Slide
Centre Interdisciplinaire
de Recherche et d’Innovation
en Cybersécurité et Société
de Recherche et d’Innovation
en Cybersécurité et Société
1.
Tardif, N.; Therrien, C. -E.; Bouchard, S.
Re-Examining Psychological Mechanisms Underlying Virtual Reality-Based Exposure for Spider Phobia Journal Article
In: Cyberpsychology, Behavior, and Social Networking, vol. 22, no. 1, pp. 39–45, 2019, ISSN: 21522715, (Publisher: Mary Ann Liebert Inc.).
Abstract | Links | BibTeX | Tags: animal, Animals, Fear, Heart Rate, human, Humans, phobia, Phobic Disorders, physiology, psychology, questionnaire, spider, Spiders, Surveys and Questionnaires, virtual reality exposure therapy
@article{tardif_re-examining_2019,
title = {Re-Examining Psychological Mechanisms Underlying Virtual Reality-Based Exposure for Spider Phobia},
author = {N. Tardif and C. -E. Therrien and S. Bouchard},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060171246&doi=10.1089%2fcyber.2017.0711&partnerID=40&md5=43737ac357efea6e35bd5668eb17e040},
doi = {10.1089/cyber.2017.0711},
issn = {21522715},
year = {2019},
date = {2019-01-01},
journal = {Cyberpsychology, Behavior, and Social Networking},
volume = {22},
number = {1},
pages = {39–45},
abstract = {The proposed study aims at expanding results from a previous study on mechanisms of change after exposure in virtual reality (VR) and documenting the impact of adding tactile and haptic feedback. It was predicted that change in the severity of spider phobia according to the Fear of Spiders Questionnaire (FSQ) would be significantly predicted by change in dysfunctional beliefs toward spiders and self-efficacy, over and above the variance explained by a physiological measure of fear during exposure (heart rate) and presence during the immersion. Participants (N = 59) were randomly assigned to the presentation of visual stimuli only, visual plus tactile stimuli, or visual, tactile plus haptic feedback stimuli. A standard multiple regression was conducted to predict change on the FSQ using the following predictors: beliefs about spiders, beliefs about one's own behavior when facing spiders, perceived self-efficacy, disgust, presence, and heart rate. Only changes in beliefs about spiders and in perceived self-efficacy significantly predicted the reduction in fear of spiders. This result enhances our understanding of the mechanisms involved in exposure conducted in VR. Analyses of variance also show that participants reported statistically significant changes in their clinical condition, with little added value to the addition of tactile and haptic feedback. The advantages of tactile and haptic stimulation are questioned, at least in the context of only one brief exposure session and the equipment used. © 2019, Mary Ann Liebert, Inc.},
note = {Publisher: Mary Ann Liebert Inc.},
keywords = {animal, Animals, Fear, Heart Rate, human, Humans, phobia, Phobic Disorders, physiology, psychology, questionnaire, spider, Spiders, Surveys and Questionnaires, virtual reality exposure therapy},
pubstate = {published},
tppubtype = {article}
}
The proposed study aims at expanding results from a previous study on mechanisms of change after exposure in virtual reality (VR) and documenting the impact of adding tactile and haptic feedback. It was predicted that change in the severity of spider phobia according to the Fear of Spiders Questionnaire (FSQ) would be significantly predicted by change in dysfunctional beliefs toward spiders and self-efficacy, over and above the variance explained by a physiological measure of fear during exposure (heart rate) and presence during the immersion. Participants (N = 59) were randomly assigned to the presentation of visual stimuli only, visual plus tactile stimuli, or visual, tactile plus haptic feedback stimuli. A standard multiple regression was conducted to predict change on the FSQ using the following predictors: beliefs about spiders, beliefs about one's own behavior when facing spiders, perceived self-efficacy, disgust, presence, and heart rate. Only changes in beliefs about spiders and in perceived self-efficacy significantly predicted the reduction in fear of spiders. This result enhances our understanding of the mechanisms involved in exposure conducted in VR. Analyses of variance also show that participants reported statistically significant changes in their clinical condition, with little added value to the addition of tactile and haptic feedback. The advantages of tactile and haptic stimulation are questioned, at least in the context of only one brief exposure session and the equipment used. © 2019, Mary Ann Liebert, Inc.
2.
