Fig. 3.

Results of experiments 7 and 8 (see also Fig. S3). All tests were two tailed. (A) Results of experiment 7. Control participants produced a significantly larger number of “same” responses for forward than for backward probes in the easy condition [paired t test, t (14) = 4.93, P < 0.001], but this bias was not significant [paired t test, t (14) = 1.59, P = 0.13] and was significantly smaller in the awkward movement condition [repeated measures ANOVA, F (1, 14) = 5.41, P = 0.04]. IDs 1, 2, and 4 showed the same profile, with a significant forward bias in the easy condition [all χ² (1) > 4, all Ps < 0.05] of the same size as that of the controls [all modified t tests, 0.61 < ts (14) < 1.10, all Ps > 0.05], but showed either no bias (IDs 1 and 4) or a significantly smaller bias [ID2: χ² (1) > 16, P < 0.01] in the awkward condition. IDs 3 and 5 did not show any significant bias in the easy condition [both χ² (1) < 1, both Ps > 0.5] but showed either a significant backward bias [ID3, χ² (1) = 9.77, P < 0.01] or forward bias [ID5, χ² (1) > 30, P < 0.05] in the awkward condition. (B) Results of experiment 8. Control participants produced a significantly larger number of “same” responses for forward than for backward probes in the easy movement condition [paired t test, t (14) = 4.64, P < 0.001], but this bias was not significant [paired t test, t (14) = 0.89, P = 0.38] and was significantly smaller in the awkward movement condition [repeated measures ANOVA, F (1, 14) = 5.43, P = 0.03]. IDs 1 and 4 showed the same profile of a significant forward bias in the easy movement condition [both χ² (1) > 6.64, both Ps < 0.01] that was significantly larger than in the awkward movement condition [both χ² (1) > 6, P < 0.01] and was the same size as that of the controls [both modified t tests, −0.3 < ts (14) < 0.93, both Ps > 0.05]. ID3 showed the same trend, although it was not significant [χ² (1) = 1.83, P = 0.1]. ID5 showed a significant backward bias in both conditions [both χ² (1) > 20, Ps < 0.01].