Study's senior author, Sliman Bensmaia, PhD, assistant professor in the Department of Organismal Biology and Anatomy at the University of Chicago, said that coarse textures are reflected in the spatial pattern of responses by one set of receptors, but that's only a small part of the story.
He said that most of what humans consider to be natural textures are represented in temporal patterns of activation in the other two groups of receptors.
In the experiments performed in this study, Bensmaia and his colleagues used a drum covered with strips of such coarse textures, along with several materials with finer textures, such as sandpaper, fabrics and plastics.
The drum then ran the textures across the fingertips of Rhesus macaques, whose somatosensory system is similar to humans, while the researchers recorded the neuronal responses.
While the coarse textures produced the familiar SA1 response, the SA1 afferents did not fire at all for the majority of the finer textures.
Instead, two sets of afferents that have not been implicated previously in texture sensation, rapidly adapting (RA) and Pacinian (PC) fibers, responded in a temporal pattern that followed the vibrations produced in the skin by scanning the surface.
A new study has been published online in the Proceedings of the National Academy of Sciences.
--ANI (Posted on 01-10-2013)