The effect of label mixing on vocabulary acquisition: A cross-situational statistical word learning study

Learning to map novel words onto their intended referents is a complex challenge, and one that becomes even harder when acquiring multiple languages. We investigated how label mixing affected learning novel words in one versus two languages. In a cross-situational word learning study, 80 adult participants learned either one-to-one word–object mappings, or two-to-one mappings, reflecting different challenges in learning one or two languages. We manipulated whether mappings co-occurred locally, where repetitions were prevalent, or whether co-occurrences were more distributed throughout exposure. Learners acquired two-to-one mappings better when they did not occur in local co-occurrences, but there was no effect of learning conditions for one-to-one mappings. Whether participants were proficient or not in an additional language did not have an observable effect on the learning. We suggest that local co-occurrences of multiple labels, as in language mixing environments, increase the challenge of learning words, though this effect may be only short-lived.