Lateralization of object-shape information in semantic processing

An experiment was conducted to examine whether perceptual information, specifically the shape of objects, is activated during semantic processing. Subjects judged whether a target word was related to a prime word. Prime-target pairs that were not associated, but whose referents had similar shapes (e.g. LADDER-RAILROAD) yielded longer "no" responses than unassociated prime-target pairs, suggesting that shape information had been activated. A visual-field manipulation showed that, in right-handed subjects, this effect was localized in the left hemisphere. This finding is consistent with behavioral, brain imaging, and lesion data, which suggest that object shape at the category level is represented in the left hemisphere. (C) 2004 Elsevier B.V. All rights reserved.