Published online by Cambridge University Press: 29 November 2013
We review the characteristics of developmental language disorders (primary language impairment, reading disorders, autism, Down syndrome) and acquired language disorders (aphasia, dementia, traumatic brain injury) among multilingual and multicultural individuals. We highlight the unique assessment and treatment considerations pertinent to this population, including, for example, concerns of language choice and availability of measures and of normative data in multiple languages. A summary of relevant, recent research studies is provided for each of the language disorders selected.
Abutalebi, J., & Green, D. W. (2008). Control mechanisms in bilingual language production: Neural evidence from language switching studies. Language and Cognitive Processes, 23 (4), 557–582. doi: 10.1080/01690960801920602
Abutalebi and Green have put forward a model of bilingual language processing, employing the notion of inhibitory control. In their work they have demonstrated that, given evidence for the language nonselective activation in bilinguals, bilinguals practice inhibitory control to manage activation and inhibition of their languages. Furthermore, they concluded that existing evidence points to a convergence of the underlying representation of the two languages of bilinguals. The authors proposed a complex neuronal mechanism that engages cortical and subcortical brain regions to explain how, amid the overlapping language representation and the co-activation of the languages, bilinguals resolve competition between their languages and select the appropriate language for communication. When this network is impaired, as in aphasia, language-selection impairment may result.
Gollan, T. H., Salmon, D. P., Montoya, R. I., & da Pena, E. (2010). Accessibility of the nondominant language in picture naming: A counterintuitive effect of dementia on bilingual language production. Neuropsychologia, 48 (5), 1356–1366. doi: 10.1016/j.neuropsychologia.2009.12.038
Gollan and colleagues have set out to compare naming performance of bilinguals with and without dementia. They studied 29 Spanish-English bilingual with a diagnosis of probable Alzheimer's disease and 42 neurologically healthy individuals. In each group, about half of the participants were dominant in Spanish and about half dominant in English. When the authors compared naming accuracy in the clinical and control groups, they found greater difference for the dominant language than the nondominant language. This was true for both participants who were dominant in English and those who were dominant in Spanish. The authors concluded that despite reports that suggest that bilinguals with Alzheimer's disease prefer using their first language, impairment may be more evident in their dominant (typically first) language.
Kavé, G., Eyal, N., Shorek, A., & Cohen-Mansfield, J. (2008). Multilingualism and cognitive state in the oldest old. Psychology and Aging, 23 (1), 70–78. doi: 10.1037/0882–7974.23.1.70
This intriguing study by Kavé and colleagues suggests that the potential cognitive advantage associated with being bilinguals extends beyond bilingualism. The authors analyzed interview data collected from a large sample (over 800 participants) of people age 75 and older who spoke two, three, four, or multiple languages, and found a positive correlation between participants’ scores on a dementia screening test and the number of languages they spoke. Further study with more specific and sensitive measures is warranted to confirm and extend this promising finding.
McBride-Chang, C., Liu, P. D., Wong, T., Wong, A., & Shu, H. (2012). Specific reading difficulties in Chinese, English, or both: Longitudinal markers of phonological awareness, morphological awareness, and RAN in Hong Kong Chinese children. Journal of Learning Disabilities, 45 (6), 503–514. doi: 10.1177/0022219411400748
This longitudinal study by McBride-Chang and colleagues addresses how reading difficulties may manifest differently between the languages of Chinese-English biscriptal readers in Hong Kong and explores reasons for these differences. The authors looked at the relative contributions of morphological and phonological awareness tested in Chinese to reading proficiency in typically developing and poor readers of these two orthographically distant languages. The results highlight the connection between poor reading in Chinese and morphological awareness vs. poor reading in English and poor English word recognition. Slow performance on rapid-naming tasks and poor phonological awareness, characteristic of poor readers of both languages, suggest that these factors may reflect skill sets important for reading in both languages. Sociolinguistic factors are also considered.
Paradis, J. (2010a). The interface between bilingual development and specific language impairment. Applied Psycholinguistics, 31 (2), 227–252. doi: 10.1017/S0142716409990373
In a keynote article, Paradis provided a carefully crafted analysis of current research on bilingual language development as it pertains to specific language impairment. The author discussed current theories about the underlying impairment in SLI and critically reviewed studies that support and challenge these theories across languages and in multilingual children. Paradis then addressed the implications of this body of research for assessment and differential diagnosis of bilingual children with and without SLI along with considerations for improving efficacy of language intervention. The commentaries and author's response that follow this article offer insight into the challenges facing researchers as they attempt to disentangle SLI and typical bilingual language performance.