Monodialectal and bidialectal infants use of the Mutual Exclusivity Bias in early word learning

Durrant, S. , Gunning, L. , Jenkins, H. & Floccia, C.

Plymouth University

At around 18 months infants are entering a period of rapid vocabulary growth employing a range of strategies to support this, one being the Mutual Exclusivity Bias (Liittschwager & Markman, 1994). This bias explains how infants match a novel word with an object in their environment for which they currently have no name. This strategy has been repeatedly identified in monolingual infant populations, however, not surprisingly, multilingual infants performance lies on a continuum with bilingual infants occasionally and trilingual infants never applying it (Byers-Heinlein and Werker, 2009). Indeed for these infants this rule is often inappropriate as each object they encounter has at least two nouns to which it can be mapped. An interesting case for further exploration are infants hearing multiple dialects of a single language. It has been demonstrated that these infants store dialect specific representations of familiar words. This could then impact on their use of Mutual Exclusivity as they have multiple representations - one for each dialect to which they are exposed. Following the procedure of Halberda (2003), here we presented 18 month bidialectal infants with pairs of images with one being named (the target). The target was either a name-known object paired with a name known or name-unknown distracter, or a name-unknown object paired with a name-known distracter. Looking times to the intended target following naming were recorded and analysed. Preliminary results show no evidence of Mutual Exclusivity in either group, as revealed by no naming effect for name-unknown target trials. A naming effect was found for name-known trials irrespective of distracter for monodialectal infants, however bidialectal infants only identified the target correctly when both images were name-known. This suggests that the presence of an unknown image is impacting on name-known object naming for bidialectal but not monodialectal infants.