Adaptation assessed in terms of error sensitivity (left) or error correction (right). Here we plot data from several different studies10,17,23, including the present one, using two ways to consider trial-by-trial changes in hand angle as a function of error size (Methods section). a Error sensitivity, operationalized as the change in hand angle divided by error size, starts at an early maximum and quickly decays as errors increase in size. b The same data, plotted in terms of the untransformed error correction, shows a function that starts small and then saturates, suggesting that the motor system continues to produce a robust, invariant response over a wide range of error sizes. Plotting the aftereffect data in terms of a sensitivity function (c) also fails to capture the relative invariance of these data within a given experimental context (d). Note the one discrepant point from Exp. 1 in panels C and D from the 1° clamp condition; we suspect this is due to an insufficient number of trials to approximate asymptotic performance. Error bars denote SEM.