The Influence of Stimulus Speed and Cognitive Factors on Cortical Responses to Vection-inducing Stimuli

Vection is the illusion of self-motion elicited by visual cues without corresponding physical movement. Using electroencephalography, alpha activity has been found to increase in the parieto-occipital regions following vection onset. Variability in individuals' perception of upright has been reported to affect vection. Yet objective measures of this phenomenon are missing, and our understanding of how cognitive factors influence vection is limited. In this study, vection onset, offset, and neurophysiological data were recorded while participants viewed vection-inducing stimuli. Participants completed depersonalization and anxiety questionnaires and a field dependence test. Only state anxiety accounted for a substantial amount of variance in vection intensity scores. Alpha power varied as across time and stimulus speed, decreasing after vection onset and only in response to the slow-moving stimulus. This suggests that stimulus intensity may cause variation in neural responses. The results of this study can aid in the development of an objective measure of vection.