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BACKGROUND The current use of Virtual Reality (VR) interventions, based on Cognitive Behavioral Therapy principles, has been proven effective as an additional component to standard psychological therapy for obesity. These interventions... more
BACKGROUND The current use of Virtual Reality (VR) interventions, based on Cognitive Behavioral Therapy principles, has been proven effective as an additional component to standard psychological therapy for obesity. These interventions successfully promote healthy behaviors and address negative body image concerns. However, they have not fully addressed certain underlying causes of obesity, such as lack of motivation to change, low self-efficacy, and internalized weight stigma, which often impede treatment adherence and long-term lifestyle habit changes. To tackle these concerns, the present study introduces the VR self-counseling paradigm, which incorporates embodiment and body-swapping techniques, along with motivational strategies, to help people with obesity effectively address some of the root causes of their condition. OBJECTIVE To assess the clinical efficacy of ConVRself, a VR platform that allows participants to engage in motivational self-conversations. METHODS A randomize...
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IntroductionWe aim to examine the usability of a Virtual Reality (VR) platform, called ConVRSelf, which has been designed to address the needs of People Living With Obesity (PLWO).MethodsFourteen participants with a desire to eat... more
IntroductionWe aim to examine the usability of a Virtual Reality (VR) platform, called ConVRSelf, which has been designed to address the needs of People Living With Obesity (PLWO).MethodsFourteen participants with a desire to eat healthier and exercise more (6 normal weight and 8 PLWO; Mean age = 41.86, SD = 13.89) were assigned to the experimental group (EG) or the control group (CG). EG participants, after being trained on motivational interviewing skills, engaged in a virtual self-conversation using embodiment and body swapping techniques, which aimed to normalize and resolve their ambivalence to change lifestyle habits. CG participants, embodied in their virtual bodies, participated in a pre-established discourse with a virtual counselor giving them psychoeducational advice about how to change lifestyle habits. A mixed-methods design was used, involving a semi-structured interview and self-report questionnaires, including readiness to change habits (Readiness Rulers), body owner...
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IntroductionPrevious research has shown that it is feasible to integrate motivational interviewing techniques with behavioural and psychological interventions for the treatment of obesity. Moreover, these combined interventions have the... more
IntroductionPrevious research has shown that it is feasible to integrate motivational interviewing techniques with behavioural and psychological interventions for the treatment of obesity. Moreover, these combined interventions have the potential to improve health-related outcomes of people living with obesity (PLWO) and to afford maintenance of behavioural changes over time. In addition, the use of virtual reality (VR) embodiment techniques in the treatment of eating disorders and obesity has promising preliminary effectiveness. The objective of this study is to assess the clinical efficacy of a VR intervention that uses embodiment and body-swapping techniques and has been specifically developed to cover the needs of PLWO.Methods and analysisA randomised control trial will be carried out with an estimated sample of 96 participants with body mass index (BMI)>30. The whole duration of the trial will be 12 months. Participants will be recruited from the external consultations of th...
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Research Interests: Psychology, Social Psychology, Embodied Cognition, Intergroup Relations, Racism, and 15 moreMedicine, Multidisciplinary, Empathy, Virtual Reality, Humans, Race relations, Female, Young Adult, Interpersonal Relations, Mimicry, PLoS one, African Americans, Middle Aged, Adult, and European Continental Ancestry Group
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This thesis describes methods for modelling and visualising fabrics and garments on human body shapes by means of computer systems. The focus is on automatic real-time simulation but, at the same time, realistic appearance of garments is... more
This thesis describes methods for modelling and visualising fabrics and garments on human body shapes by means of computer systems. The focus is on automatic real-time simulation but, at the same time, realistic appearance of garments is important. Very high physical accuracy in the simulation of mechanical properties of cloth is relaxed, however. We first introduce an image-based collision detection (IBCD) mechanism which harnesses the rasterisation, depth buffer and interpolation units of existing graphics hardware for robust and efficient collision detection and response between body-scan and garment surfaces. We introduce directional velocity modification (DVM), a numerical method to overcome a phenomenon called super-elasticity of conventional mass spring particle systems (MSPS). A reverse engineering technique is presented that enables us to extract assembly information and data for realistic visualisation from photographs of real garments. The images used in this technique are acquired in a set-up that includes a high resolution digital imaging device. Body landmark data is used automatically to pre-position garment panels around a body-scan before virtual sewing. We show that DVM generates visually pleasing garments on static and animated body-scans. The efficiency of the IBCD is demonstrated by a comparison with a traditional geometry based method. A system that exploits the developed techniques was created for Bodymetrics Ltd., at their request. This system is integrated with a 3D whole body scanner for fully automatic virtual try-on of clothes in a department store. The system presents a world first installation and was reported in several newspapers and fashion magazines. While it demonstrates the efficiency and robustness of the developed methods, clothes shoppers can benefit in that the system gives quicker fit-feedback than a traditional mirror in a changing room and can display their dressed body from any angle and distance. In collaboration with a garment designer we also tested the system in a design scenario. In an evaluation of the commercial potential of the developed methods the major players in markets closely related to virtual try-on technology are identified and market entry strategies are discussed.
