Effects of electrical brain stimulation on brain indices and presence experience in immersive, interactive virtual reality

Abstract

The subjective presence experience in virtual reality (VR) is associated with distinct brain activation patterns. Particularly, the dorsolateral prefrontal cortex (DLPFC) seems to play a central role. We investigated the effects of electric brain stimulation (transcranial direct current, tDCS) on the presence experience as well as on brain activity and connectivity. Thirty-eight participants received either anodal (N = 18) or cathodal (N = 20) stimulation of the DLPFC before interacting in an immersive VR as well as sham stimulation. During VR interaction, EEG and heart rate were recorded. After VR interaction, participants rated their subjective presence experience using standardized questionnaires. Cathodal stimulation led to stronger brain connectivity than sham stimulation. Increased brain connectivity was associated with numerically lower levels of subjective presence. Anodal stimulation did not lead to changes in brain connectivity, and no differences in subjective presence ratings were found between the anodal and sham stimulation. These results indicate that cathodal tDCS over the DLPFC leads to a more synchronized brain state, which might hamper the activity in networks, which are generally associated with the evolvement of the subjective presence experience. Our results underline the importance of the DLPFC for the presence experience in VR.

Age and gender effects on presence, user experience and usability in virtual environments–first insights

“…Consequently, these studies cannot be used as a comparison to our results. Very few studies, however, investigate age and gender effects on Presence [40][41][42], for which a comparison to our results of the same can be made. Additionally, no work so far has looked at both factors in one study.…”

“…Additionally, no work so far has looked at both factors in one study. Literature investigating the effects of Age on Presence was so far mostly related to the younger population and to a less-well balanced male to female ratio [41]. Further, in one study presented by Kober [41], only one group used a VR setup, and for another group on the elderly, patients with brain lesions were included, forming a significant confounder as brain injury might impair or alter the mechanisms of how Presence is forming.…”

“…Literature investigating the effects of Age on Presence was so far mostly related to the younger population and to a less-well balanced male to female ratio [41]. Further, in one study presented by Kober [41], only one group used a VR setup, and for another group on the elderly, patients with brain lesions were included, forming a significant confounder as brain injury might impair or alter the mechanisms of how Presence is forming. All of the four studies in Kober [41] used different Presence questionnaires and sample sizes to the effect that the results are difficult to compare.…”

“…Further, in one study presented by Kober [41], only one group used a VR setup, and for another group on the elderly, patients with brain lesions were included, forming a significant confounder as brain injury might impair or alter the mechanisms of how Presence is forming. All of the four studies in Kober [41] used different Presence questionnaires and sample sizes to the effect that the results are difficult to compare. Our study used a standardized setup with a larger sample size (n = 57) and a large age range amongst participants to specifically address these issues.…”

“…A meta-analysis of Peck et al [39] discussed potential gender bias on simulator sickness and suggested researching whether such biases could be evident for other factors like Presence. Very few studies, however, investigate age and gender effects on Presence [40][41][42]. Additionally, no work so far has looked at both factors in one study.…”