Psychologist Kimberley Wilson and Dr Xand van Tulleken take a journey around the human body, asking what it can tell us about our innate capacity for change. In this episode, Kimberley and Xand are on the trail of the body’s longest cranial nerve – the vagus nerve – a critical highway which unites the body and brain, and a key part of the parasympathetic nervous system, which is responsible for rest and relaxation. They discover why you really are what you eat, find out how vagus nerve stimulation (VNS) is being used to treat conditions including epilepsy and depression, and explore the future of bioelectronic medicine. And they answer the question: how much influence do our bodies have over our minds? Producer: Dan Hardoon Executive Producer: Kate Holland A Whistledown Production for BBC Radio 4