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.
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.
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.
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.
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-
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 developed
by Virtual.sys of Milan, Italy, was used. TheHMD displays 624 lines of 210 pixel to each eye(52 H and 41 V field of view) and uses LCD
VIRTUAL REALITY VS. VIRTUAL BODY 133
technology (two active matrix colour LCDs). ALogitech 3D Mouse provided head tracking.In VEBIM we did not use a stereoscopic dis-
play. Previous researchers regard stereoscopyas important because it provides the user witha good cue of depth.45 However, the refreshrate of graphics decrease by 50% for the needof two different images for each eye. Conse-quently, we decided against implementing astereoscopic display. To compensate for thelack of depth cue, we included perspective cues(light and shade, relative size, textural gradi-ent, interposition and motion parallax) in thevirtual environment.
Motion input systemThe data glove-type motion input device is
very common in virtual environments for itsability of sensing many degrees of freedom si-multaneously. However, the operator is alsofrequently confused for the difficulty in cor-rectly using it, especially when there is a timedelay contained in the feed-back loop.To provide an easy way ofmotion in VEBIM,
we used a two-button joystick-type input de-vice: pressing the upper button the operatormoves forward, pressing the lower button theoperator moves backward. The direction of themovement is given by the rotation of operator'shead.
The virtual environmentVEBIM is a five-zone virtual environment
developed using the Sense 8 World ToolKit forWindows (V. 2.02). VEBIM consists of twoparts (zones 1-2 and zones 3-4-5).The first two zones are designed both to give
the subject a minimum level of skill in per-ceiving, moving through and manipulating ob-jects in VR, and to focus attention on eating andfood choice. The two environments can also beused by the therapist for a comprehensive as-sessment of stimuli that could elicit abnormaleating behaviour. This assessment is normallypart of the Temptation Exposure with Re-sponse Prevention protocol. The next threezones are designed to modify the body experi-ence of the subject. To do this, the virtual en-vironment integrated the therapeutic methodsused by Butters and Cash27 and Wooley and
Wooley.31 In particular in VEBIM we used thevirtual environment in the same way as guidedimagery35 is used in the cognitive and vi-sual/motorial approach.To assess the body image, at the beginning
and at the end of the virtual experience eachsubject is submitted to the BIVRS
Virtual Reality Scale.34'36 BIVRS is a three-partvirtual environments in which the user have tochoose from seven figures of different sizewhich vary from underweight to overweight(this version of VEBIM was developed to beused exclusively by female subjects; so, all theimages showed in BIVRS are female silhouettesonly. Subjects are asked to choose the figuresthat they think reflect their current and theirideal body sizes. The discrepancy betweenthese two measures is an indication of theirlevel of dissatisfaction. In the first two zones(one for real body and one for ideal body), thesubject chooses from seven 2D images that areshown at the same time. In the third zone, thesubject chooses from seven 3D rotating images.The 3D images can be changed using two ar-row buttons located around the images.We decided to use both 2D and 3D images
to improve the effectiveness of the scale. Evenif existing body image scales use mainly 2D im-ages, using 3D makes it easier for the subjectto perceive the differences between the silhou-ettes, especially for specific body areas (breasts,stomach, hips and thighs).After the two 3D body silhouettes are cho-
sen, the application drives the user to VEBIM:33Zone 1. In this zone, the subject becomes ac-
quainted with the appropriate control device,the head-mounted display and the recognitionof collisions. To move into the next zone sub-jects have to weigh themselves on a virtual bal-ance. The balance is used for two functions:
It is intended to be an inevitable obstaclefor the user, who must focus her attentionon this object, representing the importanceof the "weight" dimension in the experi-ences to come thereafter.
It can be used, if needed by the therapist,to display the initial weight of the subject,as acquired in the dialogue box at the be-ginning of BIVRS.
Zone 2a and 2b. These zones show a kitchen(2a) and an office (2b). Each of these rooms isfurnished with typical items, and contains dif-ferent foods and drinks. When the user decideto "eat" or "drink" something, all she have todo is to "touch" a specific item. In this way thefood is "eaten" and the corresponding caloricintake is automatically recorded in a text file,which is used later to calculate the total incomeof calories. At the end of the second zone is lo-cated a second virtual balance. According tothe "eaten" food and to the caloric intake in-serted at the beginning of BIVRS the balancewill show the new weight of the subject (in kilo-grams).
Zone 3. In this zone, the subject is exposedto a series of panels textured with pictures ofmodels, in the typical way of the advertisingworld. The images are used as stimuli to sup-port a cognitive approach: the elicited feelingsare subject to an analysis by the therapist ac-cording to the Label Shifting and ObjectiveCounters methods. The feelings and their as-sociated beliefs are identified, broken downinto their logical components, replaced withtwo or more descriptive words, and then criti-cally analysed.Zone 4. In this zone, the user find a large
mirror. Standing by it the subject can look ather real body, previously digitised using anEPSON Photo PC camera. The vision of herown body usually elicits in the user strongfeelings that can be matched using the Coun-terattacking and the Countering cognitivemethods. The mirror is also used, as indicatedby Wooley and Wooley,31 to instruct the userto imagine herself as different on severaldimensions including size, race, and beinglarger or smaller in particular areas. The useris also asked to imagine herself as younger,older, what she looks and feels like before andafter eating, as well as before and after acad-emic-vocational and social successes and fail-ures.
Zone 5. This zone consists of a long corridorending with a room containing four doors ofdifferent dimensions. The subject can move
into the last zone only by choosing the doorcorresponding exactly to his width. This pro-cedure is the same indicated by Wooley andWooley31 to improve the awareness of the bodydistortion.
