Figure 1.

Stimuli. (a) Stimuli were male faces seen from 2 different views and with 2 different lightings. The lower left and upper right faces are counterlit (incongruent view and lighting). (b) Averaged histograms for red, green, and blue (RGB) color channels that were imposed on each image. As a consequence of the color histogram equalization, the images have the same light and spatial-signal energy. (c) Face familiarity was systematically varied, resulting in new, seen, and known faces. The 7 new faces that are shown are a subset of a total of 180 new faces that were used in this study. The 4 familiar faces are the 4 right-most faces.