Auditory Self-Motion Simulation is Facilitated by Haptic and Vibrational Cues Suggesting the Possibility of Actual Motion

Sound fields rotating around stationary blindfolded listeners sometimes elicit auditory circular vection, the illusion that the listener is physically rotating. Experiment 1 investigated whether auditory circular vection depends on participants\u27 situational awareness of "movability", i.e., whether they sense/know that actual motion is possible or not. While previous studies often seated participants on movable chairs to suspend the disbelief of self-motion, it has never been investigated whether this does, in fact, facilitate auditory vection. To this end, 23 blindfolded participants were seated on a hammock chair with their feet either on solid ground ("movement impossible") or suspended ("movement possible") while listening to individualized binaural recordings of two sound sources rotating synchronously at 60 degrees. Although participants never physically moved, situational awareness of movability facilitated auditory vection. Moreover, adding slight vibrations like the ones resulting from actual chair rotation increased the frequency and intensity of vection. Experiment 2 extended these findings and showed that nonindividualized binaural recordings were as effective in inducing auditory circular vection as individualized recordings. These results have important implications both for our theoretical understanding of self-motion perception and for the applied field of self-motion simulations, where vibrations, non-individualized binaural sound, and the cognitive/perceptual framework of movability can typically be provided at minimal cost and effort

Moving Sounds Enhance the Visually-Induced Self-Motion Illusion (Circular Vection) in Virtual Reality

While rotating visual and auditory stimuli have long been known to elicit self-motion illusions (“circular vection”), audiovisual interactions have hardly been investigated. Here, two experiments investigated whether visually induced circular vection can be enhanced by concurrently rotating auditory cues that match visual landmarks (e.g., a fountain sound). Participants sat behind a curved projection screen displaying rotating panoramic renderings of a market place. Apart from a no-sound condition, headphone-based auditory stimuli consisted of mono sound, ambient sound, or low-/high-spatial resolution auralizations using generic head-related transfer functions (HRTFs). While merely adding nonrotating (mono or ambient) sound showed no effects, moving sound stimuli facilitated both vection and presence in the virtual environment. This spatialization benefit was maximal for a medium (20 degrees × 15 degrees) FOV, reduced for a larger (54 degrees × 45 degrees) FOV and unexpectedly absent for the smallest (10 degrees × 7.5 degrees) FOV. Increasing auralization spatial fidelity (from low, comparable to five-channel home theatre systems, to high, 5 degree resolution) provided no further benefit, suggesting a ceiling effect. In conclusion, both self-motion perception and presence can benefit from adding moving auditory stimuli. This has important implications both for multimodal cue integration theories and the applied challenge of building affordable yet effective motion simulators

THE ROLE OF HEAD MOVEMENTS IN SIMULATOR SICKNESS GENERATED BY A VIRTUAL ENVIRONMENT

Virtual environments (VEs) are being used in a variety of applications, including training, rehabilitation and clinical treatment. To effectively utilize VEs in these situations it is important to try to understand some of the effects of VE exposure. The purpose of this study was to investigate head and body movements in virtual and real environments during building clearing and the relationship between these movements and simulator sickness. The data for the current study were drawn from a larger team training study which investigated the use of VEs for training building clearing. The goal of the first part of this study was to compare head movements made in a real world (RW) environment to head movements made in a VE (Analysis I). The goal of second part of this study was to examine the relationship between head movements and simulator sickness in a VE (Analysis II). The first analysis used two independent samples t-tests to examine the differences between head movements made in a VE and head movements made in a RW environment. The t-tests showed that subjects in the VE moved their heads less, t(23.438)=12.690, p\u3c0.01, and less often, t(46)=8.682, p\u3c0.05, than subjects in the RW. In the second analysis, a 3 x 20 ANOVA found a significant difference between groups with low, med, and high simulator sickness scores, F(2,21)=4.221, p\u3c0.05, ήp2= 0.287, where subjects who reported being the most sick tended to restrict their head movements more than the other two groups. For VEs to progress as a useful tool, whether for training, therapy, etc., it will be necessary to identify the variable(s) that cause people to become motion sick and restrict their head movement during VE exposure. Future studies should seek to investigate more continuous measures of sickness, perhaps psychophysiological measures, and possible effects of a negative transfer of training due to the restriction of head movements in VEs