St-Jacques, J.; Bouchard, S.; Bélanger, C.
In: Journal of Clinical Psychiatry, vol. 71, no. 7, pp. 924–931, 2010, ISSN: 01606689.
Abstract | Links | BibTeX | Tags: Adolescent, Animals, article, Child, clinical article, clinical trial, cognitive therapy, Combined Modality Therapy, Computer-Assisted, controlled clinical trial, controlled study, exposure, female, follow up, human, Humans, Implosive Therapy, Internal-External Control, male, motivation, outcome assessment, phobia, Phobic Disorders, predictor variable, priority journal, psychotherapy, randomized controlled trial, school child, Spiders, Therapy, treatment outcome, User-Computer Interface, virtual reality
@article{st-jacques_is_2010,
title = {Is virtual reality effective to motivate and raise interest in phobic children toward therapy? A clinical trial study of in vivo with in virtuo versus in vivo only treatment exposure},
author = {J. St-Jacques and S. Bouchard and C. Bélanger},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955295979&doi=10.4088%2fJCP.08m04822blu&partnerID=40&md5=d542122407b00dcaecc8c51dcaf40610},
doi = {10.4088/JCP.08m04822blu},
issn = {01606689},
year = {2010},
date = {2010-01-01},
journal = {Journal of Clinical Psychiatry},
volume = {71},
number = {7},
pages = {924–931},
abstract = {Objective: The first objective of this study was to assess if a combined treatment with mostly virtual reality-based (in virtuo) exposure increases phobic children's motivation toward therapy compared to children who only receive in vivo exposure. Another objective was the assessment of motivation as a predictor of treatment outcome. Method: Thirty-one DSM-IV-diagnosed arachnophobic participants aged from 8 to 15 years were randomly assigned to 1 of 2 treatment conditions: in vivo exposure alone or in virtuo plus in vivo exposure. Measures of motivation were taken at pretest and at the end of each part of the treatment; some other measures were taken at each session. The "Why Are You in Therapy?" questionnaire for children was the target measure of motivation and the main variable in the study. Outcome measures were taken at pretest, at the end of each part of the treatment, and at the 6-month follow-up. This study was conducted between September 2006 and March 2007. Results: The results showed that children who received in virtuo exposure did not show a higher level of motivation toward their treatment than those who received in vivo exposure, but statistically significant interactions were found for both parts of the treatment. Multiple regression analysis confirmed that motivation was a significant predictor of outcome (P < .01), especially extrinsic integrated motivation. Participants in the combined treatment were significantly more phobic before beginning treatment, but both treatments appeared successful (P < .001). Conclusions: In this study, the use of virtual reality did not increase motivation toward psychotherapy. At the end of the second part of therapy, all participants were comparably efficient in facing a live tarantula. These results bear important clinical implications concerning how to use virtual reality with children and concerning motivation of children toward therapy in general. They are discussed in the light of how to present in virtuo therapy to children. Trial Registration: controlled-trials.com Identifier: ISRCTN87716831. © Copyright 2010 Physicians Postgraduate Press, Inc.},
keywords = {Adolescent, Animals, article, Child, clinical article, clinical trial, cognitive therapy, Combined Modality Therapy, Computer-Assisted, controlled clinical trial, controlled study, exposure, female, follow up, human, Humans, Implosive Therapy, Internal-External Control, male, motivation, outcome assessment, phobia, Phobic Disorders, predictor variable, priority journal, psychotherapy, randomized controlled trial, school child, Spiders, Therapy, treatment outcome, User-Computer Interface, virtual reality},
pubstate = {published},
tppubtype = {article}
}
Objective: The first objective of this study was to assess if a combined treatment with mostly virtual reality-based (in virtuo) exposure increases phobic children's motivation toward therapy compared to children who only receive in vivo exposure. Another objective was the assessment of motivation as a predictor of treatment outcome. Method: Thirty-one DSM-IV-diagnosed arachnophobic participants aged from 8 to 15 years were randomly assigned to 1 of 2 treatment conditions: in vivo exposure alone or in virtuo plus in vivo exposure. Measures of motivation were taken at pretest and at the end of each part of the treatment; some other measures were taken at each session. The "Why Are You in Therapy?" questionnaire for children was the target measure of motivation and the main variable in the study. Outcome measures were taken at pretest, at the end of each part of the treatment, and at the 6-month follow-up. This study was conducted between September 2006 and March 2007. Results: The results showed that children who received in virtuo exposure did not show a higher level of motivation toward their treatment than those who received in vivo exposure, but statistically significant interactions were found for both parts of the treatment. Multiple regression analysis confirmed that motivation was a significant predictor of outcome (P < .01), especially extrinsic integrated motivation. Participants in the combined treatment were significantly more phobic before beginning treatment, but both treatments appeared successful (P < .001). Conclusions: In this study, the use of virtual reality did not increase motivation toward psychotherapy. At the end of the second part of therapy, all participants were comparably efficient in facing a live tarantula. These results bear important clinical implications concerning how to use virtual reality with children and concerning motivation of children toward therapy in general. They are discussed in the light of how to present in virtuo therapy to children. Trial Registration: controlled-trials.com Identifier: ISRCTN87716831. © Copyright 2010 Physicians Postgraduate Press, Inc.
