Virtual Reality Treatment of Flying Phobia

Transcription

1 206 IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 6, NO. 3, SEPTEMBER 2002 Virtual Reality Treatment of Flying Phobia Rosa M. Baños, Cristina Botella, Concepción Perpiñá, Mariano Alcañiz, Jose Antonio Lozano, Jorge Osma, and Myriam Gallardo Abstract Flying phobia (FP) might become a very incapacitating and disturbing problem in a person s social, working, and private areas. Psychological interventions based on exposure therapy have proved to be effective, but given the particular nature of this disorder they bear important limitations. Exposure therapy for FP might be excessively costly in terms of time, money, and efforts. Virtual reality (VR) overcomes these difficulties as different significant environments might be created, where the patient can interact with what he or she fears while in a totally safe and protected environment the therapist s consulting room. This paper intends, on one hand, to show the different scenarios designed by our team for the VR treatment of FP, and on the other, to present the first results supporting the effectiveness of this new tool for the treatment of FP in a multiple baseline study. Index Terms Anxiety disorders, flying phobia (FP), virtual exposure, virtual reality (VR). I. INTRODUCTION FLYING phobia (FP) is an important problem affecting a great percentage of the general population. Approximately 25% of adult people experience a significant anxiety level when required to fly; from those, 10% avoid such a situation [1]. However, these data contrast with the evidence shown by the statistics on airplane safety. According to the U.S. Department Transportation Document report of 1985 [1], air transportation is safer that any other such as car, boat, bus, etc. Despite all these data, the number of persons suffering from FP is much greater than the corresponding figure of persons suffering from phobias to other much more insecure transportation means [1]. According to DSM-IV [2] this problem would be diagnosed as a specific situational phobia, since what characterizes FP is an intense fear experienced in situations related to flying by plane. It is important to consider that the feared situations may not only include flying, but also taking somebody to the airport, for instance. Anticipatory anxiety may also appear, e.g., when buying the plane ticket, confirming the flight, waiting at the boarding area, or even at home while packing for the trip. Such a fear makes the person try to avoid airplane related situations or, in case he/she does not avoid, endure them with great distress. The person may face those situations but experience a considerable amount of anxiety and perform some kind of safety behaviors Manuscript received December 18, 2000; revised April 15, This work was supported in part by the I+D FEDER Program under Grant 1FD C R. M. Baños and C. Perpiñá are with the Departamento de Personalidad, Evaluacion y Tratamientos Psicologicos, Universidad de Valencia, Valencia 46040, Spain. C. Botella, J. Osma, and M. Gallardo are with the Departamento de Psicologia Basica, Clinica y Psicobiologia, Universidad Jaume I, Castellón, Spain. M. Alcañiz and J. A. Lozano are with the MedicLaboratory, Universidad Politecnica de Valencia, Valencia 46040, Spain. Publisher Item Identifier /TITB such as taking tranquilizers or alcohol, choosing the seats next to the emergency exits or the aisle, not looking through the windows, etc. Despite that from this perspective FP seems to appear as an easy issue in terms of assessment and diagnosis, the truth is that we are dealing with a heterogeneous problem. The fears reported by the persons with FP are many and of diverse nature. Flying phobics may be afraid of having an airplane crash, of the physical sensations of anxiety they might experience, of heights, of moving away from a safe place such as home, of being closed, of loosing control or not having control over the situation, etc. That is, fear of flying appears not to be a unitary phenomenon [3], [4]. It can be a situational phobia or the expression of other phobias (such as claustrophobia, acrophobia, or agoraphobia) or even of panic disorder. Thus, it is of basic importance to examine all these conditions because in the case FP is just a sign of a problem of greater magnitude, treatment should be aimed to the main disorder. Despite the high prevalence of this problem, well-designed and controlled treatment outcome studies are scarce [3], [5] [9]. Actually, many authors have raised their complaints about the neglect suffered by this type of phobia [4]. One of the possible explanations to this fact may lie in the difficulty and high cost that any research or treatment would imply. The psychological treatment that has proven to