Anatomical correlates for category-specific naming of living and non-living things

Introduction: Selective naming categories impairments for living and non-living things are widely reported in brain damaged patients. Electrostimulation mapping was used to study the possible anatomical segregation of living/non-living categories in a prospective series of patients operated on for tumor removal. Materials and methods: Fifty brain mappings (patients with no language impairment; range: 14-80. years; mean: 48. years; 26 males; 5 left handed) were performed in 46 left and 4 right hemispheres using two linguistically controlled tasks (naming for living and non-living things) during an awake surgery procedure. Fifteen regions and four macro cortical areas were designed to analyze the distribution of the interference sites. Results: Over 761 sites stimulated in the lateral hemispheres, 130 naming interferences sites were detected in small cortical areas (<1cm2). High individual variability was observed for living/non-living word retrieval localization and organization with a majority (62%) of shared living/non-living interferences. Specific living (12%) or non-living (26%) interferences were found too. In group analysis, no statistical significant anatomical localization was observed for living items in left lateral hemispheric cortex. A statistical significant representation of interference sites for non-living objects was found (Generalized Estimating Equation methodology, z-test=2.28, p=0.027) in the left posterolateral temporoparietal cortex. No influence of histopathology, gender and age on anatomical localization of naming categories was detected. Conclusion: The existence of dedicated neural structures for naming non-living things in the left posterolateral temporoparietal cortex is supported by this study although high individual differences exist in the organization of word categories retrieval. © 2011 Elsevier Inc.