Using visuo-kinetic virtual reality to induce illusory spinal movement: the MoOVi Illusion

BackgroundIllusions that alter perception of the body provide novel opportunities to target brain-based contributions to problems such as persistent pain. One example of this, mirror therapy, uses vision to augment perceived movement of a painful limb to treat pain. Since mirrors can’t be used to induce augmented neck or other spinal movement, we aimed to test whether such an illusion could be achieved using virtual reality, in advance of testing its potential therapeutic benefit. We hypothesised that perceived head rotation would depend on visually suggested movement.MethodIn a within-subjects repeated measures experiment, 24 healthy volunteers performed neck movements to 50oof rotation, while a virtual reality system delivered corresponding visual feedback that was offset by a factor of 50%–200%—the Motor Offset Visual Illusion (MoOVi)—thus simulating more or less movement than that actually occurring. At 50oof real-world head rotation, participants pointed in the direction that they perceived they were facing. The discrepancy between actual and perceived direction was measured and compared between conditions. The impact of including multisensory (auditory and visual) feedback, the presence of a virtual body reference, and the use of 360oimmersive virtual reality with and without three-dimensional properties, was also investigated.ResultsPerception of head movement was dependent on visual-kinaesthetic feedback (p = 0.001, partial eta squared = 0.17). That is, altered visual feedback caused a kinaesthetic drift in the direction of the visually suggested movement. The magnitude of the drift was not moderated by secondary variables such as the addition of illusory auditory feedback, the presence of a virtual body reference, or three-dimensionality of the scene.DiscussionVirtual reality can be used to augment perceived movement and body position, such that one can perform a small movement, yet perceive a large one. The MoOVi technique tested here has clear potential for assessment and therapy of people with spinal pain.

Download Full-text

The application of virtual reality and augmented reality in Oral & Maxillofacial Surgery

BMC Oral Health ◽

10.1186/s12903-019-0937-8 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 5

Author(s):

Ashraf Ayoub ◽

Yeshwanth Pulijala

Keyword(s):

Virtual Reality ◽

Augmented Reality ◽

Virtual Environment ◽

Orthognathic Surgery ◽

Maxillofacial Surgery ◽

The Body ◽

Historical Perspectives ◽

Virtual And Augmented Reality ◽

The Impact

Abstract Background Virtual reality is the science of creating a virtual environment for the assessment of various anatomical regions of the body for the diagnosis, planning and surgical training. Augmented reality is the superimposition of a 3D real environment specific to individual patient onto the surgical filed using semi-transparent glasses to augment the virtual scene.. The aim of this study is to provide an over view of the literature on the application of virtual and augmented reality in oral & maxillofacial surgery. Methods We reviewed the literature and the existing database using Ovid MEDLINE search, Cochran Library and PubMed. All the studies in the English literature in the last 10 years, from 2009 to 2019 were included. Results We identified 101 articles related the broad application of virtual reality in oral & maxillofacial surgery. These included the following: Eight systematic reviews, 4 expert reviews, 9 case reports, 5 retrospective surveys, 2 historical perspectives, 13 manuscripts on virtual education and training, 5 on haptic technology, 4 on augmented reality, 10 on image fusion, 41 articles on the prediction planning for orthognathic surgery and maxillofacial reconstruction. Dental implantology and orthognathic surgery are the most frequent applications of virtual reality and augmented reality. Virtual planning improved the accuracy of inserting dental implants using either a statistic guidance or dynamic navigation. In orthognathic surgery, prediction planning and intraoperative navigation are the main applications of virtual reality. Virtual reality has been utilised to improve the delivery of education and the quality of training in oral & maxillofacial surgery by creating a virtual environment of the surgical procedure. Haptic feedback provided an additional immersive reality to improve manual dexterity and improve clinical training. Conclusion Virtual and augmented reality have contributed to the planning of maxillofacial procedures and surgery training. Few articles highlighted the importance of this technology in improving the quality of patients’ care. There are limited prospective randomized studies comparing the impact of virtual reality with the standard methods in delivering oral surgery education.

