A New Realistic 3D Body Representation in Virtual Environments for the Treatment of Disturbed Body Image in Eating Disorders

Visualizing the Unseen: Illustrating and Documenting Phantom Limb Sensations and Phantom Limb Pain With C.A.L.A

Currently, there is neither a standardized mode for the documentation of phantom sensations and phantom limb pain, nor for their visualization as perceived by patients. We have therefore created a tool that allows for both, as well as for the quantification of the patient's visible and invisible body image. A first version provides the principal functions: (1) Adapting a 3D avatar for self-identification of the patient; (2) modeling the shape of the phantom limb; (3) adjusting the position of the phantom limb; (4) drawing pain and cramps directly onto the avatar; and (5) quantifying their respective intensities. Our tool (C.A.L.A.) was evaluated with 33 occupational therapists, physiotherapists, and other medical staff. Participants were presented with two cases in which the appearance and the position of the phantom had to be modeled and pain and cramps had to be drawn. The usability of the software was evaluated using the System Usability Scale and its functional range was evaluated using a self-developed questionnaire and semi-structured interview. In addition, our tool was evaluated on 22 patients with limb amputations. For each patient, body image as well as phantom sensation and pain were modeled to evaluate the software's functional scope. The accuracy of the created body image was evaluated using a self-developed questionnaire and semi-structured interview. Additionally, pain sensation was assessed using the SF-McGill Pain Questionnaire. The System Usability Scale reached a level of 81%, indicating high usability. Observing the participants, though, identified several operational difficulties. While the provided functions were considered useful by most participants, the semi-structured interviews revealed the need for an improved pain documentation component. In conclusion, our tool allows for an accurate visualization of phantom limbs and phantom limb sensations. It can be used as both a descriptive and quantitative documentation tool for analyzing and monitoring phantom limbs. Thus, it can help to bridge the gap between the therapist's conception and the patient's perception. Based on the collected requirements, an improved version with extended functionality will be developed.

Analyzing the Sociodemographic Factors Impacting the Use of Virtual Reality for Controlling Obesity

Obesity is one of the most pressing issues in society today. Virtual reality has been used in the design of tools that promotes obesity control. However, the design of current VR tools lacks the involvement of prospective users and health practitioners. Such engagement is crucial in gathering semantic information that identifies stakeholders’ needs and ensures that all aspects of health are considered. Therefore, this paper aims to study the sociodemographic factors and individual-level characteristics and preferences that make the design of any obesity-control VR tool effective and satisfactory for a wide range of users. The paper also aims to solicit opinions of health practitioners to identify best health aspects that should be available in the design of any VR tool for obesity control. Organizations, businesses, and people will be able to readily augment such VR technologies on the semantic web, as well as on personal and mobile devices.

Distortions of perceived volume and length of body parts

We experience our body as a 3D, volumetric object in the world. Measures of our conscious body image, in contrast, have investigated the perception of body size along one or two dimensions at a time. There is, thus, a discrepancy between existing methods for measuring body image and our subjective experience of having 3D body. Here we assessed in a sample of healthy adults the perception of body size in terms of its 1D length and 3D volume. Participants were randomly assigned to two groups using different measuring units (other body part and non-body object). They estimated how many units would fit in a perceived size of body segments and the whole body. The patterns of length and volume misperception across judged segments were determined as their perceived size proportional to their actual size. The pattern of volume misperception paints the representation of 3D body proportions resembling those of a somatosensory homunculus. The body parts with a smaller actual surface area relative to their volume were underestimated more. There was a tendency for body parts underestimated in volume to be overestimated in length. Perceived body proportions thus changed as a function of judgement type while showing a similarity in magnitude of the absolute estimation error, be it an underestimation of volume or overestimation of length. The main contribution of this study is assessing the body image as a 3D body representation, and thus extending beyond the conventional 'allocentric' focus to include the body on the inside. Our findings highlight the value of studying the perceptual distortions "at the baseline", i.e., in healthy population, so as to advance the understanding of the nature of perceptual distortions in clinical conditions.

Using psychophysical tools to quantify body image perception: a tutorial

ABSTRACT This article presents a tutorial about two protocols that can be used to measure an individual's perception of body image, direct and indirect , and which follow S.S. ( Stevens 1951) methods. Two psychophysical task approaches illustrate the ability of individuals to quantify body image distortions. We selected psychophysical tasks that indirectly assess a participant's behavioral component of body image (i.e., satisfaction tendencies about body image); and second, the cognitive component of body image (i.e., individuals' perceptual accuracy in magnitude estimation tasks, which depend on a familiarity with interval scales and the use of numbers and ratios to represent physical dimensions of stimuli). We determined individuals' perceptual sensitivity (i.e., his or her perceptual style ) to manipulations of the body's size by using Stevens' power function ( Stevens, 1951).

