Language organization and language change in bilinguals

Two experimental studies with bilingual speakers examined the influence of (I) semantic organization across language, (2) input language change and (3) output language change on speech encoding during a sentence completion task. The first study used fluent Welsh-English bilinguals while the second used fluent French-English bilinguals; all subjects were at school in the U.K. A model proposed how subjects with different degree of overlap in bilingual semantic organization achieved functional separation of the two languages. Predictions derived from this were tested and were substantially confirmed for both groups of bilinguals. It was concluded that subjects have different degrees of overlap in semantic organization of their two languages and that this influences speech encoding where input or output language changes are present.     

Nonselective access of spelling–sound knowledge for Korean‐English bilinguals

An intense debate in monolingual research concerns the presence of phonological recoding in word recognition. Research supporting the phonological recoding hypothesis in monolingual research suggests the possibility of phonological recoding even in L2 recognition. There has been some experimental evidence showing phonological priming between L1 and L2 for alphabetic bilinguals (e.g., French‐Dutch). In the present study, lexical decision experiments used either L1 or L2 primes with targets from the other language at SOAs of 140 ms and 250 ms for Korean‐English bilinguals. It was found that phonological information activated by either an L1 or L2 prime can interact with phonological information in the other language. That is, L2 shares phonological information with L1, and its spelling–sound knowledge is activated, apparently automatically, at an SOA of 140 ms. The consistent pattern of phonological priming of both L1 and L2 targets at the 140 ms SOA indicates that the spelling–sound knowledge of bilingual lexicons is activated when any linguistic form is presented. Importantly, this indiscriminate activation of spelling–sound knowledge in the Korean‐English bilingual system occurs in the absence of any common orthographic cues because the two languages have totally different writing systems.     

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.     

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。     

Shared and separate systems in bilingual language processing: converging evidence from eyetracking and brain imaging

The neurological and cognitive aspects of bilingual language processing were examined in late Russian-English bilinguals using headband-mounted eyetracking and functional neuroimaging. A series of three eyetracking studies suggested that, at early stages of word recognition, bilinguals can activate both languages in parallel, even when direct linguistic input is in one language only. A functional neuroimaging study suggested that, although the same general structures are active for both languages, differences within these general structures are present across languages and across levels of processing. For example, different centers of activation were associated with first versus second language processing within the left Inferior Frontal Gyrus, but not within the Superior Temporal Gyrus. We suggest that parallel activation (as found with eyetracking) and shared cortical structures (as found with fMRI) may be characteristic of early stages of language processing (such as phonetic processing), but the two languages may be using separate structures at later stages of processing (such as lexical processing).     

第二语言水平对双语者语言抑制能力的影响——来自英语–汉语单通道双语者和英语–美国手语双通道双语者的证据

采用同形异义词干扰任务考察第二语言水平对英语–汉语单通道双语者和英语–美国手语双通道双语者语言抑制能力的影响。结果发现:(1)高水平英语–汉语单通道双语者的语言抑制能力较强,但低水平英语–汉语单通道双语者与英语单语者的语言抑制能力没有显著差异,说明少量的双语经验不足以导致双语认知优势;(2)不同水平的英语–美国手语双通道双语者的语言抑制能力差异不显著。所以如此,与英语–美国手语双通道双语者不存在口语和手语的双语表征加工竞争有关。整个研究表明,双语认知优势效应与双语者的二语水平以及通道经验有关。     

Translation norms for English and Spanish: The role of lexical variables,word class,and L2 proficiency in negotiating translation ambiguity

We present a set of translation norms for 670 English and 760 Spanish nouns, verbs and class ambiguous items that varied in their lexical properties in both languages, collected from 80 bilingual participants. Half of the words in each language received more than a single translation across participants. Cue word frequency and imageability were both negatively correlated with number of translations. Word class predicted number of translations: Nouns had fewer translations than did verbs, which had fewer translations than class-ambiguous items. The translation probability of specific responses was positively correlated with target word frequency and imageability, and with its form overlap with the cue word. Translation choice was modulated by L2 proficiency: Less proficient bilinguals tended to produce lower probability translations than more proficient bilinguals, but only in forward translation, from Ll to L2. These findings highlight the importance of translation ambiguity as a factor influencing bilingual representation and performance. The norms can also provide an important resource to assist researchers in the selection of experimental materials for studies of bilingual and monolingual language performance. These norms may be downloaded from www.psychonomic.org/archive.     

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。     

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.     

