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Giuseppe Riva Applied Technology for Psychology Lab.
Centro Auxologico Italiano
P.O. Box 1 28044
Intra (NO) - Italy
Eating Disorders, that are one of the most common pathologies of the occidental society, have long been associated with alterations in the perceptual/cognitive representations of the body. Infact, a large number of studies have highlighted the fact that the perception of one's own body and the experiences associated with it represent one of the key problems of anorexic, bulimic and obese subjects.This has encouraged a large number of researchers to study methods of intervention designed to support normal therapeutical procedures and specifically aimed at patients' modes of representing their bodies. An interesting possibility could be the integration of these methods of intervention within a virtual environment. Two methods are currently in use. The first is a cognitive/behavioural approach aimed at influencing patients' feelings of dissatisfaction; the second is a visual/motorial approach with the aim of influencing the level of bodily awareness. A choice of this type would not only make it possible to integrate them but also to use the psychological effects provoked by the VR experience for therapeutical purposes.
In a recent study, Cioffi (1993) analysed these psychological effects and found that, in a VR, the self-perception of one's own body undergoes profound changes: about 40% of the subjects felt as if they had "dematerialised" or as if they were in the absence of gravity; 44% of the men and 60% of the women claimed not to feel their bodies. Such effects, could be of great help during the course of a therapy aimed at influencing the way the body is experienced, because they lead to a greater awareness of the perceptual and sensory/motorial processes associated with them. Keywords: Virtual Environment, Virtual Reality, Eating Disorders, Body Image 1.
The perceptual world created by our senses and our mind is so functional a representation of the physical world that most people live out their lives without ever suspecting that contact with the physical world is mediate. The physical world, including our body, is not given directly in our experience but is inferred through observation and critical reasoning. This means that, in everyday life, the body as a representation/image/idea plays an important and often under-rated role. It is interesting to note that these representations are not limited to visual "images" (i.e., pictures in one's head of one's body) but comprise the schema of all sensory input internally and externally derivedÑlived experiences processed and represented within a maturing psychic apparatus.
1.1 Body Schema and Body Image This "virtual body" has been the subject of a number of studies which, however, often make reference to concepts and theories different one from the other: "body percept", "body image", "body concept", "body schema" and "body values". Recently, an attempt has been made to incorporate all of the forms of perceptive/cognitive representation of the human body within two fundamental concepts (Gallager, 1986; Fisher, 1990): body schema and body image. According to Head (1926), the body schema is the model/representation of one's own body upon which postures and movements are judged. This representation can be considered the result of comparisons and integrations at the cortical level of past sensory experiences (postural, tactile, visual, kinesthetic and vestibular) with current sensations. This gives rise to an almost completely unconscious "plastic" reference model that makes it possible to move easily in space and to recognise the parts of one's own body in all situations. If a body schema can be considered a perceptual model of the body, body image is a cognitive/social/emotional model. According to Schilder, body image can be defined as "the mental picture that we have of our bodies" or, in other words, "the way our bodies appear to us" (Schilder, 1950). Expanding on Schilder's idea, Allamani et al. (1990) refer to body image as "a complex psychological organisation which develops through the bodily experience of an individual and affects both the schema of behaviour and a fundamental nucleus of self-image" (page 121). Infact, body image not only derives from person-social context relations and the individual's cognitive and emotional developments, but also contributes to both of these processes. In other words, how one thinks and feels about one's body will influence one's social relations and one's other psychological characteristics.
1.2 Definitions of Body Experience Disturbance Body experience disturbance has been used by a wide variety of researchers and clinicians to designate a great number of phenomena with little or no overlapping characteristics (Thompson, 1992). For instance, the phrase has been used to refer to phantom limb syndrome, neuropsychological deficits (anosognosia), and the psychodynamic concept of "body boundary" (Thompson, 1990). This paper will focus exclusively on a physical appearance related definition that is quite broadÑbody experience disturbance is any form of affective, cognitive, behavioral, or perceptual disturbance that is directly concerned with an aspect of physical appearance.
