Krista Byers-Heinlein | Concordia University (Canada) (original) (raw)

Papers by Krista Byers-Heinlein

Past research has shown that young monolingual children exhibit language-based social biases: the... more Past research has shown that young monolingual children exhibit language-based social biases: they prefer native language to foreign language speakers. The current research investigated how children’s language preferences are influenced by their own bilingualism and by a speaker’s bilingualism. Monolingual and bilingual four- to six-year-olds heard pairs of adults (a monolingual and a bilingual, or two monolinguals) and chose the person with whom they wanted to be friends. Whether they were from a largely monolingual or a largely bilingual community, monolingual children preferred monolingual to bilingual speakers, and native language to foreign language speakers. In contrast, bilingual children showed similar affiliation with monolingual and bilingual speakers, as well as for monolingual speakers using their dominant versus non-dominant language. Exploratory analyses showed that individual bilinguals displayed idiosyncratic patterns of preference. These results reveal that language-based preferences emerge from a complex interaction of factors, including preference for in-group members, avoidance of out-group members, and characteristics of the child as they relate to the status of the languages within the community. Moreover, these results have implications for bilingual children’s social acceptance by their peers.

Developmental Science

Young children engage in essentialist reasoning about natural kinds, believing that many traits a... more Young children engage in essentialist reasoning about natural kinds, believing that many traits are innately determined. This study investigated whether personal experience with second language acquisition could alter children’s essentialist biases. In a switched-at-birth paradigm, five- and six-year-old monolingual and simultaneous bilingual children expected that a baby’s native language, an animal’s vocalizations, and an animal’s physical traits would match those of a birth rather than an adoptive parent. We predicted that sequential bilingual children, who had been exposed to a new language after age three, would show greater understanding that languages are learned. Surprisingly, sequential bilinguals showed reduced essentialist beliefs about all traits: they were significantly more likely than other children to believe that human language, animal vocalizations, and animal physical traits would be learned through experience rather than innately endowed. These findings suggest that bilingualism in the preschool years can profoundly change children’s essentialist biases.

International Journal of Behavioral Development, Jun 4, 2014

Previous research indicates that monolingual infants have difficulty learning minimal pairs (i.e.... more Previous research indicates that monolingual infants have difficulty learning minimal pairs (i.e., words differing by one phoneme) produced by a speaker uncharacteristic of their language environment and that bilinguals might share this difficulty. To clearly reveal infants’ underlying phonological representations, we minimized task demands by embedding target words in naming phrases, using a fully crossed, between-subjects experimental design. We tested 17-month-old French-English bilinguals’ (N 1⁄4 30) and English monolinguals’ (N 1⁄4 31) learning of a minimal pair (/kεm/ – /gεm/) produced by an adult bilingual or monolingual. Infants learned the minimal pair only when the speaker matched their language environment. This vulnerability to subtle changes in word pronunciation reveals that neither monolingual nor bilingual 17-month-olds possess fully generalizable phonological representations.

Language Learning

One of the most enduring questions in the field of bilingualism is whether bilingual infants and ... more One of the most enduring questions in the field of bilingualism is whether bilingual infants and children initially have “one language system or two”. Research with adults indicates that while bilinguals do not represent their languages in two fully encapsulated language systems, they are able to functionally differentiate their languages. This paper proposes that bilinguals differentiate their languages insofar as they can treat elements of their languages as belonging to different categories. Several lines of research with bilingual adults and children are considered in the context of perceptual and conceptual language categories. The paper ends with a discussion of how language categories might emerge over the course of early bilingual development, and outlines directions for future research.

LEARNing Landscapes, 2013

Many children in North America and around the world grow up exposed to two languages from an earl... more Many children in North America and around the world grow up exposed to two languages from an early age. Parents of bilingual infants and toddlers have important questions about the costs and benefits of early bilingualism, and how to best support language acquisition in their children. Here, we separate common myths from scientific findings to answer six of parents’ most common questions about early bilingual development.

