David Birdsong

Degree of foreign accent in English sentences produced by Korean children and adults

The purpose of this longitudinal study was to evaluate the influence of age (adult vs. child) and length of residence (LOR) in an L2-speaking country (3 vs. 5 years) on degree of foreign accent in a second language (L2). Korean adults and children living in North America, and age-matched groups of native English (NE) adults and children, recorded English sentences in sessions held 1.2 years apart (T1 vs. T2). NE-speaking listeners rated the sentences for overall degree of perceived foreign accent using a 9-point scale. The native Korean (NK) children received significantly higher ratings than the NK adults did, but lower ratings than the NE children. The NK children—even those who had arrived as young children and been enrolled in English-medium schools for an average of 4 years—spoke English with detectable foreign accents. The effects of LOR and the T1–T2 differences were non-significant for both the NK adults and the NK children. The findings were inconsistent with the hypothesis that adult–child differences in L2 speech learning are due to the passing of a critical period. The suggestion is made that the milder foreign accents observed for children than adults are due, at least in part, to the greater L2 input typically received by immigrant children than adults.

A developmental study of English vowel production and perception by native Korean adults and children

Abstract This study examined the production and perception of English vowels by native Korean (NK) learners of English on two occasions separated by about 1 year. A preliminary experiment revealed that NK adults classified some pairs of contrastive English vowels using two different Korean vowels whereas other pairs showed classification overlap, implying they would be difficult for Korean learners of English to discriminate. In two subsequent experiments, NK adults and children differing in length of residence in North America (3 vs. 5 years; 4 groups of 18 each) were compared to age-matched native English (NE) speakers. In Experiment 2, NK children were found to discriminate English vowels more accurately than NK adults but less accurately than NE children. In Experiment 3, English words containing /i ɪ e ɪ e ae ɑ ʌ/ were elicited using a picture-naming task. Some vowels produced by NK children were heard as intended significantly more often than vowels produced by NK adults. Acoustic analyses revealed that NK children produced significantly larger between-vowel contrasts than NK adults but did not differ from NE children. Taken together, the results suggested that although children are more successful than adults in learning the phonetic properties of second-language vowels, they might continue to differ from age-matched native speakers in certain respects as uncovered by the vowel discrimination test in Experiment 2.

Nativelikeness and Non-Nativelikeness in L2A Research.

Abstract This commentary addresses the use of nativelikeness and non-nativelikeness in research relating to the age factor in L2A. I suggest that, in the context of the Critical Period Hypothesis as it applies to L2A, the criteria of nativelikeness and non-nativelikeness may be subject to abuse. I also argue that the use of the monolingual native standard for falsification of the CPH is undermined by departures from monolingual nativelikeness that are artifacts of the nature of bilingualism. Finally, I discuss ways that evidence of (non-) nativelikeness can be put to constructive use in research that investigates the upper limits of L2A attainment.

Release Bursts in English Word-Final Voiceless Stops Produced by Native English and Korean Adults and Children

The aim of this study was to evaluate the acquisition of statistical properties of a second language (L2). Stop consonants are permitted in word-final position in both English and Korean, but they are variably released in English and invariably unreleased in Korean. Native Korean (K) adults and children living in North America and age-matched native English (E) speakers repeated English words ending in released tokens of /t/ and /k/ at two times separated by 1.2 years. The judgments of E-speaking listeners were used to determine if the stimuli were repeated with audible release bursts. Experiments 1 and 2 revealed fewer final releases for K than E adults, and fewer releases for /t/ (but not /k/) for K than E children. Nearly all /t/ and /k/ tokens were heard as intended in experiment 3, which evaluated intelligibility. However, the K adults’ /k/ tokens were identified with less certainty than the E adults’. Taken together, the results suggested that noncontrastive (i.e., statistical) properties of an L2 can be learned by children, and to a somewhat lesser extent by adults.

Dominance, Proficiency, and Second Language Grammatical Processing.

