Enacting Intersubjectivity: A Cognitive and Social Perspective on the Study of Interactions F. Morganti, A. Carassa, G. Riva (Eds.) Amsterdam, IOS Press, 2008, pp. 223-236 15 Filling the Gap: Dynamic Representation of Occluded Action Wolfgang PRINZ, Gertrude RAPINETT Abstract. In this chapter we examine the time course of dynamic-action representations using an experimental paradigm for studying partially occluded action. To address this issue we focus on transitions between perceptual mechanisms (taking care of representing action before and after occlusion), and substitute mechanisms for simulation (taking care of representing the action during occlusion). Does simulation just carry on old processes – or initiate new ones? We discuss first results concerning the impact that features of unoccluded action segments make on the representation of occluded segments. These results suggest that action simulation is a creative process, creating novel invisible actions rather than extrapolating visible actions. Observers thus fill the gap by creating something new, not by carrying on something old. Contents 15.1 Introduction....................................................................................................... 223 15.2 Paradigm and basic observations ...................................................................... 226 15.3 Linear extrapolation .......................................................................................... 228 15.4 Starting from scratch ........................................................................................ 231 15.5 Taking goals into account ................................................................................. 233 15.6 Conclusions....................................................................................................... 234 15.7 References......................................................................................................... 235 15.1 Introduction Visual occlusion is a commonplace thing. When we look around in our environment, many things and events are spatially and temporally occluded. For instance, the persons we are talking to may partially be occluded by a table in front of them and, as they leave the room through a door and then reappear through another door, they may even be entirely occluded for some time. Still, we as observers have a clear sense of their physical presence while they are partially or completely invisible. The issue of occlusion – i.e. what may happen behind the occluder and how we can know what is happening – has stimulated the fantasy of artists for a long time. One of the reasons may be that, in the case of occlusion, perceptual representation