Susan C. Bobb

Language selectivity is the exception, not the rule: Arguments against a fixed locus of language selection in bilingual speech

Bilingual speech requires that the language of utterances be selected prior to articulation. Past research has debated whether the language of speaking can be determined in advance of speech planning and, if not, the level at which it is eventually selected. We argue that the reason that it has been difficult to come to an agreement about language selection is that there is not a single locus of selection. Rather, language selection depends on a set of factors that vary according to the experience of the bilinguals, the demands of the production task, and the degree of activity of the nontarget language. We demonstrate that it is possible to identify some conditions that restrict speech planning to one language alone and others that open the process to cross-language influences. We conclude that the presence of language nonselectivity at all levels of planning spoken utterances renders the system itself fundamentally nonselective.

Language selection in bilingual speech : Evidence for inhibitory processes

Although bilinguals rarely make random errors of language when they speak, research on spoken production provides compelling evidence to suggest that both languages are active when only one language is spoken (e.g., [Poulisse, N. (1999). Slips of the tongue: Speech errors in first and second language production. Amsterdam/Philadelphia: John Benjamins]). Moreover, the parallel activation of the two languages appears to characterize the planning of speech for highly proficient bilinguals as well as second language learners. In this paper, we first review the evidence for cross-language activity during single word production and then consider the two major alternative models of how the intended language is eventually selected. According to language-specific selection models, both languages may be active but bilinguals develop the ability to selectively attend to candidates in the intended language. The alternative model, that candidates from both languages compete for selection, requires that cross-language activity be modulated to allow selection to occur. On the latter view, the selection mechanism may require that candidates in the nontarget language be inhibited. We consider the evidence for such an inhibitory mechanism in a series of recent behavioral and neuroimaging studies.

When bilinguals choose a single word to speak: Electrophysiological evidence for inhibition of the native language

Behavioral and event-related potential (ERP) measures are reported for a study in which relatively proficient Chinese-English bilinguals named identical pictures in each of their two languages. Production occurred only in Chinese (the first language, L1) or only in English (the second language, L2) in a given block with the order counterbalanced across participants. The repetition of pictures across blocks was expected to produce facilitation in the form of faster responses and more positive ERPs. However, we hypothesized that if both languages are activated when naming one language alone, there might be evidence of inhibition of the stronger L1 to enable naming in the weaker L2. Behavioral data revealed the dominance of Chinese relative to English, with overall faster and more accurate naming performance in L1 than L2. However, reaction times for naming in L1 after naming in L2 showed no repetition advantage and the ERP data showed greater negativity when pictures were named in L1 following L2. This greater negativity for repeated items suggests the presence of inhibition rather than facilitation alone. Critically, the asymmetric negativity associated with the L1 when it followed the L2 endured beyond the immediate switch of language, implying long-lasting inhibition of the L1. In contrast, when L2 naming followed L1, both behavioral and ERP evidence produced a facilitatory pattern, consistent with repetition priming. Taken together, the results support a model of bilingual lexical production in which candidates in both languages compete for selection, with inhibition of the more dominant L1 when planning speech in the less dominant L2. We discuss the implications for modeling the scope and time course of inhibitory processes.

Language switching in picture naming: What asymmetric switch costs (do not) tell us about inhibition in bilingual speech planning

Meuter and Allport (1999) were among the first to implicate an inhibitory mechanism in bilingual language control. In their study, bilinguals took longer to name a number in the L1 directly following an L2 naming trial than to name a number in the L2 following an L1 naming trial, suggesting that bilinguals suppress the more dominant L1 during L2 production. Since then, asymmetric switch costs have not been replicated in all subsequent studies, and some have questioned whether switch costs necessarily reveal language inhibition. Based on methodological grounds and interpretability problems, we conclude that switch costs may not be the most reliable index of inhibition in bilingual language control. We review alternative proposals for the source of switch costs, and point to other indices of inhibition within the switching paradigm and from adapted paradigms.

Two Languages in Mind: Bilingualism as a Tool to Investigate Language, Cognition, and the Brain

A series of discoveries in the past two decades has changed the way we think about bilingualism and its implications for language and cognition. One is that both of the bilingual’s languages are always active. The parallel activation of the two languages is thought to give rise to competition that imposes demands on the bilingual to control the language not in use to achieve fluency in the target language. The second is that there are consequences of bilingualism that affect the native as well as the second language: The native language changes in response to second-language use. The third is that the consequences of bilingualism are not limited to language but appear to reflect a reorganization of brain networks that hold implications for the ways in which bilinguals negotiate cognitive competition more generally. The focus of recent research on bilingualism has been to understand the relations among these discoveries and their implications for language, cognition, and the brain across the life span.

