Proceedings of the Annual Meeting of the Cognitive Science Society

One proposal for how children acquire lexical categories is on the basis of their distributional signatures. Given that thelanguage children are exposed to gradually changes as they get older, it is possible that such changes impact the qualityof distributional information, and therefore the efficiency with which lexical categories are acquired. To test this idea, wecompiled a corpus of American-English child-directed speech and ordered it by increasing age of the target child. Next,we investigated the quality of distributional cues about lexical category membership in the first and second half of theage-ordered corpus. As predicted, we found that the quality of distributional information co-varies with age of the targetchild. Specifically, we found that distributional evidence for the noun category was of higher quality in speech to youngercompared to older children. In light of these findings, we recommend that distributional accounts of lexical categoryacquisition take into consideration language change during the first six years of development.