Identification of famous faces and buildings: a functional neuroimaging study of semantically unique items.

Several functional imaging experiments have clearly established that the fusiform gyri are preferentially responsive to faces, whereas the parahippocampal/lingual gyri are more responsive to buildings. Other studies have demonstrated that famous faces additionally activate the anterior temporal cortex relative to unfamiliar faces, animals, tools, body parts and maps. One explanation for this apparent specialization for known people could be that famous faces are 'semantically unique items'. In other words, they carry unique semantic associations that are not shared by other perceptually similar category members. If this hypothesis is correct, the anterior temporal cortex should also respond to other semantically unique items, such as famous buildings. In this PET study, we investigated the effect of fame (famous relative to non-famous) on activation elicited by famous and non-famous faces and buildings during a same-different matching task. We found that, when the task was held constant, category-specific activations in the fusiform and parahippocampal/lingual areas were not modulated by fame. In contrast, in the left anterior middle temporal gyrus there was an effect of fame that was common to faces and buildings. These results suggest that the identification of famous faces and buildings involves category-specific perceptual processing in the fusiform and parahippocampal/lingual regions, respectively, and shared analysis of unique semantic attributes in the left anterior temporal cortex.