Humans Struggle to Perceive Congruence in Visuo-Haptic Textures.

Multisensory assessment of objects and textures is ubiquitous in human lives. It has been shown that people can optimally integrate tactile and visual cues to extract sensory cues. It is less clear though how the congruence between tactile and visual cues is perceived when people interact with everyday objects such as fabrics. In this study, we investigate the human accuracy to detect visuo-haptic discrepancy within common fabrics. Participants had to detect the congruent one among two pairs of visuo-haptic textures consisting in a visual texture projected on a semi-mirror and a real texture underneath the visual one, which could be touched but not seen. Overall, participants did not accurately detect congruent visuo-haptic pairs and their performance correlated with the average similarity between the visual and tactile textures. Correlation analysis may suggest a role of the coefficient of kinetic friction to detect the visuo-haptic discrepancy.