| Literature DB >> 26354311 |
Sofia Adelaide Osimo1, Rodrigo Pizarro1, Bernhard Spanlang1, Mel Slater1.
Abstract
When people see a life-sized virtual body (VB) from first person perspective in virtual reality they are likely to have the perceptual illusion that it is their body. Additionally such virtual embodiment can lead to changes in perception, implicit attitudes and behaviour based on attributes of the VB. To date the changes that have been studied are as a result of being embodied in a body representative of particular social groups (e.g., children and other race). In our experiment participants alternately switched between a VB closely resembling themselves where they described a personal problem, and a VB representing Dr Sigmund Freud, from which they offered themselves counselling. Here we show that when the counsellor resembles Freud participants improve their mood, compared to the counsellor being a self-representation. The improvement was greater when the Freud VB moved synchronously with the participant, compared to asynchronously. Synchronous VB movement was associated with a much stronger illusion of ownership over the Freud body. This suggests that this form of embodied perspective taking can lead to sufficient detachment from habitual ways of thinking about personal problems, so as to improve the outcome, and demonstrates the power of virtual body ownership to effect cognitive changes.Entities:
Mesh:
Year: 2015 PMID: 26354311 PMCID: PMC4564809 DOI: 10.1038/srep13899
Source DB: PubMed Journal: Sci Rep ISSN: 2045-2322 Impact factor: 4.379
Figure 1The counselling scenario.
(A) Stereo 1PP view from the participant in his lookalike body, looking towards the Freud counsellor. He sees himself from 1PP and also in the mirror to his left. (B) Stereo 1PP view from the Freud body looking towards the lookalike representation of the participant. He sees himself as Freud from 1PP and also in the mirror to his right. Readers may fuse the two images in each of (A,B) into one stereo image by crossing their eyes. (C) The participant with the HMD and the motion capture suit. Note how the posture is reflected in (A) through the motion capture. (D) The participant being scanned to make his lookalike body.
Body Ownership and Agency Questionnaire.
| Variable Name | Statement |
|---|---|
| Even though the body I see might not physically look like me, I feel that the virtual body I see when I look down towards myself is my body. | |
| Even though the body I see might not physically look like me, I feel that the virtual body I see reflected in the mirror is my body. | |
| I feel that the movements of the virtual body are caused by my own movements. | |
| The body I see in the virtual world physically looks like me. |
Each statement was scored on a 1–7 Likert scale where 1 indicates no agreement and 7 complete agreement.
Figure 2Box plots for the body ownership related questions by condition (Table 1).
The medians are shown as the thick horizontal lines, and the boxes are the interquartile ranges (IQR). The whiskers extend from L = max(p25−1.5 × IQR, x1) to U = min(p75 + 1.5 × IQR, xn), where p25, p75 are the 25th and 75th percentiles respectively, and x1 and xn are the smallest and largest data points respectively. Points outside this range are shown individually. Async and Sync refer to the asynchronous and synchronous virtual body movements, and Self and Freud refer to the counsellor virtual bodies. n = 10 for Async & Freud, n = 12 for each of the other two conditions.
Figure 3Box plots of pre- and post-experiment measures on POMS and SAM.
Mixed Effects regression of dPOMSTotal on Counsellor and SUDS (Experiment 1).
| Term | Coef. | Robust S.E. | P | 95% C.I. | Cohen’s |
|---|---|---|---|---|---|
| Intercept | −19.47 | 8.36 | 0.020 | −35.87 to −3.08 | |
| Counsellor (Self = 0, Freud = 1) | 25.00 | 12.00 | 0.037 | 1.47 to 48.52 | |
| SUDS | 2.97 | 2.24 | 0.184 | −1.41 to 7.35 | |
| Counsellor × SUDS | −9.43 | 3.97 | 0.017 | −17.21 to −1.65 | 0.35 |
Overall goodness of fit Wald χ2(3) = 8.45, P = 0.0375. (n = 12 groups with 2 sets of observation per group).
Mixed Effects regression of dSAMHappy on Counsellor and SUDS (Experiment 1).
| Term | Coef. | Robust S.E. | P | 95% C.I. | Cohen’s |
|---|---|---|---|---|---|
| Intercept | −0.75 | 0.68 | 0.273 | −2.08 to 0.59 | |
| Counsellor (Self = 0, Freud = 1) | 0.81 | 0.27 | 0.003 | 0.27 to 1.34 | 0.33 |
| SUDS | 0.46 | 0.22 | 0.033 | 0.04 to 0.89 | 0.10 |
Overall goodness of fit Wald χ2 (2) = 18.17, P = 0.0001. (n = 12 groups with 2 sets of observation per group).
Mixed Effects regression of dSAMIntensity on Counsellor and SUDS (Experiment 1).
| Term | Coef. | Robust S.E. | P | 95% C.I. | Cohen’s |
|---|---|---|---|---|---|
| Intercept | −2.24 | 2.07 | 0.278 | −6.30 to 1.81 | |
| Counsellor (Self = 0, Freud = 1) | 7.58 | 2.88 | 0.009 | 1.92 to 13.23 | |
| SUDS | 0.43 | 0.68 | 0.532 | −0.91 to 1.77 | |
| Counsellor × SUDS | −2.25 | 0.93 | 0.016 | −4.08 to −0.42 | 0.52 |
Overall goodness of fit Wald Chi-Squared(3) = 9.82, P = 0.020. (n = 10 groups with 2 sets of observation per group, 1 group with one missing observation).
Regression of dPOMSTotal on SUDS and MyBodyPCA (Experiment 2).
| Term | Coef. | Robust S.E. | P | 95% C.I. | Cohen’s |
|---|---|---|---|---|---|
| Intercept | 11.49 | 9.80 | 0.257 | −9.17 to 32.16 | |
| SUDS | −8.75 | 2.98 | 0.009 | −15.04 to −2.45 | |
| MyBodyPCA | 13.65 | 6.46 | 0.050 | 0.02 to 27.28 | |
| SUDS × MyBodyPCA | −5.42 | 1.99 | 0.014 | −9.62 to −1.23 | 0.20 |
Overall goodness of fit F(3,17) = 4.36, P = 0.005, R-Squared = 0.41 (n = 21, one missing observation).
Regression of dSAMHappy on SUDS and Visuomotor (Experiment 2).
| Term | Coef. | Robust S.E. | P | 95% C.I. | Cohen’s |
|---|---|---|---|---|---|
| Intercept | −1.16 | 0.85 | 0.187 | −2.93 to 0.61 | |
| Visuomotor (Async = 0,Sync = 1) | 0.70 | 0.35 | 0.062 | −0.04 to 1.43 | 0.23 |
| SUDS | 0.65 | 0.23 | 0.012 | 0.16 to 1.14 | 0.47 |
Overall goodness of fit F(2,19) = 6.09, P = 0.028, R-Squared = 0.38, (n = 22).
Regression of dSAMHappy on SUDS and MyBodyPCA (Experiment 2).
| Term | Coef. | Robust S.E. | P | 95% C.I. | Cohen’s |
|---|---|---|---|---|---|
| Intercept | 0.04 | 0.55 | 0.941 | −1.11 to 1.20 | |
| MyBodyPCA | 0.43 | 0.12 | 0.003 | 0.17 to 0.69 | 0.84 |
| SUDS | 0.46 | 0.16 | 0.011 | 0.12 to 0.80 | 0.36 |
Overall goodness of fit F(2,18) = 12.06, P = 0.0005, R-Squared = 0.59 (n = 21, one missing).