Creation of virtual reality stimulus for a psychophysiological body balance measurement

Tero Alatalo¹, Martti Juhola¹, Veikko Surakka^1,2, Timo Tossavainen¹

¹Department of Computer Sciences, University of Tampere, Tampere, Finland; ²Department of Clinical Neurophysiology, Tampere University Hospital, Tampere, Finland

Abstract: Virtual reality methods and equipment can be used to create stimulations for several psychophysiological measurements. Such stimulations can be flexibly modified and their versatility is wide; in principle even such could be prepared that are not possible in the real physical world like virtual flying in the space. For the generation of virtual reality stimulations we constructed a three-dimensional (3D) graphics engine to measure body balance variations in response to emotional stimulation. The stimulation was implemented as a virtual reality scene, where the subject watched a street view with a human figure approaching the subject at a constant speed. The functioning of the system was tested by measuring body balance variations while the approaching figure’s facial expression was angry, neutral, or happy. The results showed that our young, healthy subjects were slightly, but still statistically significantly affected by the stimulation of the approaching figure. Thus, the whole system offers a tool for controlled experimental studies for analyzing body balance, for example, during stimulating approach-withdrawal behavior. There are several opportunities to further develop new visual psychophysiological stimulations and test forms.

Keywords: virtual reality stimulations, signal analysis, body balance measurements, approachwithdrawal behavior, emotions