Download Full-text

Comparing VR- and AR-Based Try-On Systems Using Personalized Avatars

Electronics ◽

10.3390/electronics9111814 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1814

Author(s):

Yuzhao Liu ◽

Yuhan Liu ◽

Shihui Xu ◽

Kelvin Cheng ◽

Soh Masuko ◽

...

Keyword(s):

Virtual Reality ◽

Augmented Reality ◽

Mobile Application ◽

User Study ◽

User Studies ◽

Apparel Shopping ◽

Shopping Experience ◽

Online Experience ◽

The Impact ◽

Virtual Body

Despite the convenience offered by e-commerce, online apparel shopping presents various product-related risks, as consumers can neither physically see nor try products on themselves. Augmented reality (AR) and virtual reality (VR) technologies have been used to improve the shopping online experience. Therefore, we propose an AR- and VR-based try-on system that provides users a novel shopping experience where they can view garments fitted onto their personalized virtual body. Recorded personalized motions are used to allow users to dynamically interact with their dressed virtual body in AR. We conducted two user studies to compare the different roles of VR- and AR-based try-ons and validate the impact of personalized motions on the virtual try-on experience. In the first user study, the mobile application with the AR- and VR-based try-on is compared to a traditional e-commerce interface. In the second user study, personalized avatars with pre-defined motion and personalized motion is compared to a personalized no-motion avatar with AR-based try-on. The result shows that AR- and VR-based try-ons can positively influence the shopping experience, compared with the traditional e-commerce interface. Overall, AR-based try-on provides a better and more realistic garment visualization than VR-based try-on. In addition, we found that personalized motions do not directly affect the user’s shopping experience.

Download Full-text

Can explicit visual feedback of postural sway efface the effects of sensory manipulations on mediolateral balance performance?

Journal of Neurophysiology ◽

10.1152/jn.00103.2014 ◽

2016 ◽

Vol 115 (2) ◽

pp. 907-914 ◽

Cited By ~ 13

Author(s):

L. Eduardo Cofré Lizama ◽

Mirjam Pijnappels ◽

N. Peter Reeves ◽

Sabine M. P. Verschueren ◽

Jaap H. van Dieën

Keyword(s):

Visual Feedback ◽

Repeated Measures ◽

Visual Information ◽

Postural Sway ◽

Center Of Mass ◽

The Body ◽

Body Center ◽

Explicit Feedback ◽

Dominant Frequencies ◽

Visual Conditions

Explicit visual feedback on postural sway is often used in balance assessment and training. However, up-weighting of visual information may mask impairments of other sensory systems. We therefore aimed to determine whether the effects of somatosensory, vestibular, and proprioceptive manipulations on mediolateral balance are reduced by explicit visual feedback on mediolateral sway of the body center of mass and by the presence of visual information. We manipulated sensory inputs of the somatosensory system by transcutaneous electric nerve stimulation on the feet soles (TENS) of the vestibular system by galvanic vestibular stimulation (GVS) and of the proprioceptive system by muscle-tendon vibration (VMS) of hip abductors. The effects of these manipulations on mediolateral sway were compared with a control condition without manipulation under three visual conditions: explicit feedback of sway of the body center of mass (FB), eyes open (EO), and eyes closed (EC). Mediolateral sway was quantified as the sum of energies in the power spectrum and as the energy at the dominant frequencies in each of the manipulation signals. Repeated-measures ANOVAs were used to test effects of each of the sensory manipulations, of visual conditions and their interaction. Overall, sensory manipulations increased body sway compared with the control conditions. Absence of normal visual information had no effect on sway, while explicit feedback reduced sway. Furthermore, interactions of visual information and sensory manipulation were found at specific dominant frequencies for GVS and VMS, with explicit feedback reducing the effects of the manipulations but not effacing these.