Perceptual compasses: spatial navigation in multisensory environments

Moving through space is a crucial activity in daily human life. The main objective of my Ph.D. project consisted of investigating how people exploit the multisensory sources of information available (vestibular, visual, auditory) to efficiently navigate. Specifically, my Ph.D. aimed at i) examining the multisensory integration mechanisms underlying spatial navigation; ii) establishing the crucial role of vestibular signals in spatial encoding and processing, and its interaction with environmental landmarks; iii) providing the neuroscientific basis to develop tailored assessment protocols and rehabilitation procedures to enhance orientation and mobility based on the integration of different sensory modalities, especially addressed to improve the compromised navigational performance of visually impaired (VI) people. To achieve these aims, we conducted behavioral experiments on adult participants, including psychophysics procedures, galvanic stimulation, and modeling. In particular, the experiments involved active spatial navigation tasks with audio-visual landmarks and selfmotion discrimination tasks with and without acoustic landmarks using a motion platform (Rotational-Translational Chair) and an acoustic virtual reality tool. Besides, we applied Galvanic Vestibular Stimulation to directly modulate signals coming from the vestibular system during behavioral tasks that involved interaction with audio-visual landmarks. In addition, when appropriate, we compared the obtained results with predictions coming from the Maximum Likelihood Estimation model, to verify the potential optimal integration between the available multisensory cues. i) Results on multisensory navigation showed a sub-group of integrators and another of non-integrators, revealing inter-individual differences in audio-visual processing while moving through the environment. Finding these idiosyncrasies in a homogeneous sample of adults emphasizes the role of individual perceptual characteristics in multisensory perception, highlighting how important it is to plan tailored rehabilitation protocols considering each individual’s perceptual preferences and experiences. ii) We also found a robust inherent overestimation bias when estimating passive self-motion stimuli. This finding shed new light on how our brain processes and elaborates the available cues building a more functional representation of the world. We also demonstrated a novel impact of the vestibular signals on the encoding of visual environmental cues without actual self-motion information. The role that vestibular inputs play in visual cues perception, and space encoding has multiple consequences on humans’ ability to functionally navigate in space and interact with environmental objects, especially when vestibular signals are impaired due to intrinsic (vestibular disorders) or environmental conditions (altered gravity, e.g. spaceflight missions). Finally, iii) the combination of the Rotational-Translational Chair and the acoustic virtual reality tool revealed a slight improvement in self-motion perception for VI people when exploiting acoustic cues. This approach shows to be a successful technique for evaluating audio-vestibular perception and improving spatial representation abilities of VI people, providing the basis to develop new rehabilitation procedures focused on multisensory perception. Overall, the findings resulting from my Ph.D. project broaden the scientific knowledge about spatial navigation in multisensory environments, yielding new insights into the exploration of the brain mechanisms associated with mobility, orientation, and locomotion abilities

Practical, appropriate, empirically-validated guidelines for designing educational games

There has recently been a great deal of interest in the potential of computer games to function as innovative educational tools. However, there is very little evidence of games fulfilling that potential. Indeed, the process of merging the disparate goals of education and games design appears problematic, and there are currently no practical guidelines for how to do so in a coherent manner. In this paper, we describe the successful, empirically validated teaching methods developed by behavioural psychologists and point out how they are uniquely suited to take advantage of the benefits that games offer to education. We conclude by proposing some practical steps for designing educational games, based on the techniques of Applied Behaviour Analysis. It is intended that this paper can both focus educational games designers on the features of games that are genuinely useful for education, and also introduce a successful form of teaching that this audience may not yet be familiar with

Proceedings of the 5th international conference on disability, virtual reality and associated technologies (ICDVRAT 2004)

The proceedings of the conferenc

Response surface methods applied to submarine concept exploration

CIVINS (Civilian Institutions) Thesis documentIt is estimated that 70 to 85 percent of a naval ship's life-cycle cost is determined during the concept exploration phase which places an importance in the methodology used by the designer to select the concept design. But trade-off studies are guided primarily by past experience, rules-of-thumb, and designer preference. This approach is ad hoc, not efficient and may not lead to an optimum concept design. Even worse, once the designer has a 'good' concept design, he has no process or methodology to determine whether a better concept design is possible or not. A methodology is required to search the design space for an optimal solution based on the specified preferences from the customer. But the difficulty is the design space, which is non-linear, discontinuous, and bounded by a variety of constraints, goals, and thresholds. Then the design process itself is difficult to optimize because of the coupling among decomposed engineering disciplines and sub-system interactions. These attributes prevent application of mature optimization techniques including Lagrange multipliers, steepest ascent methods, linear programming, non-linear programming, and dynamic programming. To further improve submarine concept exploration, this thesis examines a statistical technique called Response Surface Methods (RSM). The purpose of RSM is to lead to an understanding of the relationship between the input (factors) and Output (response) variables, often to further the optimization of the underlying process. The RSM approach allows the designers to find a local optimal and examine how the design factors affect the response in the region around the generated optimal point.http://archive.org/details/responsesurfacem1094510921CIVIN