Face recognition without awareness

Abstract

PH has been completely unable to recognise faces since sustaining a closed head injury some four years ago, but can recognise familiar people from their names. His performance on face processing tasks is, however, comparable to that of normal subjects if explicit recognition is not required. Thus he can make same/different identity judgements more quickly for familiar than unfamiliar face photographs, and faster matching of familiar faces is only found for identity matches involving the face's internal features. When making semantic categorisation decisions to printed names he shows interference from distractor faces belonging to an incorrect category, even when the faces in each category are matched on physical appearance. When learning to associate the occupation or the name with photographs of faces, his performance is better with true (face and person's actual name or occupation) than untrue (face and another person's name or occupation) pairings. Covert recognition can also be demonstrated for faces of people PH has only met since his accident. These findings show that in prosopagnosia, much of the processing of familiar faces can remain intact despite absence of awareness that recognition has occurred.