be the most effective in the treatment of phobias is in vivo exposure. However, the resources and time necessary to carry out this type of exposure have daunted many researchers, therapists, and patients. The group of Rothbaum and Hodges was one of the pioneers in considering fear of flying as an ideal candidate for virtual reality (VR) exposure therapy [10]. They accounted for a series of reasons, to which we add some more. First, VR has demonstrated to be a useful tool for activating several fears, and some of them are of relevance for FP, such as acrophobia [11], [12] and claustrophobia [13]. Those fears were capable of being activated by means of VR and consequently they were extinguished by repeated and controlled virtual exposure. Second, as mentioned above, in vivo exposure for FP is expensive and, furthermore, difficult to plan, as all the variables needed to manage a well-graded exposure cannot be controlled. That is why the alternative choice for treatment was imagination exposure. Compared with the latter, VR exposure creates a greater sense of presence and is much more immersive. This is a core issue since therapy is aimed at facilitating emotional processing, which requires activation of the fear structures in order for them to be modified [14], [15]. Third, it is not too difficult to design scenarios including the basic aspects of fear of flying and improving reality judgment by means of instigators such as real airplane seats or sound effects of real planes. Fourth, we believe that it is absolutely justified to invest resources in /02$ IEEE

2 BAÑOS et al.: VIRTUAL REALITY TREATMENT OF FLYING PHOBIA 207 this problem as fear of flying has considerable financial and personal repercussions. Regarding to the former, air companies estimated that FP caused $ in lost revenue for the U.S. flight industry in 1982 [16], [17]. Regarding personal repercussions, FP may pose important limitations in the daily life of both people suffering from this problem and the ones close to them, in terms of work issues, leisure, and quality of life in general. Last, consider that the costs of hardware and software necessary to apply VR therapy are decreasing at a fast pace, turning an important limitation of VR two years ago into a totally affordable issue. Several studies proving that FP can be effectively treated by means of VR have been already published [10], [18] [24]. Most of these studies have used the package designed by Rothbaum and Hodges team. In their software, the virtual scenarios are located inside the plane. The study we present here includes other scenarios relating anticipatory fears that flying phobics may exhibit. The aims of this study are twofold: showing the different scenarios designed by our team for the VR treatment of FP, and offering results that support the effectiveness of this technological tool for the treatment of FP in a multiple baseline study. II. METHOD A. Participants Four persons who sought treatment to overcome their fear of flying at the Psychological Assistance Service of the Jaume I University took part in the study. All participants met DSM-IV criteria [2] for specific phobia, situational type (FP). Participant 1 (P1) was a 40-year-old white female, married, with one child, working in a bank office. Her phobia began 15 years ago; after having two complicated flights (no accident or emergency) she went back home on a boat. From then on, she flew only once, three years ago. Her main fear was to have an accident. She received treatment in an air company therapeutic program (six years ago), and a private psychologist treated her as well one year ago. Her problem limits her in terms of her leisure time, as she would like to travel with her family in vacation. She rated the severity of her problem as seven (on a scale of zero to ten). Participant 2 (P2) was a 41-year-old white male, married, working as a dentist. His fear of flying started 18 years ago, in his first flight. At the beginning of his problem, he counted the number of flights he took, but in flight number 13 the plane had to go back to its destination airport due to weather problems, and he stopped counting his flights. However, he started praying before takeoff. His main fear was having an accident. He rated the severity of his problem as six. Participant 3 (P3) was a 41-year-old white female, married, with two children, working as a university lecturer. She reported having fear of flying for ever, but it got worse ten years ago when she was aware of her great anxiety (she had a panic attack). She was afraid of having an accident, and of being unable to get out in case of an emergency. She rated the severity of her problem as seven. Participant 4 (P4) was a 23-year-old white female, single, undergraduate psychology student. She