3.
Michaliszyn, D.; Marchand, A.; Bouchard, S.; Martel, M. -O.; Poirier-Bisson, J.
A randomized, controlled clinical trial of in virtuo and in vivo exposure for spider phobia Journal Article
In: Cyberpsychology, Behavior, and Social Networking, vol. 13, no. 6, pp. 689–695, 2010, ISSN: 21522723 (ISSN).
Abstract | Links | BibTeX | Tags: Adolescent, adult, analysis of variance, animal, Animals, article, behavior therapy, clinical trial, computer interface, Computer Simulation, controlled clinical trial, controlled study, Diagnostic and Statistical Manual of Mental Disorders, female, follow up, Follow-Up Studies, hospitalization, human, Humans, Implosive Therapy, Intention to Treat Analysis, interview, male, methodology, Middle Aged, phobia, Phobic Disorders, psychologic test, Psychological, questionnaire, Questionnaires, randomized controlled trial, Severity of Illness Index, spider, Spiders, treatment outcome, User-Computer Interface
@article{michaliszyn_randomized_2010,
title = {A randomized, controlled clinical trial of in virtuo and in vivo exposure for spider phobia},
author = {D. Michaliszyn and A. Marchand and S. Bouchard and M. -O. Martel and J. Poirier-Bisson},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650262716&doi=10.1089%2fcyber.2009.0277&partnerID=40&md5=8efc6b65de8b3477ca3cd0fa8fcab93a},
doi = {10.1089/cyber.2009.0277},
issn = {21522723 (ISSN)},
year = {2010},
date = {2010-01-01},
journal = {Cyberpsychology, Behavior, and Social Networking},
volume = {13},
number = {6},
pages = {689–695},
abstract = {The present study compared the efficacy of virtual reality (VR) in virtuo exposure and in vivo exposure in the treatment of spider phobia. Two treatment conditions were compared to a waiting-list condition. A 3-month follow-up evaluation was conducted in order to assess the durability of the treatment effects. Participants were randomly assigned to the treatment groups. A total of 16 participants received the in virtuo treatment, and 16 received the in vivo treatment. The waiting-list condition included 11 participants. Participants received eight 1.5-hour treatment sessions. Efficacy was measured with the Fear of Spiders Questionnaire, the Spider Beliefs Questionnaire (SBQ-F), and a Behavioral Avoidance Test (BAT). In addition, a clinician administered the Structured Interview for DSM-IV to assess DSM-IV's criteria for specific phobia and severity. Clinical and statistically significant improvements were found for both groups. Differences in treatment groups were found on one of five measures of fear: greater improvement on the SBQ-F beliefs subscale was associated with in vivo exposure. Copyright 2010, Mary Ann Liebert, Inc.},
keywords = {Adolescent, adult, analysis of variance, animal, Animals, article, behavior therapy, clinical trial, computer interface, Computer Simulation, controlled clinical trial, controlled study, Diagnostic and Statistical Manual of Mental Disorders, female, follow up, Follow-Up Studies, hospitalization, human, Humans, Implosive Therapy, Intention to Treat Analysis, interview, male, methodology, Middle Aged, phobia, Phobic Disorders, psychologic test, Psychological, questionnaire, Questionnaires, randomized controlled trial, Severity of Illness Index, spider, Spiders, treatment outcome, User-Computer Interface},
pubstate = {published},
tppubtype = {article}
}
The present study compared the efficacy of virtual reality (VR) in virtuo exposure and in vivo exposure in the treatment of spider phobia. Two treatment conditions were compared to a waiting-list condition. A 3-month follow-up evaluation was conducted in order to assess the durability of the treatment effects. Participants were randomly assigned to the treatment groups. A total of 16 participants received the in virtuo treatment, and 16 received the in vivo treatment. The waiting-list condition included 11 participants. Participants received eight 1.5-hour treatment sessions. Efficacy was measured with the Fear of Spiders Questionnaire, the Spider Beliefs Questionnaire (SBQ-F), and a Behavioral Avoidance Test (BAT). In addition, a clinician administered the Structured Interview for DSM-IV to assess DSM-IV's criteria for specific phobia and severity. Clinical and statistically significant improvements were found for both groups. Differences in treatment groups were found on one of five measures of fear: greater improvement on the SBQ-F beliefs subscale was associated with in vivo exposure. Copyright 2010, Mary Ann Liebert, Inc.
