Velocity perception of the Bayesian observer models. Perceived velocity, v', is plotted against real velocity, v, for the basic (A) and full (B) Bayesian observer models, on both forearm (top panels) and fingertip (bottom panels). In all cases, real velocity was increased by reducing IST at fixed ISD (4 cm for forearm; 4 mm for fingertip). (A) Basic observer: Perceived velocity, v' = l'/t, was derived from Equation 3. Real velocity v* = 28.28 cm/s (Equation 4) results in peak perceived velocity v'max = 14.14 cm/s (Equation 5). (B). Full observer: Perceived velocity, v' = l'/t', was determined from Equations 2 and 16, with σt set to 5 ms. Dotted lines in all panels: x = y. (A) and (B): σs was set to 1 cm (forearm) or 1 mm (finger), and σv to 10 cm/s.