The majority of research on human perception and action examines sensors and effectors in relative isolation. What is less often considered in these research domains is that humans interact with a perceived world in which they themselves are part of the perceptual representation, as are the positions and actions (potential or ongoing) of other active beings. It is this self-in-world representation that we call embodiment. Increasingly, research demonstrates that embodiment is fundamental to both executing and understanding spatially and interpersonally directed action.It has been theorized to play a role in reaching and grasping, locomotion and navigation, infant imitation, spatial and social perspective taking, and neurological dysfunctions as diverse as phantom limb pain and autism. Few formal ideas have been put forward, however, to describe how selfrepresentation functions at a mechanistic level and what neural structures support those functions. This volume reports on the 2006 Carnegie Symposium on Cognition, which brought together the contributions to these issues from a group of researchers who span perspectives of behavioral science, neuroscience, developmental psychology and computation. Together they share their findings, ideas, aspirations, and concerns.