Serving as a two-way ‘electrical superhighway’, the vagus nerve – which is actually a pair of nerves – allows for communication between the brain and the heart, lungs and abdominal organs. And because of this, it has been shown to help control things such as the heart rate, breathing, digestion and even immune responses. Now, scientists and health influencers are asking whether stimulating the vagus nerve could transform physical and mental health. Science correspondent Linda Geddes tells Ian Sample about her recent investigation into the hype and science surrounding the vagus nerve, and also whether her own experiment with an allegedly nerve-stimulating device is having any effect. Help support our independent journalism at theguardian.com/sciencepod