Developmental prosopagnosia: A case analysis and treatment study.

This paper reports a treatment case study focused on face perception impairments designed for AL, an 8-year-old child with prosopagnosia. AL's prosopagnosia was characterized by deficits at the level of structural encoding-that is, he was unable to achieve normal basic perception of faces. This impairment then impacted on all subsequent aspects of familiar- and unfamiliar-face processing. Detailed assessment of feature processing revealed impairments in perception of facial features with a dissociation between relatively good perception of the mouth feature and poor perception of eye and nose features. Interestingly, results also suggested at least partial internal representation of facial features despite long-standing deficits in perception of these features. A treatment programme focused on training in perception, and analysis of facial features and familiar-face naming was conducted. Treatment resulted in excellent face naming for familiar faces, a decreased reliance on nonfacial cues and a reduction in AL's tendency to misidentify unfamiliar faces as family members.