A CONTROLLED STUDY
SubjectsForty-eight women participated in the study.
The sample was randomly divided into twogroups: the experimental group (Mean age:22.6 5.84; Mean weight: 55.1 4.43; Meanheight: 168.29 cm 6.20) and the control group(Mean age: 23.1 4.63; Mean weight: 55.8 3.98; Mean height: 171.01 cm 5.80). All thesubjects gave informed consent and were freeof psychiatric and physical illness.
The experimental group was submitted toVEBIM for no ore than 10 min and no less thaneight. All the subjects included in this groupreached zone 5.
All the subjects were given three scales forassessing body experience: the Figure RatingScale
FRS,47 the Contour Drawing Rating Scale-CDRS48 and the Breast/Chest Rating Scale-BCRS.49 On these tests subjects, rate the figures
based on the following instructional protocol,(a) current size and (b) ideal size. The differ-ence between the ratings is called the self-idealdiscrepancy score and is considered to representthe individual's dissatisfaction.The findings of Keeton, Cash, and Brown,50
support the usefulness of the self-ideal dis-crepancy score in the assessment of body im-age, as it was shown to relate to other body im-age indices and other clinically relevantmeasures. All the scales have good test-retestreliability.The experimental group was assessed at two
points in time: just before entering the virtualenvironment and just after. Control group sam-ple, too, was assessed twice at a ten minutesdistance.
VIRTUAL REALITY VS. VIRTUAL BODY 135
Table 1. Means and SD for the Body Image Scores in the Experimental Group
Experiment Real FRS Ideal FRS Real CDRS Ideal CDRS Real BCRS Ideal BCRSBeforeAfter
2.61 0.8a2.91 0.7a
ap < 0.005.
Statistical analysisA power calculation was made to verify the
opportunity to obtain statistically significantdifferences between the pre- and post-VRscores. Given the low statistical power, we de-cided to use exact methods, a series of statisti-cal algorithms developed by the HarvardSchool of Public Health, that enable researchersto make reliable inferences when data aresmall, sparse, heavily tied or unbalanced.51 Theexact method used to compare the scores wasthe marginal homogeneity test.52
ResultsTable 1 presents the means and standard de-
viations for the ratings of body image. The mar-ginal homogeneity test reported significant dif-ferences in the Ideal Figure Rating Scale scoresobtained by the experimental group: the scoreswere higher (p > .005) after experiencing theprocedure used. An analysis of the discrepancyindexes showed a significant lower value forFigure Rating Scale (p < .05) after the virtualexperience: body dissatisfaction of the subjectswas reduced after the virtual experience. Nosignificant differences were found in the con-trol group (Table 2).
Although there is much potential for the useof immersive virtual reality environments inclinical psychology, some problems have lim-ited their application in this field. Some users
have experienced side effects, during and afterexposure to virtual reality environments. Thesymptoms experienced by these users are sim-ilar to those which have been reported duringand after exposures to simulators with widefield-of-view displays.53-56 These side effectshave been collectively referred to as "simula-tor sickness"57 and are characterised by threeclasses of symptoms: ocular problems (e.g.,eyestrain, blurred vision and fatigue); disori-entation and balance disturbances; nausea. Ex-posure duration of less than 10 min to immer-sive VR environments has been shown to resultin significant incidences of nausea, disorienta-tion, and ocular problems.58The first interesting result of this study is the
lack of side effects and simulation sickness inour samples after the experience in the virtualenvironment, confirming the possibility of us-ing it for therapeutic purposes. This result, con-firmed in both studies, is even more interest-ing given the sample used. In fact, females tendto be more susceptible to motion sickness thanmales.59The other obtained result is the reduction in
the body dissatisfaction of the subjects after thevirtual experience. Usually body image treat-ment involves a cognitive/behavioural or a vi-suomotor therapy that require many sessions.The possibility of inducing a change in thebody dissatisfaction after an 8-10 min VR ses-sion can be useful to improve the efficacy of theexisting approaches. As such, the proceduremight be helpful as a part of a comprehensivetreatment package to break through the "resis-tance" to treatment in clinical subjects.18,60
Table 2. Means and SD for the Body Image Scores in the Control Group
Real FRS Ideal FRS Real CDRS Ideal CDRS Real BCRS
Of course these results are preliminary only.From a clinical viewpoint, the issues that wehave to address in the future are:
Further testing of VEBIM. Even if the dataobtained in this study are very promising,we have to test VEBIM with clinical andnonclinical subjects.
A follow-up study to check how long the in-fluence of the virtual environment lasts. In thestudy, we have limited the VR experienceto just one session, but from a therapeuticviewpoint, it seems more reasonable to re-peat the procedure.
How to integrate VEBIM into the usual cog-nitivebehavioural treatments. Even if theprocedure might be helpful as a part of acomprehensive treatment package tobreak through the "resistance" to treat-ment in clinical subjects, it is important todefine a specific therapeutic protocol to bealso used by clinicians and therapists notdirectly involved in the VREPAR 2 project.
This research is part of the Virtual Reality En-vironments for Psycho-neuro-physiologicalAssessemnt and Rehabilitation
VREPAR 2project, an European Commission funded re-search project (DGXIII
Telematics for HealthCare
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Address reprint requests to:Giuseppe Riva
Applied Technology for Neuro-Psychology LabIstituto Auxologico Italiano
P.O. Box 128044 Verbania, Italy