Virtual Reality vs. Virtual Body: The Use of Virtual Environments in the Treatment of Body Experience Disturbances

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  • CyberPsychology & BehaviorVolume 1, Number 2, 1998Mary Ann Liebert, Inc.

    Virtual Reality vs. Virtual Body:The Use of Virtual Environments in the Treatment

    of Body Experience Disturbances

    GIUSEPPE RIVA, Ph.D.

    ABSTRACT)

    The disturbances of body image associated with the eating disorders can be considered as acomplex judgement bias strictly linked to attentional and memory biases for body related in-formation. This biased information processing occurs automatically, outside the person'sawareness, making these disturbances difficult to treat. Two different therapeutical ap-proaches are actually used: a visual/motorial therapy with the aim of influencing the level ofbodily awareness and a cognitive/behavioural therapy to influence patients' feelings of dis-satisfaction. This paper describes a virtual environment that integrate these two approacheswithin a virtual experience. This choice would not only make it possible to intervene simul-taneously on all of the forms of bodily representations, but also to use the psycho-physio-logical effects provoked on the body by the virtual experience for therapeutic purposes. Thepaper also present a study on a preliminary sample (48 normal subjects) to test the efficacyof the approach.

    INTRODUCTION

    VIRTUAL REALITY (VR) IS A MEDIUM that Sdefined in terms of its effects on basicperception and higher-order psychologicalprocesses.1 Steuer2 defines VR in terms of hu-man experience as "a real or simulated envi-ronment in which a perceiver experiencestelepresence". In fact, VR creates a sense of per-sonal presence by simulating as closely as pos-sible the range and intensity of stimuli that hu-man senses detect in perceiving the naturalworld. In immersion VR you know you are"there" because the virtual world respond, likethe real world to your body and head move-ments.1'2

    Applied Technology for Neuro-Psychology Lab IstitutoAuxologico Italiano, P.O. Box 1, 28044 Verbania, Italy.

    However, it is well known that the biases,distortions, time delays, and noises induced bythe virtual experience alter the human opera-tor's normal sensorimotor loops and affectbody perceptions, too. Such effects, attributableto the reorganisational and reconstructivemechanisms necessary to adapt the subjects tothe qualitatively distorted world of VR, couldbe of great help during the course of a therapyaimed at influencing the way the body is ex-perienced.This paper will describe the characteristics

    and preliminary evaluation of a battery of VRtasks to modify body image distortions andbody dissatisfaction associated with eating dis-orders. The battery was developed by the Eu-ropean Community funded VREPAR project(HC 1053) to support an in-patient eating dis-order treatment program.

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  • 130

    THE EXPERIENCE OF THE BODY

    We experience our bodies through a "virtualbody" composed by two multidimensionalcognitive constructs:3 the body schema and thebody image.According to Head,4 the body schema is a

    model/representation of one's own body thatconstitutes a standard against which posturesand body movements are judged. This repre-sentation can be considered the result of com-parisons and integration at the cortical level ofpast sensory experiences (postural, tactile, vi-sual, kinaesthetic and vestibular) with currentsensations. This gives rise to an almost com-pletely unconscious "plastic" reference modelthat makes it possible to move easily in spaceand to recognise the parts of one's own bodyin all situations.If the body schema can be considered a per-

    ceptual model of the body, the body image isa cognitive/social/emotional model. In fact,body image is not only a cognitive constructionbut also a reflection of wishes, emotional atti-tudes, and interactions with others. Accordingto Schilder,5 the body image can be defined as"the picture of our own body which we formin our mind, that is to say, the way in whichthe body appears to ourselves" (p. 11). Ex-panding on Schilder's idea, Allamani and Al-legranzi6 refer to body image as "a complexpsychological organisation which developsthrough the bodily experience of an individualand affects both the schema of behaviour anda fundamental nucleus of self-image" (p. 121).Gallagher3 analysed recent psychological

    studies on the relationship between body im-age and body schema. His report stated thatperformances of the body schema may placeconstraints on intentional consciousness. Morein particular, the studies indicated that changesin various aspects of body schema have an ef-fect on the way subjects perceive their ownbodies, that is, changes in body schema lead tochanges in body images. More generally,changes in body schema also affect spatial per-ception and perception of objects. They oper-ate as constraining and enabling factors thatlimit and define the possibilities of intentionalconsciousness.

