Cunnings’ proposed theory can explain why second language (L2) learners have difficulty resolving certain types of dependencies (i.e., backward-looking dependencies) but not others (i.e., forward-looking dependencies). However, his theory should be more explicit about the mechanism underlying late L2 learners’ and native speakers’ different weightings of retrieval cues, and research framed within his theory should strive to tease apart age-of-acquisition effects from bilingualism effects.

This study investigated whether lifelong bilingualism can be associated with enhanced executive control, particularly mental flexibility, and with a modulation of an age-related decline in these functions. We compared performance of middle-aged and elderly speakers of German and bilingual speakers of Dutch and Frisian in a cued task-switching paradigm. All bilinguals were fluent in the same, closely-related language pairs. Bilinguals incurred significantly lower switching costs than monolinguals, and elderly bilinguals were less affected by an age-related increase in switching costs than monolinguals. Bilinguals did not differ from monolinguals in the size of the mixing costs. Our findings suggest that lifelong bilingualism correlates with enhanced ability to shift between mental sets, as well as increased resistance to proactive interference. The fact that we found significant group differences – while some previous studies did not – may be attributable to the choice of our task and to the cognateness of the languages involved.

Whether bilingualism affects executive functions is a topic of intense debate. While some studies have provided evidence of enhanced executive functions in bilinguals compared to monolinguals, other studies have failed to find advantages. In the present study, we investigated whether high opportunity of language switching could contribute to bilingual advantage. Advantages have been consistently found with Catalan–Spanish bilinguals who experience frequent opportunities of language switching. Fewer opportunities are experienced by speakers of Italian and one of the Italian dialects, the participants of our study. We anticipated reduced or no advantages with these participants. In Experiment 1, subjective estimates of familiarity with dialect failed to show a relationship with performances in different tasks involving executive control. In Experiment 2, we compared Italian–Venetian dialect bilinguals to Italian monolinguals in the flanker task, and no advantages were found either. Contrasting with results from Catalan–Spanish bilinguals, our results suggest that language switching plays a role in bilingual advantages.

The target article makes a strong case that L2 comprehenders recover linguistic representations that are qualitatively similar to those recovered by L1 comprehenders. Moreover as they attempt to link non-adjacent elements, they do so using the same basic mechanism: cue-based retrieval in a content-addressable memory (Van Dyke & Lewis, 2003). In this commentary, I will not address the empirical adequacy of the argument, but instead consider some interesting theoretical challenges it poses for our understanding of working memory in sentence processing.

The primary aim of my target article was to demonstrate how careful consideration of the working memory operations that underlie successful language comprehension is crucial to our understanding of the similarities and differences between native (L1) and non-native (L2) sentence processing. My central claims were that highly proficient L2 speakers construct similarly specified syntactic parses as L1 speakers, and that differences between L1 and L2 processing can be characterised in terms of L2 speakers being more prone to interference during memory retrieval operations. In explaining L1/L2 differences in this way, I argued a primary source of differences between L1 and L2 processing lies in how different populations of speakers weight cues that guide memory retrieval.

Differences between monolinguals and bilinguals are often attributed to crosslinguistic influence. This paper compares production of discourse connectives by Dutch–Russian bilinguals (Dutch-dominant), typically-developing Dutch/Russian monolinguals and Russian-speaking children with SLI. If non-target-like production in bilinguals is due to crosslinguistic influence, bilinguals should perform differently from both impaired and unimpaired monolinguals. However, if differences between bilinguals and monolinguals are due to other factors (e.g., input quantity, processing capacities), bilinguals’ language production might be similar to that of children with SLI. The results demonstrate that language dominance determines the direction of crosslinguistic influence. In terms of frequency distributions of Russian connectives across pragmatic contexts, the bilingual group performed differently from both monolingual groups and the differences were compatible with the structural properties of Dutch. However, based on error rates and types bilinguals could not be distinguished from the SLI group, suggesting that factors other than crosslinguistic influence may also be at play.

