Manipulating the need for intentional language selection in bilingual production and visual comprehension

The Research Proposal asks two questions: (1) Does day-to-day communication in bilinguals require effortful control - in particular when switching languages? (2) If bilinguals do apply such effortful control regularly, does it result in superior cognitive abilities that translate to other cognitive tasks, and superior cognitive resilience in aging and neurodegeneration? Both questions are fundamental, the first - for the scientific understanding of bilingualism, and the second - for potentially exploiting the benefits of bilingualism to augment brain "power" and health, hence the considerable potential for impact.

These questions are also very timely. At the beginning of the millennium, empirical studies provided seemingly unanimous support for the notions that bilingual communication is both effortful and cognitively beneficial. However, over the last 5-8 years serious doubts have started to emerge. First, the laboratory tasks which suggest bilingual communication is effortful may not be entirely ecologically valid, and thus not provide a solid basis for inferences regarding real-life communication in bilinguals. Second, some of the initial reports of superior cognitive performance in bilinguals compared to monolinguals were not replicated. the primary aim of this project is to address a conundrum in the research on bilingualism - whereby claims of early studies on widespread cognitive benefits of bilingualism have not been supported by more recent evidence. Thus, whilst many still believe that bilingualism conveys cognitive advantages, the credible evidence for such advantages is thin.

To overcome this impasse, the project proposes a radical three-fold approach. First, instead of assuming that day-to-day balancing (and switching) between languages in bilinguals is always effortful, it will conduct a comprehensive web- and lab-based survey of experience in bilinguals to determine what tasks, activities, situations require balancing of languages, and which of these tasks/activities are especially effortful. Second, instead of relying exclusively on extant laboratory paradigms whose ecological validity is unknown at best (and low at worst), the project will develop 1-2 new paradigms, on the basis of the data from the above-mentioned survey, as well as alter existing laboratory paradigms. The novel paradigms will be extensively investigated in the lab using behavioural (response time and accuracy) and neuroscientific measures to elucidate the psychological processes likely at play. Third, instead of "blanket-testing" of bilinguals using various cognitive tests, the project will aim to develop and test much more specific predictions regarding tasks and activities where bilingualism isn't required but may still be advantageous - as informed by the above-mentioned survey.

The project is likely to generate truly ground-breaking evidence on the communicative experience in bilinguals, and novel laboratory tasks which model key aspects of such experience. Since bilingualism is of increasing societal prevalence and importance, and research on bilingualism is frequently published in high-impact psychology and neuroscience journals, the outcomes of this project are likely to have a substantial scientific, but also societal, impact.