Frontiers in Developmental Psychology

Journal of Experimental Child Psychology, 2013

Languages function as independent and distinct conventional systems, and thus each language uses ... more Languages function as independent and distinct conventional systems, and thus each language uses different words to label the same objects. This study investigated whether 2-year-old children recognize that speakers of their native language and speakers of a foreign language do not share the same knowledge. Two groups of children unfamiliar with Mandarin were tested: monolingual English-learning children (n = 24) and bilingual children learning English and another language (n = 24). An English speaker taught children the novel label fep. On English mutual exclusivity trials, the speaker asked for the referent of a novel label (wug) in the presence of the fep and a novel object. Both monolingual and bilingual children disambiguated the reference of the novel word using a mutual exclusivity strategy, choosing the novel object rather than the fep. On similar trials with a Mandarin speaker, children were asked to find the referent of a novel Mandarin label kuò. Monolinguals again chose the novel object rather than the object with the English label fep, even though the Mandarin speaker had no access to conventional English words. Bilinguals did not respond systematically to the Mandarin speaker, suggesting that they had enhanced understanding of the Mandarin speaker’s ignorance of English words. The results indicate that monolingual children initially expect words to be conventionally shared across all speakers, native and foreign. Early bilingual experience facilitates children’s discovery of the nature of foreign language words.

Cognition, 2013

In ambiguous word learning situations, infants can use systematic strategies to determine the ref... more In ambiguous word learning situations, infants can use systematic strategies to determine the referent of a novel word. One such heuristic is disambiguation. By age 16–18 months, monolinguals infer that a novel noun refers to a novel object rather than a familiar one (Halberda, 2003), while at the same age bilinguals and trilinguals do not reliably show dis- ambiguation (Byers-Heinlein & Werker, 2009; Houston-Price, Caloghiris, & Raviglione, 2010). It has been hypothesized that these results reflect a unique aspect of the bilingual lexicon: bilinguals often know many translation equivalents, cross-language synonyms such as English dog and Mandarin goˇu. We studied the role of vocabulary knowledge in the development of disambiguation by relating 17–18 month-old English–Chinese bilin- gual infants’ performance on a disambiguation task to the percentage of translation equiv- alents in their comprehension vocabularies. Those bilingual infants who understood translation equivalents for more than half the words in their vocabularies did not show dis- ambiguation, while infants who knew a smaller proportion of translation equivalents showed disambiguation just as same-aged monolinguals do. These results demonstrate that the structure of the developing lexicon plays a key role in infants’ use of disambiguation.

Developmental Psychobiology, 2013

Human infants become native-language listeners through a process of perceptual narrowing. Monoli... more Human infants become native-language listeners through a process of perceptual narrowing. Monolingual infants are initially sensitive to a wide range of language-relevant contrasts. However, as they mature and gain native-language experience, their sensitivity to non-native contrasts declines. Here, we consider the case of infants growing up bilingual as a window into how increased variation affects early perceptual development. These infants encounter different meaningful contrasts in each of their languages, and must also attend to contrasts that occur between their languages. Bilingual infants share many classic developmental patterns with monolinguals. However, they also show unique developmental patterns in the perception of native distinctions such as U-shaped trajectories and dose-response relationships, and show some enhanced sensitivity to non-native distinctions. Analogous developmental patterns can be observed in individuals exposed to two non-linguistic systems in domains such as music and face perception. Some preliminary evidence suggests that bilingual individuals might retain more sensitivity to non-native contrasts, reaching a less narrow end state than monolinguals. Nevertheless, bilingual infants do become perceptually-specialized native listeners to both of their languages, despite increased variation and differing patterns of perceptual development in comparison to monolinguals.

Bilingualism: Language and Cognition, Jan 2013

Abstract Children growing up bilingual face a unique linguistic environment. The current study in... more Abstract Children growing up bilingual face a unique linguistic environment. The current study investigated whether early bilingual experience influences the developmental trajectory of associative word learning, a foundational mechanism for lexical acquisition. Monolingual and bilingual infants (N= 98) were tested on their ability to learn dissimilar-sounding words (lif and neem) in the Switch task.

To rise to the challenge of acquiring their native language, infants must deploy tools to support... more To rise to the challenge of acquiring their native language, infants must deploy tools to support their learning. This thesis compared infants growing up in two very different language environments, monolingual and bilingual, to better understand these tools and how their development and use changes with the context of language acquisition. The first set of studies− Chapter 2− showed that infants adapt very early-developing tools to the context of their prenatal experience.

