title: Manipulating Bodily Presence Affects Cross-Modal Spatial Attention: A Virtual-Reality-Based ERP Study.
abstract: Earlier studies have revealed cross-modal visuo-tactile interactions in endogenous spatial attention. The current research used event-related potentials (ERPs) and virtual reality (VR) to identify how the visual cues of the perceiver's body affect visuo-tactile interaction in endogenous spatial attention and at what point in time the effect takes place. A bimodal oddball task with lateralized tactile and visual stimuli was presented in two VR conditions, one with and one without visible hands, and one VR-free control with hands in view. Participants were required to silently count one type of stimulus and ignore all other stimuli presented in irrelevant modality or location. The presence of hands was found to modulate early and late components of somatosensory and visual evoked potentials. For sensory-perceptual stages, the presence of virtual or real hands was found to amplify attention-related negativity on the somatosensory N140 and cross-modal interaction in somatosensory and visual P200. For postperceptual stages, an amplified N200 component was obtained in somatosensory and visual evoked potentials, indicating increased response inhibition in response to non-target stimuli. The effect of somatosensory, but not visual, N200 enhanced when the virtual hands were present. The findings suggest that bodily presence affects sustained cross-modal spatial attention between vision and touch and that this effect is specifically present in ERPs related to early- and late-sensory processing, as well as response inhibition, but do not affect later attention and memory-related P3 activity. Finally, the experiments provide commeasurable scenarios for the estimation of the signal and noise ratio to quantify effects related to the use of a head mounted display (HMD). However, despite valid a-priori reasons for fearing signal interference due to a HMD, we observed no significant drop in the robustness of our ERP measurements.
authors.affiliation: Helsinki Institute for Information Technology, Department of Computer Science, Aalto UniversityEspoo, Finland; Social Psychology, Department of Social Research, University of HelsinkiHelsinki, Finland.
authors.forename: Ville J
authors.initials: VJ
authors.lastname: Harjunen
authors.affiliation: Helsinki Institute for Information Technology, Department of Computer Science, Aalto UniversityEspoo, Finland; Helsinki Institute for Information Technology, Department of Computer Science, University of HelsinkiHelsinki, Finland.
authors.forename: Imtiaj
authors.initials: I
authors.lastname: Ahmed
authors.affiliation: Helsinki Institute for Information Technology, Department of Computer Science, Aalto UniversityEspoo, Finland; Helsinki Institute for Information Technology, Department of Computer Science, University of HelsinkiHelsinki, Finland.
authors.forename: Giulio
authors.initials: G
authors.lastname: Jacucci
authors.affiliation: Helsinki Institute for Information Technology, Department of Computer Science, Aalto UniversityEspoo, Finland; Information and Service Economy, School of Business, Aalto UniversityHelsinki, Finland; Helsinki Collegium for Advanced Studies, University of HelsinkiHelsinki, Finland.
authors.forename: Niklas
authors.initials: N
authors.lastname: Ravaja
authors.affiliation: Department of Psychology, Liverpool Hope University Liverpool, UK.
authors.forename: Michiel M
authors.initials: MM
authors.lastname: Spapé
keywords: bodily presence; cross-modal spatial attention; event-related potentials; head mounted display; virtual reality