Face images subtended a visual angle of approximately 12 9 8 from a distance of 50 cm. The images were displayed on a Sony SDM-M81 18-inch LCD monitor set to a resolution of 1,152 9 870 and a refresh rate of 75 Hz. The experiment was run in Matlab 7.6.0 (R2008a) (Math-Works, Natick, MA, USA) with the Psychophysics Toolbox extensions on an Apple Mac mini computer.