Abstract Infants growing up bilingual provide a unique window into how the language environment i... more Abstract Infants growing up bilingual provide a unique window into how the language environment interacts with word learning and word comprehension mechanisms. The present studies used a preferential looking paradigm to investigate monolingual and bilingual 18-month-old infants' responses to familiar and novel words. Monolinguals and bilinguals both responded to familiar words with increased attention to the target object.

Bilingualism: Language and Cognition, Jan 2013

Is parental language mixing related to vocabulary acquisition in bilingual infants and children? ... more Is parental language mixing related to vocabulary acquisition in bilingual infants and children? Bilingual parents (who spoke English and another language; N = 181) completed the Language Mixing Scale, a new self-report measure that assesses how frequently parents use words from two different languages in the same sentence, such as borrowing words from another language or code switching between two languages in the same sentence. Concurrently, English vocabulary size was measured in the bilingual children of these parents. Most parents reported regular language mixing in interactions with their child. Increased rates of parental language mixing were associated with significantly smaller comprehension vocabularies in 1.5-year-old bilingual infants, and marginally smaller production vocabularies in 2-year-old bilingual children. Exposure to language mixing might obscure cues that facilitate young bilingual children’s separation of their languages and could hinder the functioning of learning mechanisms that support the early growth of their vocabularies.

Previous research has shown that by the time of birth, the neonate brain responds specially to th... more Previous research has shown that by the time of birth, the neonate brain responds specially to the native language when compared to acoustically similar non-language stimuli. In the current study, we use Near Infrared Spectroscopy to ask how prenatal language experience might shape the brain response to language in newborn infants. To do so, we examine the neural response of neonates when listening to familiar versus unfamiliar language, as well as to non-linguistic backwards language. Twenty monolingual English-exposed neonates aged 0-3 days were tested. Each infant heard low-pass filtered sentences of forward English (familiar language), forward Tagalog (unfamiliar language), and backwards English and Tagalog. During exposure, neural activation was measured across twelve channels on each hemisphere. Our results indicate a bilateral effect of language familiarity on neonates’ brain response to language. Differential brain activation was seen when neonates listened to forward Tagalog (unfamiliar language) as compared to other types of language stimuli. We interpret these results as evidence that the pre-natal experience with the native language gained in utero influences how the newborn brain responds to language across brain regions sensitive to speech processing.

Journal of Phonetics, 2011

"PRIMIR (Processing Rich Information from Multidimensional Interactive Representations; Curtin & ... more "PRIMIR (Processing Rich Information from Multidimensional Interactive Representations; Curtin & Werker, 2007; Werker & Curtin, 2005) is a framework that encompasses the bidirectional relations between infant speech perception and the emergence of the lexicon. Here, we expand its mandate by considering infants growing up bilingual. We argue that, just like monolinguals, bilingual infants have access to rich information in the speech stream and by the end of their first year, they establish not only language-specific phonetic category representations, but also encode and represent both sub-phonetic and indexical detail. Perceptual biases, developmental level, and task demands work together to influence the level of detail used in any particular situation. In considering bilingual acquisition, we more fully elucidate what is meant by task demands, now understood both in terms of external demands imposed by the language situation, and internal demands imposed by the infant (e.g. different approaches to the same apparent task taken by infants from different backgrounds). In addition to the statistical learning mechanism previously described in PRIMIR, the necessity of a comparison–contrast mechanism is discussed. This refocusing of PRIMIR in the light of bilinguals more fully explicates the relationship between speech perception and word learning in all infants.
&"

Psychological Science, 2010

The first steps toward bilingual language acquisition have already begun at birth. When tested on... more The first steps toward bilingual language acquisition have already begun at birth. When tested on their preference for English versus Tagalog, newborns whose mothers spoke only English during pregnancy showed a robust preference for English. In contrast, newborns whose mothers spoke both English and Tagalog regularly during pregnancy showed equal preference for both languages. A group of newborns whose mothers had spoken both Chinese and English showed an intermediate pattern of preference for Tagalog over English. Preference for two languages does not suggest confusion between them, however. Study 2 showed that both English monolingual newborns and Tagalog-English bilingual newborns could discriminate English from Tagalog. The same perceptual and learning mechanisms that support acquisition in a monolingual environment thus also naturally support bilingual acquisition.