4.
Côté, S.; Bouchard, S.
Cognitive mechanisms underlying virtual reality exposure Journal Article
In: Cyberpsychology and Behavior, vol. 12, no. 2, pp. 121–129, 2009, ISSN: 10949313 (ISSN).
Abstract | Links | BibTeX | Tags: Adaptation, adult, aged, Animals, arachnophobia, Arousal, article, avoidance behavior, cardiovascular response, clinical article, cognition, Culture, female, Heart Rate, human, Humans, Implosive Therapy, male, Middle Aged, Personality Assessment, phobia, Phobic Disorders, prediction, Psychological, questionnaire, Questionnaires, regression analysis, scoring system, Self Efficacy, spider, Spiders, structured interview, task performance, treatment outcome, User-Computer Interface, virtual reality, Young Adult
@article{cote_cognitive_2009,
title = {Cognitive mechanisms underlying virtual reality exposure},
author = {S. Côté and S. Bouchard},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-64749106909&doi=10.1089%2fcpb.2008.0008&partnerID=40&md5=e9bd263ea9e1940b66910d9651bd119e},
doi = {10.1089/cpb.2008.0008},
issn = {10949313 (ISSN)},
year = {2009},
date = {2009-01-01},
journal = {Cyberpsychology and Behavior},
volume = {12},
number = {2},
pages = {121–129},
abstract = {Many studies have assessed virtual reality exposures efficacy, but very few examined its treatment processes. The addition of objective measures of arousal and information processing mechanisms would be a valuable contribution in order to provide a more complete and detailed picture. The goal of this study was to better document the cognitive mechanisms associated with therapeutic change after an in virtuo exposure treatment. Twenty-eight adults suffering from arachnophobia were assessed and received an exposure-based treatment using virtual reality. General outcome and specific processes measures included a battery of standardized questionnaires, a pictorial emotional Stroop task, a Behavioral Avoidance Test, and a measure of participants' cardiac response while they looked at a live tarantula. The analyses showed that changes in perceived self-efficacy and dysfunctional beliefs were the best predictors of change in general outcome and cardiac response; change in dysfunctional beliefs were the best predictor of change in behavioral avoidance. These innovative results provide a very detailed and organized picture of the complex cognitive mechanisms involved in therapeutic change following in virtuo exposure for arachnophobia. © 2009 Mary Ann Liebert, Inc.},
keywords = {Adaptation, adult, aged, Animals, arachnophobia, Arousal, article, avoidance behavior, cardiovascular response, clinical article, cognition, Culture, female, Heart Rate, human, Humans, Implosive Therapy, male, Middle Aged, Personality Assessment, phobia, Phobic Disorders, prediction, Psychological, questionnaire, Questionnaires, regression analysis, scoring system, Self Efficacy, spider, Spiders, structured interview, task performance, treatment outcome, User-Computer Interface, virtual reality, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Many studies have assessed virtual reality exposures efficacy, but very few examined its treatment processes. The addition of objective measures of arousal and information processing mechanisms would be a valuable contribution in order to provide a more complete and detailed picture. The goal of this study was to better document the cognitive mechanisms associated with therapeutic change after an in virtuo exposure treatment. Twenty-eight adults suffering from arachnophobia were assessed and received an exposure-based treatment using virtual reality. General outcome and specific processes measures included a battery of standardized questionnaires, a pictorial emotional Stroop task, a Behavioral Avoidance Test, and a measure of participants' cardiac response while they looked at a live tarantula. The analyses showed that changes in perceived self-efficacy and dysfunctional beliefs were the best predictors of change in general outcome and cardiac response; change in dysfunctional beliefs were the best predictor of change in behavioral avoidance. These innovative results provide a very detailed and organized picture of the complex cognitive mechanisms involved in therapeutic change following in virtuo exposure for arachnophobia. © 2009 Mary Ann Liebert, Inc.
