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Designed emotions: challenges and potential methodologies for improving multisensory cues to enhance user engagement in immersive systems

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Abstract

In this article, we report on challenges and potential methodologies to support the design and validation of multisensory techniques. Such techniques can be used for enhancing engagement in immersive systems. Yet, designing effective techniques requires careful analysis of the effect of different cues on user engagement. The level of engagement spans the general level of presence in an environment, as well as the specific emotional response to a set trigger. Yet, measuring and analyzing the actual effect of cues is hard as it spans numerous interconnected issues. In this article, we identify the different challenges and potential validation methodologies that affect the analysis of multisensory cues on user engagement. In doing so, we provide an overview of issues and potential validation directions as an entry point for further research. The various challenges are supported by lessons learned from a pilot study, which focused on reflecting the initial validation methodology by analyzing the effect of different stimuli on user engagement.

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References

  1. Beckhaus, S., Kruijff, E.: Unconventional human computer interfaces. ACM SIGGRAPH 2004 course notes (2004)

  2. Mine, M.: Towards virtual reality for the masses. In: Proc. Work. Virtual Environ. 2003—EGVE ’03. ACM Press, New York, pp. 11–17 (2003)

  3. Schell, J., Shochet, J.: Designing interactive theme park rides. IEEE Comput. Graph Appl. 21, 11–13 (2001)

    Article  Google Scholar 

  4. Park, C., Ko, H., Kim, I.-J., et al.: The making of Kyongju VR theatre. In: Proceedings of the IEEE Virtual Reality Conference, p. 269 (2002)

  5. Biocca, F., Levy, M.R.: Communication in the age of virtual reality. L. Erlbaum Associates Inc. (1995)

  6. Held, R.M., Durlach, N.I.: Telepresence. Presence Teleoper. Virtual Environ. 1, 109–112 (1992)

    Article  Google Scholar 

  7. Rizzo, A., Kim, G.J.: A SWOT analysis of the field of virtual reality rehabilitation and therapy. Presence Teleoper. Virtual Environ. 14, 119–146 (2005)

    Article  Google Scholar 

  8. Dinh, H., Walker, N., Song, C., et al.: Evaluating the importance of multi-sensory input on learning and the sense of presence in virtual environments. In: Proceedings of the IEEE Virtual Reality, pp. 222–228 (1999)

  9. Goldstein, E.: Sensation and Perception, 5th edn. Brooks Cole, Monterey (2002)

    Google Scholar 

  10. Meehan, M., Insko, B., Whitton, M., Brooks, F.P.: Physiological measures of presence in stressful virtual environments. ACM Trans. Graph. 21, 645–652 (2002)

    Article  Google Scholar 

  11. Slater, M., Brogni, A., Steed, A.: Physiological responses to breaks in presence: a pilot study. In: The 6th Annual International Workshop on Presence (2003)

  12. Dillon, C., Keogh, E., Freeman, J., Davidoff, J.: Presence: is your heart in it. In: Proceedings of the 4th Annual International Workshop on Presence (2001)

  13. Jang, E.-H., Park, B.-J., Park, M.-S., et al.: Analysis of physiological signals for recognition of boredom, pain, and surprise emotions. J. Physiol. Anthropol. 34, 25 (2015)

    Article  Google Scholar 

  14. Morgan, R., Heise, D.: Structure of emotions. Soc. Psychol. Q 51, 19–31 (1988)

    Article  Google Scholar 

  15. Sykes, J., Brown, S.: Affective gaming—measuring emotion through the gamepad. In: Proceedings of the 2003 ACM Conference on Human Factors in Computing Systems (CHI 2003) (2003), pp. 732–733

  16. Shiota, M., Keltner, D., Mossman, A.: The nature of awe: elicitors, appraisals, and effects on self-concept. Cogn. Emot. 21, 944–963 (2007)

    Article  Google Scholar 

  17. Rudd, M., Vohs, K.D., Aaker, J.: Awe expands people’s perception of time, alters decision making, and enhances well-being. Psychol. Sci. 23, 1130–6 (2012)