Philosophical Transactions of the Royal Society B, 2009

"At the macrostructure level of language milestones, language acquisition follows a nearly identi... more "At the macrostructure level of language milestones, language acquisition follows a nearly identical course whether children grow up with one or with two languages. However, at the microstructure level, experimental research is revealing that the same proclivities and learning mechanisms that support language acquisition unfold somewhat differently in bilingual versus monolingual environments. This paper synthesizes recent findings in the area of early bilingualism by focusing on the question of how bilingual infants come to apply their phonetic sensitivities to word learning, as they must to learn minimal pair words (e.g. ‘cat’ and ‘mat’). To this end, the paper reviews antecedent achievements by bilinguals throughout infancy and early childhood in the following areas: language discrimination and separation, speech perception, phonetic and phonotactic development, word recognition, word learning and aspects of conceptual development that underlie word learning. Special consideration is given to the role of language dominance, and to the unique challenges to language acquisition posed by a bilingual environment.
Keywords: bilingualism; language development; infancy;"

Developmental Science, 2009

How infants learn new words is a fundamental puzzle in language acquisition. To guide their word ... more How infants learn new words is a fundamental puzzle in language acquisition. To guide their word learning, infants exploit systematic word-learning heuristics that allow them to link new words to likely referents. By 17 months, infants show a tendency to associate a novel noun with a novel object rather than a familiar one, a heuristic known as disambiguation. Yet, the developmental origins of this heuristic remain unknown. We compared disambiguation in 17- to 18-month-old infants from different language backgrounds to determine whether language experience influences its development, or whether disambiguation instead emerges as a result of maturation or social experience. Monolinguals showed strong use of disambiguation, bilinguals showed marginal use, and trilinguals showed no disambiguation. The number of languages being learned, but not vocabulary size, predicted performance. The results point to a key role for language experience in the development of disambiguation, and help to distinguish among theoretical accounts of its emergence.

Trends in Cognitive Sciences, 2008

Many children grow up in bilingual families and acquire two first languages. Emerging research is... more Many children grow up in bilingual families and acquire two first languages. Emerging research is advancing the view that the capacity to acquire language can be applied equally to two languages as to one but that bilingual and monolingual acquisition nonetheless differ in some nontrivial ways. To probe the first steps toward acquisition, researchers recently have begun to use experimental methods to study preverbal bilingual infants. We review the literature in this growing field, focusing on how infants growing up bilingual use surface acoustic information to separate, categorize and begin to learn their two languages. These new data invite the expansion of standard linguistic theories to account for how a single architecture can support the acquisition of two languages simultaneously.

Child Development, 2007

Despite the prevalence of bilingualism, language acquisition research has focused on monolingual ... more Despite the prevalence of bilingualism, language acquisition research has focused on monolingual infants. Monolinguals cannot learn minimally different words (e.g., ‘‘bih’’ and ‘‘dih’’) in a laboratory task until 17 months of age (J. F. Werker, C. T. Fennell, K. M. Corcoran, & C. L. Stager, 2002). This study was extended to 14- to 20-month-old bilingual infants: a heterogeneous sample (English and another language; N 5 48) and two homogeneous samples (28 English – Chinese and 25 English – French infants). In all samples, bilinguals did not learn similar-sounding words until 20 months, indicating that they use relevant language sounds (i.e., consonants) to direct word learning developmentally later than monolinguals, possibly due to the increased cognitive load of learning two languages. However, this developmental pattern may be adaptive for bilingual word learning.

Past research has shown that young monolingual children exhibit language-based social biases: the... more Past research has shown that young monolingual children exhibit language-based social biases: they prefer native language to foreign language speakers. The current research investigated how children’s language preferences are influenced by their own bilingualism and by a speaker’s bilingualism. Monolingual and bilingual four- to six-year-olds heard pairs of adults (a monolingual and a bilingual, or two monolinguals) and chose the person with whom they wanted to be friends. Whether they were from a largely monolingual or a largely bilingual community, monolingual children preferred monolingual to bilingual speakers, and native language to foreign language speakers. In contrast, bilingual children showed similar affiliation with monolingual and bilingual speakers, as well as for monolingual speakers using their dominant versus non-dominant language. Exploratory analyses showed that individual bilinguals displayed idiosyncratic patterns of preference. These results reveal that language-based preferences emerge from a complex interaction of factors, including preference for in-group members, avoidance of out-group members, and characteristics of the child as they relate to the status of the languages within the community. Moreover, these results have implications for bilingual children’s social acceptance by their peers.