reported flying with mild distress, but it increased markedly two years ago. She related it to the news on mass media about plane accidents, and to the story of a friend who had a difficult flight (with no accident). She took her last plane six months ago. She experienced anticipatory anxiety from the moment that she knew she had to take a plane. Her main fear was of having an accident. Her problem interfered with her personal relationships (her boyfriend lived far away and she could see him more often if she could fly without fear), and rated its severity as eight. B. Measures 1) Anxiety Disorders Interview Schedule (ADIS-IV) [25]: It is a structured diagnostic interview designed to assess the history of occurrence of any anxiety disorder in accordance with the DSM-IV criteria. For the purpose of this study, the specific phobias section was used. 2) Subjective Units of Discomfort Scale (SUDS) [26]: Participants were asked to rate their anxiety level on an eleven-point scale (0: no anxiety; 10: extreme anxiety) during the exposure sessions. 3) Fear Record (FR): The target behavior (fear of flying) was rated by the participants on a daily basis in terms of their degree of fear, avoidance, and firmness of their main catastrophic thought. These ratings ranged from 0 ( None ) to 10 ( Extreme ). 4) Maladjustment Scales (MS) [27]: This instrument assesses the impairment that the problem causes in several areas of the participant s life using an 11-point scale (0: None ; 10: Extreme ). Only rates on global impairment were used in this study. The scale has shown high internal consistency, discriminant and concurrent validities, and it is sensitive to treatment outcome [28]. 5) Danger Expectations and Flying Anxiety Scales (DEFAS) [29]): This instruments consists of two subscales in a fourpoint Likert format (0: Never; 3: Most Times). The first is a nine-item scale assessing danger expectations (frequency of catastrophic thoughts about the occurrence of possible dangers). The second, consists of ten items assessing the person s anxiety expectations (probability that he or she is going to experience unpleasant physiological symptoms during the flight). The DEFAS has shown high internal consistency, test-retest reliability, and good discriminant and concurrent validity [29]. 6) Fear of Flying Questionnaire (FFQ) [30]: This is a 34-item self-report questionnaire in which the person rates his/her level of fear or discomfort in different flying-related situations (scale ranging from 0 to 9). The FFQ consists in three subscales assessing 1) anxiety during flight (16 items); 2) anxiety experienced before takeoff (13 items); and 3) anxiety experienced when observing either neutral or unpleasant flying-related situations (five items). The questionnaire has shown high internal consistency, test-retest reliability, good discriminant validity, and it is sensitive to treatment outcome [30]. C. Apparatus The hardware used consisted in a Pentium-based platform (Intel Pentium III, 450-MHz, 128-Mb RAM, graphic engine: Riva TNT2 with 64-Mb RAM) running on a windows

3 208 IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 6, NO. 3, SEPTEMBER 2002 NT/2000 operating system. The display system consisted of a head-mounted display (HMD). We used for the first time the HMD model V6 from Virtual Research, but after performing several tests on sense of presence using different hardware configuration, we decided to use a cheaper HMD, the virtual I/O Glasses. We used a stereoscopic display mode for this device, since it has been demonstrated that stereoscopy provides a good cue of depth to the user, and hence increases the patient s sense of presence in the virtual environment (VE). An Intersense II three dimensional (3-D) digitizer was used for head tracking. As a motion input device we used a standard mouse. D. Virtual Scenarios There are many graphic formats and software destined to generate three-dimensional (3-D) objects and even complete VEs, but just the geometry is not enough to model a VE. A series of properties (such as sounds to be played, movement of objects, and user interface) are also necessary. For this purpose, there is a very extended language capable to model all these additional properties, virtual reality modeling language (VRML), and also several development tools such as WorldUp from Sense8 Corp, Nemo, etc. We decided to create our own development environment based on the 3D Graphic Library WorldToolkit v. 9.0 form Sense8. The reason behind was the need to incorporate some characteristics that commercial tools do not support such as deforming 3-D geometries in real time within the VEs; using a database allowing to personalize some of the VE parameters to each user; and saving the data obtained while the user navigates the VE. Our