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The Effects of Immersion and Increased Cognitive Load on Time Estimation in a Virtual Reality Environment The Effects of Immersion and Increased Cognitive Load on Time Estimation in a Virtual Reality Environment by Mehrdad Ghomi B.Sc, The University of British Columbia, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Electrical and Computer Engineering) The University of British Columbia (Vancouver) October 2018 c Mehrdad Ghomi, 2018 The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: ”The Effects of Immersion and Increased Cognitive Load on Time Estimation in a Virtual Reality Environment” Submitted by Mehrdad Ghomi in partial fulfillment of the requirements for the degree of Master of Applied Science in Electrical and Computer Engineer- ing. Examining Committee: Dr. Sid Fels (Co-supervisor, Electrical and Computer Engineering) Dr. Bernie Garrett (co-supervisor, Nursing) Dr. Mathew Yedlin (Committee Chair, Electrical and Computer Engineering) ii Abstract The perceived duration of a time interval can seem shorter or longer relative to real time (i.e., solar time or clock time) depending on what fills that time interval. Re- search has suggested that increased immersion alters a users ability to reproduce a given duration whilst doing a simple task or playing a game in an Immersive Virtual Environment (IVE). Virtual Reality (VR) allows users to experience vir- tual environments similar to the real world. The contribution of this experimental research is to explore the effects of undertaking a cognitive spatial task and immer- sion within a VR environment on a persons perception of time. A VR experience using a cognitive task (maze navigation) was compared with a non VR (control) experience of the same task to explore if the effects exist and if the effects are more significant in an IVE compared to a screen-based simple multimedia experience. Also, a VR experience of the environment without any task was compared to the same environment with the cognitive task to establish the effect of a spatial cogni- tive task on temporal perception. More specifically, this study measured how much temporal distortion is achievable utilizing cognitive tasks in a VR experience. In this thesis the use of cognitive tasks and VR are the independent variables and the perceived duration of the experiment (time) is the dependent variable. Obtained data suggest that being immersed in a VR experience results in 16.10% underesti- mation of time, while a non-VR experience results in 7.5% overestimation of time. Moreover, navigating mazes that involve a high cognitive load results in 6.45% underestimation of time. Finally, the combination of VR and high cognitive load (navigating the mazes without guiding lines in a VR experience) result in 22.18% underestimation of time. Finally, the implications of this research are discussed at the end of this thesis. iii Lay Summary Virtual reality (VR) technologies have granted users the possibility of experiencing virtual environments in similar ways as experiencing the real world. One area of interest in the development of VR is the way in which people perceive time within a VR experience. The goal of this study is to identify whether immersion within VR (using head mounted devices) and cognition load (performing spatial cognitive tasks) result in the underestimation of the passage of time by the user. The contribution of this research is the investigation of the effects of cognitive load and immersion on our perception of time. The results suggest that increased immersion in VR and cognitive activity (undertaking spatial tasks, such as navigation) reduces the perceived duration of time. iv Preface This thesis is original, unpublished, independent work by the author. In the second chapter (Background Knowledge), sections 2.1 (Factors that influence temporal perception) and 2.2 (VR and related work on temporal perception) contain descrip- tions of other research, which are cited. Dr. Sidney Fels and Dr. Bernie Garrett were the supervisors of the research. The Statistical Opportunity for Students (SOS) program experts from University of British Columbia (UBC) Department of Statistics helped me with my data analysis in chapter 3.6 of this thesis. The necessary ethical review was requested from the UBC Behavioral Research Ethics Board (BREB) and approval was obtained (H17-00106) (See Appendix C) before recruitment for the experiment. v Table of Contents Abstract . iii Lay Summary . iv Preface . v Table of Contents . vi List of Tables . ix List of Figures . x Glossary . xi Acknowledgments . xii Dedication . xiii 1 Introduction . 1 1.1 Problem Identification . 1 1.2 Statement of the Purpose . 3 1.3 Research Questions . 4 1.4 Investigation . 