Developmental Science

Young children engage in essentialist reasoning about natural kinds, believing that many traits a... more Young children engage in essentialist reasoning about natural kinds, believing that many traits are innately determined. This study investigated whether personal experience with second language acquisition could alter children’s essentialist biases. In a switched-at-birth paradigm, five- and six-year-old monolingual and simultaneous bilingual children expected that a baby’s native language, an animal’s vocalizations, and an animal’s physical traits would match those of a birth rather than an adoptive parent. We predicted that sequential bilingual children, who had been exposed to a new language after age three, would show greater understanding that languages are learned. Surprisingly, sequential bilinguals showed reduced essentialist beliefs about all traits: they were significantly more likely than other children to believe that human language, animal vocalizations, and animal physical traits would be learned through experience rather than innately endowed. These findings suggest that bilingualism in the preschool years can profoundly change children’s essentialist biases.

International Journal of Behavioral Development, Jun 4, 2014

Previous research indicates that monolingual infants have difficulty learning minimal pairs (i.e.... more Previous research indicates that monolingual infants have difficulty learning minimal pairs (i.e., words differing by one phoneme) produced by a speaker uncharacteristic of their language environment and that bilinguals might share this difficulty. To clearly reveal infants’ underlying phonological representations, we minimized task demands by embedding target words in naming phrases, using a fully crossed, between-subjects experimental design. We tested 17-month-old French-English bilinguals’ (N 1⁄4 30) and English monolinguals’ (N 1⁄4 31) learning of a minimal pair (/kεm/ – /gεm/) produced by an adult bilingual or monolingual. Infants learned the minimal pair only when the speaker matched their language environment. This vulnerability to subtle changes in word pronunciation reveals that neither monolingual nor bilingual 17-month-olds possess fully generalizable phonological representations.

Language Learning

One of the most enduring questions in the field of bilingualism is whether bilingual infants and ... more One of the most enduring questions in the field of bilingualism is whether bilingual infants and children initially have “one language system or two”. Research with adults indicates that while bilinguals do not represent their languages in two fully encapsulated language systems, they are able to functionally differentiate their languages. This paper proposes that bilinguals differentiate their languages insofar as they can treat elements of their languages as belonging to different categories. Several lines of research with bilingual adults and children are considered in the context of perceptual and conceptual language categories. The paper ends with a discussion of how language categories might emerge over the course of early bilingual development, and outlines directions for future research.

LEARNing Landscapes, 2013

Many children in North America and around the world grow up exposed to two languages from an earl... more Many children in North America and around the world grow up exposed to two languages from an early age. Parents of bilingual infants and toddlers have important questions about the costs and benefits of early bilingualism, and how to best support language acquisition in their children. Here, we separate common myths from scientific findings to answer six of parents’ most common questions about early bilingual development.

Frontiers in Developmental Psychology

Journal of Experimental Child Psychology, 2013

Languages function as independent and distinct conventional systems, and thus each language uses ... more Languages function as independent and distinct conventional systems, and thus each language uses different words to label the same objects. This study investigated whether 2-year-old children recognize that speakers of their native language and speakers of a foreign language do not share the same knowledge. Two groups of children unfamiliar with Mandarin were tested: monolingual English-learning children (n = 24) and bilingual children learning English and another language (n = 24). An English speaker taught children the novel label fep. On English mutual exclusivity trials, the speaker asked for the referent of a novel label (wug) in the presence of the fep and a novel object. Both monolingual and bilingual children disambiguated the reference of the novel word using a mutual exclusivity strategy, choosing the novel object rather than the fep. On similar trials with a Mandarin speaker, children were asked to find the referent of a novel Mandarin label kuò. Monolinguals again chose the novel object rather than the object with the English label fep, even though the Mandarin speaker had no access to conventional English words. Bilinguals did not respond systematically to the Mandarin speaker, suggesting that they had enhanced understanding of the Mandarin speaker’s ignorance of English words. The results indicate that monolingual children initially expect words to be conventionally shared across all speakers, native and foreign. Early bilingual experience facilitates children’s discovery of the nature of foreign language words.

