Today's imaging technology can practically gauge brain activity in real time. But scans of a single brain don't offer much information about real life, according to P. Read Montague. "There's a reason that you don't have a cocktail party one person at a time," says Montague, professor of neuroscience at the Baylor College of Medicine. One partygoer – standing alone, nursing a drink, and chitchatting to no one – hardly replicates people gabbing and gossiping in groups. "The most important things in human life come down to relationships with other people," says Michael Huerta, associate director of neuroscience and basic behavioral science at the National Institute of Mental Health.