Rapid extraction of mean identity from sets of faces.

Recent evidence suggests that the notion that the visual system can rapidly extract summary statistics from complex scenes extends to representing sets of faces in terms of mean emotion or gender. Here we show that observers can also extract a mean identity from a set of faces with different identities. Observers first saw a set of four faces with different identities and were subsequently asked whether or not a single test face had been present in the preceding set. They were significantly more likely to respond that the test face had been present in the set if it was the morphed mean of all four set faces than when it was an actual set member. This finding suggests that representations based on summary statistics are available for face identity.