Cognition, 2013

In ambiguous word learning situations, infants can use systematic strategies to determine the ref... more In ambiguous word learning situations, infants can use systematic strategies to determine the referent of a novel word. One such heuristic is disambiguation. By age 16–18 months, monolinguals infer that a novel noun refers to a novel object rather than a familiar one (Halberda, 2003), while at the same age bilinguals and trilinguals do not reliably show dis- ambiguation (Byers-Heinlein & Werker, 2009; Houston-Price, Caloghiris, & Raviglione, 2010). It has been hypothesized that these results reflect a unique aspect of the bilingual lexicon: bilinguals often know many translation equivalents, cross-language synonyms such as English dog and Mandarin goˇu. We studied the role of vocabulary knowledge in the development of disambiguation by relating 17–18 month-old English–Chinese bilin- gual infants’ performance on a disambiguation task to the percentage of translation equiv- alents in their comprehension vocabularies. Those bilingual infants who understood translation equivalents for more than half the words in their vocabularies did not show dis- ambiguation, while infants who knew a smaller proportion of translation equivalents showed disambiguation just as same-aged monolinguals do. These results demonstrate that the structure of the developing lexicon plays a key role in infants’ use of disambiguation.

Developmental Psychobiology, 2013

Human infants become native-language listeners through a process of perceptual narrowing. Monoli... more Human infants become native-language listeners through a process of perceptual narrowing. Monolingual infants are initially sensitive to a wide range of language-relevant contrasts. However, as they mature and gain native-language experience, their sensitivity to non-native contrasts declines. Here, we consider the case of infants growing up bilingual as a window into how increased variation affects early perceptual development. These infants encounter different meaningful contrasts in each of their languages, and must also attend to contrasts that occur between their languages. Bilingual infants share many classic developmental patterns with monolinguals. However, they also show unique developmental patterns in the perception of native distinctions such as U-shaped trajectories and dose-response relationships, and show some enhanced sensitivity to non-native distinctions. Analogous developmental patterns can be observed in individuals exposed to two non-linguistic systems in domains such as music and face perception. Some preliminary evidence suggests that bilingual individuals might retain more sensitivity to non-native contrasts, reaching a less narrow end state than monolinguals. Nevertheless, bilingual infants do become perceptually-specialized native listeners to both of their languages, despite increased variation and differing patterns of perceptual development in comparison to monolinguals.

Bilingualism: Language and Cognition, Jan 2013

Abstract Children growing up bilingual face a unique linguistic environment. The current study in... more Abstract Children growing up bilingual face a unique linguistic environment. The current study investigated whether early bilingual experience influences the developmental trajectory of associative word learning, a foundational mechanism for lexical acquisition. Monolingual and bilingual infants (N= 98) were tested on their ability to learn dissimilar-sounding words (lif and neem) in the Switch task.

To rise to the challenge of acquiring their native language, infants must deploy tools to support... more To rise to the challenge of acquiring their native language, infants must deploy tools to support their learning. This thesis compared infants growing up in two very different language environments, monolingual and bilingual, to better understand these tools and how their development and use changes with the context of language acquisition. The first set of studies− Chapter 2− showed that infants adapt very early-developing tools to the context of their prenatal experience.

Abstract Infants growing up bilingual provide a unique window into how the language environment i... more Abstract Infants growing up bilingual provide a unique window into how the language environment interacts with word learning and word comprehension mechanisms. The present studies used a preferential looking paradigm to investigate monolingual and bilingual 18-month-old infants' responses to familiar and novel words. Monolinguals and bilinguals both responded to familiar words with increased attention to the target object.

Bilingualism: Language and Cognition, Jan 2013

Is parental language mixing related to vocabulary acquisition in bilingual infants and children? ... more Is parental language mixing related to vocabulary acquisition in bilingual infants and children? Bilingual parents (who spoke English and another language; N = 181) completed the Language Mixing Scale, a new self-report measure that assesses how frequently parents use words from two different languages in the same sentence, such as borrowing words from another language or code switching between two languages in the same sentence. Concurrently, English vocabulary size was measured in the bilingual children of these parents. Most parents reported regular language mixing in interactions with their child. Increased rates of parental language mixing were associated with significantly smaller comprehension vocabularies in 1.5-year-old bilingual infants, and marginally smaller production vocabularies in 2-year-old bilingual children. Exposure to language mixing might obscure cues that facilitate young bilingual children’s separation of their languages and could hinder the functioning of learning mechanisms that support the early growth of their vocabularies.