5.
Côté, S.; Bouchard, S.
Documenting the efficacy of virtual realityexposure with psychophysiological and information processing measures Journal Article
In: Applied Psychophysiology Biofeedback, vol. 30, no. 3, pp. 217–232, 2005, ISSN: 10900586 (ISSN).
Abstract | Links | BibTeX | Tags: adult, analysis of variance, Animals, arachnophobia, Arousal, article, avoidance behavior, cardiovascular response, clinical article, emotion, Emotions, exposure, Fear, female, Heart Rate, human, Humans, information processing, male, medical documentation, Mental Processes, Middle Aged, outcomes research, phobia, phobias, Phobic Disorders, Psychophysiology, questionnaire, Reproducibility of Results, self report, spider, Spiders, standardization, stimulus response, task performance, threat, treatment outcome, User-Computer Interface, virtual reality, Visual Perception, visual stimulation
@article{cote_documenting_2005,
title = {Documenting the efficacy of virtual realityexposure with psychophysiological and information processing measures},
author = {S. Côté and S. Bouchard},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-25144467954&doi=10.1007%2fs10484-005-6379-x&partnerID=40&md5=12308d48c2d79eff9c6446385244c27c},
doi = {10.1007/s10484-005-6379-x},
issn = {10900586 (ISSN)},
year = {2005},
date = {2005-01-01},
journal = {Applied Psychophysiology Biofeedback},
volume = {30},
number = {3},
pages = {217–232},
abstract = {Many outcome studies have been conducted to assess the efficacy of virtual reality in the treatment of specific phobias. However, most studies used self-report data. The addition of objective measures of arousal and information processing mechanisms would be a valuable contribution in order to validate the usefulness of virtual reality in the treatment of anxiety disorders. The goal of this study was to document the impact of virtual reality exposure (VRE) on cardiac response and automatic processing of threatening stimuli. Twenty-eight adults suffering from arachnophobia were assessed and received an exposure-based treatment using virtual reality. General outcome and specific processes measures included a battery of standardized questionnaires, a pictorial emotional Stroop task, a behavioral avoidance test and a measure of participants' inter-beat intervals (IBI) while they were looking at a live tarantula. Assessment was conducted before and after treatment. Repeated measures ANOVAs revealed that therapy had a positive impact on questionnaire data, as well as on the behavioral avoidance test. Analyses made on the pictorial Stroop task showed that information processing of spider-related stimuli changed after treatment, which also indicates therapeutic success. Psychophysiological data also showed a positive change after treatment, suggesting a decrease in anxiety. In sum, VRE led to significant therapeutic improvements on objective measures as well as on self-report instruments. © 2005 Springer Science+Business Media, Inc.},
keywords = {adult, analysis of variance, Animals, arachnophobia, Arousal, article, avoidance behavior, cardiovascular response, clinical article, emotion, Emotions, exposure, Fear, female, Heart Rate, human, Humans, information processing, male, medical documentation, Mental Processes, Middle Aged, outcomes research, phobia, phobias, Phobic Disorders, Psychophysiology, questionnaire, Reproducibility of Results, self report, spider, Spiders, standardization, stimulus response, task performance, threat, treatment outcome, User-Computer Interface, virtual reality, Visual Perception, visual stimulation},
pubstate = {published},
tppubtype = {article}
}
Many outcome studies have been conducted to assess the efficacy of virtual reality in the treatment of specific phobias. However, most studies used self-report data. The addition of objective measures of arousal and information processing mechanisms would be a valuable contribution in order to validate the usefulness of virtual reality in the treatment of anxiety disorders. The goal of this study was to document the impact of virtual reality exposure (VRE) on cardiac response and automatic processing of threatening stimuli. Twenty-eight adults suffering from arachnophobia were assessed and received an exposure-based treatment using virtual reality. General outcome and specific processes measures included a battery of standardized questionnaires, a pictorial emotional Stroop task, a behavioral avoidance test and a measure of participants' inter-beat intervals (IBI) while they were looking at a live tarantula. Assessment was conducted before and after treatment. Repeated measures ANOVAs revealed that therapy had a positive impact on questionnaire data, as well as on the behavioral avoidance test. Analyses made on the pictorial Stroop task showed that information processing of spider-related stimuli changed after treatment, which also indicates therapeutic success. Psychophysiological data also showed a positive change after treatment, suggesting a decrease in anxiety. In sum, VRE led to significant therapeutic improvements on objective measures as well as on self-report instruments. © 2005 Springer Science+Business Media, Inc.
