What happens to the brain when consciousness goes offline? Scientists uncover how disrupted brain communication can alter awareness, memory and our sense of self

For almost a hundred years now, general anaesthesia has made it possible for surgeons to perform operations where patients do not have any sense of what is going on in their body. But the agents which are responsible for this fascinating state are posing a fundamental mystery to neuroscientists: how does the process of loss of consciousness affect the brain?

The explanation is not as straightforward as just turning the brain off.