How Humans Remember So Many Faces: Face Space Model?
The current consensus in the literature is that we can remember such an extraordinarily large number of faces because we use a vector based mathematical model called the "Face Space model". According to this model we remember faces by what makes them specifically different from the average face rather than having a photographic memory for faces as a whole. This explanation has been used to generate the powerful face recognition algorithms we are beginning to see employed in intelligent CCTV systems.
Quoted on Wed Jun 22nd, 2011