    Article  Google Scholar 

  18. Ark, W., Dryer, D., Lu, D.: The emotion mouse. In: Proceedings HCI International ’99, pp. 818–823 (1999)

  19. Picard, R.: Affective Computing. MIT Press, Cambridge (1997)

    Book  Google Scholar 

  20. Calvo, R., D’Mello, S.: Affect detection: an interdisciplinary review of models, methods, and their applications. IEEE Trans. Affect. Comput. 1, 18–37 (2010)

    Article  Google Scholar 

  21. D’mello, S.K., Kory, J.: A review and meta-analysis of multimodal affect detection systems. ACM Comput. Surv. 47, 1–36 (2015)

  22. O’Brien, H., Toms, E.: Examining the generalizability of the User Engagement Scale (UES) in exploratory search. Inf. Process. Manag. 49, 1092–1107 (2013)

    Article  Google Scholar 

  23. Attfield, S., Kazai, G., Lalmas, M., Piwowarski: Towards a science of user engagement. In: Proceedings of WSDM Work User Modeling for Web Applications (2011)

  24. Lehmann, J., Lalmas, M., Yom-Tov, E., Dupret, G.: User modeling, adaptation, and personalization. Information Systems and Applications, incl. Internet/Web, and HCI, vol. 7379. Springer, Berlin (2012)

  25. Jacques, R.: Engagement as a design concept for multimedia. Can. J. Educ. Commun. 24, 49–59 (1995)

    Google Scholar 

  26. Lalmas, M., O’Brien, H., Yom-Tov, E.: Measuring User Engagement. Morgan & Claypool, San Rafael (2014)

  27. Slater, M., Linakis, V., Usoh, M., Kooper, R.: Immersion, presence, and performance in virtual environments: an experiment with tri-dimensional chess. In: Proceedings of the ACM Virtual Reality Software and Technology, pp. 163–172 (1996)

  28. Steuer, J.: Defining virtual reality: dimensions determining telepresence. J. Commun. 42(4), 73–93 (1992)

  29. Ryan, R.M., Rigby, C.S., Przybylski, A.: The motivational pull of video games: a self-determination theory approach. Motiv. Emot. 30, 344–360 (2006)

    Article  Google Scholar 

  30. Ijsselsteijn, W., de Kort, Y., Poels, K.: The game experience questionnaire: development of a self-report measure to assess the psychological impact of digital games. Manuscript in Preparation

  31. Bernhaupt, R.: Evaluating user experience in games. Human–Computer Interaction Series. Springer, London (2010)

  32. Lenay, C., Gapenne, O., Hanneton, S., et al.: Sensory substitution: limits and perspectives. In: Hatwell, Y., Streri, A., Gentaz, E. (eds.) Touching for Knowing. John Benjamins Publishing Company, pp. 275–292 (2003)

  33. Loomis, J.: Sensory replacement and sensory substitution: overview and prospects for the future. In: Converging Technologies for Improving Human Performance: Nanotechnology, Biotechnology, Information Technology and Cognitive Science, (US NBIC 2002), NSF-DOC Converging Technologies Report, p. 220 (2002)

  34. Kruijff, E.: Human-potential driven design of 3D user interfaces. In: Proceedings of the IEEE International Conference on Artificial Reality and Telexistence, pp. 129–136 (2013)

  35. Kruijff, E.: Unconventional 3D User Interfaces for Virtual Environments. Graz University of Technology, PhD Thesis (2007)

  36. Pulkki, V.: Spatial Sound Generation and Perception by Amplitude Panning Techniques. Helsinki University of Technology, PhD Thesis (2001)

  37. Afonso, C., Beckhaus, S.: How to not hit a virtual wall. In: Proceedings of the 6th Audio Mostly Conference: A Conference on Interaction with Sound—AM ’11, pp 101–108. ACM Press, New York (2011)

  38. Naer, M., Staadt, O., Gross, M.: Spatialized audio rendering for immersive virtual environments. In: Proceedings of the ACM Symposium on Virtual Reality Software Technology (VRST 2002), pp 65–72. ACM Press, New York (2002)

  39. Tsingos, N., Gallo, E., Drettakis, G.: Perceptual audio rendering of complex virtual environments. ACM Trans. Graph. 23, 249 (2004)

