Recent research in Bilingual Aphasia

Impaired L1 and executive control after left basal ganglia damage in a bilingual Basque-Spanish person with aphasia.

Clinical Linguistics and Phonetics (2011).

Adrover-Roig D, Galparsoro-Izagirre N, Marcotte K, Ferré P, Wilson MA, Inés Ansaldo A.

Bilinguals must focus their attention to control competing languages. In bilingual aphasia, damage to the fronto-subcortical loop may lead to pathological language switching and mixing and the attrition of the more automatic language (usually L1). We present the case of JZ, a bilingual Basque-Spanish 53-year-old man who, after haematoma in the left basal ganglia, presented with executive deficits and aphasia, characterised by more impaired language processing in Basque, his L1. Assessment with the Bilingual Aphasia Test revealed impaired spontaneous and automatic speech production and speech rate in L1, as well as impaired L2-to-L1 sentence translation. Later observation led to the assessment of verbal and non-verbal executive control, which allowed JZ’s impaired performance on language tasks to be related to executive dysfunction. In line with previous research, we report the significant attrition of L1 following damage to the left basal ganglia, reported for the first time in a Basque-Spanish bilingual. Implications for models of declarative and procedural memory are discussed.

Therapy for naming difficulties in bilingual aphasia: which language benefits?

Croft S, Marshall J, Pring T, Hardwick M.

International Journal of Language and Communication disorders. 2011 Jan;46(1):48-62

BACKGROUND:

The majority of the world’s population is bilingual. Yet, therapy studies involving bilingual people with aphasia are rare and have produced conflicting results. One recent study suggested that therapy can assist word retrieval in bilingual aphasia, with effects generalizing to related words in the untreated language. However, this cross-linguistic generalisation only occurred into the person’s stronger language (L1). While indicative, these findings were derived from just three participants, and only one received therapy in both languages.

AIMS:

This study addressed the following questions. Do bilingual people with aphasia respond to naming therapy techniques developed for the monolingual population? Do languages respond differently to therapy and, if so, are gains influenced by language dominance? Does cross-linguistic generalisation occur and does this depend on the therapy approach? Is cross-linguistic generalisation more likely following treatment in L2 or L1?

METHODS & PROCEDURES:

The study involved five aphasic participants who were bilingual in English and Bengali. Testing showed that their severity and dominance patterns varied, so the study adopted a case series rather than a group design. Each person received two phases of naming therapy, one in Bengali and one in English. Each phase treated two groups of words with semantic and phonological tasks, respectively. The effects of therapy were measured with a picture-naming task involving both treated and untreated (control) items. This was administered in both languages on four occasions: two pre-therapy, one immediately post-therapy and one 4 weeks after therapy had ceased. Testing and therapy in Bengali was administered by bilingual co-workers.

OUTCOMES & RESULTS:

Four of the five participants made significant gains from at least one episode of therapy. Benefits arose in both languages and from both semantic and phonological tasks. There were three instances of cross-linguistic generalisation, which occurred when items had been treated in the person’s dominant language using semantic tasks.

CONCLUSIONS & IMPLICATIONS:

This study suggests that ‘typical’ naming treatments can be effective for some bilingual people with aphasia, with both L1 and L2 benefiting. It offers evidence of cross-linguistic generalisation, and suggests that this is most likely to arise from semantic therapy approaches. In contrast to some results in the academic literature, the direction of generalisation was from LI to L2. The theoretical implications of these findings are considered. Finally, the results support the use of bilingual co-workers in therapy delivery.

 

Neural Circuitry of the Bilingual lexicon: Effect of Age of Second language Acquisition

Frederic Isel, Annette Baumgaertner, Johannes Thran, Jurgen. M. Meisel, & Christian Buchel

Brain and Cognition, 72(2), 169-180 (2010)

Numerous studies have proposed that changes of the human language faculty caused by neural maturation can explain the substantial differences in ultimate attainment of grammatical competences between first language (L1) acquirers and second language (L2) learners. However, little evidence on the effect of neural maturation on the attainment of lexical knowledge in L2 is available. The present functional magnetic resonance study addresses this question via a cross-linguistic neural adaptation paradigm. Age of acquisition (AoA) of L2 was systematically manipulated. Concrete nouns were repeated across language (e.g., French–German, valisesuitcase–Koffersuitcase). Whereas early bilinguals (AoA of L2 10 years) showed larger RE effects in the middle portion of the left insula and in the right middle frontal gyrus (MFG). We suggest that, as for grammatical knowledge, the attainment of lexical knowledge in L2 is affected by neural maturation. The present findings lend support to neurocognitive models of bilingual word recognition postulating that, for both early and late bilinguals, the two languages are interconnected at the conceptual level.

