Convergent cortical representation of semantic processing in bilinguals

This study examined whether semantic processes in two languages (English and Spanish) are mediated by a common neural system in fluent bilinguals who acquired their second language years after acquiring their first language. Functional magnetic resonance imaging was performed while bilingual participants made semantic and nonsemantic decisions about words in Spanish and English. There was greater activation for semantic relative to nonsemantic decisions in left and right frontal regions, with greater left frontal activation. The locations of activations were similar for both languages, and no differences were found when semantic decisions for English and Spanish words were compared directly. These results demonstrate a shared frontal lobe system for semantic analysis of the languages and are consistent with cognitive research on bilingualism indicating that the two languages of a bilingual person access a common semantic system.     

Bilinguals in a monolingual and a bilingual speech mode: The effect on lexical access

The time course of lexical access in fluent Portuguese-English bilinguals and in English speaking monolinguals was examined during the on-line processing of spoken sentences using the phoneme-triggered lexical decision task (Blank, 1980). The bilinguals were tested in two distinct speech modes: a monolingual, English or Portuguese, speech mode, and a bilingual, code-switching, speech mode. Although the bilingual’s lexical decision response times to word targets in the monolingual speech modes were identical to those of the monolingual subjects, their response times to code-switched word targets in the bilingual mode were significantly slower. In addition, the bilinguals took longer to detect nonwords in both the monolingual and bilingual modes. These results confirm that bilinguals cannot totally deactivate their other language when in a monolingual speech mode. It is hypothesized that bilinguals search both lexicons when confronted with nonwords, even when in a totally monolingual mode, and that they search the base-language lexicon before the other lexicon when in a bilingual, code-switching, speech mode.     

Bimodal bilinguals reveal the source of tip-of-the-tongue states

Bilinguals report more tip-of-the-tongue (TOT) failures than monolinguals. Three accounts of this disadvantage are that bilinguals experience between-language interference at (a) semantic and/or (b) phonological levels, or (c) that bilinguals use each language less frequently than monolinguals. Bilinguals who speak one language and sign another help decide between these alternatives because their languages lack phonological overlap. Twenty-two American Sign Language (ASL)-English bilinguals, 22 English monolinguals, and 11 Spanish-English bilinguals named 52 pictures in English. Despite no phonological overlap between languages, ASL-English bilinguals had more TOTs than monolinguals, and equivalent TOTs as Spanish-English bilinguals. These data eliminate phonological blocking as the exclusive source of bilingual disadvantages. A small advantage of ASL-English over Spanish-English bilinguals in correct retrievals is consistent with semantic interference and a minor role for phonological blocking. However, this account faces substantial challenges. We argue reduced frequency of use is the more comprehensive explanation of TOT rates in all bilinguals.     

Matching words to concepts in two languages: A test of the concept mediation model of bilingual representation

A categorization paradigm was used to investigate the relations between lexical and conceptual connections in bilingual memory. Fifty-one more fluent and less fluent English-French bilinguals viewed category names (e.g.,vegetable) and then decided whether a target word (e.g.,peas) was a member of that category. The category names and target words appeared in both English and French across experimental conditions. Because category matching requires access to conceptual memory, only relatively fluent bilinguals, who are able to directly access meaning for their second language, were expected to be able to use category information across languages. The performance of lessfluent bilinguals was expected to reflect reliance on lexical-level connections between languages, requiring translation of second-language words. The results provided evidence for concept mediation by more-fluent bilinguals, because categorization latencies were independent of the language of the category name. However, the performance of less-fluent bilinguals indicated that they did not follow a simple lexical translation strategy. Instead, these subjects were faster at categorizing words in both languages when the language of the category name matched the language of the target word, suggesting that they were able to access limited conceptual information from the second language. A model of the development of concept mediation during second language acquisition is described.     

Automatic and controlled processes in the first- and second-language reading of fluent bilinguals

Many fluent bilinguals read their two languages with equal levels of comprehension but read their second language at a slower rate. The present study examined whether, compared with first language reading, slower second-language reading is associated with reduced involvement of automatic processing during lexical access. Subjects were bilinguals with fluent speaking and listening skills under ordinary conditions of communication and with equivalent comprehension of their first and second languages when reading and listening under speeded conditions. Half these subjects, however, read their first and second languages equally fast, and half read the second language more slowly than the first. Subjects were tested on a lexical decision task that manipulated expectations about the semantic relatedness of prime and target words and the stimulus onset asynchrony between them. Bilinguals with equal first- and second-language reading rates produced in each language a pattern of reaction times suggesting automatic processing, whereas bilinguals with a slower second-language reading rate did so in their first language but not in their second.     

