Fig. 4. Area of the field potential equivalent to the sensory response (FPSR) negative peak as a cylindrical object (metal or plastic, oriented perpendicular to the skin) was moved from rostral to caudal along the body, passing through the center of the receptive field (gray bar, 0 mm). The horizontal dotted line indicates the area of the FPSR negative peak in the absence of any object, as a control value.