Previous research has shown that by the time of birth, the neonate brain responds specially to th... more Previous research has shown that by the time of birth, the neonate brain responds specially to the native language when compared to acoustically similar non-language stimuli. In the current study, we use Near Infrared Spectroscopy to ask how prenatal language experience might shape the brain response to language in newborn infants. To do so, we examine the neural response of neonates when listening to familiar versus unfamiliar language, as well as to non-linguistic backwards language. Twenty monolingual English-exposed neonates aged 0-3 days were tested. Each infant heard low-pass filtered sentences of forward English (familiar language), forward Tagalog (unfamiliar language), and backwards English and Tagalog. During exposure, neural activation was measured across twelve channels on each hemisphere. Our results indicate a bilateral effect of language familiarity on neonates’ brain response to language. Differential brain activation was seen when neonates listened to forward Tagalog (unfamiliar language) as compared to other types of language stimuli. We interpret these results as evidence that the pre-natal experience with the native language gained in utero influences how the newborn brain responds to language across brain regions sensitive to speech processing.

Journal of Phonetics, 2011

"PRIMIR (Processing Rich Information from Multidimensional Interactive Representations; Curtin & ... more "PRIMIR (Processing Rich Information from Multidimensional Interactive Representations; Curtin & Werker, 2007; Werker & Curtin, 2005) is a framework that encompasses the bidirectional relations between infant speech perception and the emergence of the lexicon. Here, we expand its mandate by considering infants growing up bilingual. We argue that, just like monolinguals, bilingual infants have access to rich information in the speech stream and by the end of their first year, they establish not only language-specific phonetic category representations, but also encode and represent both sub-phonetic and indexical detail. Perceptual biases, developmental level, and task demands work together to influence the level of detail used in any particular situation. In considering bilingual acquisition, we more fully elucidate what is meant by task demands, now understood both in terms of external demands imposed by the language situation, and internal demands imposed by the infant (e.g. different approaches to the same apparent task taken by infants from different backgrounds). In addition to the statistical learning mechanism previously described in PRIMIR, the necessity of a comparison–contrast mechanism is discussed. This refocusing of PRIMIR in the light of bilinguals more fully explicates the relationship between speech perception and word learning in all infants.
&"

Psychological Science, 2010

The first steps toward bilingual language acquisition have already begun at birth. When tested on... more The first steps toward bilingual language acquisition have already begun at birth. When tested on their preference for English versus Tagalog, newborns whose mothers spoke only English during pregnancy showed a robust preference for English. In contrast, newborns whose mothers spoke both English and Tagalog regularly during pregnancy showed equal preference for both languages. A group of newborns whose mothers had spoken both Chinese and English showed an intermediate pattern of preference for Tagalog over English. Preference for two languages does not suggest confusion between them, however. Study 2 showed that both English monolingual newborns and Tagalog-English bilingual newborns could discriminate English from Tagalog. The same perceptual and learning mechanisms that support acquisition in a monolingual environment thus also naturally support bilingual acquisition.

Philosophical Transactions of the Royal Society B, 2009

"At the macrostructure level of language milestones, language acquisition follows a nearly identi... more "At the macrostructure level of language milestones, language acquisition follows a nearly identical course whether children grow up with one or with two languages. However, at the microstructure level, experimental research is revealing that the same proclivities and learning mechanisms that support language acquisition unfold somewhat differently in bilingual versus monolingual environments. This paper synthesizes recent findings in the area of early bilingualism by focusing on the question of how bilingual infants come to apply their phonetic sensitivities to word learning, as they must to learn minimal pair words (e.g. ‘cat’ and ‘mat’). To this end, the paper reviews antecedent achievements by bilinguals throughout infancy and early childhood in the following areas: language discrimination and separation, speech perception, phonetic and phonotactic development, word recognition, word learning and aspects of conceptual development that underlie word learning. Special consideration is given to the role of language dominance, and to the unique challenges to language acquisition posed by a bilingual environment.
Keywords: bilingualism; language development; infancy;"