This study investigates the relationship between intra-sentential codeswitching restrictions after subject pronouns, negative elements, and interrogatives and language-specific syntactic structures. Data are presented from two languages that have non-cognate lexicons but share identical phrase structure and syntactic mechanisms and exactly the same grammatical morphemes except for pronouns, negators, and interrogative words. The languages are the Quichua of Imbabura province, Ecuador and Ecuadorian Media Lengua (ML), consisting of Quichua morphosyntax with Spanish-derived lexical roots. Bilingual participants carried out un-timed acceptability judgment and language-identification tasks and concurrent memory-loaded repetition on utterances in Quichua, ML, and various mixtures of Quichua and ML. The acceptability and classification data show a main effect for category of single-word switches (significant differences for lexical vs. interrogative, negative, and for acceptability, pronoun) and repetition data show significant differences between lexical vs. interrogatives and negators. Third-person pronouns (which require an explicit antecedent) also differ significantly from lexical items. Logical-semantic factors may contribute to code-switching restrictions.

Previous studies have shown effects of bilingualism on inhibitory control in preschool children. However, these effects only held for ‘conflict tasks’, and not delay of gratification tasks, and other domains of executive functioning were not investigated. For older children, previous studies have found relationships between bilinguals’ advantages and home language environment. This study investigates effects of bilingualism and bilingual home language environment on executive functioning in three-year-old children. 200 bilingual and 829 monolingual three-year-olds performed tasks of inhibitory control, working memory, and selective attention. Home language environment characteristics were assessed through a parental questionnaire. The bilinguals outperformed the monolinguals on a conflict task only, and this effect was very small. Further analyses showed broader effects on inhibitory control that were related to home language environment: Bilinguals whose parents spoke different languages outperformed bilinguals whose parents spoke the same language on both the conflict task and a delay of gratification task.

We study how the learning of argument structure constructions in a second language (L2) is affected by two basic input properties often discussed in literature – the amount of input and the time of L2 onset. To isolate the impact of the two factors on learning, we use a computational model that simulates bilingual construction learning. In the first two experiments we manipulate the sheer amount of L2 exposure, both in absolute and in relative terms (that is, in relation to the amount of L1 exposure). The results show that higher cumulative amount of L2 exposure leads to higher performance. In the third experiment we manipulate the prior amount of L1 input before the L2 onset (that is, the time of L2 onset). Given equal exposure, we find no negative effect of the later onset on learners’ performance. This has implications for theories of order of acquisition and bilingual construction learning.

This study examined how noun reading by bilinguals is influenced by orthographic similarity with their translation equivalents in another language. Eye movements of Dutch–English bilinguals reading an entire novel in L1 and L2 were analyzed.

In L2, we found a facilitatory effect of orthographic overlap. Additional facilitation for identical cognates was found for later eye movement measures. This shows that the complex, semantic context of a novel does not eliminate cross-lingual activation in natural reading.

In L1 we detected non-identical cognate facilitation for first fixation durations of longer nouns. Identical cognate facilitation was found on total reading times for high frequent nouns. This study is the first to show cognate facilitation in L1 reading of narrative text. This shows that even when reading a novel in the mother tongue, lexical access is not restricted to the target language.

In the domain of bilingualism, a main issue of interest has been to determine whether the two languages are shared at a conceptual level and which variables modulate the access to the conceptual system. In this study, we focused on the effects of two variables related to word-type. We tested proficient unbalanced Spanish–English bilinguals in a masked translation priming paradigm conducted in the two translation directions (L1 to L2, and L2 to L1), by orthogonally manipulating for the first time concreteness and cognate status. The stimulus onset asynchrony (SOA) was also manipulated (50 ms vs 100 ms). Results revealed modulations in masked priming effects as a function of cognate status and translation direction. However, the effect of concreteness was only observed at the long SOA. The findings are discussed in light of the most relevant models of bilingual memory, mainly the Distributed Feature Model (de Groot, 1992a).

