Developmental Prosopagnosia (DP) results from a failure to develop the cognitive mechanisms necessary for adequate face identity recognition. Individuals with DP do not report brain injury, have typical vision, and do not have general intellectual impairments, yet they report everyday difficulties recognising familiar faces. (White et al, 2016). In the study below (click on the image to access the paper), Mike Burton and colleagues assess familiar and unfamiliar face recognition in individuals with DP. 

http://www.tandfonline.com/doi/full/10.1080/17470218.2016.1173076

White, D., Rivolta, D., Burton, A. M., Al-Janabi, S., & Palermo, R. (2016). Face matching impairment in developmental prosopagnosia. The Quarterly Journal of Experimental Psychology.

Abstract: Developmental prosopagnosia (DP) is commonly referred to as ‘face blindness’ (the opposite end of the face recognition spectrum to Super-recognisers (DJR addition), a term that implies a perceptual basis to the condition. 

However, DP presents as a deficit in face recognition and is diagnosed using memory-based tasks. Here, we test face identification ability in six people with DP, who are severely impaired on face memory tasks, using tasks that do not rely on memory. 

First, we compared DP to control participants on a standardised test of unfamiliar face matching using facial images taken on the same day and under standardised studio conditions (Glasgow Face Matching Test; GFMT). DP participants did not differ from normative accuracy scores on the GFMT. 

Second, we tested face matching performance on a test created using images that were sourced from the Internet and so vary substantially due to changes in viewing conditions and in a person’s appearance (Local Heroes Test; LHT). 

DP participants show significantly poorer matching accuracy on the LHT relative to control participants, for both unfamiliar and familiar face matching. Interestingly, this deficit is specific to ‘match’ trials, suggesting that people with DP may have particular difficulty in matching images of the same person that contain natural day-to-day variations in appearance. 

We discuss these results in the broader context of individual differences in face matching ability.