Ramon Guevara Erra of the Université Paris Descartes and colleagues have reported a new insight into the nature of consciousness. The researchers recorded the brain activity of people while they were sleeping, awake, and having epileptic seizures. They found that normal wakeful states are characterised by the greatest number of interactions between brain networks, equating to the highest entropy values. This means there is higher information content in the networks associated with conscious states and suggests that consciousness could be the result of optimising information processing.