Intrapersonal, Interpersonal, and Hybrid Interactions in Virtual Reality

Virtual reality and related media and communication technologies have a growingimpact on professional application fields and our daily life. Virtual environmentshave the potential to change the way we perceive ourselves and how we interactwith others. In comparison to other technologies, virtual reality allows for theconvincing display of a virtual self-representation, an avatar, to oneself and also toothers. This is referred to as user embodiment. Avatars can be of varying realismand abstraction in their appearance and in the behaviors they convey. Such userembodyinginterfaces, in turn, can impact the perception of the self as well asthe perception of interactions. For researchers, designers, and developers it is ofparticular interest to understand these perceptual impacts, to apply them to therapy,assistive applications, social platforms, or games, for example. The present thesisinvestigates and relates these impacts with regard to three areas: intrapersonaleffects, interpersonal effects, and effects of social augmentations provided by thesimulation.With regard to intrapersonal effects, we specifically explore which simulationproperties impact the illusion of owning and controlling a virtual body, as wellas a perceived change in body schema. Our studies lead to the construction ofan instrument to measure these dimensions and our results indicate that thesedimensions are especially affected by the level of immersion, the simulation latency,as well as the level of personalization of the avatar.With regard to interpersonal effects we compare physical and user-embodied socialinteractions, as well as different degrees of freedom in the replication of nonverbalbehavior. Our results suggest that functional levels of interaction are maintained,whereas aspects of presence can be affected by avatar-mediated interactions, andcollaborative motor coordination can be disturbed by immersive simulations.Social interaction is composed of many unknown symbols and harmonic patternsthat define our understanding and interpersonal rapport. For successful virtualsocial interactions, a mere replication of physical world behaviors to virtual environmentsmay seem feasible. However, the potential of mediated social interactionsgoes beyond this mere replication. In a third vein of research, we propose andevaluate alternative concepts on how computers can be used to actively engage inmediating social interactions, namely hybrid avatar-agent technologies. Specifically,we investigated the possibilities to augment social behaviors by modifying andtransforming user input according to social phenomena and behavior, such as nonverbalmimicry, directed gaze, joint attention, and grouping. Based on our resultswe argue that such technologies could be beneficial for computer-mediated socialinteractions such as to compensate for lacking sensory input and disturbances indata transmission or to increase aspects of social presence by visual substitution oramplification of social behaviors.Based on related work and presented findings, the present thesis proposes theperspective of considering computers as social mediators. Concluding from prototypesand empirical studies, the potential of technology to be an active mediator of socialperception with regard to the perception of the self, as well as the perception ofsocial interactions may benefit our society by enabling further methods for diagnosis,treatment, and training, as well as the inclusion of individuals with social disorders.To this regard, we discuss implications for our society and ethical aspects. Thisthesis extends previous empirical work and further presents novel instruments,concepts, and implications to open up new perspectives for the development ofvirtual reality, mixed reality, and augmented reality applications.