Are bilingual advantages dependent upon specific tasks or specific bilingual experiences?

Paap and Greenberg concluded that there is no coherent evidence for bilingual advantages in executive processing. More optimistic researchers believe that the advantages may be restricted to certain types of bilinguals. Recent large-scale and lifespan investigations that tested highly fluent bilinguals from communities where the same two languages are spoken by most residents reported no bilingual advantages in any age group or in any of the tasks used to measure executive functioning. The present study takes a complementary approach by examining a sample that is quite homogeneous in terms of current life experiences, but heterogeneous in terms of its exposure to second languages. The composite database of 168 bilinguals and 216 monolinguals is used to explore for differences based on: (1) the age of acquiring a second language (L2), (2) the relative proficiency of an L2 and (3) the number of languages used. Across 12 different measures of executive function, derived from 4 different nonverbal tasks, there was no consistent evidence supporting the hypotheses that either early bilingualism, highly fluent balanced bilingualism, or trilingualism enhances inhibitory control, monitoring or switching. In fact, when statistically significant effects did occur, they more often disconfirmed than confirmed these hypotheses.     

Visual field asymmetries for rhyme and semantic tasks in fluent and nonfluent bilinguals.

A tachistoscopic study investigated hemispheric specialization among fluent and nonfluent bilinguals for rhyme and semantic tasks in both their languages. Fluent bilinguals gave faster responses and made fewer errors in their responses to the words presented in the RVF(LH) while the opposite happened for nonfluent, which indicates greater RH participation in the first stages of a second language. Fluent bilinguals performed better not only in the second but also in their native language, suggesting superior language skills on the part of fluent bilinguals. A LVF(RH) superiority was obtained for semantic tasks, indicating RH participation in semantic judgments. Another finding was a high ratio of first-born children among fluent bilinguals, potentially explained in terms of parental attitudes toward first- versus later born children.     

Effects of the degree of meaning similarity on cross-language semantic priming in highly proficient bilinguals

This study aimed to determine if access to meaning can be directly achieved from the words in the two languages, examining the influence of the degree of semantic overlap between related words across languages in the pattern of priming effects. Nonassociative semantically related words (members of the same category) were used, avoiding explicitly associative relationships. Using a priming paradigm, highly proficient Catalan–Spanish bilinguals were visually presented with pairs of words that either were translations of each other, had a very close semantic relationship (in terms of shared features), a close semantic relationship, or no semantic relationship at all. Participants performed either a lexical decision task (Experiment 1) or a semantic decision task (Experiment 2). The main results of the study were the same in both language directions (Spanish–Catalan and Catalan–Spanish), showing that the degree of semantic overlap (in terms of shared features) between words in different languages can modulate priming effects, regardless of the language of the prime and the task used. These results demonstrate that there is cross-language activation of shared semantic representations and, thus, that highly proficient bilinguals can have direct access to word meaning from the two languages.     

Age-related differences in interlingual priming: a behavioural and electrophysiological investigation

Reaction time (RT) and the N400 ERP component were measured to examine age-related differences in bilingual language processing. Although young bilinguals appear to access both languages simultaneously (i.e., non-selective access), little is known about language selection in older adults. The effect of language context on language selectivity was investigated using interlingual homographs (IH; i.e., words with identical orthography but distinct semantic features in two languages, e.g., coin meaning 'corner' in French and 'money' in English). Younger and older French/English bilinguals were presented with triplets of letter strings comprised of a language context cue, an IH, and a target word, in a lexical decision semantic priming task. RT and ERP results support non-selective language access in young adults; however, the older bilinguals used the language context cue to bias their reading of the IH. Results are discussed in terms of age-related changes in language processing and context use in bilinguals.     

Learning across languages: bilingual experience supports dual language statistical word segmentation

Bilingual acquisition presents learning challenges beyond those found in monolingual environments, including the need to segment speech in two languages. Infants may use statistical cues, such as syllable‐level transitional probabilities, to segment words from fluent speech. In the present study we assessed monolingual and bilingual 14‐month‐olds’ abilities to segment two artificial languages using transitional probability cues. In Experiment 1, monolingual infants successfully segmented the speech streams when the languages were presented individually. However, monolinguals did not segment the same language stimuli when they were presented together in interleaved segments, mimicking the language switches inherent to bilingual speech. To assess the effect of real‐world bilingual experience on dual language speech segmentation, Experiment 2 tested infants with regular exposure to two languages using the same interleaved language stimuli as Experiment 1. The bilingual infants in Experiment 2 successfully segmented the languages, indicating that early exposure to two languages supports infants’ abilities to segment dual language speech using transitional probability cues. These findings support the notion that early bilingual exposure prepares infants to navigate challenging aspects of dual language environments as they begin to acquire two languages.     

