Population analysis comparing preferred axes for familiar versus unfamiliar faces. Distribution of cosine similarities between axes computed using 1,000 - 36 unfamiliar faces and 36 omitted unfamiliar faces (orange), and between axes computed using 1,000 - 36 unfamiliar faces and 36 familiar faces (blue) are shown. Preferred axes were computed using the top ten shape and top ten appearance features of presented faces. Inset, control experiment with 36 low-contrast faces in place of 36 familiar faces.
