For the article “Entrainment to Video Displays in Primary Visual Cortex of Macaque and Humans,” by Patrick E. Williams, Ferenc Mechler, James Gordon, Robert Shapley, and Michael J. Hawken, which appeared on pages 8278-8288 of the September 22, 2004 issue, the authors would like to add a reference (given below). The paper by Gur and Snodderly (1997) includes examples of single units recorded in awake macaque V1 that were phase locked to the 60 Hz refresh rate of a CRT video display.