The key to unlocking the virtual body: virtual reality in the treatment of obesity and eating disorders

Obesity and eating disorders are usually considered unrelated problems with different causes. However, various studies identify unhealthful weight-control behaviors (fasting, vomiting, or laxative abuse), induced by a negative experience of the body, as the common antecedents of both obesity and eating disorders. But how might negative body image--common to most adolescents, not only to medical patients--be behind the development of obesity and eating disorders? In this paper, I review the "allocentric lock theory" of negative body image as the possible antecedent of both obesity and eating disorders. Evidence from psychology and neuroscience indicates that our bodily experience involves the integration of different sensory inputs within two different reference frames: egocentric (first-person experience) and allocentric (third-person experience). Even though functional relations between these two frames are usually limited, they influence each other during the interaction between long- and short-term memory processes in spatial cognition. If this process is impaired either through exogenous (e.g., stress) or endogenous causes, the egocentric sensory inputs are unable to update the contents of the stored allocentric representation of the body. In other words, these patients are locked in an allocentric (observer view) negative image of their body, which their sensory inputs are no longer able to update even after a demanding diet and a significant weight loss. This article discusses the possible role of virtual reality in addressing this problem within an integrated treatment approach based on the allocentric lock theory.

A program for assessing body image disturbance using adjustable partial image distortion

Body image disturbance has been one of the most widely studied areas in the literature on eating disorders. Some of the tasks designed to assess it have been used to estimate the sizes of specific parts of the body, whereas others have served to make estimations of overall body size. In recent years, the introduction of innovative computing procedures has allowed the two approaches to be combined and has made their application more straightforward. The program we describe here (Body Image Assessment Software, or BIAS) evaluates body image distortions and body dissatisfaction via the on-screen presentation of a scale image, the different components of which can be modified by the patient. The program was developed using Microsoft Access 2000 and Visual Basic for applications. It can be run on any computer with Windows and Microsoft Access 2000 or Microsoft Access 2000 RunTime, which makes it particularly easy to use and enables direct analysis of the recorded data through the use of applications such as SPSS.

Klinische Cyberpsychologie: Die Anwendung virtueller Realitäten in der psychologischen Diagnostik und Behandlung

Zusammenfassung. Theoretischer Hintergrund und Fragestellung: Eine von Jahr zu Jahr steigende Anzahl von Publikationen signalisiert die Entstehung eines neuen Gebiets der Klinischen Psychologie, das man “Klinische Cyberpsychologie“ nennen könnte. Die vorliegende Arbeit versucht vor allem einen Überblick über die neuesten Ergebnisse der Anwendung “virtueller Realitäten“ (VR) in der psychologischen Diagnostik und Behandlung zu geben. Methode: Es wurden drei Ansätze unterschieden: a) Die E-Therapie, b) die VR-Therapie und c) die VR-Teletherapie. Diese Dreiteilung gilt im Wesentlichen auch für den Bereich der Diagnostik, Beratung und Rehabilitation. Ergebnisse und Schlussfolgerungen: Mit Hilfe computergenerierter virtueller Szenarien kann eine wirklichkeitsnahe Reizmodellierung vorgenommen werden, die nicht nur eine gut kontrollierbare Reizdarbietung ermöglicht, sondern darüber hinaus auch eine interaktive Gestaltung zulässt. Dies gibt Anlass zur Hoffnung, dass durch den gezielten Einsatz virtueller Systeme die psychologische Diagnostik und Behandlung wesentlich verbessert werden kann.

The use of alternative delivery systems and new technologies in the treatment of patients with eating disorders

OBJECTIVE

The purpose of the current article is to review the literature regarding the use of alternative delivery systems, such as telemedicine, and new technologies, such as the use of hand-held computers, in the treatment of patients with eating disorders.

METHOD

The literature is reviewed in the following areas: self-help (supervised and unsupervised), telemedicine, telephone therapy, e-mail, internet, computer software, CD-ROMs, portable computers, and virtual reality techniques.

RESULTS

A growing literature suggests a number of alternative delivery systems hold promise, in particular permitting patients to access services who otherwise would not be able to receive treatment. Although most of these areas are early in their development, a growing literature supports the utility of several of these approaches.

DISCUSSION

Although the literature in this area is limited, and the research base is small, a number of these technologies appear to hold substantial promise for the treatment of patients with eating disorders.

Avatars in clinical psychology: a framework for the clinical use of virtual humans

Early applications of virtual reality (VR) technology in psychological assessment, treatment, and research have yielded promising results. In particular, an increasing number of studies analyze the unique features of the experience made by patients during their exposure to virtual environments. However, the majority of these studies explore how patients navigate in the virtual spaces and interact with virtual objects. Only a few of them investigate the features of inhabited virtual environments, where real people and autonomous virtual humans are able to interact and to cooperate. In particular, there is a lack of discussion of the role that such autonomous virtual humans could have in VR-aided psychotherapy. The main goal of this paper is to identify a framework for future research in this area. Three levels of analysis are identified. The purpose of the first two levels is the identification of the key "physical" features (e.g., appearance, structure) and "internal" characteristics (e.g., behavior, degree of autonomy, perceptual capabilities) needed by an effective simulation. The third level is concerned with the evaluation of the interaction characteristics required for a successful relationship between the patient and the virtual human.