The Ascription of Intentions in Gaze-Contingent Social Encounters

Observing the gaze of others not only helps us understand their motives and intentions but also to engage in interactions with them. Therefore, one of the most important assessments we have to do when observing someone’s gaze is whether their gaze behavior is meant as a signal to us. For persons with difficulties in understanding and interpreting the intentions of others, as is the case in autism spectrum disorder (ASD), this situation can be especially challenging. This thesis addressed the problem of how we are able to interpret and understand the gaze behavior of others in order to communicate successfully. As a first step, it examines which kinds of inferences regarding the general intentions of another person are possible from the passive observation of gaze behavior (study 1). Turning towards gaze interactions, it then outlined a theoretical concept and a taxonomy of social gaze, allowing for holistic considerations of ongoing gaze encounters (study 2). The practical implementation of this approach in form of the new agent interaction platform TriPy was presented in study 3. Subsequently, an investigation of the inference of communicative intentions in ongoing gaze interactions was performed (study 4). Study 5 then compared the performance of healthy participants with that of persons with ASD, finding that the latter especially have trouble in interactive situations. As an outlook to the future direction of social gaze investigations and their application in clinical contexts, study 6 introduced a new technical system for avatar-mediated communication between two persons combined with machine learning based data analysis. Before these studies are presented in more detail, a theoretical background is provided by introducing central phenomena of social gaze as well as describing impairments in gaze communication in ASD. In addition, methodological requirements and challenges in the investigation of social gaze are elucidated. After presenting the individual studies, the results obtained in this thesis are integrated in a general discussion focusing on our understanding of social gaze, its clinical implications, as well as potential future directions in social gaze research