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This article presents a solution for the rendering of immersive VR using real-time global illumination. One of the important reasons for using VR in an application is that participants should respond realistically to virtual objects and... more
This article presents a solution for the rendering of immersive VR using real-time global illumination. One of the important reasons for using VR in an application is that participants should respond realistically to virtual objects and events—for example, in applications concerned with training or rehabilitation. Therefore, investigating the factors that might be critical in producing such realistic responses is an important area of scientific investigation, with implications for the engineering of successful VR applications. 1 An obvious factor to consider is the realism of the illumination. While a static globally illuminated
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... 4. Collision detection Collision detection is one of the crucial parts in fast cloth simulation. ... Using this technique it is possible to find a collision only by comparing the depth value of the garment point with the according... more
... 4. Collision detection Collision detection is one of the crucial parts in fast cloth simulation. ... Using this technique it is possible to find a collision only by comparing the depth value of the garment point with the according depth information of the body stored in the depth maps. ...
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Research Interests: Information Systems, Psychophysics, Computer Science, Human Computer Interaction, Immersive Virtual Learning Environment, and 11 moreVirtual Reality, Virtual Environment, Illusion, Virtual Machine, Avatar, Frequency Response Function, Markov chain, Field of View, Head Mounted Display, Optical Head Mounted Display, and Higher order
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In this paper we present a system for rendering with real-time global illumination in virtual reality (VR). We describe the virtual light field rendering algorithm and show how it is suitable for real-time VR applications and describe how... more
In this paper we present a system for rendering with real-time global illumination in virtual reality (VR). We describe the virtual light field rendering algorithm and show how it is suitable for real-time VR applications and describe how it is integrated with the XVR sys-tem for real-time GPU-based rendering in a CAVETM. This render-ing method achieves real-time rendering of L(S|D)∗E solutions in time independent of illumination complexity and largely indepen-dent of geometric complexity. The method also supports dynamic changes to scene elements, such as a virtual character that moves through the scene with appropriate shadows and reflections.
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This paper describes a fast technique for dressing virtual humans with different pieces of clothing. It exploits a mass-spring cloth model but applies a new velocity modification approach to overcome its super-elasticity. The algorithm... more
This paper describes a fast technique for dressing virtual humans with different pieces of clothing. It exploits a mass-spring cloth model but applies a new velocity modification approach to overcome its super-elasticity. The algorithm for cloth-body collision detection and response is based on image-space interference tests, unlike most of the existing ones, which use objectspace checks. The modern workstations ’ graphics hardware is used not only to compute the depth maps of the body contours but also to interpolate the body normal vectors. As a result the approach is very fast and makes it possible to sew a garment around a virtual human body in about a second.
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Abstract: This paper describes a technique for cloth-body collision detection applicable to simulation of apparel on walking humans. It is based on image-space interference tests but employs a new approach with layers of depth maps to... more
Abstract: This paper describes a technique for cloth-body collision detection applicable to simulation of apparel on walking humans. It is based on image-space interference tests but employs a new approach with layers of depth maps to resolve the problem arising from overlapping body parts. The modern workstations ’ graphics hardware is used to generate the depth maps of the body as well as to interpolate the normal vectors and velocities of each body vertex. The latter information is necessary for proper collision response. Images showing the result of applying this technique are given at the end of the paper.
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When people see a life-sized virtual body (VB) from first person perspective in virtual reality they are likely to have the perceptual illusion that it is their body. Additionally such virtual embodiment can lead to changes in perception,... more
When people see a life-sized virtual body (VB) from first person perspective in virtual reality they are likely to have the perceptual illusion that it is their body. Additionally such virtual embodiment can lead to changes in perception, implicit attitudes and behaviour based on attributes of the VB. To date the changes that have been studied are as a result of being embodied in a body representative of particular social groups (e.g., children and other race). In our experiment participants alternately switched between a VB closely resembling themselves where they described a personal problem, and a VB representing Dr Sigmund Freud, from which they offered themselves counselling. Here we show that when the counsellor resembles Freud participants improve their mood, compared to the counsellor being a self-representation. The improvement was greater when the Freud VB moved synchronously with the participant, compared to asynchronously. Synchronous VB movement was associated with a mu...
