Extended Reality and Time Perception: An Integrated Approach and Experimental Framework

Experiencing the passage of time is an inherent aspect of human life, and therefore, of the experience in interactive applications. Time perception is a growing research subject with numerous research questions such as how to model the human processing of time, what affects it, how to modulate it, and what can be the benefits of modulating it. This research is embedded in the EU-funded ChronoPilot project, which aims to modulate time perception to the advantage of its user, in order to induce flow or reduce stress. With the recent growth of mediated reality technologies, in particular with the rising popularity of Virtual Reality (VR) and Augmented Reality (AR) dedicated Head Mounted Displays (HMDs), interactive computer applications can now deliver multi-sensory stimuli in immersive experiences; which offers unique possibilities to modulate time perception. However, integrating time modulation as part of the user experience in immersive applications comes with numerous challenges in integration, such as the selection of stimuli, the intent of the time modulation, or even the technical integration. In this thesis, as part of the ChronoPilot research project and based on my research from the past years, this thesis will try to provide guidelines and tools to help integrate time perception modulation within eXtended Reality (XR) applications. More specifically, the focus lies on the use of rhythmic stimuli in time modulation, on the implications of XR in a time modulation context, and specifications of a Unity framework dedicated to (Multi-)User studies. Rhythmic stimuli were approached first as a way to synchronize multi-sensory modulation; however, our results suggest that a multi-sensory rhythmic stimulus have fundamentally different effects on time perception than an equivalent single-sensory stimulus. Furthermore, the rhythmic stimuli tested depend heavily on contextual factors, such as fatigue and task familiarity. Regarding the implication of using XR, it was observed that using XR in a time perception modulation context may lead to differences both due to the technology being used or the design and implementation of in-environment interactions. The main contribution of the thesis is the development of the XR MUSE framework, which is built with the aim of allowing extended reproducibility and cross-experiments integrations. The developed technology has been of great help in developing interactive applications implementing intentional time perception modulation in non-timing tasks and is ready to be used for any interactive application prototyping.