A role for left temporal pole in the retrieval of words for unique entities

Both lesion and functional imaging studies have implicated sectors of high- order association cortices of the left temporal lobe in the retrieval of wo rds for objects belonging to varied conceptual categories. In particular, t he cortices located in the left temporal pole have been associated with nam ing unique persons from faces. Because this neuroanatomical-behavioral asso ciation might be related to either the specificity of the task (retrieving a name at unique level) or to the possible preferential processing of faces by anterior temporal cortices, we performed a PET imaging experiment to te st the hypothesis that the effect is related to the specificity of the word retrieval task. Normal subjects were asked to name at unique level entitie s from two conceptual categories: famous landmarks and famous faces. In sup port of the hypothesis, naming entities in both categories was associated w ith increases in activity in the left temporal pole. No main effect of cate gory (faces vs. landmarks /buildings) or interaction of task and category w as found in the left temporal pole. Retrieving names for unique persons and for names for unique landmarks activate the same brain region. These findi ngs are consistent with the notion that activity in the left temporal pole is Linked to the level of specificity of word retrieval rather than the con ceptual class to which the stimulus belongs. (C) 2001 Wiley-Liss, Inc.