Developmental Science, 2009

How infants learn new words is a fundamental puzzle in language acquisition. To guide their word ... more How infants learn new words is a fundamental puzzle in language acquisition. To guide their word learning, infants exploit systematic word-learning heuristics that allow them to link new words to likely referents. By 17 months, infants show a tendency to associate a novel noun with a novel object rather than a familiar one, a heuristic known as disambiguation. Yet, the developmental origins of this heuristic remain unknown. We compared disambiguation in 17- to 18-month-old infants from different language backgrounds to determine whether language experience influences its development, or whether disambiguation instead emerges as a result of maturation or social experience. Monolinguals showed strong use of disambiguation, bilinguals showed marginal use, and trilinguals showed no disambiguation. The number of languages being learned, but not vocabulary size, predicted performance. The results point to a key role for language experience in the development of disambiguation, and help to distinguish among theoretical accounts of its emergence.

Trends in Cognitive Sciences, 2008

Many children grow up in bilingual families and acquire two first languages. Emerging research is... more Many children grow up in bilingual families and acquire two first languages. Emerging research is advancing the view that the capacity to acquire language can be applied equally to two languages as to one but that bilingual and monolingual acquisition nonetheless differ in some nontrivial ways. To probe the first steps toward acquisition, researchers recently have begun to use experimental methods to study preverbal bilingual infants. We review the literature in this growing field, focusing on how infants growing up bilingual use surface acoustic information to separate, categorize and begin to learn their two languages. These new data invite the expansion of standard linguistic theories to account for how a single architecture can support the acquisition of two languages simultaneously.

Child Development, 2007

Despite the prevalence of bilingualism, language acquisition research has focused on monolingual ... more Despite the prevalence of bilingualism, language acquisition research has focused on monolingual infants. Monolinguals cannot learn minimally different words (e.g., ‘‘bih’’ and ‘‘dih’’) in a laboratory task until 17 months of age (J. F. Werker, C. T. Fennell, K. M. Corcoran, & C. L. Stager, 2002). This study was extended to 14- to 20-month-old bilingual infants: a heterogeneous sample (English and another language; N 5 48) and two homogeneous samples (28 English – Chinese and 25 English – French infants). In all samples, bilinguals did not learn similar-sounding words until 20 months, indicating that they use relevant language sounds (i.e., consonants) to direct word learning developmentally later than monolinguals, possibly due to the increased cognitive load of learning two languages. However, this developmental pattern may be adaptive for bilingual word learning.

• Participants. 181 parents et leur enfant âgé de 17 à 26 mois (l'enfant devait être exposé à l'a... more • Participants. 181 parents et leur enfant âgé de 17 à 26 mois (l'enfant devait être exposé à l'anglais et à une autre langue).• Procédure. Chaque parent a rempli un questionnaire concernant les différents repères: 1. La personne: Pourcentage de vos interactions avec votre enfant en anglais? Pourcentage dans une autre langue? 2. Le contexte: Quelle (s) langue (s) utilisez-vous avec votre enfant dans les situations suivantes: lorsque vous êtes seuls, à la maison, avec des amis, avec la famille, pendant des activités, lors des sorties.

▪ If infants successfully use phonetic perception skills, they should be surprised by the switch ... more ▪ If infants successfully use phonetic perception skills, they should be surprised by the switch in the similar-sounding words at test. ▪ Despite having refined phonetic perception by 12 months, infants appear to have difficulty applying these skills to early word learning. ▪ Both monolingual and bilingual infants confuse similarsounding novel words in the task at 14 months, looking equivalently at the 'same and 'switch' trials. ▪ Monolingual infants do not reliably succeed in disambiguating the minimal pair until 17 months.

Discussion• It is common for bilingual infants to hear two different languages from the same indi... more Discussion• It is common for bilingual infants to hear two different languages from the same individual, in the same context, and even in the same sentence.• Because consistent person, context, and sentence-‐level cues may be less available than previously assumed, bilingual infants might have to use such cues probabilis cally rather than determinis cally.• Inconsistent cues might have developmental consequences: other data indicate that language mixing predicts smaller vocabulary size in 18-‐and 24-‐month-‐olds