    RIVA

    BODY EXPERIENCE AND EATINGDISORDERS

    Body experience disturbance has been usedby a wide variety of researchers and cliniciansto designate a great number of phenomenawith little or no overlapping characteristics.7For instance, the phrase has been used to referto phantom limb syndrome, neuropsychologi-cal deficits (anosognosia), and the psychody-namic concept of "body boundary."7 Thisarticle will focus exclusively on a physical ap-pearance related definition that is quitebroadbody experience disturbance is anyform of affective, cognitive, behavioural, orperceptual disturbance that is directly con-cerned with an aspect of physical appearance.Body experience has a long and storied as-

    sociation with eating- and weight-related prob-lems.711 Bruch12'13 articulated the integral roleof body experience in the development, main-tenance, and treatment of anorexia nervosa. Inlater years, researchers also agreed that bodyexperience was a central factor in bulimia ner-vosa.14'15 Finally, although often ignored as afeature of obesity (see ref. 7), Stunkard andBurt16 demonstrated almost 30 years ago theimportance of body experience to an under-standing of individuals with excessive weight.One index of the importance of body experi-

    ence disturbance involves its relevance toagreed-on clinical disorders. The Diagnosticand Statistical Manual of Mental Disorders IV14contains a body image criterion that is requiredfor the diagnosis of anorexia nervosa or bulimianervosa. It has also been suggested that, whenthere is psychological comorbidity with obe-sity, it may be strongly due to problematicbody experience issues.6 Today, researchersand clinicians agree that including an assess-ment and evaluation of body experience dis-turbance is crucial to any treatment programtargeting obesity or eating disorders.

    Some studies concerning the efficacy of thecognitive/behavioural treatment of anorexiahave indicated that patients who make a largeroverestimate of their own bodily dimensions17or who are more pleased with their own phys-ical appearance18 gain less weight after a pe-riod of treatment. Furthermore, among those

  • VIRTUAL REALITY VS. VIRTUAL BODY 131

    who manage to reach their target weight, post-treatment weight loss correlates directly withthe way in which patients perceive their ownsize.19Also in the treatment of bulimic subjects,

    body experience has been shown to play an im-portant role in assessing the outcome of treat-ment. In particular, the degree of satisfactionthat patients have in relation to their bodies hasbeen shown to be related both to a reductionin bulimic behaviour and to subsequent re-lapses.Probably, the disturbances of body image as-

    sociated with the eating disorders can be con-ceptualised as a type of cognitive bias.20~22Research on cognitive bias in psychiatric dis-orders has focused primarily upon depressionand anxiety disorders.23'24 In recent years, thistype of research has expanded to other formsof psychopathology, including the eating dis-orders.The essence of this cognitive perspective is

    that the central psychopathological concerns ofan individual bias the manner in which infor-mation is processed. In most cases, it is pre-sumed that this biased information processingoccurs automatically. Also, it is generally pre-sumed that the process occurs more or less out-side the person's awareness unless the personconsciously reflects upon his or her thoughtprocesses (as in cognitive therapy). Mineka andSutton24 have identified four common types ofcognitive bias in research related to depressionand anxiety disorders: attentional bias, mem-ory bias, judgmental bias, and associative bias.Three of these four types of cognitive bias havebeen the focus of research related to eating dis-orders: preoccupation with body size, bodydysphoria, and related problems.According to Williamson,21 body size over-

    estimation can be considered as a complexjudgement bias, strictly linked to attentionaland memory biases for body-related informa-tion: "If information related to body is selec-tively processed and recalled more easily, it isapparent how the self-schema becomes sohighly associated with body-related informa-tion. ... If the memories related to body arealso associated with negative emotion, activa-tion of negative emotion should sensitise the

    person to body-related stimuli causing evengreater body size overestimation" (pp. 49-50).

    USING VR FOR BODY IMAGETREATMENT

    In contrast to the great number of publica-tions on body image, only a few papers focuson the treatment of a disturbed body image ineating disorders.7 Although some general in-tervention programs for the treatment ofanorexia nervosa and bulimia nervosa have in-cluded a component that dealt with body im-age disturbances, in many of these treatments,this aspect of treatment has been virtually ig-nored. For example, in a review of cogni-tivebehavioral treatments of bulimia nervosa,Garner, Fairburn, and Davis25 cataloged 22treatment components of the 19 available treat-ment studies. The treatment of body image dis-turbance was not listed as one of the 22 inter-vention procedures. Rosen10 found that theoverwhelming majority of studies either failedto target body image dysfunction or failed tomeasure changes following treatment.In general, two direct and specific approaches