In search of the language switch: An fMRI study of picture naming in Spanish-English bilinguals

For many years, researchers investigating the brain bases of bilingualism have concentrated on two basic questions. The first concerns the nature of language representation. That is, are a bilinguals' two languages represented in distinct or overlapping areas of the brain. The second basic question in the neuropsychology of bilingualism concerns the neural correlates of language switching, that is, the areas that are active when bilinguals switch from one language to the other. Performance between single-language and dual-language picture naming was compared in a group of six Spanish-English bilinguals using behavioral measures and functional magnetic resonance imaging. Participants showed slower reaction times and increased activation in the dorsolateral prefrontal cortex in the mixed language condition relative to single language condition. There was no evidence that each language was represented in different areas of the brain. Results are consistent with the view that language switching is a part of a general executive attentional system and that languages are represented in overlapping areas of the brain in early bilinguals.     

In Search of the Language Switch: An fMRI Study of Picture Naming in Spanish–English Bilinguals

For many years, researchers investigating the brain bases of bilingualism have concentrated on two basic questions. The first concerns the nature of language representation. That is, are a bilinguals' two languages represented in distinct or overlapping areas of the brain. The second basic question in the neuropsychology of bilingualism concerns the neural correlates of language switching, that is, the areas that are active when bilinguals switch from one language to the other. Performance between single-language and dual-language picture naming was compared in a group of six Spanish–English bilinguals using behavioral measures and functional magnetic resonance imaging. Participants showed slower reaction times and increased activation in the dorsolateral prefrontal cortex in the mixed language condition relative to single language condition. There was no evidence that each language was represented in different areas of the brain. Results are consistent with the view that language switching is a part of a general executive attentional system and that languages are represented in overlapping areas of the brain in early bilinguals.     

Priming Effects on Tip-of-the-Tongue States in Farsi-English Bilinguals

The tip-of-the-tongue (TOT) phenomenon, the inability to immediately retrieve a word one desires, was studied in bilingual Farsi-English-speaking adults. One question was whether insufficient activation or increased inhibition underlie TOT states in bilinguals. Another was whether bilinguals have common or separate lexicons for their two languages. Participants heard a definition in either Farsi or English, followed by either a Farsi or English prime word related in meaning or sound, or not at all related, to the target word. Participants supplied the target word that best fit the definition. Similar-sound primes increased TOTs for English definitions and targets, with a trend for more correct responses as well, suggesting that the similar-sound prime word facilitates rather than inhibits retrieval, supporting the transmission deficit hypothesis. Primes had the same effect for same and different language conditions, suggesting that both Farsi and English map onto a single lexicon, supporting the single-store model of bilingual memory.     

Asymmetrical cross-language priming effects

Three experiments were conducted to examine cross-language priming in bilinguals. The first was a cross-language primed lexical decision task experiment with Chinese-English bilinguals. Subjects made lexical decisions about primary associate targets in the two languages at the same rate, but priming occurred only when the prime was in their first language (L1), Chinese, and the target was in their second language (L2), English. Experiment 2 produced the same pattern of asymmetrical priming with two alphabetic languages, French and Dutch. In Experiment 3, the crucial stimuli were translation equivalents. In contrast to the results of Experiments 1 and 2, priming occurred across languages in both the L1-L2 and L2-L1 conditions. However, this priming was also asymmetrical, with more priming occurring in the L1-L2 condition. A tentative separate-interconnected model of bilingual memory is described. It suggests that the representations of words expressed in different languages are stored in separate memory systems, which may be interconnected via one-to-one links between same translation-equivalent representations as well as meaning-integration processes.     

Classifying Human Long-term Memory: Evidence from Converging Dissociations

This paper reviews the support for multiple human long-term memory systems that is provided by experimental findings of dissociations reported in the literature. Four putative systems are examined: episodic, semantic, perceptual representation (PRS) and procedural memory. The four systems are contrasted for four different forms of dissociations (functional, developmental, pharmacological and brain damage). At least one example of 23 of the 24 different types of dissociations is described. It is argued that this evidence from converging dissociations provides support for the existence of multiple long-term memory systems. The studies reviewed provide some hints about the critical neural substrates of different systems. This neuroanatomical information was compared and found to be consistent with the results of available functional neuroimaging studies.     

Native language influences on word recognition in a second language: a megastudy

Many studies have reported that word recognition in a second language (L2) is affected by the native language (L1). However, little is known about the role of the specific language combination of the bilinguals. To investigate this issue, the authors administered a word identification task (progressive demasking) on 1,025 monosyllabic English (L2) words to native speakers of French, German, and Dutch. A regression approach was adopted, including a large number of within- and between-language variables as predictors. A substantial overlap of reaction time patterns was found across the groups of bilinguals, showing that word recognition results obtained for one group of bilinguals generalize to bilinguals with different mother tongues. Moreover, among the set of significant predictors, only one between-language variable was present (cognate status); all others reflected characteristics of the target language. Thus, although influences across languages exist, word recognition in L2 by proficient bilinguals is primarily determined by within-language factors, whereas cross-language effects appear to be limited. An additional comparison of the bilingual data with a native control group showed that there are subtle but significant differences between L1 and L2 processing.     