Download Full-text

Visual self-motion feedback affects the sense of self in virtual reality

10.1101/636944 ◽

2019 ◽

Author(s):

Aubrieann Schettler ◽

Ian Holstead ◽

John Turri ◽

Michael Barnett-Cowan

Keyword(s):

Body Image ◽

Virtual Reality ◽

Visual Feedback ◽

Sense Of Self ◽

Body Schema ◽

The Body ◽

The Self ◽

Top Down ◽

Biological Sex ◽

Self Motion

AbstractWe assessed how self-motion affects the visual representation of the self. We constructed a novel virtual reality experiment that systematically varied an avatar’s motion and also biological sex. Participants were presented with pairs of avatars that visually represented the participant (“self avatar”), or another person (“opposite avatar”). Avatar motion either corresponded with the participant’s motion, or was decoupled from the participant’s motion. The results show that participants identified with i) “self avatars” over “opposite avatars”, ii) avatars moving congruently with self-motion over incongruent motion, and importantly iii) identification with the “opposite avatar” over the “self avatar” when the opposite avatar’s motion was congruent with self-motion. Our results suggest that both self-motion and biological sex are relevant to the body schema and body image and that congruent bottom-up visual feedback of self-motion is particularly important for the sense of self and capable of overriding top-down self-identification factors such as biological sex.

Download Full-text

The Effect of Visuomotor Latency on Steering Behavior in Virtual Reality

Frontiers in Virtual Reality ◽

10.3389/frvir.2021.727858 ◽

2021 ◽

Vol 2 ◽

Author(s):

Pooya Rahimian ◽

Jodie M. Plumert ◽

Joseph K. Kearney

Keyword(s):

Virtual Reality ◽

Visual Feedback ◽

Computing Time ◽

Major Disruption ◽

A Minor ◽

Teleoperation Systems ◽

The Impact ◽

Work Supports ◽

User Actions ◽

Insight Into

Visual feedback latency in virtual reality systems is inherent due to the computing time it takes to simulate the effects of user actions. Depending upon the nature of interaction and amount of latency, the impact of this latency could range from a minor degradation to a major disruption of performance. The goal of this study was to examine how visuomotor latency impacts users’ performance in a continuous steering task and how users adapt to this latency with experience. The task involved steering a bike along an illuminated path in a dark environment viewed in an HTC Vive head-mounted virtual reality display. We examined how users adapt to visuomotor latency in two different conditions: 1) when the user controlled the steering while the bike moved forward at a constant speed, and 2) when the user controlled the steering and the speed of the bike through pedaling and braking. We found that users in both conditions started with a large steering error at the beginning of exposure to visuomotor latency but then quickly adapted to the delay. We also found that when users could control their speed, they adjusted their speed based on the complexity of the path (i.e., proximity to turns) and they gradually increased their speed as they adapted to latency and gained better control over their movement. The current work supports the idea that users can adapt to visual feedback delay in virtual reality regardless of whether they control the pace of movement. The results inform the design of virtual reality simulators and teleoperation systems and give insight into perceptual-motor adaptation in the presence of latency.

Download Full-text

Virtual-Reality-Induced Visual Perturbations Impact Postural Control System Behavior

Behavioral Sciences ◽

10.3390/bs9110113 ◽

2019 ◽

Vol 9 (11) ◽

pp. 113 ◽

Cited By ~ 4

Author(s):

Harish Chander ◽

Sachini N. K. Kodithuwakku Arachchige ◽

Christopher M. Hill ◽

Alana J. Turner ◽

Shuchisnigdha Deb ◽

...