development tool, named DIVE, is in its third version and is based on script language, PYTHON, above the 3D Graphic Library. Apart from the user s movements, the actions that can happen inside a VE are: an object moves following a fixed trajectory; an object suffers a deformation following a defined pattern; a sound starts to play and increases or decreases its intensity; and a light turns on and its intensity increases or decreases. In DIVE, a timer controls each one of these functions. Timers contain values going from 0% to 100% and they are similar to the wires moving all what happens inside the VEs. A timer can be fired using different commands [Play, Stop, Swing, Go(10), Jump(10), GoTo(50), etc ] triggered by an EVENT. Events are activated by the user actions or by timers reaching some predefined level. An event can be activated, for example, because the user has stepped on an object or has clicked on it. Although there are plenty of functions to make almost anything happen inside the VE, all of them work under the same explained philosophy. To graduate the difficulty levels of the VEs, three different settings were created so that they allowed the construction of exposure hierarchies with increasing degrees of difficulty. 1) First Scenario: Planning the Trip: We have a room recreating the moment of packing up. There are a suitcase and some clothing on a bed, a bedside table with an alarm clock showing the time, the air ticket next to the clock, a chest of drawers and a radio on top, a closet with more clothes inside it (female or male clothes, depending on the participant s gender), and a large window showing the outside. In this scenario, the therapist can choose daytime or nighttime, and good or bad weather. The outside view and the news on the radio change accordingly to the situation chosen by the therapist. The patient can interact with several objects; he/she can open the door to leave the room, open and close drawers and closet, introduce his/her clothes in the suitcase, open and close the suitcase, turn the radio on and off, and pick up the suitcase and the air ticket. 2) Second Scenario: At the Airport: We are now at an airport s boarding lounge. The patient can walk about but not interact. As in the previous scenario, the therapist can modify time of day and weather. Furthermore, the therapist can control the following events. 1) Updating of the flight information board: information about boarding departing planes is heard through the airport megaphones, and the flights on the information board move upwards, showing that the patient s departure is close. 2) Planes taking off: the patient can observe how other planes take off (under the therapist s control) through the large window that overlooks the runway. 3) People talking: two people converse about weather and the possibilities of having an air accident. 4) Entering the plane, after the announcement of the imminent departure of the flight. 3) Third Scenario: On Board: The patient is in his/her seat and cannot get up or move about the plane. He/she can interact, though, with several objects roll up and down the window s blind, pull down and back the front seat tray, pick up and turn the pages of a magazine placed on the front seat rack, listening to three different radio channels at different volumes, fasten and unfasten his/her seatbelt. The virtual body of the patient is different according to his/her gender. As in the previous scenarios, the therapist controls time of day and weather, and also provokes different events: 1) Takeoff: After the captain s welcome message and the air crew safety procedures, the plane runs slowly to the runway s head, engines roaring, and takes off. 2) Turbulence: the air crew informs that the plane has entered a zone of turbulence and requires the passengers to fasten their seatbelts; the plane bounces randomly until the therapist decides to end the turbulence; then, movement stops and the air-crew informs the passengers that they can unfasten their seatbelts. 3) Landing: preceded by the captain s message and the air-crew instruction of fastening seatbelts; engine sounds increase, the sound of tires hitting the ground is heard, and the plane reduces speed until stopping at the runway end. E. Design A multiple baseline design across subjects [31] was used to demonstrate the effects of treatment on the patient s target behavior. Given the fact that not all participants were available when the study started, we decided to apply the nonconcurrent multiple baseline design between subjects proposed by Watson and Workman [32]. Baselines length was one, two, or three weeks, so that as participants were seeking help at the Psychological Assistance Service, they could be randomly assigned to one of the three possibilities. P1 and P2 were assigned to the

