A case of perceptual completion in spatio-temporal tactile space

Abstract

We reproduced a perceptual phenomenon where a tactile stimulus moving on the fingertip jumps instantly over a gap but is felt as if the space of the gap was perceptually obliterated. This phenomenon was recently demonstrated on the forearm using brushes. On the fingertip, we elicited this effect using virtual edges and measured psychometric response curves obtained by varying the time taken by the moving edge to traverse the gap between the first and the third portion of the stimulus. Most people failed to detect 2 mm gaps when the traversal time fell below 0.2 s. The gaps were consistently detected when they were traversed at same the speed as that of the moving edge in the first and third portion of the stimulus. We discuss the implications of these findings.