Does categorical perception in the left hemisphere depend on language?

Categorical perception (CP) refers to the influence of category knowledge on perception and is revealed by a superior ability to discriminate items across categories relative to items within a category. In recent years, the finding that CP is lateralized to the left hemisphere in adults has been interpreted as evidence for a kind of CP driven by language. The present research challenges this conclusion. In 2 experiments, we found that CP for novel object categories was stronger in the left hemisphere than in the right, consistent with a role for language. However, both labeled and unlabeled categories gave rise to such effects, and to comparable degrees. These results suggest that left-lateralized CP does not depend on language but rather may reflect the left hemisphere's more general propensity for categorical processing. Our findings raise implications for research on linguistic relativity. (PsycINFO Database Record (c) 2012 APA, all rights reserved).