Adult Learning of Novel Words in a Non-native Language: Consonants, Vowels, and Tones.

While words are distinguished primarily by consonants and vowels in many languages, tones are also used in the majority of the world's languages to cue lexical contrasts. However, studies on novel word learning have largely concentrated on consonants and vowels. To shed more light on the use of tonal information in novel word learning and its relationship with the development of phonological categories, the present study explored how adults' ability to learn minimal pair pseudowords in a tone language is modulated by their native phonological knowledge. Twenty-four adult speakers of three languages were tested: Cantonese, Mandarin, and French. Eye-tracking was used to record eye movements of these learners, while they were watching animated cartoons in Cantonese. On each trial, adults had to learn two new label-object associations, while the labels differed minimally by a consonant, a vowel, or a tone. Learning would therefore attest to participants' ability to use phonological information to distinguish the paired words. Results first revealed that adult learners in each language group performed better than chance in all conditions. Moreover, compared to native Cantonese adults, both Mandarin- and French-speaking adults performed worse on all three contrasts. In addition, French adults were worse on tones when compared to Mandarin adults. Lastly, no advantage for consonantal information in native lexical processing was found for Cantonese-speaking adults as predicted by the "division of labor" proposal, thus confirming crosslinguistic differences in consonant/vowel weight between speakers of tonal vs. non-tonal languages. These findings establish rapid novel word learning in a non-native language (long-term learning will have to be further assessed), modulated by native phonological knowledge. The implications of the findings of this adult study for further infant word learning studies are discussed.

A methodological investigation of the Intermodal Preferential Looking paradigm: Methods of analyses, picture selection and data rejection criteria.

The Intermodal Preferential Looking paradigm provides a sensitive measure of a child's online word comprehension. To complement existing recommendations (Fernald, Zangl, Portillo, & Marchman, 2008), the present study evaluates the impact of experimental noise generated by two aspects of the visual stimuli on the robustness of familiar word recognition with and without mispronunciations: the presence of a central fixation point and the level of visual noise in the pictures (as measured by luminance saliency). Twenty-month-old infants were presented with a classic word recognition IPL procedure in 3 conditions: without a fixation stimulus (No Fixation - noisiest condition), with a fixation stimulus before trial onset (Fixation, intermediate), and with a fixation stimulus, a neutral background and equally salient images (Fixation Plus - least noisy). Data were systematically analyzed considering a range of data selection criteria and dependent variables (proportion of looking time towards the target, longest look, and time-course analysis). Critically, the expected pronunciation and naming interaction was only found in the Fixation Plus condition. We discuss the impact of data selection criteria and the dependent variable choice on the modulation of these effects across the different conditions.

Consonant/vowel asymmetry in early word form recognition.

Previous preferential listening studies suggest that 11-month-olds' early word representations are phonologically detailed, such that minor phonetic variations (i.e., mispronunciations) impair recognition. However, these studies focused on infants' sensitivity to mispronunciations (or omissions) of consonants, which have been proposed to be more important for lexical identity than vowels. Even though a lexically related consonant advantage has been consistently found in French from 14 months of age onward, little is known about its developmental onset. The current study asked whether French-learning 11-month-olds exhibit a consonant-vowel asymmetry when recognizing familiar words, which would be reflected in vowel mispronunciations being more tolerated than consonant mispronunciations. In a baseline experiment (Experiment 1), infants preferred listening to familiar words over nonwords, confirming that at 11 months of age infants show a familiarity effect rather than a novelty effect. In Experiment 2, which was constructed using the familiar words of Experiment 1, infants preferred listening to one-feature vowel mispronunciations over one-feature consonant mispronunciations. Given the familiarity preference established in Experiment 1, this pattern of results suggests that recognition of early familiar words is more dependent on their consonants than on their vowels. This adds another piece of evidence that, at least in French, consonants already have a privileged role in lexical processing by 11 months of age, as claimed by Nespor, Peña, and Mehler (2003).

English-learning one- to two-year-olds do not show a consonant bias in word learning.

Following the proposal that consonants are more involved than vowels in coding the lexicon (Nespor, Peña & Mehler, 2003), an early lexical consonant bias was found from age 1;2 in French but an equal sensitivity to consonants and vowels from 1;0 to 2;0 in English. As different tasks were used in French and English, we sought to clarify this ambiguity by using an interactive word-learning study similar to that used in French, with British-English-learning toddlers aged 1;4 and 1;11. Children were taught two CVC labels differing on either a consonant or vowel and tested on their pairing of a third object named with one of the previously taught labels, or part of them. In concert with previous research on British-English toddlers, our results provided no evidence of a general consonant bias. The language-specific mechanisms explaining the differential status for consonants and vowels in lexical development are discussed.

A "bat" is easier to learn than a "tab": effects of relative phonotactic frequency on infant word learning.

Many studies have shown that during the first year of life infants start learning the prosodic, phonetic and phonotactic properties of their native language. In parallel, infants start associating sound sequences with semantic representations. However, the question of how these two processes interact remains largely unknown. The current study explores whether (and when) the relative phonotactic probability of a sound sequence in the native language has an impact on infants' word learning. We exploit the fact that Labial-Coronal (LC) words are more frequent than Coronal-Labial (CL) words in French, and that French-learning infants prefer LC over CL sequences at 10 months of age, to explore the possibility that LC structures might be learned more easily and thus at an earlier age than CL structures. Eye movements of French-learning 14- and 16-month-olds were recorded while they watched animated cartoons in a word learning task. The experiment involved four trials testing LC sequences and four trials testing CL sequences. Our data reveal that 16-month-olds were able to learn the LC and CL words, while14-month-olds were only able to learn the LC words, which are the words with the more frequent phonotactic pattern. The present results provide evidence that infants' knowledge of their native language phonotactic patterns influences their word learning: Words with a frequent phonotactic structure could be acquired at an earlier age than those with a lower probability. Developmental changes are discussed and integrated with previous findings.