Discrepancies Between Felt and Judged Presence: The Role of Touch on Presence in Virtual Reality

Vision is well documented as the dominant sense in Virtual Reality (VR), yet the role of touch in the "Sense of Object Presence" (SOOP) remains under-explored. This study investigated the relative importance of unisensory (touch, vision) and multisensory information on SOOP using novel mid-air haptics (ultrasound) to provide tactile feedback without physical contact in a virtual environment. Forty-four participants completed two counterbalanced experimental blocks: an implicit reaction-time task (reacting to target stimuli) and an explicit metacognitive task (rating confidence in object presence). Participants were placed in a lifelike virtual environment where they were moving along railway tracks in a cavern in a minecart, and they intermittently felt and saw objects on their outstretched right hand. We manipulated sensory modality (Unisensory vs Multisensory) and temporal order (e.g., touch-first vs. vision-first) to assess their impact on presence. Results indicated that multisensory integration significantly enhanced perceptual confidence and reaction speeds compared to unisensory conditions. However, A key dissociation emerged between unisensory modalities. While participants reacted significantly faster to visual stimuli, they achieved higher perceptual accuracy with touch. Furthermore, although faster reaction times correlated with general presence scores, participants retrospectively rated touch as feeling significantly more "real" than vision. These findings highlight a potential disconnect between real-time "felt" presence and retrospective "judged" presence.