Dr Karen-Anne McVey Neufeld, Brain Body Institute, McMaster University [Image credit: Getty Images)