Who turned the clock? Effects of Manipulated Zeitgebers, Cognitive Load and Immersion on Time Estimation

Current virtual reality (VR) technologies have enormous potential to allow humans to experience computer-generated immersive virtual environments (IVEs). Many of these IVEs support near-natural audiovisual stimuli similar to the stimuli generated in our physical world. However, decades of VR research have been devoted to exploring and understand differences between perception and action in such IVEs compared to real-world perception and action. Although, significant differences have been revealed for spatiotemporal perception between IVEs and the physical world such as distance underestimation, there is still a scarcity of knowledge about the reasons for such perceptual discrepancies, in particular regarding the perception of temporal durations in IVEs. In this article, we explore the effects of manipulated zeitgebers, cognitive load and immersion on time estimation as yet unexplored factors of spatiotemporal perception in IVEs. We present an experiment in which we analyze human sensitivity to temporal durations while experiencing an immersive head-mounted display (HMO) environment. We found that manipulations of external zeitgebers caused by a natural or unnatural movement of the virtual sun had a significant effect on time judgments. Moreover, using the dual-task paradigm the results show that increased spatial and verbal cognitive load resulted in a significant shortening of judged time as well as an interaction with the external zeitgebers. Finally, we discuss the implications for the design of near-natural computer-generated virtual worlds.