For the first time, scientists have identified the individual neurons critical to human social reasoning, a cognitive process that requires us to acknowledge and predict others’ hidden beliefs and thoughts. A team of neuroscientists at Massachusetts General Hospital (MGH) and Massachusetts Institute of Technology (MIT) had a rare look at how individual neurons represent the beliefs of others by recording neuron activity in patients undergoing neurosurgery to alleviate symptoms of motor disorders such as Parkinson’s disease. Their findings are published in Nature.