4 BAÑOS et al.: VIRTUAL REALITY TREATMENT OF FLYING PHOBIA 209 one-week baseline, P3 to the two-week baseline, and P4 to the three-week baseline. F. Procedure To establish the participant s diagnostic status, an experienced clinical psychologist applied the Admission Interview. Another experienced psychologist, blind to the study, acted as an independent assessor, and confirmed the presence or absence of fear of flying and other anxiety disorders. In the same session, the self-report instruments described above were also administered. All participants signed a consent form stating their knowledge of taking part in an experimental study. At the end of the second session, participants were provided with a fear record (FR) and instructed to monitor their fear of their target behavior. They were asked to keep the record on a daily basis throughout the entire process. The same self-report scales fulfilled at the beginning of treatment were administered again immediately after the last VR exposure session (posttreatment assessment). G. Treatment A total of eight treatment sessions, exclusively focused on fear of flying, were carried out for all participants on a weekly session basis. The first and second sessions focused on psychoeducation (information about anxiety, flying phobia, aircraft safety, exposure, and virtual exposure). In the remaining six sessions, VR graded exposure to the three VEs described above was applied. VR exposure sessions lasted approximately min each. A monitor allowed the therapist to observe the VE the participants were being exposed to. The therapist s instructions in the VR sessions were similar to those used in regular in vivo exposures. Anxiety level (SUDS) was assessed every 5 min. III. RESULTS Regarding the FR, Fig. 1 shows the daily fear and avoidance ratings along baseline periods. Due to design requirements, treatment started according to the order established by the random assignment of participants to the baseline conditions. A decrease of fear and avoidance during baseline is observed for P1. Although it would have been desirable to gather more data on the stability of her fear, it was decided to comply with the design guidelines. Nonetheless, fear stability can be inferred from the duration of her problem (15 years). In all cases, treatment brought about an important decrease in all four participants fear and avoidance when they had to face their target behavior. The fear and avoidance of target behaviors decreased upon treatment completion for each participant, from 7 to 10 scores of fear and avoidance at pretreatment, to 1 and 2 scores at posttreatment on a 0 10 scale. Fig. 2 shows the daily ratings on catastrophic thoughts. A decrease of this rating during baseline is observed again for P1. In all cases, catastrophic thought conviction decreased upon treatment completion for each participant, reaching scores between 0 and 2 at posttreatment (based on a 0 10 scale). Results on self-report measures are shown in Table I. Before treatment, all participants received high scores in all the different questionnaires, but these scores decreased upon treatment Fig. 1. Fear and avoidance records for target behavior. completion, both in the measures assessing expectations and in the measures assessing the level of fear in flying related situations. There was also a decrease in the global impairment that the problem caused in the participants life. IV. DISCUSSION In this study, the VR software for the treatment of flying phobia was designed taking into account all the key characteristics of this problem, including anticipatory anxiety. This is one difference between the present software and the one developed by Rothbaum et al. [10] that focus exclusively in the actual flight moment, inside the aircraft. The goal of the present software was to achieve a high emotional implication on the patient s side, avoiding scenarios nonclinically significant. This software appears to induce anxiety in persons suffering from fear of flying, as seen in the four participants in this study. They were able to get into the VEs and feel really anxious. The