2. Body experience and eating disorders Body experience have a long and storied association with eating and weight related problems (Stunkard & Mendelson, 1961; Garfinkel & Garner, 1982; Barrios et al., 1989; Rosen, 1990; Thompson, 1990; Valtolina et al., 1994; Thompson, 1995). Bruch (1962) articulated the integral role of body experience in the development, maintenance, and treatment of anorexia nervosa. In later years, researchers also agreed that body experience was a central factor in bulimia nervosa (American Psychiatric Association, 1994; Thompson, Berland, Linton, & Weinsier, 1986).
Finally, although often ignored as a feature of obesity (see Thompson, 1990), Stunkard and Burt (1967) demonstrated almost 30 years ago the importance of body experience to an understanding of individuals with excessive weight. One index of the importance of body experience disturbance involves its relevance to agreed-on clinical disorders. The Diagnostic and Statistical Manual of Mental Disorders IV (American Psychiatric Association, 1994) contains a body image criterion that is required for the diagnosis of anorexia nervosa or bulimia nervosa. In addition, one type of Somatoform DisorderÑBody Dysmorphic DisorderÑis a specific clinical syndrome consisting of extreme body image disparagement. It has also been suggested that, when there is psychological comorbidity with obesity, it may be strongly due to problematic body experience issues (Thompson, 1992).
Today, researchers and clinicians agree that including an assessment and evaluation of body experience disturbance is crucial to any treatment program targeting obesity or eating disorders. Some studies concerning the efficacy of the cognitive-behavioural treatment of anorexia have indicated that patients who make a larger overestimate of their own bodily dimensions (Casper et al., 1979) or who are more pleased with their own physical appearance (Vandereychken et al., 1988) gain less weight after a period of treatment.
Furthermore, among those who manage to reach their target weight, post-treatment weight loss correlates directly with the way in which patients perceive their own size (Button, 1986). Also in the treatment of bulimic subjects, body experience has been shown to play an important role in determining the outcome of treatment. In particular, the degree of satisfaction that patients have in relation to their bodies has been shown to be related both to a reduction in bulimic behaviour and to subsequent relapses (Conners et al., 1984; Freeman et al., 1985). This has encouraged a large number of researchers to study methods of intervention designed to support normal therapeutical procedures and specifically aimed at patients' modes of representing their bodies. Two methods are currently in use. The first is a cognitive/behavioural approach aimed at influencing patients' feelings of dissatisfaction with different parts of their bodies by means of individual interviews, relaxation and imaginative techniques (Butter & Cash, 1987). The second is a visual/motorial approach which makes use of videorecordings of particular gestures and movements with the aim of influencing the level of bodily awareness (Wooley & Wooley, 1985).
3. Virtual reality and body experience Virtual reality (VR) was born as an imitative technology designed to make it possible to operate in a sensory/motorial manner that is as similar as possible to actual reality (Antinucci, 1994a, 1994b). Infact, it tries to create a sense of personal presence by simulating as closely as possible the range and intensity of stimuli that human senses detect in perceiving the natural world. In immersion VR you know you are "there" because the virtual world respond like the real world to your body and head movements (Heeter, 1992). VR is therefore capable of globally redefining the conditions and means of experience because of its capacity to involve the perceptual and sensory dimension of the interacting subject in a completely totalising manner (Cioffi, 1993). This means that VR can be used to create situations in which the subject can intervene in both a symbolic/reconstructive and a perceptual/motorial manner, allowing the simultaneous measurement not only of the two modes of representation themselves, but also of the effects of their interaction.
3.1 A new challenge An interesting possibility could be the integration of the two methods (cognitive-behavioural and visual-motorial) commonly used in the treatment of body experience disturbances within a virtual environment. A choice of this type would not only make it possible to intervene simultaneously on body image and the body schema, but also to use the psychological effects provoked by the experience for therapeutical purposes. In a recent study, Cioffi (1993) analysed these psychological effects and found that, in a VR, the self-perception of one's own body undergoes profound changes that are similar to those achieved in the 1960s by many psychologists in their studies of perceptual distorsion. In particular, about 40% of the subjects felt as if they had "dematerialised" or as if they were in the absence of gravity; 44% of the men and 60% of the women claimed not to feel their bodies. Perceptual distorsions, leading to a few seconds of instability and a mild sense of confusion, were also observed in the period immediately following the virtual experience. Such effects, attributable to the reorganisational and reconstructive mechanisms necessary to adapt the subjects to the qualitatively distorted world of VR, could be of great help during the course of a therapy aimed at influencing the way the body is experienced, because they lead to a greater awareness of the perceptual and sensory/motorial processes associated with them. When a particular event or stimulus violates the information present in the body schema (as occurs during a virtual experience), the information itself becomes accessible at a conscious level (Baars, 1988). This facilitates the process of modification and, by means of the mediation of the self (which tries to integrate and maintain the consistency of the different representations of the body), also makes it possible to influence body image.
