Virtual reality (VR) is increasingly gaining importance as a valuable methodical tool for psychological research. The greatest benefit of using VR is generating rich, complex and vivid, but still highly controllable settings. As VR has been found to elicit lifelike psychophysiological and emotional responses, we examined by means of a height exposure whether VR resembles physical reality to the necessary degree to constitute a suitable framework for investigating real-life behavior in a controlled experimental context. As hypothesized, participants behaved in VR exactly as would be appropriate in a real environment: Being exposed to great height, participants walked significantly slower across a virtual steel girder construction protruding from a high-rise building as compared to participants who traversed the very same construction on the ground level. In the height condition, this realistic behavior could be predicted on basis of the participants’ trait anxiety. Aligned with the behavioral responses, they showed realistic psychophysiological responses, i.e., an elevated heart rate when exposed to height. Interestingly, participants of the height condition reported a greater sense of presence, which indicates that emotions have an elevating effect on presence. As a conclusion, our findings provide further evidence that VR evokes lifelike responses at both behavioral and psychophysiological level and therefore increases ecological validity of psychological experiments.

Behavioral realism and lifelike psychophysiological responses in virtual reality by the example of a height exposure.

Virtual reality (VR) is a potentially promising tool for enhancing real-world locomotion in individuals with mobility impairment through its ability to provide personalized performance feedback and simulate real-world challenges. However, it is unknown whether novel locomotor skills learned in VR show sustained transfer to the real world. Here, as an initial step towards developing a VR-based clinical intervention, we study how young adults learn and transfer a treadmill-based virtual obstacle negotiation skill to the real world. On Day 1, participants crossed virtual obstacles while walking on a treadmill, with the instruction to minimize foot clearance during obstacle crossing. Gradual changes in performance during training were fit via non-linear mixed effect models. Immediate transfer was measured by foot clearance during physical obstacle crossing while walking over-ground. Retention of the obstacle negotiation skill in VR and retention of over-ground transfer were assessed after 24 h. On Day 1, participants systematically reduced foot clearance throughout practice by an average of 5 cm (SD 4 cm) and transferred 3 cm (SD 1 cm) of this reduction to over-ground walking. The acquired reduction in foot clearance was also retained after 24 h in VR and over-ground. There was only a small, but significant 0.8 cm increase in foot clearance in VR and no significant increase in clearance over-ground on Day 2. Moreover, individual differences in final performance at the end of practice on Day 1 predicted retention both in VR and in the real environment. Overall, our results support the use of VR for locomotor training as skills learned in a virtual environment readily transfer to real-world locomotion. Future work is needed to determine if VR-based locomotor training leads to sustained transfer in clinical populations with mobility impairments, such as individuals with Parkinson’s disease and stroke survivors.

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Locomotor skill acquisition in virtual reality shows sustained transfer to the real world

While multiple studies suggest that female-identified participants are more likely to experience cybersickness in virtual reality (VR), our systematic review of 71 eligible VR publications (59 studies and 12 surveys) pertaining to gender and cybersickness reveals a number of confounding factors in study design (e.g., a variety of technical specifications, tasks, content), a lack of demographic data, and a bias in participant recruitment. Our review shows an ongoing need within VR research to more consistently include and report on women’s experiences in VR to better understand the gendered possibility of cybersickness. Based on the gaps identified in our systematic review, we contribute study design recommendations for future work, arguing that gender considerations are necessary at every stage of VR study design, even when the study is not ‘about’ gender.

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You’re Making Me Sick: A Systematic Review of How Virtual Reality Research Considers Gender & Cybersickness

Fear is an evolutionary adaption to a hazardous environment, linked to numerous complex behavioral responses, e.g., the fight-or-flight response, suiting their respective environment. However, for the sake of experimental control, fear is mainly investigated under rather artificial laboratory conditions. The latter transform these evolutionary adaptions into artificial responses, like keystrokes. The immersive, multidimensional character of virtual reality (VR) enables realistic behavioral responses, overcoming aforementioned limitations. To investigate authentic fear responses from a holistic perspective, participants explored either a negative or a neutral VR cave. To promote real-life behavior, we built a physical replica of the cave, providing haptic sensations. Electrophysiological correlates of fear-related approach and avoidance tendencies, i.e., frontal alpha asymmetries (FAA) were evaluated. To our knowledge, this is the first study to simultaneously capture complex behavior and associated electrophysiological correlates under highly immersive conditions. Participants in the negative condition exhibited a broad spectrum of realistic fear behavior and reported intense negative affect as opposed to participants in the neutral condition. Despite these affective and behavioral differences, the groups could not be distinguished based on the FAAs for the greater part of the cave exploration. Taking the specific behavioral responses into account, the obtained FAAs could not be reconciled with well-known FAA models. Consequently, putting laboratory-based models to the test under realistic conditions shows that they may not unrestrictedly predict realistic behavior. As the VR environment facilitated non-mediated and realistic emotional and behavioral responses, our results demonstrate VR’s high potential to increase the ecological validity of scientific findings (video abstract: https://www.youtube.com/watch?v=qROsPOp87l4&feature=youtu.be ).

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Authentic Fear Responses in Virtual Reality: A Mobile EEG Study on Affective, Behavioral and Electrophysiological Correlates of Fear

Teleportation has become the de facto standard of locomotion in Virtual Reality (VR) environments. However, teleportation with parabolic and linear target aiming methods is restricted to horizontal 2D planes and it is unknown how they transfer to the 3D space. In this paper, we propose six 3D teleportation methods in virtual environments based on the combination of two existing aiming methods (linear and parabolic) and three types of transitioning to a target (instant, interpolated and continuous). To investigate the performance of the proposed teleportation methods, we conducted a controlled lab experiment (N = 24) with a mid-air coin collection task to assess accuracy, efficiency and VR sickness. We discovered that the linear aiming method leads to faster and more accurate target selection. Moreover, a combination of linear aiming and instant transitioning leads to the highest efficiency and accuracy without increasing VR sickness.

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SkyPort: Investigating 3D Teleportation Methods in Virtual Environments

Most virtual environments that people locomote through with head-mounted displays are flat to match the physical environment that people are actively walking on. In this paper we simulated stair climbing, and evaluated how well people could assess the distance they had climbed after several minutes of the activity under various conditions. We varied factors such as the presence of virtual feet (shoes), whether the stairwell was open or enclosed, the presence or absence of passive haptic markers, and whether a subject was ascending or descending. In general, the distance climbed or descended was overestimated, consistent with prior work on the perception of height. We find that subjects have significantly better ability to estimate their error with the presence of virtual shoes than without, and when the environment was open. Having shoes also resulted in significantly higher ratings of presence. We also find a significant tendency for females to show higher ratings of simulator sickness.

Noorin Suhaila Asjad

Papers

Perception of height in virtual reality: a study of climbing stairs