The left temporal pole is important for retrieving words for unique concrete entities

Background: The neuroanatomical basis of lexical retrieval has been studied intensively. The current review focuses on the special case of proper nouns. Aims: This article reviews a programme of research that has used both lesion-deficit and functional-imaging (PET) approaches to investigate the neuroanatomical basis for lexical retrieval of proper nouns. In lesion-deficit studies we found that damage to the left temporal polar (TP) region leads to reliable and specific impairments in naming famous persons (e.g., oGeorge Clooneyo) and famous landmarks (e.g., oGolden Gate Bridgeo). In functional-imaging studies we found that when participants name famous persons and landmarks they produce specific activation (increases in regional cerebral blood flow) in the left TP region. Main Contribution: These findings converge with lesion and functional-imaging data from other laboratories to support the idea that the left TP region is important for the retrieval of names for unique concrete entities, persons and landmarks being typical examples of such categories of entities. Conclusions: We have interpreted these results within a theoretical framework which suggests that left TP contains convergence regions that operate as intermediaries between conceptual knowledge retrieval and lexical retrieval for classes of unique concrete entities.