Aims and objectives: Recent studies that have investigated novel word learning have demonstrated an advantage for bilinguals compared to monolinguals. The study reported here sought to explore whether a word learning advantage is revealed only for early bilinguals with comparable proficiency in both their languages, or whether such advantages are also observed in individuals with relatively late experience of, and less proficiency in, a second language. Methodology: We tested the acquisition of novel words in an unknown language using identification and naming tasks in three groups of 20 participants: monolingual Tamil speakers; early Tamil-English bilingual speakers; and late Tamil-English bilingual speakers. Data and analysis: The data was analysed using a non-parametric Kruskal-Wallis test followed by linear regressions. Findings: The results showed a bilingual advantage for word learning as evidenced by superior performance in both the naming and identification tasks and, critically, late bilinguals outperformed monolinguals. Originality: The results of the present study revealed, for the first time, a bilingual advantage in word learning even when individuals acquire their second language later in life. Significance: The results suggest that the positive effects of bilingualism may generalise beyond non-linguistic tasks, perhaps affecting a general language learning mechanism. Moreover, this seems to occur even in late bilingualism. This is in contrast to the reported effects on cognitive control mechanisms that show only weaker advantages for individuals who learned a second language later in life.

Much of the world's population speaks more than one language, and there has been a great deal of media attention given to the potential benefits of bilingualism. In this paper we provide a critical overview of the literature on bilingualism as it relates to older adults. We address whether there is indeed a cognitive advantage from speaking more than one language, and whether it can help preserve cognitive and linguistic function as we age, and potentially reduce the impact of dementia. We also focus on the patterns of language impairment after stroke (aphasia) in bilingual speakers and the issues relating to clinical management of bilingual aphasia.

Previous research has suggested that the advantages for cognitive control abilities in bilinguals are attenuated when socio-economic status (SES) is controlled (e.g., Morton & Harper, 2007). This study examined the effect of SES on cognitive control in illiterate monolingual and bilingual individuals who lived in adverse social conditions. We tested monolinguals and bilinguals using Simon and Attentional Network task while controlling for two potential confounding factors: SES and literacy. Bilinguals were faster for both trials with and without conflict demonstrating overall faster response times (global advantage) compared to monolinguals on both tasks. However, no bilingual advantage was found for conflict resolution on the Simon task and attentional networks on the Attentional Network task. The overall bilingual effects provide evidence for a bilingual advantage even among individuals without literacy skills and of very low SES. This indicates a strong link between bilingualism and cognitive control over and above effects of SES.