Language lateralization in English-French bilinguals

Forty English-French bilinguals divided into equal numbers of nonfluent and fluent subjects took part in a dichotic listening test involving both intralingual and interlingual conditions. No difference in lateralization was found between primary and secondary language in either condition. In the intralingual condition, however, fluent bilinguals showed a significantly lower right ear advantage than did their nonfluent counterparts. In the interlingual condition, French-dominant subjects were found to be more ambilateral than English-dominant subjects, while both groups tended to respond preferentially to French words. These results suggest that growing bilingual proficiency does increase left ear/right hemisphere participation, but in intralingual situations only. Moreover, when both languages are contrasted, French appears to be more salient than English.     

双语经验降低言语产生过程中通达能力的研究综述

言语产生是指个体通过口头言语表达想法、感受,而通达过程是言语产生的关键过程。本文以言语产生的不同语言水平为线索,综合分析双语经验对言语产生过程中通达能力的影响,结果发现双语经验降低了言语产生中的通达效率。在此基础上,从跨语言干扰、语言使用频率和词汇量三个角度归纳双语通达劣势的原因。未来的研究应该考察双语经验对言语加工中不同方面的影响,并且对相关解释进行整合。     

Dual language use in sign-speech bimodal bilinguals: fNIRS brain-imaging evidence

The brain basis of bilinguals’ ability to use two languages at the same time has been a hotly debated topic. On the one hand, behavioral research has suggested that bilingual dual language use involves complex and highly principled linguistic processes. On the other hand, brain-imaging research has revealed that bilingual language switching involves neural activations in brain areas dedicated to general executive functions not specific to language processing, such as general task maintenance. Here we address the involvement of language-specific versus cognitive-general brain mechanisms for bilingual language processing. We study a unique population, bimodal bilinguals proficient in signed and spoken languages, and we use an innovative brain-imaging technology, functional Near-Infrared Spectroscopy (fNIRS; Hitachi ETG-4000). Like fMRI, the fNIRS technology measures hemodynamic change, but it is also advanced in permitting movement for unconstrained speech and sign production. Participant groups included (i) hearing ASL–English bilinguals, (ii) ASL monolinguals, and (iii) English monolinguals. Imaging tasks included picture naming in “Monolingual mode” (using one language at a time) and in “Bilingual mode” (using both languages either simultaneously or in rapid alternation). Behavioral results revealed that accuracy was similar among groups and conditions. By contrast, neuroimaging results revealed that bilinguals in Bilingual mode showed greater signal intensity within posterior temporal regions (“Wernicke’s area”) than in Monolingual mode. Significance: Bilinguals’ ability to use two languages effortlessly and without confusion involves the use of language-specific posterior temporal brain regions. This research with both fNIRS and bimodal bilinguals sheds new light on the extent and variability of brain tissue that underlies language processing, and addresses the tantalizing questions of how language modality, sign and speech, impact language representation in the 7brain.     

熟练潮-普双言者的语义通达机制:来自通道比较的证据

采用跨语言启动的范畴判断范式,通过2个实验,考察了熟练潮-普双言者在听觉通道内和听-视跨通道条件下的语义通达机制。结果发现,无论是以潮州话词语为启动词,还是以普通话词语为启动词,当词对具有高语义相关时,启动词均对目标词产生了显著的跨语言启动效应;在听觉通道内,两种语言之间的启动量无差异,而在听-视跨通道条件下,L2对L1的启动量显著大于L1对L2的启动量。这些结果表明,熟练潮-普双言者共享语义(概念)表征,词汇表征既相互独立又互相联系,L1与L2的词汇均能直接通达语义表征,但其联系强度及其相互之间的词汇表征联系强度均存在通道差异性。整个研究结果支持Kroll等人的修正分级模型。     

非熟练潮-粤双言者的语义通达：来自听觉词加工的证据

采用听觉跨语言启动的语义判断范式, 考察非熟练潮-粤双言者的两种方言之间的语义通达方式。结果发现, 无论是以潮语词为启动词, 还是以粤语词为启动词, 当二者具有翻译关系时, 启动词均促进对目标词的识别, 但L1对L2的启动量比L2对L1的启动量大。当启动词与目标词具有语义联想关系时, 启动词亦能促进对目标词的识别, 但L1→L2与L2→L1的启动量差异不显著。整个研究表明, 非熟练潮-粤双言者的两种方言的词汇独立表征, 语义共享表征; 第二方言的词汇能够直接通达语义表征, 不需要以第一方言的词汇为中介, 但双言的词汇表征与语义表征的联结强度仍然存在着不对称性。     

