What is overt and what is covert in congenital prosopagnosia?

The term covert recognition refers to recognition without awareness. In the context of face recognition, it refers to the fact that some individuals show behavioural, electrophysiological or autonomic indices of recognition in the absence of overt, conscious recognition. Originally described in cases of people that have lost their ability to overtly recognize faces (acquired prosopagnosia, AP), covert face recognition has more recently also been described in cases of congenital prosopagnosia (CP), who never develop typical overt face recognition skills. The presence of covert processing in a developmental disorder such as CP is a particularly intriguing phenomenon, and its investigation is relevant for a variety of reasons. From a theoretical point of view, it is useful to help shed light on the cognitive and neural underpinnings of face recognition deficits. From a clinical point of view, it has the potential to aid the design of rehabilitation protocols aimed at improving face recognition skills in this population. In the current review we selectively summarize the recent literature on covert face recognition in CP, highlight its main findings, and provide a theoretical interpretation for them.