Abstract
Herschel is a 54-year-old man with bilateral occipito-temporal lesions following two strokes. A functional MRI scan showed bilateral fusiform face areas, bilateral face-selective activation in the posterior superior temporal sulcus, bilateral lateral occipital areas, but no right or left occipital face area. Herschel was severely impaired on tests requiring recognition of famous faces, unfamiliar faces, facial expressions, and facial gender. In contrast, he scored normally on within-class object and scene memory tests involving cars, houses, landscapes, tools, sunglasses, and handguns. His performance on a challenging car memory test requiring recognition in novel views and lighting was also normal. Herschel scored normally on a sequential matching task involving objects despite near chance performance on a parallel face matching task. His results provide strong evidence for the dissociability of face recognition and within-class object recognition. Herschel however reports object recognition problems in daily life, particularly in complicated scenes, and four tests requiring recognition of degraded basic level objects revealed impairments. In two of these tasks, stimuli from the Gestalt Completion Test and the Snowy Pictures Test were presented briefly (Ekstrom et al., 1976). We also tested Herschel with an Unusual Views Test and on a task requiring recognition of spatial frequency filtered photographs (Viggiano et al., 2004). In summary, Herschel's performance indicates that face recognition and within-class object recognition involve different mechanisms, but his surprising dissociation between within-class and basic level object tasks raises interesting questions and merits further testing.