Language‐dependent memory in bilingual learning

Spanish‐English bilinguals were taught academic‐type information about History, Biology, Chemistry and Mythology in their two languages. Upon testing, it was found that memory was more accurate and retrieval was faster when the language of retrieval and the language of encoding matched than when they did not match. For accuracy, the pattern of results was influenced by bilinguals' language proficiency, so that only balanced bilinguals whose high proficiency levels were similar in both languages showed language‐dependent recall. For reaction time, bilinguals were faster to retrieve information when the languages of retrieval and encoding matched than when they mismatched, but only for material encoded in Spanish. The influence of encoding and retrieval languages on error patterns was also examined. Together, the study's findings suggest that bilingual learning may be subject to language dependency and that experience with a language may increase the strength of linguistic cues in producing language‐dependent memory. The results are consistent with previous findings of language‐dependent memory in autobiographical narratives, carry applied implications for bilingual education, and are discussed within the theoretical framework of the relationship between language and memory. Copyright © 2006 John Wiley & Sons, Ltd.     

Inside bilingualism: Language background modulates selective attention to a talker's mouth

Previous findings indicate that bilingual Catalan/Spanish‐learning infants attend more to the highly salient audiovisual redundancy cues normally available in a talker's mouth than do monolingual infants. Presumably, greater attention to such cues renders the challenge of learning two languages easier. Spanish and Catalan are, however, rhythmically and phonologically close languages. This raises the possibility that bilinguals only rely on redundant audiovisual cues when their languages are close. To test this possibility, we exposed 15‐month‐old and 4‐ to 6‐year‐old close‐language bilinguals (Spanish/Catalan) and distant‐language bilinguals (Spanish/”other”) to videos of a talker uttering Spanish or Catalan (native) and English (non‐native) monologues and recorded eye‐gaze to the talker's eyes and mouth. At both ages, the close‐language bilinguals attended more to the talker's mouth than the distant‐language bilinguals. This indicates that language proximity modulates selective attention to a talker's mouth during early childhood and suggests that reliance on the greater salience of audiovisual speech cues depends on the difficulty of the speech‐processing task.     

Identifying bilingual semantic neural representations across languages

The goal of the study was to identify the neural representation of a noun’s meaning in one language based on the neural representation of that same noun in another language. Machine learning methods were used to train classifiers to identify which individual noun bilingual participants were thinking about in one language based solely on their brain activation in the other language. The study shows reliable (p < .05) pattern-based classification accuracies for the classification of brain activity for nouns across languages. It also shows that the stable voxels used to classify the brain activation were located in areas associated with encoding information about semantic dimensions of the words in the study. The identification of the semantic trace of individual nouns from the pattern of cortical activity demonstrates the existence of a multi-voxel pattern of activation across the cortex for a single noun common to both languages in bilinguals.     

A study of semantic and syntactic processing in monolinguals and fluent early bilinguals

The present study consists of two reaction-time experiments administered in English. These experiments were designed to compare semantic and syntactic processing in English monolinguals and fluent early French-English bilinguals. Results of both experiments revealed that the bilinguals did not function as the English monolinguals did. That is, their reaction times were slower and they made twice as many errors in response to certain sentences. These findings are especially important for two reasons: (1) The bilinguals were all highly fluent, and in most cases dominant, in English, and (2) the bilinguals exhibited systematic differences in two different linguistic components (the semantic and the syntactic). The results are viewed as evidence of the interdependence of the bilinguals' languages. Some note is made of individual patterns of response, and two interpretations of linguistic interdependence are provided.     

A disadvantage in bilingual sentence production modulated by syntactic frequency and similarity across languages

Bilingual speakers access individual words less fluently, quickly, and accurately than monolinguals, particularly when accessing low-frequency words. Here we examined whether the bilingual speech production disadvantage would (a) extend to full sentences above and beyond single word retrieval and whether it would be modulated by (b) structural frequency and (c) syntactic properties of the bilingual speakers’ other language. English monolinguals, Spanish–English bilinguals and Mandarin–English bilinguals were tested in a sentence production task conducted exclusively in English. Response times were modulated by bilingualism, structural frequency, and structural similarity across the bilingual speakers’ two languages. These results refine our knowledge regarding the scope of the bilingual disadvantage, demonstrate that frequency effects apply to syntactic structures, and also suggest that syntax is partially shared across bilinguals’ two languages.