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Consumer 3D scanners and depth cameras are increasingly being used to generate content and avatars for Virtual Reality (VR) environments and avoid the inconveniences of hand modeling; however, it is sometimes difficult to evaluate... more
Consumer 3D scanners and depth cameras are increasingly being used to generate content and avatars for Virtual Reality (VR) environments and avoid the inconveniences of hand modeling; however, it is sometimes difficult to evaluate quantitatively the mesh quality at which 3D scans should be exported, and whether the object perception might be affected by its shading. We propose using a paired-comparisons test based on psychophysics of perception to do that evaluation. As psychophysics is not subject to opinion, skill level, mental state, or economic situation it can be considered a quantitative way to measure how people perceive the mesh quality. In particular, we propose using the psychophysical measure for the comparison of four different levels of mesh quality (1K, 5K, 10K and 20K triangles). We present two studies within subjects: in one we investigate the quality perception variations of seeing an object in a regular screen monitor against an stereoscopic Head Mounted Display (H...
This thesis describes methods for modelling and visualising fabrics and garments on human body shapes by means of computer systems. The focus is on automatic real-time simulation but, at the same time, realistic appearance of garments is... more
This thesis describes methods for modelling and visualising fabrics and garments on human body shapes by means of computer systems. The focus is on automatic real-time simulation but, at the same time, realistic appearance of garments is important. Very high physical accuracy in the simulation of mechanical properties of cloth is relaxed, however. We first introduce an image-based collision detection (IBCD) mechanism which harnesses the rasterisation, depth buffer and interpolation units of existing graphics hardware for robust and efficient collision detection and response between body-scan and garment surfaces. We introduce directional velocity modification (DVM), a numerical method to overcome a phenomenon called super-elasticity of conventional mass spring particle systems (MSPS). A reverse engineering technique is presented that enables us to extract assembly information and data for realistic visualisation from photographs of real garments. The images used in this technique ar...
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This paper describes a technique for garment simulation and collision detection implemented on modern Graphics Processors (GPU). It exploits a mass-spring cloth model with velocity modification approach to overcome the super-elasticity.... more
This paper describes a technique for garment simulation and collision detection implemented on modern Graphics Processors (GPU). It exploits a mass-spring cloth model with velocity modification approach to overcome the super-elasticity. Our novel algorithms for cloth-body and cloth-cloth collision detection and response are based on image-space interference tests. For collision detection a 3D texture is generated, in which each slice represents depth and normal information for collision detection and response. These algorithms were implemented to build a fast web-based virtual try-on system. Our simulation starts from flat garment pattern meshes and performs the entire seaming and cloth draping simulation on the GPU. By mapping cloth properties of real fabric measurements we are able to approximate the real drape behaviour of different types of fabric, taking into account different warp and weft fabric drape properties. As the results section shows the average time of dressing a vir...
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This paper describes the makings of an experiment to test various hypotheses relating to how and under what conditions people would respond to a virtual fire occurring within a social setting. An analogy is drawn with making a movie, and... more
This paper describes the makings of an experiment to test various hypotheses relating to how and under what conditions people would respond to a virtual fire occurring within a social setting. An analogy is drawn with making a movie, and all the steps involved, from the specification of the hypotheses through to a full analysis of one participant are presented. Some conclusions are drawn about presence.
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Research Interests: Psychology and Medicine
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There is an alarming level of violence by police in the US towards African Americans. Although this may be rooted in explicit racial bias, the more intractable problem is overcoming implicit bias, bias that is non-conscious but... more
There is an alarming level of violence by police in the US towards African Americans. Although this may be rooted in explicit racial bias, the more intractable problem is overcoming implicit bias, bias that is non-conscious but demonstrated in actual behavior. If bias is implicit, it is difficult to change through explicit methods that attempt to change attitudes. We carried out a study using virtual reality (VR) with 38 officers in a US police department, who took part in an interrogation of an African American suspect alongside an officer who was racially abusive towards the suspect. Seventeen of the participants witnessed the interview again from a third person perspective (Observer) and 21 from the embodied perspective of the suspect, now a victim of the interrogation (Victim condition), having been assigned randomly to these two groups. Some weeks later, all witnessed aggression by an officer towards an African American man in a virtual cafe scenario. The results show that the ...
