In the article “Heterogeneous Origins of Human Sleep Spindles in Different Cortical Layers” by Donald J. Hagler, István Ulbert, Lucia Wittner, Loránd Erőss, Joseph R. Madsen, Orrin Devinsky, Werner Doyle, Dániel Fabó, Sydney S. Cash, and Eric Halgren, which appeared on pages 3013–3025 of the March 21, 2018 issue, formatting errors were accidentally introduced into Figure 8B during the printing process. The figure has been corrected on-line, and is displayed below. This correction does not affect the conclusions of the paper.