Tactile Perception of Texture Shape with Different Sharpness from Finger Friction to Brain Activation

In order to systematically study the tactile perception of texture shape from finger friction to brain response, skin friction, brain fMRI, and subjective cognitive experiment were carried out during fingers exploring textured surfaces. Samples with different texture shape were chosen. The results indicated that friction, subjective evaluation, activated brain range and intensity are effective parameters to represent tactile perception. The friction was constitued by adhesive friction and deformation friction during perceived the textures. The adhesive force was larger than deformation force.The order of friction force perceived different texture shape was flat shape>round shape> sharp shape. The stickiness was mainly affected by contact area and adhesive friction. The sharpness was mainly affected by stress on the tacitle receptors and deformation friction. The comfortableness was affected by the surface friction and stress on the tactile receptor. During feeling the shape texture, somatosensory cortex region were significantly activated which included precentral gyrus and postcentral gyrus. The comfortable feeling was inversely proportional to the brain range and intensity. The texture with poor comfortable feeling stimulated large brain range and intensity, meanwhile there was negative activation phenomenon.