4. Description of the project The above considerations have led to the design of the following research:
The aim of the study is to construct a virtual reality environment aimed at allowing the assessment of the distorsion of body representations and supporting the treatment of subjects with eating disorders. More precisely, the study is designed to evaluate the effect that a cognitive/behavioral therapy which includes VR treatment may have on eating disorders, in particular on the capacity to maintain the results obtained after a period of therapy.
4.2 Instruments For the reasearch we are actually using a Thunder 100/C virtual reality systems by Virtual.sys of Milano-Italy. The Thunder 100/C is a Pentium based VR system (100mhz, 32 mega RAM, graphic engine: Diamond Stealth 64 S3/964 4Mb VRam). The stereoscopic head mounted display was specially developed by Virtual.sys (double active matrix 0.7Ó color LCD, 56 H. FOV, 120000 pixel, Logitech 3D Mouse tracking system).
4.3 Population A group of obese/anorexic/bulimic patients admitted to hospital (Istituto Scientifico Ospedale S. Giuseppe di Piancavallo) for a period of therapy. 4.4 Methodology After having verified their eligibility for an experience in VR by means of a battery of psychological and physiological tests, a first group of subjects will undergo rehabilitation therapy using VR, a second group will follow a traditional body perception intervention therapy, and a third group will not receive any specific supportive therapy of this type. All of the subjects will also be treated using the normal medical/cognitive/behavioural therapy routinely adopted by the hospital. The virtual environment, which will be adapted as much as possible to the characteristics of each individual subject, will consist of a series of "zones" (Figure 1). In each of these zones, the subject will do a series of exercises aimed at influencing and correcting: - eating behaviours; - the subject's body image and body schema. The various phases will have the following characteristics: - the patients will be able to modify their virtual image in real time; - they will be able to explore the virtual world in an autonomous manner; - there will be visual and aural elements of reinforcement. Before and after the rehabilitation phase, a battery of tests measuring the level of distorsion of the body schema and the characteristics of body image will be administered in order to be able to verify the effects provoked by the VR. The efficacy of the various treatments will be evaluated at the end of the period of hospital therapy and during a follow-up period of 1-2 years.
Figure 1: Structure of the virtual environment ZONE 2A | ZONE 1 --+--> ZONE 3 --> ZONE 4 --> ZONE 5--> ZONE 6 | ZONE 2B The virtual environment is a 6-zone structure consisting of two parts (zones 1-2 and zones 3-4-5-6).
* The first two zones are designed: - both to give the subject a minimum level of skill in perceiving, moving through and manipulating objects in VR; - and to focus his attention on eating and food choice.
Zone 1: In this zone the subject familiarises with the appropriate control device, the head mounted display and how to recognise collisions. To move into the next zone the subject has to weigh himself using a virtual balance.
Zone 2a and 2b: these zones show a kitchen (2a) and a office (2b). The subject can move between them and interact with the objects. Some of them are foods that the subject can take and "eat". To move into the next zone the subject has to weigh himself again (his starting weight will be modified according to the actions made and the food eaten).
* The next four zones are designed to modify the body experience of the subject integrating the therapeutical methods used by Butter & Cash (1987) and Wooley & Wooley (1985). Both at the beginning of zone 3 and at the end of zone 6 the subject is submitted to a series of procedures/tasks aimed at assessing his body experience.
Zone 3: this zone consists of four corridors whose walls show images of female and male models.
Zone 4: this is a room furnished with a large mirror. Standing by it the subject can look at his real body (previously digitised using a video camera).
Zone 5: this zone consists of a long corridor ending with a room containing four doors of different dimensions. The subject can move into the last zone only choosing the door corresponding exactly to his width and height.
Zone 6: this is a large room whose leading walls (north and south) show the body of the subject. The first image is a static one (real body) and cannot be changed, while the second one (ideal body) can be changed by the subject according to his own desire (by using a morphing-like system).
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