The processing and comprehension of wh-questions among second language speakers of German

Using the self-paced reading paradigm, the present study examines whether highly proficient second language (L2) speakers of German (English first language) use case-marking information during the on-line comprehension of unambiguous wh-extractions, even when task demands do not draw explicit attention to this morphosyntactic feature in German. Results support previous findings, in that both the native and the L2 German speakers exhibited an immediate subject preference in the matrix clause, suggesting they were sensitive to case-marking information. However, only among the native speakers did this subject preference carry over to reading times in the complement clause. The results from the present study are discussed in light of current debates regarding the ability of L2 speakers to attain nativelike processing strategies in their L2.

The role of language proficiency, cognate status and word frequency in the assessment of Spanish-English bilinguals verbal fluency

Abstract Purpose: Assessment tools are needed to accurately index performance in bilingual populations. This study examines the verbal fluency task to further establish the relative sensitivities of letter and category fluency in assessing bilingual language skills in Spanish–English bilinguals. Method: English monolinguals and Spanish–English bilinguals had 1 minute to name words belonging to a category (e.g. animals) or starting with a letter (e.g. A). Number of words retrieved, proficiency, cognate and frequency effects were examined. Result: In their dominant language (English), bilinguals and monolinguals showed similar fluency patterns, generating more words in category than letter tasks. This category advantage disappeared for bilinguals tested in their non-dominant language (Spanish). Further, bilinguals retrieved a higher percentage of cognates (e.g. lagoon-laguna) than monolinguals across tasks and languages. In particular, as proficiency increased in their non-dominant language, bilinguals were more likely to produce cognates (including cognates with lower word frequencies). Conclusion: While bilinguals and monolinguals performed largely the same, bilinguals showed fine-grained differences from monolinguals in both their dominant and non-dominant languages. Based on these results, it is recommended that clinicians evaluate findings from bilinguals’ verbal fluency tasks with attention to language proficiency, cognate words produced and relative to normative data that match their clients’ language histories.

What bilinguals tell us about cognitive control : overview to the special issue

The current special issue presents the state of the art on the topics of both bilingual language control and executive function, with a particular focus on how bilingualism and cognitive control interact. The contributions to this issue investigate the mechanisms that allow bilinguals to regulate their languages and address how different aspects of language processing might be causally related to cognitive control. Taken together, these papers suggest a more complex engagement and coordination of executive control networks than revealed in past research and a need to more fully characterise those aspects of bilingual language experience that contribute to regulatory processes.

Auditory word recognition across the lifespan: Links between linguistic and nonlinguistic inhibitory control in bilinguals and monolinguals

Recent research suggests that bilingual experience reconfigures linguistic and nonlinguistic cognitive processes. We examined the relationship between linguistic competition resolution and nonlinguistic cognitive control in younger and older adults who were either bilingual or monolingual. Participants heard words in English and identified the referent among four pictures while eye-movements were recorded. Target pictures (e.g., cab) appeared with a phonological competitor picture (e.g., cat) and two filler pictures. After each eye-tracking trial, priming probes assessed residual activation and inhibition of target and competitor words. When accounting for processing speed, results revealed that age-related changes in activation and inhibition are smaller in bilinguals than in monolinguals. Moreover, younger and older bilinguals, but not monolinguals, recruited similar inhibition mechanisms during word identification and during a nonlinguistic Stroop task. Results suggest that, during lexical access, bilinguals show more consistent competition resolution and recruitment of cognitive control across the lifespan than monolinguals.

Predicting visual information during sentence processing: Toddlers activate an object's shape before it is mentioned

We examined the contents of language-mediated prediction in toddlers by investigating the extent to which toddlers are sensitive to visual shape representations of upcoming words. Previous studies with adults suggest limits to the degree to which information about the visual form of a referent is predicted during language comprehension in low constraint sentences. Toddlers (30-month-olds) heard either contextually constraining sentences or contextually neutral sentences as they viewed images that were either identical or shape-related to the heard target label. We observed that toddlers activate shape information of upcoming linguistic input in contextually constraining semantic contexts; hearing a sentence context that was predictive of the target word activated perceptual information that subsequently influenced visual attention toward shape-related targets. Our findings suggest that visual shape is central to predictive language processing in toddlers.