Language and syntactic impairment following stroke in late bilingual aphasics

Purpose

Bilingual aphasia generally affects both languages. However, the age of acquisition of the second language (L2) seems to play a role in the anatomo-functional correlation of the syntactical/grammatical processes, thus potentially influencing the L2 syntactic impairment following a stroke. The present study aims to analyze the influence of late age of acquisition of the L2 on syntactic impairment in bilingual aphasic patients.

Methods

Twelve late bilingual participants (speaking French as L2 and either English, German, Italian or Spanish as L1) with stroke-induced aphasia participated in the study. The MAST or BAT aphasia batteries were used to evaluate overall aphasia score. An auditory syntactic judgement task was developed and used to test participants syntactic performance.

Results

The overall aphasia scores did not differ between L1 and L2. In a multiple case analysis, only one patient had lower scores in L2. However, four patients presented significantly lower performances in syntactic processing in the late L2 than in their native language (L1). In these four patients the infarct was localized, either exclusively or at least partially, in the pre-rolandic region.

Conclusion

This pilot study suggests that, in late bilingual aphasics, syntactic judgment abilities may be more severely impaired in L2, and that this syntactic deficit is most likely to occur following anterior lesions.     

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.     

The effect of bilingualism on lexical learning and memory across two language modalities: some evidence for a domain-specific,but not general,advantage

ABSTRACT

The present study was conducted to replicate bilingual advantages in short-term memory for language-like material and word learning in young adults and extend this research to the sign domain, ultimately with the goal of investigating the domain specificity of bilingual advantages in cognition. Data from 112 monolingual hearing non-signers and 78 bilingual hearing non-signers were analysed for this study. Participants completed a battery of tasks assessing sign and word learning, short-term memory, working memory capacity, intelligence, and a language and demographic questionnaire. Overall, the results of this study suggested a bilingual advantage in memory for speech-like material – no other advantage (or disadvantage) was found. Results are discussed within the context of recent large-scale experimental and meta-analytic studies that have failed to find bilingual advantages in domain-general abilities such as attention control and working memory capacity in young adults.     

Interference suppression vs. response inhibition: An explanation for the absence of a bilingual advantage in preschoolers’ Stroop task performance

The well-documented advantage that bilingual speakers demonstrate across the lifespan on measures of controlled attention is not observed in preschoolers’ performance on Stroop task variations. We examined the role of task demands in explaining this discrepancy. Whereas the Color/Word Stroop used with adult participants requires interference suppression, the Stroop task typically used with preschoolers requires only response inhibition. We developed an age-appropriate conflict task that measures interference suppression. Fifty-one preschool children (26 bilinguals) completed this new Bivalent Shape Task and the Day/Night task used in previous research. Bilingual in comparison to monolingual children performed better on incongruent trials of the Bivalent Shape Task, but did not differ on other measures. The results indicate that the discrepancy between preschoolers and older individuals in performance on Stroop task adaptations results from characteristics of the task rather than developmental differences. Further, the findings provide additional support for the importance of interference suppression as a mechanism underlying the bilingual advantage.     

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.     

Theory of Mind and Executive Functions in Young Bilingual Children

Few studies have explored the relationship between theory of mind (ToM), executive function (EF), and bilingualism at the same time. In this study 14 young bilingual children were compared with monolingual children on a test battery composed of 5 ToM tests, 5 EF tests, and 1 test of general language ability. The result showed that despite significantly lower verbal ability, the bilingual children outperformed the monolingual ones on tests of EF. There were no differences in ToM performance. The authors argue that there is a strong relationship between bilingualism and EF, but, contrary to results from earlier studies, they could not find any relationship between bilingualism and ToM. EF did not predict ToM performance. Lack of a significant relationship could be due to the children's young age and consequently their low scores on the ToM tasks.     

Proficiency in a second language influences the processing of number words

We evaluated whether proficiency in a second language (L2) influenced the processing of numerical information. In Experiment 1, two groups of German/English bilinguals, one less proficient in English (L2) and the other more proficient in L2, performed two-digit number comparison tasks while the unit–decade compatibility was evaluated. All participants presented compatibility effect with Arabic digits regardless of their L2 proficiency. However, when bilinguals with less proficiency in L2 performed verbal number comparison tasks they showed regular compatibility effect in German and reverse compatibility effect in English, whereas more proficient bilinguals did not show compatibility effects in either German or English. In Experiment 2, the same pattern of results was obtained with highly proficient bilinguals after controlling their working memory span. These results indicate that L2 proficiency influences the processing of two-digit number words.