5 1.5 Significance of the Study . 5 2 Background Knowledge . 7 2.1 Factors That Influence Temporal Perception . 9 vi 2.2 VR and Related Work on Temporal Perception . 14 3 Methods . 18 3.1 Experiment . 19 3.1.1 Experimental Design . 20 3.1.2 Ethical Review . 20 3.2 Participant Recruitment . 21 3.2.1 Sampling Plan . 21 3.2.2 Inclusion and Exclusion Criteria . 21 3.2.3 Recruitment Methods . 22 3.3 Materials . 22 3.3.1 Location . 22 3.3.2 Hardware . 22 3.3.3 Software . 23 3.4 Instruments . 24 3.4.1 Demographic Questionnaire . 24 3.4.2 Post-experience Questionnaires . 25 3.4.3 Terminal Interview . 25 3.4.4 Data Log . 26 3.5 Procedures . 26 3.6 Analysis . 29 3.6.1 Quantitative Analysis . 29 3.6.2 Linear Mixed Effects Model . 31 3.6.3 Qualitative Analysis . 34 4 Results . 35 4.1 Quantitative Data . 35 4.1.1 Descriptive Univariate Statistics . 35 4.1.2 Inferential Statistics . 36 4.2 Qualitative Data . 39 4.2.1 Demographic Questionnaires . 39 4.2.2 Post-Experience Questionnaire Data . 40 4.2.3 Terminal Interview Data . 40 vii 5 Discussion . 42 5.1 Limitations . 47 6 Conclusion . 49 6.1 Implications and Future Work . 50 Bibliography . 52 Appendix A . 57 Appendix B . 58 Appendix C . 61 Appendix D . 65 Appendix E . 67 viii List of Tables Table 3.1 Four Experiment Conditions . 19 Table 3.2 Latin Square Design . 27 Table 4.1 Results from the four runs of the experiment for participant 1 . 38 Table 4.2 Results of the R Code for Various Experiment Conditions (A Bolded P-value indicates Significant Effect) . 38 Table 4.3 Age Distribution of Participants . 38 Table 4.4 Gender Distribution of Participants . 39 Table D.1 Factors That Effect Perception of Time . 66 Table E.1 User Study Data . 72 ix List of Figures Figure 3.1 HTC Vive Setup and Equipment . 23 Figure 3.2 Top View of the Tutorial Maze with Guiding Lines . 28 Figure 3.3 Top View of the Lobby (four Portals to the four main Mazes) . 29 Figure 3.4 View of a Maze With Guiding Lines, Pictures and Voice Overs 30 Figure 4.1 Error Distribution of all Trials (The Horizontal Axis Shows the Absolute Error in Seconds, Vertical Axis Shows the Participant Count) . 37 Figure 4.2 Actual and Perceived Time on Various Experiment Conditions 40 Figure 5.1 Actual, Perceived and Mean Error for all Four Mazes . 43 Figure 5.2 Histogram of Perceived Over Actual Ratio Distribution . 48 Figure B.1 Top View of All 4 Identical Main Mazes (2 with guiding lines and pictures, 2 without lines and pictures) . 59 Figure B.2 Players View of a Maze . 60 Figure C.1 Demographic Questionnaire . 62 Figure C.2 Post Exposure VR Experience Questionnaire . 63 Figure C.3 Post Exposure Semi-Structured Interview Questions . 64 x Glossary 3D Three-Dimensional ADHD Attention Deficit Hyperactivity Disorder ANOVA Analysis of Variance BREB Behavioral Research Ethics Board DF Degree of Freedom ECE Electrical and Computer Engineering GHZ Gigahertz GVR Game VR Environments HMD Head Mounted Display IVE Immersive Virtual Environment LME Linear Mixed Effects RDLPFC Right Dorsolateral Prefrontal Cortex RTMS Repetitive Transcranial Magnetic Stimulation SOS Statistical Opportunity for Students UBC University of British Columbia VR Virtual Reality xi Acknowledgments I want to thank my parents for making it possible for me to be able to pursue my academic career up to this point. I would like to show my gratitude to Dr. Sidney Fels and Dr. Bernie Garrett for sharing their pearls of wisdom with me during the course of this research, and I thank all of the 34 participants who participated in my user study and gave me very useful insights on the research. I want to thank Dr. Jim Little and Dr. David Poole for helping me with participant recruitment. I am also immensely grateful to Dr. Joseph Anthony for his comments on earlier versions of this research. I would like to mention that any errors are my own and should not tarnish the reputations of these esteemed persons. I would also like to thank my colleagues from the Uni- versity of British Columbia, departments of Electrical and Computer Engineering and School of Nursing who provided insight and expertise that greatly assisted this research. Finally, I thank the Department of Statistics for assistance with data analysis and suggestion of the Linear Mixed Effects Model, and also for comments that greatly improved this research. xii Dedication I dedicate all my work to my parents, who have supported me through life, without whom none of my success would be possible. xiii Chapter 1 Introduction When a man sits with a pretty girl for an hour, it seems like a minute. Let him sit on a hot stove for a minute and it’s longer than any hour. — Albert Einstein 1.1 Problem Identification The experience of time pervades every aspect of our lives.
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