Minimal-pair Word Learning by Bilingual Toddlers

Minimal-pair word learning by bilingual toddlers: the Catalan /e/-/É›/ contrast revisited

Introduction

This study concentrated on whether or not infants would be able to detect small differences in sounds of different languages. Previous research has shown that by a year old, infants will tune their ears to be able to only detect their native language (Byers-Heinlein& Fennell, 2014). Research also can tell us that bilinguals may not be able to tell differences in sounds although the sounds are from two different languages. This study in particular is curious whether or not bilingual (Spanish and Catalan) toddlers with be able to distinguish between the closely sounding Catalan /e/ and /É›/ sounds, which are also closely sounding to a Spanish vowel. Past studies have shown that prior exposure to Spanish before Catalan will block the perception of the Catalan letter (Sebastian-Galles, Echevarria & Bosch, 2005; Mora &Nadeu, 2012). This study, unlike previous studies, will investigate the bilingual children's ability to learn and encode the contrast vowels in words forming a pair. In doing so, researchers will be able to understand if a child's mind can learn words that pertain to each vowel sound (phonetic category) in ways they have not already experienced. There are two predictions presented. The first is that if the bilingual children are unable to identify the paired words involving the vowel contrasts, then the differences in the similar sounds have already been blended and the toddler can no longer identify them. Second, if the subject can hear the different vowels in words, then at two years old, the differences are still identifiable, meaning they lexical acquisition is possible. The researchers chose to mainly focus on the bilingual PRIMIR theory as a prediction, which states states that bilinguals should be able to differentiate sounds between languages. This information can be stored and reflected when the baby ages 12 months old, and the child will categorize new words into each language. It also states that with less exposure to each language comes a lower ability to categorize phonetics.

Methods

The test took place in a dark room with children sitting on their parent's laps. The children stared at a screen which would show them pictures of related words, while overhearing a woman's voice.

In this experiment, twenty Catalan monolinguals and twenty Catalan-Spanish bilingual toddlers ages around two years were studied. Of these children, twenty-five out of forty were male. This age was selected because of the fact that by 20 months old, toddlers are able to accomplish minimal-pair word tasks (Fennell, Byers-Heinlein & Werker, 2007), and results can be contrasted to other related studies with children of this age.

A female read non-words that contrasted the /e/ and /É›/ sound. While she read these words, pictures appeared on a screen in front of the children. It was expected of the children to hear the word and look at the correct pair of pictures. A habituation phase consisted of trials that showed one of the two target word-object pairs. A test phase was next (See figure 1), which showed the two from habituation next to each other. After this came testing. Children were shown blocks of 4 trials, each containing two trials of each target word-object pair. Each trial had 7 different tokens of one target word, but read in a different tone. The test phase showed pairs of objects, some "fillers" that the children were already expected to know, and some that did relate to /e/ and /É›/. The fillers were meant to be a distraction of sorts, while the related words were shown together.

Discussion

Because both groups were found to have similar PLT scores, meaning they could distinguish the contrasted word pairings close to the same rate, results indicate the both groups can phonetically categorize /e/ and /É›/ and learn new words with the different sounds. This is an indication that the lexical notion is still active at almost 2 years of age, when previously the notion indicated that this processing stopped at 12 months. This discovery of the previously unknown ability of toddlers contradicts prior thinking. This paper has been referenced in other empirical articles, including Joseph V. Casillas research, Production and Perception of the /i/-/I/ Vowel Contrast: The Case of L2 Dominant Early Learners of English (Casillas, 2014). One item that could be represented in a different study would be if the experiment were replicated with different languages, or to duplicate the experiment using a non-native sound to understand more about minimal pair learning. These findings conflict with the PRIMIR theory section of the hypothesis made by researchers. The PRIMIR model supports the thought that monolingual toddlers would out perform the bilingual toddlers when identifying a native language-specific sound. However, in this experiment, both groups performed very similarly, having close PLT. Another study focusing on the PRIMIR theory, vowel pronunciations, and input (without new variables such as unknown words) would be able to reflect on if the PRIMIR theory holds further truth. This research discusses how the identification of a similar vowel can be performed by toddlers two years old and younger, extending the previously thought time of specific language acquisition. While this extended time is conditional, it proves to the scientific community that toddlers are at some capacity able to discriminate between very closely sounding vowels. This contributes to our understanding of bilingualism as it proves that bilingual children can differentiate vowels not only between languages but also within a dialect itself.

References

K. Byers-Heinlein, & C. T. Fennell (2014). Perceptual narrowing in the context of increased variation: insights from bilingual infants. Developmental Psychobiology, 56 (2), 274-291. doi: 10.1002/dev.21167

C.T. Fennell, K. Byers-Heinlein, & J.F. Werker (2007). Using speech sounds to guide word learning: The case of bilingual infants. Child Development, 78 (5), 1510-1525. doi: 10.1111/j.1467-8624.2007.01080.x

N. Sebastián-Gallés, S. Echeverría, & L. Bosch (2005). The influence of initial exposure on lexical representation: comparing early and simultaneous bilinguals. Journal of Memory and Language, 52 (2), 240-255. doi: 10.1016/j.jml.2004.11.001

J. C. Mora, & M. Nadeu (2012). L2 effects on the perception and production of a native vowel contrast in early bilinguals. International Journal of Bilingualism, 16 (4), 484-500. doi: 10.1177/1367006911429518

Casillas, J. (2014). Production and Perception of the /i/-/I/ Vowel Contrast: The Case of L2-Dominant Early Learners of English. Phonetica, 72(2-3), 182-205. doi:10.1159/000431101