    Article  Google Scholar 

  40. Kruijff, E., Pander, A.: Experiences of using shockwaves for haptic sensations. In: Proceedings of 3D User Interface Workshop. IEEE Virtual Reality Conference, pp. 37–42 (2005)

  41. Israr, A., Williams, T., Poupyrev, I., et al.: Surround Haptics. In: ACM SIGGRAPH 2011 Emerging Technology—SIGGRAPH ’11, p. 1. ACM Press, New York (2011)

  42. Mueller, F., Vetere, F., Gibbs, M., et al.: Balancing exertion experiences. In: Proceedings of the 2012 ACM Annual Conference on Human Factors in Computing Systems—CHI ’12, p. 1853. ACM Press, New York (2012)

  43. Kaye, J.: Symbolic Olfactory Display. Massachusetts Institute of Technology, PhD Thesis (1999)

  44. Yanagida, Y., Kawato, H., Noma, H., et al.: A nose-tracked, personal olfactory display. In: Proceedings of ACM SIGGRAPH Sketches and Applications (2003)

  45. Narumi, T., Nishizaka, S., Kajinami, T., et al.: Augmented reality flavors. In: Proceedings of 2011 Annual Conference on Human Factors in Computing Systems—CHI ’11, p. 93. ACM Press, New York (2011)

  46. Ranasinghe, N., Cheok, A., Nakatsu, R., Do, E.: Simulating the sensation of taste for immersive experiences. In: Proceedings of the 2013 ACM International Workshop on Immersive Media Experiences—ImmersiveMe ’13, pp. 29–34. ACM Press, New York (2013)

  47. Feng, M., Lindeman, R., Abdel-Moati, H., Lindeman, J.: Haptic ChairIO: A system to study the effect of wind and floor vibration feedback on spatial orientation in VEs. In: Proceedings of IEEE Symposium on 3D User Interfaces, pp. 149–150 (2015)

  48. Hülsmann, F., Fröhlich, J., Mattar, N., Wachsmuth, I.: Wind and warmth in virtual reality. In: Proceedings of the 2014 Virtual Reality International Conference—VRIC ’14, pp. 1–8. ACM Press, New York (2014)

  49. Wiederhold, B., Jang, D., Kim, S., Wiederhold, M.: Physiological monitoring as an objective tool in virtual reality therapy. Cyberpsychol. Behav. 5, 77 (2002)

    Article  Google Scholar 

  50. Brogni, A., Vinayagamoorthy, V., Steed, A., Slater, M.: Variations in physiological responses of participants during different stages of an immersive virtual environment experiment. In: Proceedings of the ACM Symposium on Virtual Reality Software and Technology—VRST ’06, p. 376. ACM Press, New York (2006)

  51. Jang, D.P., Kim, I.Y., Nam, S.W., et al.: Analysis of physiological response to two virtual environments: driving and flying simulation. Cyberpsychol. Behav. 5, 11–8 (2002)

    Article  Google Scholar 

  52. Hoffman, H.: Physically touching virtual objects using tactile augmentation enhances the realism of virtual environments. In: Proceedings of the 1998 IEEE Virtual Reality Annual International Symposium. IEEE, pp. 59–63 (1998)

  53. Regenbrecht, H., Schubert, T., Friedmann, F.: Measuring the sense of presence and its relations to fear of heights in virtual environments. Int. J. Hum. Comput. Interact. 10, 233–250 (1998)

    Article  Google Scholar 

  54. Shimojo, S., Shams, L.: Sensory modalities are not separate modalities: plasticity and interactions. Curr. Opin. Neurobiol. 11, 505–509 (2001)

    Article  Google Scholar 

  55. Pai, D.: Multisensory interaction: real and virtual. In: Proceedings of the International Symposium on Robotics Research, vol. 15, pp. 489–498. Springer, Berlin (2003)

  56. Spence, C., Squire, S.: Multisensory integration: maintaining the perception of synchrony. Curr. Biol. 13, 519–521 (2003)

    Article  Google Scholar 

  57. Weisenberger, J., Poling, G.: Multisensory roughness perception of virtual surfaces: effects of correlated cues. In: Proceedings of the 12th International Symposium on Haptic Interfaces Virtual Environment and Teleoperators Systems, pp. 161–168 (2004)