Language switching in the bilingual brain: What’s next?

Recent work using functional neuroimaging with early bilinguals has found little evidence for separate neural systems for each language during picture naming (Hernandez, A. E., Dapretto, M., Mazziotta, J., & Bookheimer, S. (2001). Language switching and language representation in Spanish–English bilinguals: An fMRI study. Neuroimage, 14, 510–520). However, switching between languages in early bilinguals during picture naming shows increased activity in the Dorsolateral Prefrontal Cortex (DLPFC) suggesting the importance of maintaining goal related information in order to bias subsequent response selection (Braver, T. S., Barch, D. M., Kelley, W. M., Buckner, R. L., Cohen, N. J., Miezin, F. M., et al. (2001). Direct comparison of prefrontal cortex regions engaged by working and long-term memory tasks. Neuroimage, 14, 48–59; Cohen, J. D., Braver, T. S., & O’Reilly, R. C. (1996). A computational approach to prefrontal cortex, cognitive control and schizophrenia: Recent developments and current challenges. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences, 351, 1515–1527; O’Reilly, R. C., Braver, T. S., & Cohen, J. D. (1999). A biologically based computational model of working memory. In E. Akira Miyake, E. Priti Shah & et al. (Eds.), Models of working memory: Mechanisms of active maintenance and executive control. (pp. 375–411): New York, NY, USA). The current study set out to test early bilinguals using a picture naming paradigm. Results revealed increased activity in the DLPFC and the superior parietal lobule during language switching compared to naming of pictures in a single language. Increased activity was also observed between early learned first and second languages. The results from single language conditions revealed differences in areas devoted to language processing such as the Superior Temporal Gyrus. However, increased activity in brain areas devoted to memory, somatosensory processing and emotion were also observed. Taken together these results replicate previous studies on language switching. They also extend studies on the neural bases of bilingualism by suggesting that early bilinguals’ representation of the two languages may be mediated by neural systems not typically associated with language. The article ends by considering future directions in understanding the brain bases of language switching and single language processing in bilinguals.     

熟练中－英双语者三语词汇的语义通达

通过两个实验运用跨语言重复启动的范式考察熟练中－英双语者对不熟练的第三语言词汇的语义通达方式。实验1以三语为日语的熟练中－英双语者为被试,实验2以三语为法语的熟练中－英双语者为被试,两个实验都发现了显著的跨语言重复启动效应。实验结果表明,熟练双语者尽管已经形成了直接通达二语词汇概念意义的语义通达方式,但其并没有将此方式迁移到对三语词汇概念意义的通达,他们仍然需要以一语词为中介从而间接通达三语词汇的概念意义。综合先前系列研究的结果初步表明,第二语言的熟练水平是影响晚期双语者语义通达方式的主要因素,晚期双语者记忆表征中的语义通达方式在本质上是一种经验性变化     

Stroop范式中不同语言条件下的双语优势效应

目的:采用Stroop范式探讨不同语言条件下的双语优势效应。方法:两个实验均为2(被试类型)x 3(色词一致性)的混合实验设计,被试为熟练双语者和非熟练双语者。结果:(1)L1条件下熟练双语者的Stroop效应量小于非熟练双语者,L2条件下无显著差异。(2)熟练双语者在两个实验条件下的平均反应时均小于非熟练双语者,L2条件下的易化效应量显著大于非熟练双语者。结论:(1)熟练双语者在L1条件下的抑制控制能力好于非熟练双语者,体现了"双语优势效应";(2)熟练双语者在Stroop干扰任务中可能比非熟练双语者具有更好的信息监控能力。     

Language lateralization in bilinguals: enough already!

All clinical evidence points to the fact that both languages of bilinguals are subserved by the left hemisphere in the same proportion as in unilinguals. Half of the experimental studies have reported no significant difference in lateralization between unilinguals and bilinguals. Those studies that have reported a difference contradict each other with respect to the bilingual subpopulations that are alleged to exhibit differential laterality. In the face of the lack of demonstrated validity of dichotic, tachistoscopic, and time-sharing paradigms in reflecting laterality of language functions in bilinguals, it may be time for neuropsychologists to move on to more productive research.