Fig. 2.

Methods and results of experiment 6. (A) Materials and methods. One probe picture is the same as the target, and the others (the foils) show the actor’s hand shifted 33 ms or 66 ms forward (+) or backward (−) relative to its position on the target (depending on the condition). Shown within solid lines is an example of a trial from the easy condition ending with a one-frame-backward foil. In dotted lines is an example of a trial from the awkward condition ending with a two-frames-backward foil. (B) Results. All tests were two tailed. Control participants [paired t test, t (19) = 6.49, P < 0.001] and the five IDs [all χ² (1) > 24, all Ps < 0.001] made more “same” responses for forward than for backward probes in the easy movement condition, but this forward bias was absent (in controls and in IDs 1, 2, and 5) or was significantly smaller [in IDs 3 and 4, both χ² (1) > 20, both Ps < 0.01] in the awkward movement condition. The size of the forward bias in the easy movement condition did not differ significantly between the IDs and the controls [all modified t tests, 0.75 < ts (19) < 1.98, all Ps > 0.05].