EABCT 2006 in Paris. Why would VR works in the treatment of anxiety disorder?

Transcription

1 Why would VR works in the treatment of anxiety disorder? Stéphane Bouchard, Ph.D. Geneviève Robillard, M.Sc. & Stéphanie Dumoulin, B.A. Département de Psychoéducation et de Psychologie Laboratoire de Cyberpsychologie Université du Québec en Outaouais Context Virtual stimuli are far from being perfect replicas of the physical reality 1

2 Something let the brain works as if the stimuli are real Perceived self-efficay efficay One hypothesis Pre-frontal Amygdala / Lymbic system Automatic processing of threat-related related cues The sense of presence The illusion of being there in the virtual environment (Sadowski & Stanney, 2002). Also referred to as: suspended disbelief (Wiederhold & Wiederhold, 200); the illusion of non-mediation (Lombard & Ditton, 1997). 2

3 Study 1: Presence as a predictor of treatment outcome 22 adults SCID-diagnosed of specific phobia, subtype phobia of flying. Mean age.5 (sd = 11.52). 5% female, 5 % married. Treated with in virtuo exposure only during sessions following a standardized treatment protocol (see w3.uqo.ca/cyberpsy). Material 3

4 Instruments Fear of Flying Questionnaire (pre and post Rx). Mean pre: 12.3 (sd=1.9) Mean post: 7. (sd=9.9) Attitudes Towards Flying (pre and post Rx). Mean pre: 2.91 (sd=7.) Mean post: 15 (sd=97.99) Immersive Tendencies Questionnaire (pre Rx). Mean: 5.55 (sd=13.27) Presence was measured with a 0 to 100 question addressed to the patent every five minutes during in virtuo exposure. All observations recorded during every therapy sessions were averaged to provide a score of presence felt during the immersions in virtual reality. Mean: 0.0 (sd=22.9) Results Regression with residualized change scores to predict improvement on the Fear of Flying Q. The regression was significant [F (,17) =.1, p < 0.001, Adj R 2 =.5)]. Predictors of post FFQ t B Part sr 2 FFQ Pre Age 3.27.**. Presence * -.32 Immersive tendencies ** -. * p <.05, ** p <.01

5 Results Regression with residualized change scores to predict improvement on the Attitudes T. Flying. The regression was significant [F (,17) = 9.37, p < 0.001, Adj R 2 =.1)]. Predictors of post ATQ t B Part sr 2 ATQ Pre Age 2..1*.3 Presence * -.29 Immersive tendencies * -.3 * p <.05 Study 2 Manipulating anxiety to assess its impact on presence 29 snake phobics were immersed in an irrelevant (control) virtual environment and twice in the same experimental virtual environment. In the experimental environment, participants were falsely informed that the virtual environment was: (a) filled with poisonous hidden snakes (ANXiety), and (b) without any snakes (NO ANXiety). The ANX and NO ANX immersions were counterbalanced and participants were randomly assigned to either conditions. 5

6 Does anxiety increase presence? Snake phobics were led to believe that some environments are filled with hidden snakes. Bouchard et al. (submitted). Anxiety Measured at post immersion First Immersion (CTRL) Second Immersion Third Immersion CTRL - ANX - NOANX CTRL - NOANX - ANX Results 10 9 p <.05 p <.05 p <.05 p <.05 p <.05 p <.05 Presence 7 5 Ctrl Imm Ctrl Post Imm Ctrl During Imm 1 Post Imm 1 During Imm 2 Post Imm 2 ANX first NO ANX first ANOVA : Time (F = 9., p <.001) Interaction Time x Condition (F = 3.75, p <.02) Condition (F =.07, ns) Imm 1: r (anx / pres) =.9, p <.001 Imm 2: r (anx / pres) =.77, p <.001

7 Study 3 Manipulating presence to assess its impact on anxiety 33 adults suffering from height phobia (73% female). Task to perform in the VR environment: Take the elevator to the highest possible floor (/15), walk outside, walk on planks and cross over to the building on the other side of the street, etc. Two experimental conditions (random assignment) Strong presence (via effective immersion) Lights were shut down, a cloth covered the HMD, no other sound could be heard appart the sond from the VR environment, etc.. Poor presence (via poor immersion) Lights were on, no cloth covering the HMD, background music in the physical room, etc. Material Note: the cup on the Cy-Visor were removed in one condition. An Intertrax2 was used for head tracking. 7

8 Results Presence Immersion 1 Immersion 2 Strong presence 1st Poor presence 1st Anxiety immersion 1 immersion 2 Strong presence 1st Poor presence 1st Repeated measures ANOVA Time(F =0.27, ns) Interaction Time x Condition (F =.75, p <.05) Condition (F =1.2, ns) Repeated measures ANOVA Time(F =1.7, ns) Interaction Time x Condition (F= 12.73, p <.05) Condition (F=1., ns) Conclusion Presence predicted treatment outcome. The role of presence was not as strong as expected. Immersive tendencies was also a significant predictor. The role of presence may be to mediate the possibility to induce anxiety, then allowing to conduct functional exposure. There is a bi-directional relationship between presence and anxiety.