The prosopagnosic patient PS is involved in a computer memory game, having to match similar visual shapes (filmed in a bookstore in the center of Maastricht, formerly a church). The video is interesting because it shows that some cases of prosopagnosia like PS do not have troubles discriminating/matching visually similar shapes, contrary to a popular (but incorrect) account of acquired prosopagnosia.
see: Busigny, T., Graf, M., Mayer, E., Rossion, B. (2010). Acquired prosopagnosia as a face-specific disorder: Ruling out the general visual similarity account . Neuropsychologia, 48, 2051-2067.