  58. Lindeman, R., Noma, H.: A classification scheme for multi-sensory augmented reality. In: Proceedings of the ACM Virtual Reality Software and Technology, pp. 175–178 (2007)

  59. Sutcliffe, A.: Multimedia and Virtual Reality: Designing Multisensory User Interfaces. Psychology Press, New York (2003)

    Google Scholar 

  60. Lederman, S., Thorne, G., Jones, B.: Perception of texture by vision and touch: multidimensionality and intersensory integration. J. Exp. Psychol. Hum. Percept. Perform. 12, 169–180 (1986)

    Article  Google Scholar 

  61. Narumi, T., Kajinami, T., Tanikawa, T., Hirose, M.: Meta cookie. In: ACM SIGGRAPH 2010 Emerging Technologies—SIGGRAPH ’10, p. 1. ACM Press, New York (2010)

  62. Sekuler, R., Sekuler, A., Lau, R.: Sound alters visual motion perception. Nature 385, 308 (1997)

  63. Blake, R., Sobel, K., James, W.: Neural synergy between kinetic vision and touch. Psychol. Sci. 15(6):397–402 (2004)

  64. Bresciani, J.-P., Ernst, M., Drewing, K., et al.: Feeling what you hear: auditory signals can modulate tactile tap perception. Exp. Brain Res. 162, 172–180 (2004)

    Article  Google Scholar 

  65. Spence, C.: Just how much of what we taste derives from the sense of smell? Flavour 4, 30 (2015)

    Article  Google Scholar 

  66. Hoggan, E., Kaaresoja, T., Laitinen, P., Brewster, S.: Crossmodal congruence: the look, feel and sound of touchscreen widgets. In: Proceedings of the 10th International Conference on Multimodal Interfaces—IMCI ’08, p. 157. ACM Press, New York (2008)

  67. Bell, J., Cooper, K., Kaiser, G., Sheth, S.: Proceedings of the Second International Workshop on Games and Software Engineering: Realizing User Engagement with Game Engineering Techniques (2012)

  68. Buchenau, M., Suri, J.F.: Experience prototyping. In: Proceedings of the Conference on Designing Interactive Systems: Processes. Practices, Methods and Techniques—DIS ’00, pp. 424–433. ACM Press, New York (2000)

  69. Brown, E., Cairns, P.: A grounded investigation of game immersion. In: Extended Abstracts of the 2004 Conference on Human Factors and Computing Systems—CHI ’04, p. 1297. ACM Press, New York (2004)

  70. Dow, S.: Understanding user engagement in immersive and interactive stories (2008)

  71. Csikszentmihalyi, M.: Flow: The Psychology of Optimal Experience. Harper Perennial Modern Classics (1990)

  72. Sweetser, P., Wyeth, P.: GameFlow. Comput. Entertain. 3, 3 (2005)

    Article  Google Scholar 

  73. Slater, M., Usoh, M., Steed, A.: Depth of presence in virtual environments. Presence Teleoper. Virtual Environ. 3, 130–144 (1994)

    Article  Google Scholar 

  74. McMahan, R.P., Bowman, D.A., Zielinski, D.J., Brady, R.B.: Evaluating display fidelity and interaction fidelity in a virtual reality game. IEEE Trans. Vis. Comput. Graph. 18, 626–33 (2012)

    Article  Google Scholar 

  75. Schild, J., Masuch, M.: Formalizing the potential of stereoscopic 3D user experience in interactive entertainment. In: Holliman, N.S., Woods, A.J., Favalora, G.E., Kawai, T. (eds.) IS&T/SPIE Electronic Imaging. International Society for Optics and Photonics, p. 93911D (2015)

  76. Schild, J., LaViola, JJ., Masuch, M.: Altering gameplay behavior using stereoscopic 3D vision-based video game design. In: Proceedings of the 32nd Annual ACM Conference on Human Factors in Computing Systems—CHI ’14, pp. 207–216. ACM Press, New York (2014)

  77. Barfield, W., Zeltzer, D., Sheridan, T., Slater, M.: Presence and performance within virtual environments. In: Virtual environments and advanced interface design, pp. 473–513 (1995)

