Prosopagnosia

If you suffer from prosopagnosia, then you are unable to recognise faces.  It turns out that there’s a specific part of the human brain that has evolved to do nothing else other than to recognise faces. Here’s an interesting web page that uses the analogy of recognising stones to point out some of the tricks that people with prosopagnosia have to use to compensate for their face-blindness. 

 

(hat tip to Rachel for the link)