6.
Renaud, P.; Bouchard, S.; Proulx, R.
Behavioral avoidance dynamics in the presence of a virtual spider Journal Article
In: IEEE Transactions on Information Technology in Biomedicine, vol. 6, no. 3 SPEC., pp. 235–243, 2002, ISSN: 10897771 (ISSN).
Abstract | Links | BibTeX | Tags: adult, Affordance, animal, Animals, Anxiety, Anxiety disorder, article, Behavioral avoidance, Biomedical engineering, Chronic Disease, clinical trial, Computer Graphics, computer interface, Computer Simulation, controlled clinical trial, controlled study, Environment, Fear, female, Fractal dynamics, Fractals, head movement, Head movements, hospitalization, human, Human computer interaction, Humans, Interactive computer graphics, male, Motion Perception, movement perception, pathophysiology, Patient treatment, phobia, Phobic Disorders, Presence, psychological aspect, Psychomotor Performance, Psychophysiology, reproducibility, Reproducibility of Results, Self Assessment (Psychology), self evaluation, Sensitivity and Specificity, Severity of Illness Index, spider, Spiders, Tracking, treatment outcome, User-Computer Interface, virtual reality
@article{renaud_behavioral_2002,
title = {Behavioral avoidance dynamics in the presence of a virtual spider},
author = {P. Renaud and S. Bouchard and R. Proulx},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036708418&doi=10.1109%2fTITB.2002.802381&partnerID=40&md5=4dd582cb233d8396f7795cf93cb1b984},
doi = {10.1109/TITB.2002.802381},
issn = {10897771 (ISSN)},
year = {2002},
date = {2002-01-01},
journal = {IEEE Transactions on Information Technology in Biomedicine},
volume = {6},
number = {3 SPEC.},
pages = {235–243},
abstract = {Tracking behavior with a virtual spider and a neutral target is compared in fearful and nonfearful subjects. Head-tracking in virtual environments appears to be a scale-free behavior with long-range fractal-like patterns. Moreover, these fractal patterns change according to what the target affords the tracker and the level of behavioral avoidance manifested by the subjects. Results are interpreted in terms of ecological psychology and nonlinear dynamics, and implications for virtual reality (VR) psychology are outlined.},
keywords = {adult, Affordance, animal, Animals, Anxiety, Anxiety disorder, article, Behavioral avoidance, Biomedical engineering, Chronic Disease, clinical trial, Computer Graphics, computer interface, Computer Simulation, controlled clinical trial, controlled study, Environment, Fear, female, Fractal dynamics, Fractals, head movement, Head movements, hospitalization, human, Human computer interaction, Humans, Interactive computer graphics, male, Motion Perception, movement perception, pathophysiology, Patient treatment, phobia, Phobic Disorders, Presence, psychological aspect, Psychomotor Performance, Psychophysiology, reproducibility, Reproducibility of Results, Self Assessment (Psychology), self evaluation, Sensitivity and Specificity, Severity of Illness Index, spider, Spiders, Tracking, treatment outcome, User-Computer Interface, virtual reality},
pubstate = {published},
tppubtype = {article}
}
Tracking behavior with a virtual spider and a neutral target is compared in fearful and nonfearful subjects. Head-tracking in virtual environments appears to be a scale-free behavior with long-range fractal-like patterns. Moreover, these fractal patterns change according to what the target affords the tracker and the level of behavioral avoidance manifested by the subjects. Results are interpreted in terms of ecological psychology and nonlinear dynamics, and implications for virtual reality (VR) psychology are outlined.