Group effects of instrumentality and name relation on action naming in bilingual anomic aphasia.

 

Brain and LanguageVolume 110, Issue 1July 2009Pages 29-37
Maria Kambanaros

Verb production in sentences was investigated in two groups of late bilingual Greek-English speakers: individuals with anomic aphasia and a control group. Verb retrieval in sentences was significantly impaired in both languages for the individuals with anomic aphasia. Additional results revealed no effect of instrumentality on action naming in sentences in either language. However, there was a negative effect of verb-noun name relation on instrumental verb production in English only. Results confirm intact verb lemma retrieval for this group of bilingual individuals with anomic aphasia, but a breakdown at the level of accessing the phonological or lexical form.

Effect of treatment for bilingual individuals with aphasia: A systematic review of the evidence  

Journal of NeurolinguisticsVolume 23, Issue 4July 2010Pages 319-341
Yasmeen Faroqi-Shah, Tobi Frymark, Robert Mullen, Beverly Wang

Language proficiency in bilingualism, and hence bilingual aphasia, is a multifaceted phenomenon: influenced by variables such as age of onset, literacy, usage patterns, and emotional valence. Although the majority of the world and growing US population is bilingual, relatively little is known about the best practices for language therapy in bilingual aphasia. This systematic review was undertaken to examine three crucial questions faced by speech-language pathologists during clinical decision making: outcomes when language therapy is provided in the secondary (less-dominant) language (L2), extent of cross-language transfer (CLT) and variables that influence CLT, and outcomes when language therapy is mediated by a language broker. Data from 14 studies (N=45 aphasic individuals) indicate that treatment in L2 leads to positive outcomes (akin to L1 treatment); CLT was found to occur in most studies, especially when L1 was the language of treatment. Although limited by the methodological quality of included studies, this systematic review shows positive findings for unilingual aphasia treatment and CLT. Implications for clinical practice, models of language representation in bilinguals, and future

Lexical processing in the bilingual brain: Evidence from grammatical/morphological deficits

M Miozzo, A Costa, M Hernández… – Aphasiology, 2010

Background: A few studies have recently documented cases of proficient bilingual individuals who, subsequent to neural injury, suffered selective deficits affecting specific aspects of lexical processing. These cases involved disruption affecting the production of words from a specific grammatical category (verbs or nouns) or the production of irregular versus regular verb forms. Critically, these selective deficits were manifested in a strikingly similar manner across the two languages spoken by each of the individuals.

Aims: The present study aims at reviewing these cases of selective cross-linguistic deficits and discussing their implications for theories concerning lexical organisation in the bilingual brain.

Methods & Procedures: The studies reviewed here employed a variety of behavioural tests that were specifically designed to investigate the availability in aphasic patients of lexical information concerning nouns and verbs and their morphological characteristics.

Outcomes & Results: The brain-damaged bilingual speakers reviewed in the present study exhibited selective deficits for nouns, verbs, or irregularly inflected verbs in both of their languages.

Conclusions: The selectivity and cross-language nature of the deficits reviewed here indicates that at least certain language substrates are shared in proficient bilingual people. The fact that these deficits affect grammatical class distinctions and verb inflections—information that is part of the lexicon—further indicates that shared neural substrates support lexical processing in proficient bilingual people.

Parallel recovery in a bilingual aphasic: A neurolinguistic and fMRI study. Neuropsychology, 23(3), Marangolo, P., Rizzi, C., Peran, P., Piras, F., & Sabatini, U. (2009).

