Faces interfere with name classification in a prosopagnosic patient.

Since sustaining a severe closed head injury P.H. has been completely unable to recognise familiar faces, but remains able to identify written names. Despite his inability to recognise faces overtly, P.H. nevertheless shows a normal pattern of interference from simultaneously presented distractor faces in a politician vs nonpolitician name classification task. His reaction times for semantic (politician versus nonpolitician) classification of printed names are slowed by the presence of a face drawn from the incorrect semantic category. This interference is found even though P.H. performs at chance level when asked to overtly classify the faces used in the task. The finding demonstrates that prosopagnosic patients may covertly achieve relatively precise recognition of familiar faces and access to semantic information.