Background: Cognition of surface roughness at the same
time by the two senses (tactile and visual) is still unde-clared, and how
both effects on each other could be intriguing. The main factor for
roughness estimation of fine surface (spa-tial features below 200 µm) is
also unknown until present.
Objective: In order to see the difference between cognition of both
condition, we conducted two unimodal and two bimodal tasks involving both
modalities using fine sandpapers. Tactile stimuli consisted of six types of
different sandpapers that var-ied in their roughness, while visual stimuli
are images of the correspondence tactile stimuli
Methods: In unimodal task, subjects need to compare which stimulus perceived
were rougher, visually and tactually, while multiple sensory of visual and
tactile were mixed in bimodal task. We also varied the type of roughness in
bimodal task into two categories to discover whether there is any
acceleration or suppression by different stimuli.
Results: We found that tactile sensory was dominant in the perception of
roughness by fine surface. During cross modalities, visual information has
almost no effects toward tactile sensory, but in the other hand tactile
information had significance ef-fects onto visual sensory. Furthermore, we
found that stimuli with smaller particles bring more interference into
subject’s perception compared to bigger particles in fine surface
Conclusion: We suggest that particles sizes are as significant as the
modalities in visual, tactile, or multisensory integration of both, in
roughness perception of fine surface.