How body movement influences Virtual Reality analgesia? Interactive Technologies and Games (ITAG) Conference 2014 Health, Disability and Education Dates: Thursday 16 October 2014 - Friday 17 October 2014 Location: The Council House, NG1 2DT, Nottingham, UK

1. How body movement influences Virtual Reality analgesia?
MARCIN CZUB, JOANNA PISKORZ
INSTITUTE OF PSYCHOLOGY, UNIVERSITY OF WROCLAW

2. VR - real time simulation of 3d environment, responding to user actions, and immersing the user in the simulated environment.

3. Pict: http://en.wikipedia.org/wiki/Virtuix_Omni
https://developer.leapmotion.com/vr
http://en.wikipedia.org/wiki/Kinect

4. VR & Pain treatment

5. Analgesic efficacy of VR in the treatment of pain:
•In oncological setting – children
•Women with breast cancer - chemotherapy
•Dentistry – reduction of pain and fear
•Experimental pain paradigms: thermal pain, ischemic pain.
Das et al. (2005); Gershon et al., 2004; Hoffman et al., 2001

6. •Warm vs cold VE - hot / cold pain stimulation
•1st person vs 3rd person – racing game
•Dynamic game vs slow paced game
•More complex VE vs less complex VE
•Active participation vs passive observation of gameplay
•Looking around and interaction vs passive observation
Comparing different VE’s and interface types:

7. •The relationship between VR analgesia and the strength of one’s subjective presence in a virtual world
•Feeling and acting as if a person is located in the virtual world
•Body movements executed in relation to a given environment presence in that environment
Hoffman et al,2004; Slater et al,1998

8. •bodily engagement affective experience
•The interface that allowed for more body movement was more effective in evoking emotional reaction towards the game
Bianchi-Berthouze et al.,2007

9. Body movement
Presence
Pain alleviation

10. Design and methods

11. Independent variable:
•Type of movement (two levels) – small (mouse)and large (Kinect) Dependent variables:
• Pain tolerance (the time participants kept their hand in cold water)
• Pain intensity (Visual Analogue Scale)
• Presence (Igroup Presence Questionnaire)
Within participants experimental design
•Without no-VR control condition

12. Cold Pressor Test
•temperature 0.5-1.5 °C
•water circulator, a separate ice container, and a digital thermometer
VAS
•a horizontal 10cm continuous line - strength of experienced pain, expressed on the scale in centimeters, where 0 represented no pain, and 10 extreme pain
•commonly used in CPT, validity similar to other measures

13. Igroup Presence Questionnaire
Schubert, 2003
•Spatial presence – the sense of being located inside a VE
•Involvement – the level of engagement in a VE
•Realism – the sense of VE realism
•General – an additional item measuring the general “sense of being there”

14. •Custom made game
•Steering white sphere, collecting yellow spheres, avoiding collision with red spheres
Game

15. Equipment
•HMD’s - E-Magin Z-800, SVGA resolution, 40 deg diagonal FOV (which equals looking at a 2.7m diagonal movie screen from 3.7 m distance).
•Kinect/mouse - require only the use of a dominant limb
•both are common computer peripherals

16. Participants
•30 volunteers, students of Wroclaw universities
•20 females (average age: 20,55; SD = 1,50; min = 19, max = 24) and 10 males (average age: 25,60; SD = 9, 26 ; min = 18 ; max = 50)
•Recruited through University’s social media pages

17. Procedure
•Practice session – Kinect – until 10 points
•2 conditions, counterbalanced order
•4 minutes – maximum time in cold water
•a 15 minute break between conditions in order to warm up the hand

18. Results

20. •N = 26; T = 86.5, Z = 2.26, p = 0.024
•On average, in high motion condition participants kept their hand in a cold water for 25 seconds more.
•Effect size: r = 0.44

22. N = 22, T = 104, Z = 0.73, p = 0.47

23. •VAS after removing the goggles attention no longer distracted by the game
•Focus on the pain experience in order to assess its intensity
•VAS should be implemented into the VR application itself

24. Negative correlation between pain tolerance and pain intensity
Large movement: r = -0.38, p < 0.05
Small movement: r = - 0.42, p < 0.05

25. •Pain experienced during a cold pressor test increases slowly with time
•But it can be assumed, that participants who kept their hand in cold water longer did so because they felt less pain
Two possible, conflicting predictions could be made about the pain tolerance/pain intensity relationship:

26. IPQ results
•No significant correlations between IPQ dimensions and the pain measures used in the study
•IPQ results did not differ between conditions:
•Spatial presence: t= -1.96; p = 0.059
•Involvement: t = - 1. 21; p = 0.24
•Realism: t = - 0.37, p = 0.72
•General: t = 0.53; p = 0.60)

27. Other results:
•Kinect steering as significantly more difficult than mouse steering (t = 8.70; p < 0.0001)
•Significantly more points while steering with the computer mouse, comparing to Kinect. (t = 4.169; p = 0.0003)

29. Methodological improvements:
•Precise measurement of the amount of movement
•Implementing VAS inside the VE
•Using behavioural or physiological presence measures
•Better control over difficulty and novelty of interfaces
•Collecting physiological data – heart rate, blood pressure, respiration rate

30. Questions:
•How important are visual consequences of movement?
•Complexity of movement, number of body parts engaged
•Other experimental pain paradigms – e.g. ischemic pain
•Clinical populations – with various movement restrictions

31. Thank you