  78. Ellis, S.R.: Presence of mind: a reaction to Thomas Sheridan’s further musings on the psychophysics of presence. Presence (Camb.) 5, 247–259 (1996)

    Article  Google Scholar 

  79. Lombard, M., Ditton, T.: At the heart of it all: the concept of presence. J. Comput. Commun. 3(2) (1997)

  80. Schubert, T., Friedmann, F., Regenbrecht, H.: Visual representations and interpretations. In: Paton, R., Neilson, I. (eds.) Visual representations and interpretations, pp. 269–278. Springer, London (1999)

    Chapter  Google Scholar 

  81. Usoh, M., Catena, E., Arman, S., Slater, M.: Using presence questionnaires in reality. Presence Teleoper. Virtual Environ. 9, 497–503 (2000)

    Article  Google Scholar 

  82. Witmer, B., Singer, M.: Measuring presence in virtual environments: a presence questionnaire. Presence Teleoper. Virtual Environ. 7, 225–240 (1998)

    Article  Google Scholar 

  83. IJsselsteijn, WA., de Ridder, H., Freeman, J., Avons, SE.: Presence: concept, determinants and measurement. In: Proceedings of the SPIE, 3959, pp. 520–529

  84. Wiederhold, B.K., Rizzo, A.: Virtual reality and applied psychophysiology. Appl. Psychophysiol. Biofeedback 30, 183–185 (2005)

    Article  Google Scholar 

  85. Pugnetti, L., Meehan, M., Mendozzi, L.: Psychophysiological correlates of virtual reality: a review. Presence Teleoper. Virtual Environ. 10, 384–400 (2001)

    Article  Google Scholar 

  86. Calvert, G.A., Thesen, T.: Multisensory integration: methodological approaches and emerging principles in the human brain. J. Physiol. Paris 98, 191–205 (2004)

    Article  Google Scholar 

  87. Ernst, M.O., Bülthoff, H.H.: Merging the senses into a robust percept. Trends Cogn. Sci. 8, 162–9 (2004)

    Article  Google Scholar 

  88. Kuppens, P., Tuerlinckx, F., Russell, J.A., Barrett, L.F.: The relation between valence and arousal in subjective experience. Psychol. Bull. 139, 917–40 (2013)

    Article  Google Scholar 

  89. Posner, J., Russell, J.A., Peterson, B.S.: The circumplex model of affect: an integrative approach to affective neuroscience, cognitive development, and psychopathology. Dev. Psychopathol. 17, 715–34 (2005)

    Article  Google Scholar 

  90. Scherer, K.R.: What are emotions? And how can they be measured? Soc. Sci. Inf. 44, 695–729 (2005)

    Article  Google Scholar 

  91. Watson, D., Clark, L.A., Tellegen, A.: Development and validation of brief measures of positive and negative affect: the PANAS scales. J. Pers. Soc. Psychol. 54, 1063–70 (1988)

    Article  Google Scholar 

  92. Izard, C.: Patterns of Emotions. Elsevier Academic Press, Amsterdam (1972)

    Google Scholar 

  93. Ekman, P., Friesen, W.V., O’Sullivan, M., et al.: Universals and cultural differences in the judgments of facial expressions of emotion. J. Pers. Soc. Psychol. 53, 712–7 (1987)

    Article  Google Scholar 

  94. Bradley, M.M., Lang, P.J.: Affective reactions to acoustic stimuli. Psychophysiology 37, 204–15 (2000)

    Article  Google Scholar 

  95. Bradley, M.M., Cuthbert, B.N., Lang, P.J.: Picture media and emotion: effects of a sustained affective context. Psychophysiology 33, 662–70 (1996)

    Article  Google Scholar 

  96. Anttonen, J., Surakka, V.: Emotions and heart rate while sitting on a chair. In: Proceedings of the SIGCHI Conference on Human Factors in Computing Systems—CHI ’05, p. 491. ACM Press, New York (2005)

  97. Scheirer, J., Fernandez, R., Klein, J., Picard, R.W.: Frustrating the user on purpose: a step toward building an affective computer. Interact. Comput. 14, 93–118 (2002)

