Naming vs knowing faces in primary progressive aphasia A tale of 2 hemispheres

Objectives: This study examines the anatomical correlates of naming vs recognizing faces using a novel measure that utilizes culturally relevant and age-appropriate items, the Northwestern University Famous Faces (NUFFACE) Test, in primary progressive aphasia (PPA), a syndrome characterized by progressive language deficits and associated with cortical atrophy in areas important for word and object representations. Methods: NUFFACE Test performance of 27 controls (mean age 62.3 years) was compared with that of 30 patients with PPA (mean age 62 years). Associations between NUFFACE Test performance and cortical thickness measures were quantified within the PPA group. Results: Patients with PPA displayed significant impairment on the NUFFACE Test, demonstrating that it is a useful measure of famous-face identification for individuals with relatively young-onset dementias. Despite widespread distribution of atrophy in the PPA group, face naming impairments were correlated with atrophy of the left anterior temporal lobe while face recognition impairments were correlated with bitemporal atrophy. Conclusions: In addition to their clinical relevance for highlighting the distinction between face naming and recognition impairments in individuals with young-onset dementia, these findings add new insights into the dissociable clinico-anatomical substrates of lexical retrieval and object knowledge.