5 210 IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 6, NO. 3, SEPTEMBER 2002 scenarios, as the decrease in all measures (fear, avoidance, beliefs, expectations, etc.) shows. Furthermore, the four participants actually made a real flight with minimal anxiety following treatment, which we consider to be a very meaningful measure of improvement. Taking into account this criterion, we may consider that the VR treatment for fear of flying was successful in reducing the participants fear and avoidance. The main shortcoming of this study is the small sample size. It goes without saying that it would be necessary to apply this treatment to larger samples in a group design that includes a control group. Such a procedure would increase the confidence in this new exposure format. Another weakness of the study is its lack of physiological records. Therefore, we can only state that the treatment was successful insofar as self-reports showed change after treatment, and the participants flew with no anxiety. Other studies have also reported the clinical effectiveness of VR exposure for treating fear of flying [10], [18] [24]. This paper gives support to the previous results on VR treatment for fear of flying from a multiple baseline design, and from a different software that includes, apart from the cockpit, other scenarios addressed to cope with the anticipatory anxiety. Furthermore, participants were from a different sample to what we are used to as it was a clinical Spanish sample. All of them were persons seeking psychological help to overcome a long-lasting problem, and fulfilling DSM-IV [2] criteria. From all this it follows that the results obtained in this study together with the ones obtained in previous works, bring evidence to the usefulness of VR exposure for the treatment of fear of flying. Nonetheless, any statement regarding the effectiveness of VR must be taken with caution, since most of the work in this field is still to be done. As mentioned previously, it is necessary to carry out studies with larger samples, and using group designs that include control groups. Finally, to test the usefulness of VR in the treatment of other psychological disorders is another goal to be pursued in the near future. REFERENCES Fig. 2. Belief records for target behavior. TABLE I MEAN SCORES IN SELF-REPORTS QUESTIONNAIRES program not only achieved to induce anxiety, but also to diminish it through the prolonged virtual exposure to the different [1] T. S. Greco, A cognitive-behavioral approach to fear of flying: A practitioner s guide, Phobia Practice Res. J., vol. 2, pp. 3 15, [2] Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Amer. Psych. Assoc., Washington, DC, [3] W. A. Howard, S. M. Murphy, and J. C. Clarke, The nature and treatment of fear of flying: A controlled investigation, Behavior Therapy, vol. 14, pp , [4] L. J. Van Gerwen, P. Spinhoven, R. F. Diekstra, and R. Van Dyck, People who seek help for fear of flying: Typology of flying phobics, Behavior Therapy, vol. 28, pp , [5] J. C. Beckham, S. R. Vrana, J. G. May, D. J. Gustafson, and G. R. Smith, Emotional processing and fear measurement synchrony as indicators of treatment outcome in fear of flying, J. Behavior Therapy Experimental Psych., vol. 21, pp , [6] M. S. Denholtz, L. A. Hall, and E. T. Mann, Automated treatment of flight phobia: A 3.5-year follow-up, Amer. J. Psych., vol. 135, pp , [7] T. Haug, L. Brenne, B. H. Johnsen, K. G. Berntzen, K. G. Götestam, and K. Hughdal, A three-system analysis of fear of flying: A comparison of a consonant versus a nonconsonant treatment method, Behavior Res. Therapy, vol. 25, pp , [8] L.-G. Öst, M. Brandberg, and T. Alm, One versus five sessions of exposure in the treatment of flying phobia, Behavior Res. Therapy, vol. 11, pp , [9] C. P. Walder, J. S. McCraken, M. Herbert, P. T. James, and N. Brewitt, Psychological intervention in civilian flying phobia: Evaluation at a three-year follow-up, British J. Psych., vol. 151, pp , 1987.

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Corral, La Agorafobia: Nuevas Perspectivas de Evaluación y Tratamiento. Valencia, Spain: Promolibro, [28] E. Echeburúa, P. Corral, and J. Fernández-Montalvo, Escala de inadaptación (EI): Propiedades psicométricas en contextos clínicos, Análisis y Modificación de Conducta, to be published. [29] C. D. Sosa, J. I. Capafons, C. Viña, and M. Herrero, Evaluación del miedo a viajar en avión: Un estudio psicométrico de dos escalas de autoinforme, Psicología Conductual, vol. 3, pp , [30] X. Bornas and M. Tortella-Feliu, Descripción y análisis psicométrico de un instrumento de autoinforme para la evaluación del miedo a volar, Psicología Conductual, vol. 1, pp , [31] M. Hersen and D. H. Barlow, Single Case Experimental Designs. New York: Pergamon, [32] P. J. Watson and E. A. Workman, The nonconcurrent multiple baseline across-individuals design: An extension of the traditional multiple baseline design, J. Behavior Therapy Experimental Psych., vol. 12, pp , Rosa M. Baños received the Ph.D. degree in psychology from the University of Valencia, Valencia, Spain, in She has been a Senior Lecturer in Psychopathology at the University of Valencia since From 1991 to 1994, she was a Senior Lecturer at the University of Jaume I, Castellon, Spain. Her research activity has focused in the study of psychopathology and the treatment of various psychological disorders (emotional disorders, anxiety