“There is a big picture that brings it all into relief and my hope is that we can increase empathy and understanding,” says 2026 medicine laureate Karl Deisseroth. As a medical student, Deisseroth completed part of his training at a psychiatric clinic. He was struck by the patients’ suffering and their need for help. At the same time, he began to wonder how the brain could function so differently from one person to another. Deisseroth was awarded this year's medicine prize, together with Peter Hegemann and Georg Nagel, for discoveries leading to optogenetics – a biological technique making it possible to switch the activity of individual nerve cells in a living brain on or off. Optogenetics is now helping us understand more about how nerve cells shape memories, emotions and behaviour in the living brain. Learn more about the 2026 medicine prize: bit.ly/4ru82ml