Variation in language mixing in multilingual aphasia

Using a translanguaging framework to examine language production in a trilingual person with aphasia

When language abilities in aphasia are assessed in clinical and research settings, the standard practice is to examine each language of a multilingual person separately. But many multilingual individuals, with and without aphasia, mix their languages regularly when they communicate with other speakers who share their languages. We applied a novel approach to scoring language production of a multilingual person with aphasia. Our aim was to discover whether the assessment outcome would differ meaningfully when we count accurate responses in only the target language of the assessment session versus when we apply a translanguaging framework, that is, count all accurate responses, regardless of the language in which they were produced. The participant is a Farsi-German-English speaking woman with chronic moderate aphasia. We examined the participant's performance on two picture-naming tasks, an answering wh-question task, and an elicited narrative task. The results demonstrated that scores in English, the participant's third-learned and least-impaired language did not differ between the two scoring methods. Performance in German, the participant's moderately impaired second language benefited from translanguaging-based scoring across the board. In Farsi, her weakest language post-CVA, the participant's scores were higher under the translanguaging-based scoring approach in some but not all of the tasks. Our findings suggest that whether a translanguaging-based scoring makes a difference in the results obtained depends on relative language abilities and on pragmatic constraints, with additional influence of the linguistic distances between the languages in question.

Language abilities, not cognitive control, predict language mixing behavior in bilingual speakers with aphasia

PURPOSE

Language Mixing (LM) occurs among neurotypical bilinguals as well as among bilingual persons with aphasia (BiPWAs). The current study aimed to investigate whether LM in BiPWAs stems from a linguistic impairment, an impairment in cognitive control, or both.

METHOD

Twenty Russian-Hebrew-speaking BiPWAs were split into two groups based on aphasia severity (Severe/Moderate vs. Mild). Frequencies and patterns of LM in narrative production by BiPWAs in L1-Russian and in L2-Hebrew were analyzed. To investigate the underlying mechanisms of LM, all participants completed linguistic background questionnaires, the Bilingual Aphasia Test (BAT) in both languages, and a battery of 10 cognitive tests.

RESULTS

The results indicated an effect of aphasia severity and an effect of language. Higher LM frequency was observed in BiPWAs with severe/moderate aphasia symptoms as compared to BiPWAs with mild symptoms. In both groups, higher LM frequency was observed in L2-Hebrew narratives, the weaker post-stroke language for most participants in the sample. The results also showed qualitative LM differences in L1-Russsian and L2-Hebrew contexts. In L1-Russian narratives, BiPWAs mainly switched to L2-Hebrew nouns, while in L2-Hebrew narratives, they mainly inserted L1-Russian discourse markers and function words.

CONCLUSIONS

Linguistic factors such as pre- and post-stroke self-rated language proficiency and level of language impairment due to aphasia were found to predict LM frequency in L1-Russian and in L2-Hebrew. Cognitive abilities did not predict LM frequency. Based on our findings, we suggest that LM behavior in BiPWAs might be primarily related to language skills in L1 and L2, rather than to cognitive control impairments.

Rehabilitating an attrited language in a bilingual person with aphasia

Language difficulties can arise from reduced exposure to any given language (e.g. attrition) or after brain damage (e.g. aphasia). The manifestations of attrition and aphasia are often similar so differentiating between their effects on language loss and recovery is challenging. We investigated treatment effects for an English-Hebrew bilingual person with stroke-induced aphasia who had minimal contact with his Hebrew for over 14 years. We asked whether his attrited language could be rehabilitated, how effects of attrition and aphasia can be dissociated, and how such dissociation aids our understanding of the mechanisms involved in language recovery in aphasia. We administered a verb-based semantic treatment in Hebrew three times a week for six weeks (totalling 29 hours of therapy) and assessed changes in both Hebrew and English comprehension and production abilities across a variety of language tasks. Quantitative analyses demonstrated improvement in Hebrew production across language tasks, including those involving lexical retrieval processes that were trained during treatment. Improvement to English occurred in these same lexical retrieval tasks only. We interpret these results as indicating that the participant's attrited language (Hebrew) could be rehabilitated with both specific treatment and general exposure to Hebrew contributing to improvement. Furthermore, treatment effects transferred to the untreated English. Qualitative analyses indicated that an interaction among aphasia, incomplete mastery of Hebrew pre-stroke, and attrition contributed to the participant's language difficulties post-stroke. We conclude that partially shared underlying mechanisms of attrition and aphasia drive language processing and changes to it with treatment.

Aphasia in Multilingual Patients

PURPOSE OF REVIEW

We summarize recent published work concerning assessment and treatment of aphasia in bilingual and multilingual people and review current related models of treatment outcomes. As well, we discuss studies that address the recently debated topic of cognitive processes in bilingual individuals with aphasia, with a focus on the effects of bilingualism on aphasia recovery and its potential protective effects.

RECENT FINDINGS

Providing assessment and treatment tools that best serve multilingual individuals with aphasia and unpacking the variables and mechanisms that underlie response to treatment have emerged as goals of several recent studies. Additionally, while findings are still contradictory, some empirical studies reported that aphasia may manifest less severely in multilingual individuals and may improve faster compared to in monolingual counterparts. The findings of recent studies with the focus of aphasia in multilingual individuals are crucial to understanding theoretical and clinical aspects of brain-related language impairment in multilingual people and to the study of language representation and processing in the brain.