But what Dr Gallagher realised was that all these studies used myriad cues - facial expressions, body language and memory as well as requiring the subject to think about the task in the past, rather than computing Theory of Mind in the present. What she wanted to do was make people think about another's thoughts without any cues from body language, facial expression or memory. Her volunteers played the game of scissors, paper, stone. Two people have to choose one of the three objects at the same time. Scissors beat paper because they can cut paper, paper beats stone because it can be wrapped round the stone, and stone beats scissors because it can crush them. The volunteers were all men and played a computerised version of the game; half of them believed that they were playing against Dr Gallagher. These men tried to guess what Dr Gallagher would do next, based on the previous choice of object. The part of the brain the men who believed they were playing against a person used was called the paracingulate cortex. "The men were quite cross that I always won," says Dr Gallagher, but, in fact, all the volunteers were playing a computer with a random output.