In bilingual aphasics, the neural correlates of rehabilitation benefits and their generalization across languages are still scarcely understood. The authors present the case of a highly proficient bilingual woman (Flemish, L1/Italian, L2) with chronic aphasia who, in the presence of the same pattern of impairment in both languages, showed parallel recovery in both languages after long-term rehabilitation therapy in L2. The authors postulated that this recovery was due to the engagement of the same neural substrates. To confirm this the authors used an event-related functional magnetic resonance imaging (fMRI) paradigm to explore cortical activation during an overt picture naming task, performed in both Flemish and Italian once before and once after 2 weeks of training in L2. Behaviorally, the patient showed complete recovery of both languages. The fMRI results indicated that the same cerebral regions were recruited for both languages before and after training. Increasing activations were observed

perilesionally and in homologous contralesional areas. Our data, in agreement with previous results of fMRI studies in healthy bilinguals, indicate a promising direction for future research on the neural mechanisms associated with recovery in bilingual aphasics.

Model-driven intervention in bilingual aphasia: Evidence from a case of pathological language mixing
Ana Inés Ansaldo; Ladan Ghazi Saidi; Adelaida Ruiz 

 Aphasiology, 1464-5041, Volume 24, Issue 2, First published 2010, Pages 309 – 324

Background: Speech-language pathologists are meeting an increasing number of bilingual clients. This poses a special challenge to clinical practice, given that bilingualism adds to the complexity of aphasia patterns and clinical decisions must be made accordingly. One question that has come to the attention of clinical aphasiologists is that of the language in which therapy should be administered. This issue becomes particularly relevant in cases of involuntary language switching, when choosing between L1 and L2 implies inhibiting one of the languages. Models of lexical selection in bilingual people offer a rationale for language choice based on the specificities of bilingual aphasia within each client.

Aims: To provide evidence for model-based intervention in bilingual aphasia, particularly in cases of pathological language switching.

Methods & Procedures: This paper reports a model-driven intervention in a case of involuntary language switching following aphasia in a Spanish-English bilingual client.

Outcomes & Results: Intervention tailored to the client’s strengths resulted in improved communication skills thanks to the implementation of a self-regulated strategy to overcome involuntary language switching.

Conclusions: Model-driven descriptions of bilingual aphasia contribute to efficient intervention by identifying therapy approaches that take account of each client’s language abilities. Further, clinical data analysed within models of bilingual language processing can provide evidence for dissociations between components of the bilingual lexical system.

Non-treated languages in aphasia therapy of polyglots benefit from improvement in the treated language

Barbara Miertsch, Jürgen M. Meisel and Frédéric Isel

Journal of Neurolinguistics, 22(2), 135-150 (2009)

The present case study aims to investigate whether the treatment of a third language (L3 French) in a trilingual chronic Wernicke-aphasic patient leads to the parallel improvement of the first (L1 German) and second (L2 English) languages. After a linguistic assessment in each language by means of the Bilingual Aphasia Test (BAT) [Paradis, M. (1987). The assessment of bilingual aphasia. Hillsdale: Lawrence Erlbaum], the patient was intensively treated in his L3 twice a day for 45 min for three and a half weeks. The treatment focussed on lexical–semantic deficits. Subsequent to the treatment, the patient was tested again in the three languages. The resulting recovery pattern shows that both L2 and L3 significantly improved after treatment with a larger effect for the treated language (L3) than for the L2. In contrast, L1 (German) did not show significant improvement, probably because the test results were already above-average for the first testing (T1). The present findings lend support to cognitive models of bilingual word recognition postulating that a bilingual’s two languages share a common semantic–conceptual memory system.

Bilingual aphasia and language control: A follow-up fMRI and intrinsic connectivity study

Jubin Abutalebi, Pasquale Anthony Della Rosa, Marco Tettamanti, David W. Green and Stefano F. Cappa

Brain and Language, 109(2-3), 141-156 (2009)

In a world that is becoming more multilingual, bilingual aphasia is a clinical problem with a major clinical impact. However, at present we lack causal explanations of the many features of recovery patterns and there is no consensus about the language in which the patient should receive speech therapy. Further advance requires an understanding of the dynamics of recovery. In a novel longitudinal, single-case study, we combine fMRI and dynamic causal modeling to examine the effects of specific language treatment for picture naming on the representation and control of language areas during the course of recovery. Improved performance in the treated language was associated with increased activation in language areas. Consistent with theoretical expectations, causal modeling indicated increased connectedness of the control and language networks for the treated language. This functional approach holds great promise for investigating recovery patterns and the effects of specific language treatment in bilingual aphasic patients.