Agency is the attribution of an action to the self and is a prerequisite for experiencing responsibility over its consequences. Here we investigated agency and responsibility by studying the control of movements of an embodied avatar, via... more
Agency is the attribution of an action to the self and is a prerequisite for experiencing responsibility over its consequences. Here we investigated agency and responsibility by studying the control of movements of an embodied avatar, via brain computer interface (BCI) technology, in immersive virtual reality. After induction of virtual body ownership by visuomotor correlations, healthy participants performed a motor task with their virtual body. We compared the passive observation of the subject's 'own' virtual arm performing the task with (1) the control of the movement through activation of sensorimotor areas (motor imagery) and (2) the control of the movement through activation of visual areas (steady-state visually evoked potentials). The latter two conditions were carried out using a brain-computer interface (BCI) and both shared the intention and the resulting action. We found that BCI-control of movements engenders the sense of agency, which is strongest for sens...
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People generally show greater preference for members of their own racial group compared to racial out-group members. This type of 'in-group bias' is evident in mimicry behaviors. We tend to automatically mimic the behaviors of... more
People generally show greater preference for members of their own racial group compared to racial out-group members. This type of 'in-group bias' is evident in mimicry behaviors. We tend to automatically mimic the behaviors of in-group members, and this behavior is associated with interpersonal sensitivity and empathy. However, mimicry is reduced when interacting with out-group members. Although race is considered an unchangeable trait, it is possible using embodiment in immersive virtual reality to engender the illusion in people of having a body of a different race. Previous research has used this technique to show that after a short period of embodiment of White people in a Black virtual body their implicit racial bias against Black people diminishes. Here we show that this technique powerfully enhances mimicry. We carried out an experiment with 32 White (Caucasian) female participants. Half were embodied in a White virtual body and the remainder in a Black virtual body. ...
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Functional imaging studies have implicated the hippocampus and parahippocampal gyrus in cue-guided spatial navigation, but also many other regions. Furthermore, little is known about de-activations that take place during performance of... more
Functional imaging studies have implicated the hippocampus and parahippocampal gyrus in cue-guided spatial navigation, but also many other regions. Furthermore, little is known about de-activations that take place during performance of navigation tasks, something that is of interest given that the hippocampus is a component of the default mode network, which de-activates during attention-demanding tasks. In this study 22 healthy subjects underwent whole-brain functional Magnetic Resonance Imaging (fMRI) while they navigated toward a previously learned goal in a virtual reality environment. At a threshold of p<0.05 corrected, the subjects showed a pattern of widespread cortical activations, including the parahippocampal and retrosplenial cortex and also parts of the frontal, temporal and occipital cortex. Hippocampal activation, however, was restricted to the posterior portion of the structure bilaterally. De-activations were seen in the medial frontal cortex and other regions of ...
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... Bernhard Spanlang1, Torsten Fröhlich1, Vanessa F. Descalzo2, Angus Antley3 and Mel Slater3,4 ... running several different scenarios, in some of which the characters are non-responsive and others in which they were for here again,... more
... Bernhard Spanlang1, Torsten Fröhlich1, Vanessa F. Descalzo2, Angus Antley3 and Mel Slater3,4 ... running several different scenarios, in some of which the characters are non-responsive and others in which they were for here again, the participants could easily guess what it ...
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Structural pathology in the hippocampus is well-documented in schizophrenia, but brain functional changes have not been consistently found. We used spatial navigation in a virtual reality environment, a task that is known to produce... more
Structural pathology in the hippocampus is well-documented in schizophrenia, but brain functional changes have not been consistently found. We used spatial navigation in a virtual reality environment, a task that is known to produce robust hippocampal activation in healthy subjects, to examine task-related activations and de-activations in the disorder. Twenty-seven DSM IV schizophrenia patients and 32 healthy controls underwent fMRI while they navigated to a goal through a virtual reality town. Activations and de-activations were examined at the whole brain level and also using a region-of-interest (ROI) in the hippocampus. Spatial navigation was associated with activation in the posterior hippocampus and parahippocampal gyrus plus widespread neocortical areas. The patients showed reduced activation compared to the controls in the left dorsolateral prefrontal cortex (DLPFC) and the left occipital/temporal cortex. No differences in hippocampal activation were seen either at the whole-brain level or in the ROI analysis. The patients showed failure of de-activation affecting some but not all subregions of the default mode network. Schizophrenia is associated with task-related hypoactivation in the DLPFC during spatial navigation, but not with functional changes in the hippocampus. The failure of de-activation also found adds to evidence for default mode network dysfunction in the disorder.