Neuropsychologia 48 (2010) 978–988 Contents lists available at ScienceDirect Neuropsychologia journal homepage: www.elsevier.com/locate/neuropsychologia The cognitive and neural expression of semantic memory impairment in mild cognitive impairment and early Alzheimer’s disease Sven Joubert a,b,∗ , Simona M. Brambati b , Jennyfer Ansado b , Emmanuel J. Barbeau c , Olivier Felician d,e , Mira Didic d , Jacinthe Lacombe a,b , Rachel Goldstein a , Céline Chayer f,g,h , Marie-Jeanne Kergoat b,g,h a Département de psychologie et CERNEC, Université de Montréal, Montreal, Québec, Canada b Centre de recherche de l’Institut universitaire de gériatrie de Montréal, Montreal, Québec, Canada c Centre de recherche Cerveau et Cognition, université Paul Sabatier – CNRS, Toulouse, France d Service de Neurologie et de Neuropsychologie, AP-HM Timone, Marseille, France e Laboratoire Epilepsie et Cognition, INSERM U 751, Université de la Méditerranée, Marseille, France f Clinique de mémoire de l’Hôpital Maisonneuve-Rosemont, Montreal, Québec, Canada g Clinique de cognition de l’Institut universitaire de gériatrie de Montréal, Montreal, Québec, Canada h Département de Médecine, Université de Montréal, Montreal, Québec, Canada article info Article history: Received 2 February 2009 Received in revised form 10 November 2009 Accepted 24 November 2009 Available online 30 November 2009 Keywords: Semantic memory Naming Mild cognitive impairment Alzheimer’s disease abstract Semantic deficits in Alzheimer’s disease have been widely documented, but little is known about the integrity of semantic memory in the prodromal stage of the illness. The aims of the present study were to: (i) investigate naming abilities and semantic memory in amnestic mild cognitive impairment (aMCI), early Alzheimer’s disease (AD) compared to healthy older subjects; (ii) investigate the associa- tion between naming and semantic knowledge in aMCI and AD; (iii) examine if the semantic impairment was present in different modalities; and (iv) study the relationship between semantic performance and grey matter volume using voxel-based morphometry. Results indicate that both naming and semantic knowledge of objects and famous people were impaired in aMCI and early AD groups, when compared to healthy age- and education-matched controls. Item-by-item analyses showed that anomia in aMCI and early AD was significantly associated with underlying semantic knowledge of famous people but not with semantic knowledge of objects. Moreover, semantic knowledge of the same concepts was impaired in both the visual and the verbal modalities. Finally, voxel-based morphometry analyses revealed that semantic impairment in aMCI and AD was associated with cortical atrophy in the anterior temporal lobe (ATL) region as well as in the inferior prefrontal cortex (IPC), some of the key regions of the semantic cognition network. These findings suggest that the semantic impairment in aMCI may result from a break- down of semantic knowledge of famous people and objects, combined with difficulties in the selection, manipulation and retrieval of this knowledge. © 2009 Elsevier Ltd. All rights reserved. 1. Introduction Semantic memory concerns general world knowledge, acquired over a lifetime and shared by a same cultural group. It includes for instance knowledge about objects, people, places, concepts, facts and language. Semantic deficits have been documented in Alzheimer’s disease (AD) using a variety of standard clinical neu- ropsychological tests, such as confrontation naming (Huff, Corkin, Abbreviations: aMCI, amnestic mild cognitive impairment; MMSE, Mini-Mental State Examination; AD, Alzheimer’s disease; VBM, voxel-based morphometry. ∗ Corresponding author at: Centre de recherche de l’IUGM, 4565, chemin Queen Mary, Montreal, Québec, H3W 1W5, Canada. Tel.: +1 514 340 3540x3551; fax: +1 514 340 3548. E-mail address: sven.joubert@umontreal.ca (S. Joubert). & Growdon, 1986), visual–verbal semantic matching (Hodges & Patterson, 1995) and category fluency (Adlam, Bozeat, Arnold, Watson, & Hodges, 2006; Rosser & Hodges, 1994). Studies which have investigated semantic breakdown in AD using more sensitive experimental measures have also shown that subordinate knowl- edge is more impaired than superordinate knowledge (Chertkow & Bub, 1990; Hodges, Patterson, Oxbury, & Funnell, 1992), that bio- logical entities are more affected than non-biological entities (Fung et al., 2001; Gonnerman, Andersen, Devlin, Kempler, & Seidenberg, 1997; Whatmough et al., 2003), and that knowledge of famous peo- ple is disproportionately impaired relative to other categories of conceptual knowledge and to autobiographical memory (Greene & Hodges, 1996; Thompson, Graham, Patterson, Sahakian, & Hodges, 2002). Clinical research has shown that AD is often preceded by a clinical phase commonly referred to as amnestic mild cogni- 0028-3932/$ – see front matter © 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.neuropsychologia.2009.11.019