Interactions between facial form and facial motion during the processing of identity

Previous research has shown that facial motion can carry information about age, gender, emotion and, at least to some extent, identity. With respect to identity, two important issues remain unresolved: first it is unclear to what extent purely non-rigid facial motion contributes to the processing of identity. Secondly, as most previous studies have involved techniques that severely reduced available cues to facial form (e.g., blurring or pixelation), it is not really known how, if at all, information concerning facial form and facial motion interact. By combining recent computer animation techniques with psychophysical methods, we show that during the computation of identity the human face recognition system accesses and integrates both types of information: individual non-rigid facial motion and individual facial form. This has important implications for cognitive and neural models of face perception, which currently emphasize a separation between the processing of invariant aspects (facial form) and changeable aspects (facial motion) of faces.