We describe a novel wearable device that perceives and reports on social-emotional information in realtime human interaction. Using a wearable camera and other sensors, combined with machine perception algorithms, the system records and analyzes the facial expressions and head movements of the person with whom the wearer is interacting. We propose the application of the social-emotional prosthetic to assist the growing number of individuals diagnosed with Autism Spectrum Disorder (ASD) in perceiving communication in a natural rather than a structured environment, bootstrapping their ability to learn and develop in social settings. The wearable device is a novel exploratory platform for researchers to gain a better understanding of social-emotional communication, enabling new kinds of measurements and interventions that may also help advance the theory of Autism.