Multifactorial approaches to study bilingualism in the aging population: Past, present, future

Abstract

A better understanding and more reliable classification of bilinguals has been progressively achieved through the fine-tuning methodology and simultaneously optimizing the measurement tools. However, the current understanding is far from generalization to a larger population varying in different measures of bilingualism—L2 Age of acquisition (L2 AOA), L2 usage and exposure, and L2 proficiency. More recent studies have highlighted the importance of modeling bilingualism as a continuous variable. An in-depth look at the role of bilingualism, comparing groups, may be considered a reductionist approach, i.e., grouping based on one measure of bilingualism (e.g., L2 AOA) may not account for variability in other measures of bilingualism (L2 exposure, L2 use or L2 proficiency, amongst others) within and between groups. Similarly, a multifactorial dimension is associated with cognitive performance, where not all domains of cognition and subcomponents are equally influenced by bilingualism. In addition, socio-cultural and demographical factors may add another dimension to the impact of bilingualism on cognitive performance, especially in older adults. Nevertheless, not many studies have controlled or used the multiple socio-cultural and demographical factors as a covariate to understand the role of different aspects of bilingualism that may influence cognitive performance differently. Such an approach would fail to generalize the research findings to a larger group of bilinguals. In the present review paper, we illustrate that considering a multifactorial approach to different dimensions of bilingual study may lead to a better understanding of the role of bilingualism on cognitive performance. With the evolution of various fine-tuned methodological approaches, there is a greater need to study variability in bilingual profiles that can help generalize the result universally.

Graded bilingual effects on attentional network function in Chinese high school students

“…Evidence in support of a "bilingual advantage" may also result from these same methodological practices, together accounting for the mixed findings that permeate the extant literature. To echo a recent call by Dash and colleagues (Dash, Joanette & Ansaldo, 2022), it is crucial that future studies continue to investigate the contribution of multiple separable dimensions of bilingual language experience in order to understand the influence of bilingualism on cognitive function.…”

Variability in the effects of bilingualism on task switching of cognitively healthy and cognitively impaired older bilinguals

“…Apart from using a single language variable, another way of measuring bilingualism is to apply a composite score on several language variables based on the results of a factor analysis. Previous studies have used language information collected from the participants, performed a factor analysis to derive a composite score, and used them as a measure of bilingualism for further analysis (Luk and Bialystok, 2013;Dash et al, 2019Dash et al, , 2022Calabria et al, 2020). Such a method considers the heterogeneous nature of bilingualism and allows researchers to combine various language variables, e.g., L2 AoA, L2 usage, and proficiency information, into one bilingualism score to avoid adjustment of p-value during multiple comparisons.…”

Effects of healthy ageing and bilingualism on attention networks

“…It is important to remember that bilinguals are a heterogenous population and that simplistic comparisons between mono-vs. bilinguals may ignore inherent confounds (Bialystok, 2021b;Dash et al, 2022b;Rothman et al, 2022). The trajectory of brain function and structure adaptations (which ultimately may lead to performance benefits) are influenced by various aspects of language use and exposure (DeLuca et al, 2020): age of acquisition, proficiency, and factors to do with the context and nature of language use such as the frequency of language switching and code switching (i.e., see the Adaptive Control Model; Green & Abutalebi, 2013; for more details on how the linguistic environment influences the adaptation of control processes).…”

“…It also enables us to further examine TASK-SWITCHING EFFECTS (Fan et al, 2002). Ageing and bilingualism may impact on each of these components in different ways, possibly interacting with each other (e.g., Dash et al, 2022bDash et al, , 2022aIncera & McLennan, 2018). In this paper, we systematically investigate the effects of bilingualism and ageing on the subcomponents of attention.…”