Superportraits: Caricatures and Recognition

As Nixon's unpopularity increased during Watergate, his nose and jowls grew to impossible proportions in published caricatures. Yet the caricatures remained instantly recognizable. Caricatures can even be superportraits, with the paradoxical quality of being more like the face than the face itself.
How can we recognize such distorted images? Do caricatures derive their power from some special property of a face recognition system or from some more general property of recognition systems? Wha...