    Article  Google Scholar 

  98. Partala, T.: Affective information in human–computer interaction. VDM Verlag (2009)

  99. Fu, Y., Leong, HV., Ngai, G., et al.: Physiological mouse: towards an emotion-aware mouse. In: 2014 IEEE 38th International Computers, Software and Applications Conference Work. IEEE, pp 258–263 (2014)

  100. Asteriadis, S., Tzouveli, P., Karpouzis, K., Kollias, S.: Estimation of behavioral user state based on eye gaze and head pose-application in an e-learning environment. Multimed. Tools Appl. 41, 469–493 (2008)

    Article  Google Scholar 

  101. Steffin, M.: Virtual reality biofeedback in chronic pain and psychiatry. eMed. J. (2005). Available online at: http://www.emedicine.com/neuro/topic466.htm

  102. Bersak, D., McDarby, G., Augenblick, N., et al.: Intelligent biofeedback using an immersive competitive environment. In: Proceedings of the UbiComp (2001)

  103. Bowman, D., Kruijff, E., LaViola, J., Poupyrev, I.: 3D User Interfaces: Theory and Practice. Addison-Wesley, Boston (2005)

    Google Scholar 

  104. Nielsen, J.: Usability Engineering. Academic Press, Boston (1993)

    MATH  Google Scholar 

  105. Forlizzi, J., Battarbee, K.: Understanding experience in interactive systems. In: Proceedings of the 2004 Conference on Designing Interactive Systems: Processes, Practices, Methods, and Techniques—DIS ’04, p. 261. ACM Press, New York (2004)

  106. Schubert, T., Friedmann, F., Regenbrecht, H.: The experience of presence: factor analytic insights. Presence Teleoper. Virtual Environ. 10, 266–281 (2001)

    Article  Google Scholar 

  107. Bateman, C., Lowenhaupt, R., Nacke, L.: Player typology in theory and practice. In: DiGRA ’11—Proceedings of the 2011 DiGRA International Conference, Think Design Play, vol. 6 (2011)

  108. Ramic-Brkic, B., Chalmers, A.: Olfactory adaptation in virtual environments. ACM Trans. Appl. Percept. 11, 1–16 (2014)

    Article  Google Scholar 

  109. Feng, M., Dey, A., Lindeman, R.: An initial exploration of a multi-sensory design space: tactile support for walking in immersive virtual environments. In: Proceedings of the IEEE Symposium on 3D User Interfaces, pp. 95–104 (2016)

  110. Eidenberger, H., Mossel, A.: Indoor skydiving in immersive virtual reality with embedded storytelling. In: Proceedings of the 21st ACM Symposium on Virtual Reality Software and Technology—VRST ’15, pp. 9–12. ACM Press, New York (2015)

  111. Paddan, G.S., Griffin, M.J.: The transmission of translational seat vibration to the head—I. Vertical seat vibration. J. Biomech. 21, 191–197 (1988)

    Article  Google Scholar 

  112. Harris, L., Jenkin, M., Zikovitz, D.: Vestibular cues and virtual environments: choosing the magnitude of the vestibular cue. In: Proceedings IEEE Virtual Reality’99. IEEE Press, pp. 229–236 (1999)

  113. Picard, R., Scheirer, J.: The Galvactivator: A Glove that Senses and Communicates Skin Conductivity. In: Proceedings of the 9th International Conference on Human Computer Interaction, pp. 1538–1542 (2001)

  114. Nacke, L., Lindley, CA.: Flow and immersion in first-person shooters. In: Proceedings of the 2008 Conference on Future Play: Research, Play, Share—Future Play ’08, p. 81. ACM Press, New York (2008)

  115. Greenwald, M.K., Cook, E.W., Lang, P.J.: Affective judgment and psychophysiological response: dimensional covariation in the evaluation of pictorial stimuli. J. Psychophysiol 3(1), 51–64 (1989)

    Google Scholar 

  116. Brooke, J.: SUS: a quick and dirty usability scale. In: Usability Evaluation in Industry (1996)

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Kruijff, E., Marquardt, A., Trepkowski, C. et al. Designed emotions: challenges and potential methodologies for improving multisensory cues to enhance user engagement in immersive systems. Vis Comput 33, 471–488 (2017). https://doi.org/10.1007/s00371-016-1294-0

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