Abstract
Color vision is known to provide useful information for object and scene segmentation. Variations along the red-green (R/G) dimension facilitate finding fruit among foliage (Parraga, Troscianko, & Tolhurst, 2002) and color aides in feature segmentation during human face processing (Yip & Sinha, 2002). Evidence that color is part of the perceptual representation of individual faces is based on the finding that the relative degree of red and green in a face correlates with sex in both humans (Tarr et al. 2002) and non-human primates (Waitt et al. 2003). Here, we investigated whether changes along the R/G, but not the blue-yellow (B/Y), color dimension affect memory for faces. This prediction is based on the hypothesis that R/G provides information about the identity of a face and, moreover, that this information is an intrinsic part of our memory for an individual. In contrast, if B/Y does not provide information about identity, changes along this dimension should not affect memories for faces. We used a recognition-memory (old/new) paradigm to test how these two types of color changes influence the recognition of individual faces. A set of 190 face images from the MPI Face Database were transformed to CIELAB color space where the R/G and B/Y axes could be independently varied. For each original face image, four new images were created, two of which varied along the R/G dimension and two of which varied along the B/Y dimension. Observers studied 50 face images in their original colors and then were tested with 100 original color and transformed color images, each of which was judged as an old or new individual. Observers were significantly less likely to recognize a face they had seen before if it was altered along the R/G dimension, but were not impaired in the recognition of the same face when it was altered along the B/Y dimension. These results extend our earlier findings, suggesting that R/G color information plays a functional role in everyday face recognition.