Code-switching is prevalent in bilingual speech, and follows specific syntactic constraints. Several theories have been proposed to explain these constraints, and in this paper we focus on the Minimalist Program and the Matrix Language Frame model. Using a determiner-noun picture naming paradigm, we tested the ability of these theories to explain determiner-noun code-switches in Spanish–English bilinguals. The Minimalist Program predicts that speakers will use the determiner from the gendered language, whereas the Matrix Language Frame model predicts that the determiner will come from the language that dominates the syntactic structure in a code-switched utterance. We observed that the bilinguals had slowest naming times and decreased accuracy in Spanish determiner - English noun conditions (‘el dog’), and that adding a Matrix Language did not modulate this pattern. Although our results do not align with either theory, we conclude that they can be explained by the WEAVER++ model of speech production.

Using event related brain potentials (ERPs), we examined the neurocognitive basis of phonological discrimination of phoneme /h/ in native English speakers and Francophone late second language (L2) learners, as a function of L2 proficiency and stimulus/task demands. In Experiment 1, native and non-native (L2 only) phonological contrasts were presented as syllables during a task that directed attention to phonological form. Phonological categorization was assessed with MMN, N2b and P3b effects. In Experiment 2, the same contrasts were presented as words/ pseudowords during a task that directed attention to semantics. Phonological discrimination was assessed with N400 pseudoword effects. High proficiency L2 learners displayed similar ERPs as native speakers in both experiments; low proficiency L2 learners showed discrimination of non-native contrasts in Experiment 1 (directed attention task) only. Thus, L2 phonological discrimination by late learners may depend on stimulus/task factors and occurs in a wider range of contexts as L2 proficiency improves.

Translations often do not align directly across languages, and indirect mappings reduce the accuracy of language learning. To facilitate examination of this issue, we developed a new continuous measure for quantifying the semantic relatedness of words with more than one translation (hereafter translation-ambiguous words). Participants rated the similarity of each translation to every other translation, yielding a Translation Semantic Variability (TSV) score, ranging from 1.00 (unrelated) to 7.00 (related). Then, we determined how relatedness between translations affects translation-ambiguous word learning from German to English. German words with low TSV scores were recognized as translations more slowly and less accurately than German words with high TSV scores. TSV explains unique variance beyond the previously-used dichotomous classification of words as form vs. meaning ambiguous. We propose that the relatedness of the translation alternatives influences learning because it affects the ease with which a one-to-one mapping can be established between form and meaning.

Children's abilities to process the phonological structure of words are important predictors of their literacy development. In the current study, we examined the interrelatedness between implicit (i.e., speech decoding) and explicit (i.e., phonological awareness) phonological abilities, and especially the role therein of lexical specificity (i.e., the ability to learn to recognize spoken words based on only minimal acoustic-phonetic differences). We tested 75 Dutch monolingual and 64 Turkish–Dutch bilingual kindergartners. SEM analyses showed that speech decoding predicted lexical specificity, which in turn predicted rhyme awareness in the first language learners but phoneme awareness in the second language learners. Moreover, in the latter group there was an impact of the second language: Dutch speech decoding and lexical specificity predicted Turkish phonological awareness, which in turn predicted Dutch phonological awareness. We conclude that language-specific phonological characteristics underlie different patterns of transfer from implicit to explicit phonological abilities in first and second language learners.

We investigated bilingual advantages in general control abilities using three complex-span tasks of working memory (WM). An operation-span task served as a baseline measure of WM capacity. Additionally, two modified versions of the Stroop-span task were designed to place varying attentional-control demands during memoranda encoding by asking participants either to read the to-be-remembered item aloud (lower cognitive control; i.e., Stroop-span task) or to name the font color of the to-be-remembered item while still encoding the word for later recall (greater cognitive control; i.e., attention-impeded Stroop-span task). Twenty-six Korean–English bilinguals and 25 English-native monolinguals were tested. We found that bilinguals outperformed monolinguals on the attention-impeded Stroop-span task, but on neither the operation-span nor the Stroop-span task. Our findings demonstrate that bilingualism provides advantages in controlled processing, an important component of WM and other executive functions, suggesting that the demand for controlled processing in WM tasks moderates bilingual effects on WM.