disorders, eating disorders, etc). Her research interests include application of virtual reality to the treatment of several anxiety disorders and body image distortions in eating disorders and the study of psychological variables that may play an important role in the sense of presence and the reality attributed by the user to the virtual reality experience, and the design of measurement tools of these constructs, applied in the field of clinical psychology. She is leading a new project on attentional biases in anxiety disorders using virtual reality as a more ecological research frame for the measurement of cognitive biases. Cristina Botella received the Ph.D. degree in psychology from the University of Valencia, Valencia, Spain, in From 1980 to 1992, she lectured at the University of Valencia. From 1992 to 1994, she was Professor at Murcia University, Murcia, Spain. Since 1994, she has been Professor of Clinical Psychology at Jaume I University. She is Director of a research team at Jaume I University, working on abnormal psychology and on the development of psychological treatments. Her main subject of research has been the psychopathological study and treatment of anxiety disorders. At the present time, her main line of research is the application of Virtual Reality to the treatment of several anxiety disorders and body image distortions in eating disorders. She has been Principal Investigator in more than 20 research projects, funded by national and European institutions. She has the Director and Founder of the Emotional Disorders Clinic at Jaume I University since This service offers psychological treatments to the community and training for clinical psychologists and researchers. Concepción Perpiñá received the Ph.D. degree in psychology from the University of Valencia, Valencia, Spain, in Since 1994, she has been a Senior Lecturer at the University of Valencia. She has been working on abnormal psychology and treatment of eating disorders. She also works in the application of virtual reality to the treatment of different psychological disorders and the study of psychological variables that may play an important role in the sense of presence and the reality attributed by the user to the virtual reality experience. Mariano Alcañiz received the Ph.D. degree in industrial engineering from the Polytechnic University of Valencia, Valencia, Spain, in Since 1986, he has been a Scientific Fellow at the Department of Graphical Engineering, University of Valencia, where he has dealt with computer graphics. His current position is Senior Lector and Director of the Medical Image Computing Laboratory (MedIClab). His research interests and current activity involve computer methods and algorithms for medical image processing, 3-D medical imaging, computer-integrated surgery, and virtual reality technology applied to medicine. He is author and coauthor of more than 60 scientific papers in national and international scientific journals and conference proceedings. Dr. Alcañiz is a Member of the International Society for Computer Applications in Radiology (SCAR), Engineering in Medicine and Biology Society (IEEE-EMBS) and International Society for Computer Aided Surgery (ISCAS).

7 212 IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 6, NO. 3, SEPTEMBER 2002 Jose Antonio Lozano received the M.S. degree in computer science from the Polytechnic University of Valencia, Valencia, Spain, in Currently, he is working on his doctoral thesis, titled Development of virtual reality applications for the evaluation and the treatment of psychological disorders at the Medical Image Computing Laboratory (MedICLab), University Polytechnic of Valencia. He is MedICLab Technical Representative in the Telemedicine and Portable Virtual Environments for Clinical Psychology, a European project financed by Information Society Technologies Programme (IST) of the European Commission and the Istituto Auxologico Italiano. His main research interests include virtual reality in mental health. Some results of this research have been presented in important congresses and publications. Jorge Osma received the Ph.D. degree in industrial engineering from the University Jaume I, Castellon, Spain, in Currently, he is working on his doctoral thesis, titled Flying phobia: Virtual reality exposure. He is a Fellowship Researcher at University Jaume I. His research includes virtual reality applications on clinical psychology. Myriam Gallardo received the Ph.D. degree in industrial engineering from the University Jaume I, Castellon, Spain. Currently, she is working on her doctoral thesis, titled Delimitation of clinical subtypes of social phobia. She is a Fellowship Researcher at University Jaume I. Her research includes psychological treatment for anxiety disorders.