Anterior temporal lobe and the representation of knowledge about people

Patients with semantic dementia (SD), a neurodegenerative disease affecting the anterior temporal lobes (ATL) (1), present with striking cognitive deficits: they can have difficulties naming objects and familiar people from both pictures and descriptions (2, 3). Furthermore, SD patients make semantic errors (e.g., naming “horse” a picture of a zebra), suggesting that their impairment affects object knowledge rather than lexical retrieval. Because SD can affect object categories as disparate as artifacts, animals, and people, as well as multiple input modalities, it has been hypothesized that ATL is a semantic hub (4) that integrates information across multiple modality-specific brain regions into multimodal representations. With a series of converging experiments using multiple analysis techniques, Wang et al. (5) test the proposal that ATL is a semantic hub in the case of person knowledge, investigating whether ATL: (i) encodes multimodal representations of identity, and (ii) mediates the retrieval of knowledge about people from representations of perceptual cues