Lexie is a healthy two-year-old helping researchers test sensors designed to gauge something particularly difficult to measure scientifically - emotional responses. A wrist sensor Lexie wears provides immediate feedback on the electrical changes in the skin that increase with her perspiration. With support from the National Science Foundation, teams across the country are working to advance a new field of research called computational behavioral science. Computer scientist Rosalind Picard of MIT is developing wearable sensors to measure the subtle changes that naturally occur in the body during social interactions. Picard's group focuses largely on children with autism and other nonverbal learning disabilities that make it difficult for them to understand and communicate their emotions, and to be understood. Another team, led by computer scientist Jim Rehg at Georgia Tech, is developing new methods to monitor subtle behaviors, such as eye movements, using wearable cameras. Rehg's research group is testing a range of sensors on children, some of whom are on the autism spectrum, with the goal of designing new tools for autism research and more effective treatment.