    can be distinguished:26 a cognitive/behaviouralapproach aimed at influencing patients' feelingsof dissatisfaction with different parts of theirbodies by means of individual interviews, re-laxation, and imaginative techniques,27"30 and avisual/motorial approach which makes use ofvideorecordings of particular gestures andmovementswith the aim of influencing the levelof bodily awareness.31An interesting possibility that we tried to

    address is the integration of the different meth-ods (cognitive, behavioural and visual-motor-ial) commonly used in the treatment of bodyexperience disturbances within a virtual envi-ronment.33'34 In particular, we tried to integratethe cognitive methods of Countering, Alterna-tive Interpretation, Label Shifting and Deacti-vating, the behavioural method of TemptationExposurewith Response Prevention and the vi-sual motorial approach using the virtual envi-ronment in the same way as images in thewell-known method of guided imagery.35 Ac-cording to this method, the therapist, after in-

  • 132 RIVA

    troducing a selected image, encourages the pa-tient to associate to it in pictures, rather than inword, and to give a detailed description ofthem.It's in Leuner's belief that the imagery evokes

    intense latent feelings that are relevant to thepatient's problems. Guided imagery has beenfound to be a powerful tool in treatment ap-proach, ranging from psychoanalytic therapy36to behaviourism.37 A choice of this type wouldnot only make it possible to evoke latent feel-ings, but also to use the psycho-physiologicaleffects provoked by the experience for thera-peutic purposes.

    THE VR EXPERIENCE

    In practically all VR systems, the human op-erator's normal sensorimotor loops is alteredby the presence of distortions, time delays, andnoise.38 Such alterations, which are introducedunintentionally and usually degrade perfor-mance, affect body perceptions, too. Thesomesthetic system has a proprioceptive sub-system that senses the body's internal state,such the position of limbs and joints and thetension of the muscles and tendons. Mis-matches between the signals from the proprio-ceptive system and the external signals of a vir-tual environments alter body perceptions andcan cause discomfort or simulator sickness.39It is also well known that key biases can dis-

    tort perception of the location and orientationof objects and surfaces in virtual environments.While virtual environment interfaces may beargued to be "natural" in principle, there aremany features that can disrupt or distort thenatural coupling of actual reaching and walk-ing, so as to create problems of stability anddisorientation, lessons that have been welllearned in the flight community.40,41 Five criti-cal issues relate to gain, time delay order,travel-view decoupling, and field of view.42In a recent study, Cioffi43 analysed these ef-

    fects and found that, in a VR, the self-percep-tion of one's own body undergoes profoundchanges that are similar to those achieved inthe 1960s by many psychologists in their stud-ies of perceptual distortion. In particular, about40% of the subjects felt as if they had "dema-

    terialised" or as if they were in the absence ofgravity; 44% of the men and 60% of the womenclaimed not to feel their bodies. Perceptual dis-tortions, leading to a few seconds of instabilityand a mild sense of confusion, were also ob-served in the period immediately following thevirtual experience.Such effects, attributable to the reorganisa-

    tional and reconstructive mechanisms neces-sary to adapt the subjects to the qualitativelydistorted world of VR, could be of great helpduring the course of a therapy aimed at influ-encing the way the body is experienced, be-cause they lead to a greater awareness of theperceptual and sensory/motorial processes as-sociated with them. When a particular event orstimulus violates the information present in thebody schema (as occurs during a virtual expe-rience), the information itself becomes accessi-ble at a conscious level.44 This facilitates theprocess of modification and, by means of themediation of the self (which tries to integrateand maintain the consistency of the differentrepresentations of the body), also makes it pos-sible to influence body image.In a preliminary uncontrolled study this ap-

    proach was tested on 72 normal subjects.3 * Theresults indicated that the virtual experience in-duced in the subjects a significantly more real-istic view of their body.

    SYSTEM DESIGN ANDIMPLEMENTATION

    Starting from the above rationale, theVREPAR project has developed the VirtualEnvironment for Body Image Modification

    -VEBIM.33 VEBIM is based on a Pentium-basedimmersive VR system (166 MHz, 32 Mb RAM,graphic engine: Matrox Millennium with 4MbWRAM) including an HMD subsystem withhead-tracking and a two-button joystick-typemotion input device.

    The display systemA head-mounted display, specially devel...

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