Fig. 4

Trajectories of threshold estimates and mean steps to response. (a): Mean trajectories of the absolute threshold estimates for increased-speed perturbations (green) and decreased-speed perturbations (red) for each trial per block. The x axes end with the minimum number of trials presented to any participant in any block (this number could vary as we fixed the time and not number of perturbations per block). Shaded areas indicate ± 1 between-participant SEM. Threshold estimates started at 10% and rapidly and roughly asymptotically approached range of the final JND for both perturbation types. Dashed lines show the mean width of the 95%-confidence intervals of the estimates for each trial, computed from the QUEST’s probability density function. (b): Mean steps to response for each trial, depending on the perturbation type. Trajectories did not differ between increases (green) and decreases (red).