Grammatical category-specific deficits in Bilingual Aphasia

Mireia Hernàndez, Agnés Caño, Albert Costa, Núria Sebastián-Gallés, Montserrat Juncadella and Jordi Gascón-Bayarri

Brain and Language, 107(1), 68-80 (2008)

We report the naming performance of an early and highly proficient Spanish–Catalan bilingual (JPG) suffering from Primary Progressive Aphasia (PPA). JPG’s performance revealed a grammatical category-specific deficit, with worse performance in naming verbs than nouns. This dissociation was present in oral and written naming and in his two languages, and it seems to stem from damage to, at least, the lexical level. Despite the fact that JPG’s performance was qualitatively very similar across languages, his second language seemed to be more affected than his first language. These results indicate that the cortical organization of the two languages of highly proficient bilinguals follow similar organizational principles, one of this principles being grammatical class.

Bilingual Aphasia: A theoretical and Clinical overview

Bonnie Lorenzen and Laura. L. Murray, Indiana University, Bloomington

American Journal of Speech-Language Pathology, Vol.17, 299-317 (2008)

Purpose: To provide an overview of the potential bilingual client population in the United States, present current neurolinguistic and psycholinguistic views of bilingualism in adults with and without aphasia, review related bilingual aphasia recovery patterns and the factors that might influence these recovery patterns, and provide insight into diagnostic and therapy procedures for addressing the needs of bilingual clients with aphasia.

Method: A review of the literature was conducted to summarize and synthesize previously published research in the area of bilingual aphasia, highlight unique aspects of aphasia recovery, assessment, and treatment, and identify areas in need of future research.

Conclusions: Despite a growing understanding of bilingualism and the various recovery patterns identified with bilingual aphasia, there remains a dire need for empirically validated management techniques, particularly in terms of determining which language to target, identifying which aspects of various languages are most vulnerable to insult as well as most responsive to treatment, and establishing how to exploit language similarities to maximize treatment efficiency.

Crosslinguistic Semantic and Translation Priming in Normal Bilingual Individuals and Bilingual Aphasia.

Swathi Kiran and Keith. R. Label

Clinical Linguistics and Phonetics, 4, 277-303. (2007)

The present study examined lexical representation in early Spanish-English bilinguals using an unmasked semantic and translation priming paradigm. In Experiment 1, participants were divided into two groups based on performance (more-balanced bilinguals, MB and less-balanced bilinguals, LB) on the experimental task. In Experiment 2, four patients with bilingual aphasia (BA) performed the same experiment. Results from both experiments revealed that all groups were more accurate for English targets (S-E direction) than Spanish targets (S-E direction). In Experiment 1, semantic priming was observed from English to Spanish in both the LB and MB groups although the effect was greater for the LB group. Further, only the LB group showed priming from Spanish to English. For both normal groups, there was no difference between translation and semantic priming effects. In Experiment 2, patients with bilingual aphasia demonstrated different patterns of activation with no clear trends. Two participants demonstrated greater priming from Spanish to English whereas two participants demonstrated the opposite effect.

Effect of Semantic naming treatment on Cross-linguistic generalization in Bilingual Aphasia

Lisa. A. Edmonds and Swathi Kiran

Journal of Speech-Language and Hearing Research, Vol.49 729-748 (2006)

PURPOSE: The effect of semantic naming treatment on crosslinguistic generalization was investigated in 3 participants with English–Spanish bilingual aphasia.

METHOD: A single-subject experimental designed was used. Participants received semantic treatment to improve naming of English or Spanish items, while generalization was tested to untrained semantically related items in the trained language and translations of the trained and untrained items in the untrained language.