Keyword(s):

Virtual Reality ◽

Control System ◽

Postural Control ◽

Repeated Measures ◽

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Postural Control System ◽

Postural Responses ◽

The Impact

Background: Virtual reality (VR) is becoming a widespread tool in rehabilitation, especially for postural stability. However, the impact of using VR in a “moving wall paradigm” (visual perturbation), specifically without and with anticipation of the perturbation, is unknown. Methods: Nineteen healthy subjects performed three trials of static balance testing on a force plate under three different conditions: baseline (no perturbation), unexpected VR perturbation, and expected VR perturbation. The statistical analysis consisted of a 1 × 3 repeated-measures ANOVA to test for differences in the center of pressure (COP) displacement, 95% ellipsoid area, and COP sway velocity. Results: The expected perturbation rendered significantly lower (p < 0.05) COP displacements and 95% ellipsoid area compared to the unexpected condition. A significantly higher (p < 0.05) sway velocity was also observed in the expected condition compared to the unexpected condition. Conclusions: Postural stability was lowered during unexpected visual perturbations compared to both during baseline and during expected visual perturbations, suggesting that conflicting visual feedback induced postural instability due to compensatory postural responses. However, during expected visual perturbations, significantly lowered postural sway displacement and area were achieved by increasing the sway velocity, suggesting the occurrence of postural behavior due to anticipatory postural responses. Finally, the study also concluded that VR could be used to induce different postural responses by providing visual perturbations to the postural control system, which can subsequently be used as an effective and low-cost tool for postural stability training and rehabilitation.

Download Full-text

When Does Virtual Embodiment Change Our Minds?

Presence Teleoperators & Virtual Environments ◽

10.1162/pres_a_00263 ◽

2016 ◽

Vol 25 (3) ◽

pp. 222-233 ◽

Cited By ~ 41

Author(s):

Jakki O. Bailey ◽

Jeremy N. Bailenson ◽

Daniel Casasanto

Keyword(s):

Virtual Reality ◽

Visual Feedback ◽

Arm Movements ◽

The Body ◽

Theory Testing ◽

Body Movements ◽

Sensory Experiences ◽

Left And Right ◽

Visual Motor ◽

Sensorimotor Feedback

Can an avatar’s body movements change a person’s perception of good and bad? We discuss virtual embodiment according to theories of embodied cognition (EC), and afferent and sensorimotor correspondences. We present an example study using virtual reality (VR) to test EC theory, testing the effect of altered virtual embodiment on perception. Participants either controlled an avatar whose arm movements were similar to their own or reflected the mirror opposite of their arm movements. We measured their associations of “good” and “bad” with the left and right (i.e., space-valence associations). This study demonstrated how VR could be used to examine the possible ways that systems of the body (e.g., visual, motor) may interact to influence cognition. The implications of this research suggest that visual feedback alone is not enough to alter space-valence associations. Multiple sensory experiences of media (i.e., sensorimotor feedback) may be necessary to influence cognition, not simply visual feedback.

Download Full-text

Impact of visuomotor feedback on the embodiment of virtual hands detached from the body

Scientific Reports ◽

10.1038/s41598-020-79255-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Sofia Seinfeld ◽

Jörg Müller

Keyword(s):

Motor Performance ◽

The Body ◽

Body Ownership ◽

Motor Tasks ◽

Person Perspective ◽

Skin Conductance Responses ◽

Contradictory Evidence ◽

The Impact ◽

Physiological Reactions ◽

Virtual Body

AbstractIt has been shown that mere observation of body discontinuity leads to diminished body ownership. However, the impact of body discontinuity has mainly been investigated in conditions where participants observe a collocated static virtual body from a first-person perspective. This study explores the influence of body discountinuity on the sense of embodiment, when rich visuomotor correlations between a real and an artificial virtual body are established. In two experiments, we evaluated body ownership and motor performance, when participants interacted in virtual reality either using virtual hands connected or disconnected from a body. We found that even under the presence of congruent visuomotor feedback, mere observation of body discontinuity resulted in diminished embodiment. Contradictory evidence was found in relation to motor performance, where further research is needed to understand the role of visual body discontinuity in motor tasks. Preliminary findings on physiological reactions to a threat were also assessed, indicating that body visual discontinuity does not differently impact threat-related skin conductance responses. The present results are in accordance with past evidence showing that body discontinuity negatively impacts embodiment. However, further research is needed to understand the influence of visuomotor feedback and body morphological congruency on motor performance and threat-related physiological reactions.

