EVIDENCE OF COVERT RECOGNITION IN A PROSOPAGNOSIC PATIENT

This is a case-study of a patient (ET) who suffers from prosopagnosia, in the context of impairment to cognitive functions, following trauma tic brain injury. Despite severe perceptual difficulties in tests invo lving non-face stimuli and matching unfamiliar faces, ET showed eviden ce of ''covert'' recognition of familiar faces in a number of tasks. A lthough densely prosopagnosic, she performed at normal levels in word and object recognition tasks, and is unimpaired in her ability to reco gnise names of celebrities. She performed at the same level as control s in her ability to make a forced-choice of the correct name for a fam ous face, even though it evoked no feeling of familiarity for her. She performed at chance in a forced-choice face familiarity decision task , but showed evidence of covert recognition in a ''true'' versus ''unt rue'' face-name learning task. ET showed overt recognition of some fam ous faces using a procedure based on Sergent and Poncet's (1990) seman tic activation task. The pattern of impariment of ET's face processing abilities is interpreted in terms of an interactive activation model of face processing.