Clahsen and Felser (CF) deserve praise for their superlative synthesis of literature relating to grammatical processing, as well as for their original contributions to this area of research. CF “explore the idea that there might be fundamental differences between child L1 and adult L2 processing.” The researchers present evidence that adult second language (L2) processing is often less automatic and less efficient than first language (L1) processing. Qualitative differences are suggested as well. Adult L2 processing may be restricted to shallow computations, whereas L1 processing typically involves detailed representations. These conclusions are reached in large part by comparing highly proficient L2 learners with natives on various neurological and behavioral dimensions of processing. I propose that additional comparisons might be carried out that involve an understudied population: learners whose L2 is their dominant language.

PROCESSING FOCUS STRUCTURE IN L1 AND L2 FRENCH

This study examined the event-related potentials (ERPs) elicited by focus processing among first language (L1) speakers and second language (L2) learners of French. Participants read wh- questions containing explicit focus marking, followed by responses instantiating contrastive and informational focus. We hypothesized that L2 proficiency would modulate nativelikeness in L2 processing. For the L1 and L2 groups, widespread word-long positive shifts reflected the processing of nouns receiving informational and contrastive focus. Nouns receiving contrastive focus showed an increased anterior negativity compared to informational focus for both groups. Second language proficiency modulated the amplitude of this negativity effect, and subgroup analyses of low- and high-proficiency L2 learners showed no significant effect of focus condition among low-proficiency learners. This modulatory relationship between L2 proficiency and nativelikeness of processing is consistent with the dynamic sequence of L2 ERPs observed for morphosyntactic processing and extends those findings to the syntax-pragmatics interface phenomenon of focus processing.

The Critical Period Hypothesis for Second Language Acquisition: Tailoring the Coat of Many Colors

The present contribution represents an extension of David Singleton’s (2005) IRAL chapter, “The Critical Period Hypothesis: A coat of many colours”. I suggest that the CPH in its application to L2 acquisition could benefit from methodological and theoretical tailoring with respect to: the shape of the function that relates age of acquisition to proficiency, the use of nativelikeness for falsification of the CPH, and the framing of predictors of L2 attainment.

Uninterpretable features: psychology and plasticity in second language learnability

This commentary addresses the relevance of detectability to a theory of learning uninterpretable features in the second language (L2). Detectability of features is illustrated in an application of Signal Detection Theory. By analogy with development of phonemic categories in the first language (L1), the notion of paring down the repertoire of uninterpretable features is considered.

Plasticity, Variability and Age in Second Language Acquisition and Bilingualism

Much of what is known about the outcome of second language acquisition and bilingualism can be summarized in terms of inter-individual variability, plasticity and age. The present review looks at variability and plasticity with respect to their underlying sources, and at age as a modulating factor in variability and plasticity. In this context we consider critical period effects vs. bilingualism effects, early and late bilingualism, nativelike and non-nativelike L2 attainment, cognitive aging, individual differences in learning, and linguistic dominance in bilingualism. Non-uniformity is an inherent characteristic of both early and late bilingualism. This review shows how plasticity and age connect with biological and experiential sources of variability, and underscores the value of research that reveals and explains variability. In these ways the review suggests how plasticity, variability and age conspire to frame fundamental research issues in L2 acquisition and bilingualism, and provides points of reference for discussion of the present Frontiers in Psychology Research Topic.

Release bursts in English word‐final stops: A longitudinal study of Korean adults’ and children’s production

Stops at the end of Korean words are always unreleased. The question addressed here was whether Korean adults and children living in the U.S. can learn to release stops at the end of English words. Four groups of 18 native Koreans (NK) who differed according to age (adult versus child) and length of residence in the U.S. (3 vs 5 years at T1) participated. Two native English (NE) groups served as age‐matched controls. Production data were collected at two times (T1, T2) separated by one year. English words ending in /t/ and /k/ were then examined in perception experiments (Exp. 1, Exp. 2). NE‐speaking judges decided whether the final stop has a release burst or not. Exp. 1 showed that NE talkers released /t/ more often than NK talkers did. The effect of time was also significant. Talkers produced release bursts more often at T2 than at T1. Exp. 2 showed that, unlike Exp. 1, there were significant differences between NK adults and children. While NK children did not differ from NE children, NK adults releas...