Zusammenfassung
The interplay between vision and touch is a particularly intriguing multisensory interaction, given the propensity for visual dominance. Extending recent findings demonstrating such visual dominance over touch, we investigated how the distance of the visual stimulus from a participant’s body influenced the processing of the visual and tactile stimuli. Participants made speeded detection/discrimination responses to a random sequence of visual-only, tactile-only, and bimodal targets. Responses were near-perfect on the unimodal target trials. Bimodal target trial performance was affected by position of the visual stimulus (on vs. off body): Specifically, when the visual stimulus was at the fingertip, there were significantly more tactile than visual errors. However, moving the visual stimulus off the body eliminated the visual dominance effect. In a second experiment, visual stimuli were presented either on the participant’s fingertip or on the fingertip of a plausibly-positioned rubber hand. Even though we made no attempt to establish an illusion of ownership, the introduction of the artificial limb reestablished the visual dominance effect. Taken together, these results demonstrate that visual dominance over touch occurs for visual stimuli presented on the body as opposed to off it, regardless of whether the stimulus was delivered to the actual or to the virtual fingertip.
