The fMRI took images of each person's brain while they completed a task similar to the one they did earlier. They rated each of their friends and themselves on 48 traits, including lonely, sad, cold, lazy, overcritical, trustworthy, enthusiastic, clumsy, fashionable, helpful, smart, punctual and nice. As they expected from previous research, the researchers saw activity in the medial prefrontal cortex, a part of the brain implicated in thinking about the self and close others, as the participants thought about the personality traits of themselves and their friends. The study found that for each participant, the combined brain activity of their friends evaluating them looked a lot like their own brain activity. This suggests that order to accurately perceive another person, your neural representation of that person -- your patterns of brain activity for their identity -- has to essentially match the pattern in that persons' brain when they are thinking about themselves, Wagner said. - www.sciencedaily.com