RESULTS: Results demonstrated a within- and across-languages effect on generalization related to premorbid language proficiencies. Participant 1 (P1; equal premorbid proficiency across languages) showed within-language generalization in the trained language (Spanish) as well as crosslinguistic generalization to the untrained language (English). Participant 2 (P2) and Participant (P3) were more proficient premorbidly in English. With treatment in English, P2 showed within-language generalization to semantically related items, but no crosslinguistic generalization. With treatment in Spanish, both P2 and P3 exhibited no within-language generalization, but crosslinguistic generalization to English (dominant language) occurred. Error analyses indicated an evolution of errors as a consequence of treatment.

CONCLUSIONS: These results are preliminary because all participants were not treated in both languages. However, the results suggest that training the less dominant language may be more beneficial in facilitating crosslinguistic generalization than training the more proficient language in an unbalanced bilingual individual.

Noun and verb processing in Greek–English bilingual individuals with anomic aphasia a nd the effect of instrumentality and verb–noun name relation

Maria Kambanaros & Willem van Steenbrugg

Brain and Language, 97(2), 162-177 (2006)

Noun and verb comprehension and production was investigated in two groups of late bilingual, Greek–English speakers: individuals with anomic aphasia and a control group of non-brain injured individuals matched for age and gender. There were no significant differences in verb or noun comprehension between the two groups in either language. However, verb and noun production during picture naming was significantly worse in the bilingualindividuals with anomic aphasia in both languages, who also showed a specific verb impairment in Greek and English. The potential underlying level of breakdown of the specific verb impairment was further investigation with reference to two specific features of verbs: instrumentality and verb–noun relationship. Additional results revealed a facilitatory effect of Instrumentality in both languages. However, there was no effect of verb–noun name relation in Greek, and a negative effect of verb–noun name relation was observed in English. Lemma retrieval seemed to be intact in this group of bilingual individuals whose main problem seemed to arise during the retrieval of the phonological representation of the target word. This impairment was greater in English. The findings are discussed in terms of three current models of word production.

Nonparallel recovery in bilingual aphasia: Effects of language choice, language proficiency, and treatment.

Mira Goral, Boston University School of Medicine

International Journal of Bilingualism, Vol. 8, No. 2, 191-219 (2004)

We describe a 57-year-old Russian-Hebrew bilingual aphasic patient who received speech-language therapy in his second language (Hebrew) in the first three-and-a-half months post onset and then in his first language (Russian) for an additional month and a half. He was first diagnosed with Expressive-Receptive aphasia in both languages. After four weeks of treatment in the second language, his language skills improved and he was subsequently diagnosed with Predominantly Receptive aphasia in both languages. Three-and-a-half months post onset, he was diagnosed differently in the two languages: Predominantly Receptive aphasia in Hebrew and Amnestic aphasia in Russian. Followingadditional six weeks of therapy, this time in his first language (Russian), the patient was diagnosed as Amnestic in both his languages. We present the course of his improvement as seen in four successive evaluation periods in both the treated and nontreated languages, in all language modalities. We address various factors that may have contributed to the nonparallel recovery of the two languages and discuss the relative contribution of spontaneous recovery, therapeutic transfer, language proficiency, language use, and structural relations between the two languages.

Cognitive and cognate-based treatments for bilingual aphasia: A case study

Kathryn Kohnert

Brain and Language, 91(3), 294-302 (2004)

Two consecutive treatments were conducted to investigate skill learning and generalization within and across cognitive–linguistic domains in a 62-year-old Spanish-English bilingual man with severe non-fluent aphasia. Treatment 1 was a cognitive-based treatment that emphasized non-linguistic skills, such as visual scanning, categorization, and simple arithmetic. Treatment 2 was a lexically based treatment that trained cognates (cross-linguistic word pairs that are similar in meaning and form, such as rosa/rose) and non-cognates (cross-linguistic word pairs with shared meaning but different forms, such as mesa/table). Treatment 1 resulted in modest gains in both Spanish and English. Treatment 2 resulted in improved naming for non-cognates as well as cognates within each language. However, the generalization of gains from Spanish to English was apparent only for cognate stimuli.