Visual and proprioceptive integration of the virtual and real fingertips

Sensitivity to sensory conflicts involving visual and proprioceptive mismatches of fingertip position was explored for a virtual workspace displayed through a stereoscopic head mounted display. The virtual fingertip appeared either coincident with the actual fingertip, or displaced 2, 3, 4, or 5 cm in a direction parallel to either the sagittal or frontal planes. Observers did not reliably detect displacements smaller than 5 cm. Sensitivity to 5 cm displacements varied across the workspace, as a function of the direction of the displacement, and between the right and left hands. Implications for proprioceptive localization of the hand are discussed, as well implications for performance in virtual environments.