Postmovement ERS and variation with behavior. A, Group mean α ERS consistently increased over bins of increasing execution order, independent of perturbation type; group mean α ERS was suppressed by large errors, but only when the perturbation was constant. B, Group mean β ERS increased with execution order only when the perturbation was constant, and it was suppressed by large errors independent of perturbation type. *Significant difference (p < 0.05, Bonferroni correction for multiple comparisons). **Significant difference (p < 0.01, Bonferroni correction for multiple comparisons). Circles and bars represent mean ± SEM.