Download Full-text

User Experience and usability of a new virtual reality set-up to treat eating disorders: a pilot study

10.31234/osf.io/b38ym ◽

2020 ◽

Author(s):

Marta Matamala-Gomez ◽

Eleonora Brivio ◽

Alice CHIRICO ◽

Clelia Malighetti ◽

Olivia Realdon ◽

...

Keyword(s):

Virtual Reality ◽

Body Size ◽

Pilot Study ◽

User Experience ◽

Affective State ◽

The Body ◽

Long Term Memory ◽

Italian Women ◽

State Increase ◽

Virtual Body

Virtual Reality (VR) has progressively emerged as an effective tool for wellbeing and health in clinical populations. VR effectiveness has been tested before in Anorexia Nervosa (AN) with full-body illusion. It consists in the embodiment of patients with AN into a different virtual body to modify their long-term memory of the body as a crucial factor for the onset and maintenance of this disorder. We extended this protocol using the autobiographical recall emotion-induction technique, in which patients recall an emotional episode of their life related to their body. In this pilot study, we aimed to test the usability and User Experience (UX) of this VR-based protocol. Five Italian women with AN were embodied in a virtual body resembling their perceived body size from an ego- and an allocentric perspective while remembering episodes of their life related to their body. High levels of embodiment were reported while embodied in a virtual body resembling their real perceived body size for ownership (p<0.0001), agency (p=0.04), and self-location (p=0.023). Negative affective state increase after session 2 (p=0.012), and positive affective state increase after session 4 (p=0.006) (PANAS). However, further iteration of the VR system is needed to improve the user experience and usability of the system.

Download Full-text

Virtual Reality-Based Early Neurocognitive Stimulation in Critically Ill Patients: A Pilot Randomized Clinical Trial

Journal of Personalized Medicine ◽

10.3390/jpm11121260 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1260

Author(s):

Guillem Navarra-Ventura ◽

Gemma Gomà ◽

Candelaria de Haro ◽

Mercè Jodar ◽

Leonardo Sarlabous ◽

...

Keyword(s):

Working Memory ◽

Virtual Reality ◽

Critically Ill ◽

Outcome Measures ◽

Critically Ill Patients ◽

Repeated Measures ◽

Treatment As Usual ◽

Time Interaction ◽

Icu Discharge ◽

The Impact

This study focuses on the application of a non-immersive virtual reality (VR)-based neurocognitive intervention in critically ill patients. Our aim was to assess the feasibility of direct outcome measures to detect the impact of this digital therapy on patients’ cognitive and emotional outcomes. Seventy-two mechanically ventilated adult patients were randomly assigned to the “treatment as usual” (TAU, n = 38) or the “early neurocognitive stimulation” (ENRIC, n = 34) groups. All patients received standard intensive care unit (ICU) care. Patients in the ENRIC group also received adjuvant neurocognitive stimulation during the ICU stay. Outcome measures were a full neuropsychological battery and two mental health questionnaires. A total of 42 patients (21 ENRIC) completed assessment one month after ICU discharge, and 24 (10 ENRIC) one year later. At one-month follow-up, ENRIC patients had better working memory scores (p = 0.009, d = 0.363) and showed up to 50% less non-specific anxiety (11.8% vs. 21.1%) and depression (5.9% vs. 10.5%) than TAU patients. A general linear model of repeated measures reported a main effect of group, but not of time or group–time interaction, on working memory, with ENRIC patients outperforming TAU patients (p = 0.008, ηp2 = 0.282). Our results suggest that non-immersive VR-based neurocognitive stimulation may help improve short-term working memory outcomes in survivors of critical illness. Moreover, this advantage could be maintained in the long term. An efficacy trial in a larger sample of participants is feasible and must be conducted.

Download Full-text