Ilias Bergstrom

Drumming in Immersive Virtual Reality: The Body Shapes the Way We Play

It has been shown that it is possible to generate perceptual illusions of ownership in immersive virtual reality (IVR) over a virtual body seen from first person perspective, in other words over a body that visually substitutes the persons real body. This can occur even when the virtual body is quite different in appearance from the persons real body. However, investigation of the psychological, behavioral and attitudinal consequences of such body transformations remains an interesting problem with much to be discovered. Thirty six Caucasian people participated in a between-groups experiment where they played a West-African Djembe hand drum while immersed in IVR and with a virtual body that substituted their own. The virtual hand drum was registered with a physical drum. They were alongside a virtual character that played a drum in a supporting, accompanying role. In a baseline condition participants were represented only by plainly shaded white hands, so that they were able merely to play. In the experimental condition they were represented either by a casually dressed dark-skinned virtual body (Casual Dark-Skinned - CD) or by a formal suited light-skinned body (Formal Light-Skinned - FL). Although participants of both groups experienced a strong body ownership illusion towards the virtual body, only those with the CD representation showed significant increases in their movement patterns for drumming compared to the baseline condition and compared with those embodied in the FL body. Moreover, the stronger the illusion of body ownership in the CD condition, the greater this behavioral change. A path analysis showed that the observed behavioral changes were a function of the strength of the illusion of body ownership towards the virtual body and its perceived appropriateness for the drumming task. These results demonstrate that full body ownership illusions can lead to substantial behavioral and possibly cognitive changes depending on the appearance of the virtual body. This could be important for many applications such as learning, education, training, psychotherapy and rehabilitation using IVR.

The Plausibility of a String Quartet Performance in Virtual Reality

We describe an experiment that explores the contribution of auditory and other features to the illusion of plausibility in a virtual environment that depicts the performance of a string quartet. ‘Plausibility’ refers to the component of presence that is the illusion that the perceived events in the virtual environment are really happening. The features studied were: Gaze (the musicians ignored the participant, the musicians sometimes looked towards and followed the participants movements), Sound Spatialization (Mono, Stereo, Spatial), Auralization (no sound reflections, reflections corresponding to a room larger than the one perceived, reflections that exactly matched the virtual room), and Environment (no sound from outside of the room, birdsong and wind corresponding to the outside scene). We adopted the methodology based on color matching theory, where 20 participants were first able to assess their feeling of plausibility in the environment with each of the four features at their highest setting. Then five times participants started from a low setting on all features and were able to make transitions from one system configuration to another until they matched their original feeling of plausibility. From these transitions a Markov transition matrix was constructed, and also probabilities of a match conditional on feature configuration. The results show that Environment and Gaze were individually the most important factors influencing the level of plausibility. The highest probability transitions were to improve Environment and Gaze, and then Auralization and Spatialization. We present this work as both a contribution to the methodology of assessing presence without questionnaires, and showing how various aspects of a musical performance can influence plausibility.

Code Bending: A New Creative Coding Practice

ABSTRACT Creative coding, or artistic creation through the medium of program instructions, is constantly gaining traction, and there is a steady stream of new resources emerging to support it. However, the question of how creative coding is carried out still deserves more attention. In what ways may the act of program development be rendered conducive to artistic creativity? As one possible answer to this question, the authors present and discuss a new creative coding practice, that of code bending, alongside examples and considerations regarding its applications.

Sarka: Sonification and Somaesthetic Appreciation Design

We often take for granted that we have immediate access to our perception and experience of and through our bodies. But inward listening is a demanding activity and thus not easy to learn to perform or design for. With the Sarka mat we want to support the ability to direct attention by providing sound feedback linked to the weight distribution and motion intensity of different parts of the body, and to provide an exemplar for how such design may be conducted. The process of Sarkas creation is informed by Somaesthetic Appreciation Design. We discuss how a sonic feedback signal can influence listeners, followed by how we, in this design, worked to navigate the complex design space presented to us. We detail the design process involved, and the very particular set of limitations which this interactive sonification presented.

Soma: Live Musical Performance in Which Congruent Visual, Auditory and Proprioceptive Stimuli Fuse to Form a Combined Aesthetic Narrative

ABSTRACT Artists and scientists have long had an interest in the relationship between music and visual art, leading up to the present-day art form of correlated animation and music called visual music. Current live performance tools and paradigms for visual music, however, are subject to several limitations. The work reported here addresses these through a transdisciplinary integration of findings from several research areas, detailing the resulting ideas and their implementation in three interconnected software applications. This culminates in the art form of Soma, in which correlated auditory, visual and proprioceptive stimuli form a combined narrative.