Using virtual reality (VR) in cognitive neurosciences can facilitate the transfer of research from the lab into more life-like environments. However, it is crucial to verify that results obtained in VR experiments correspond to those obtained under laboratory/real-world conditions. As a first step in the development and validation of a VR-based test environment, we focused on auditory distance perception and analyzed event-related potentials (ERPs) evoked in a real and the corresponding virtual space.
In an auditory change detection (“oddball”) paradigm, N=20 participants were exposed to broadband sounds emitted by three loudspeakers placed at distances of 2m (near), 4m (center), and 8m (far) relative to the participant. Participants had to react to those sounds deviating in their distance and hence spatial position from the center loudspeaker (acting as standard sound). In one condition, sounds were generated by the loudspeakers themselves (real environment), whereas in the second condition virtually generated sounds were played via headphones (virtual environment). During the experiment, continuous EEG was recorded.
Across both environments, we found similar ERP patterns such as the mismatch negativity and P3a component as neuro-cognitive correlates of deviant detection and attentional orientation, respectively. Looking at ERPs evoked by the two deviant sound positions, in both environments sound emitted by the far loudspeaker generated a delayed P3a in comparison to the near loudspeaker.
Results demonstrate that similar neural processes were elicited in virtual and real spaces. Future research has to validate these indications, also by adding the visual virtual domain in more complex multisensory scenarios.