Figure 3. Localization errors systematically vary with the progression of the movement.

(A) Distance of reported hand position from hand position at movement start (‘perceived distance’; calculated as difference in the direction of the trajectory of the reporting hand) plotted against the distance of true hand position at the time of tactile stimulation from movement start (‘true distance’) of all correct TOJ trials of a single participant in Experiment 1. Each dot represents a single trial. The solid line represents veridical localization. (B) Mean localization error (teal line) of all correct TOJ trials of the same participant as in A. Each dot represents the localization error of a single trial, that is the difference between indicated hand position at the end of the trial and true hand position at the time of tactile stimulation. Blue shading represents the average movement time, with 0 ms = movement start. Note, that the localization error is positive at the beginning of the movement, indicating error in the direction of the movement. Localization error is negative toward the end of the movement, indicating error against the direction of movement. (C-D) The localization error pattern of the correct trials in B was evident across all participants for both the 2 stimulus experimental task (C) and for the 1 stimulus control task (D) and for all posture combinations. Traces reflect the group mean, shaded areas around the traces reflect s.e.m. The shaded regions in the background indicate the average movement duration, which differed slightly between conditions (see in Supplementary file 1).