In the article “Phase Entrainment of Human Delta Oscillations Can Mediate the Effects of Expectation on Reaction Speed” by Gábor Stefanics, Balázs Hangya, István Hernádi, István Winkler, Péter Lakatos, and István Ulbert, which appeared on pages 13578–13585 of the October 13, 2010 issue, the authors regret that the scaling of the probabilities reported in the circular histograms of Figure 2, A–D, I, and J, was not correct. The numbers indicated in the plots were half of the actual values; i.e., 0.02 should read 0.04, 0.04 should read 0.08, etc. The authors corrected the scaling in the revised version of Figure 2, shown below. These errors do not affect the results, interpretations, or conclusions.