How much bilingual experience is needed to affect executive control?

Abstract

A wealth of research on experience-related plasticity has shown that specific experiences, such as musical training (Herholz & Zatorre, 2012) or juggling (Draganski et al., 2004), can modify brain function and structure and induce long-term changes in cognitive behavior throughout the life span. In their comprehensive Keynote Article, Baum and Titone focus on the neural and cognitive implications of lifelong experience with multiple languages. They discuss empirical studies on bilingualism, executive control, and aging to enhance our understanding of the frequently observed executive control advantages in bilinguals and how lifelong bilingualism may contribute to the development of cognitive reserve and buffer age-related declines in executive control functions. In reframing these issues in terms of neuroplasticity, Baum and Titone propose to “embrace the inherent individual variability among bilinguals in all its glory” and identify key issues related to individual variability to pave the way to new avenues of research. We fully concur with Baum and Titone's general recommendation to embrace variability among bilinguals to advance our understanding of bilingualism, aging, and neuroplasticity, but we would like to particularly highlight the importance of the earlier stages of second language (L2) learning and the emergence of executive control advantages, a topic we believe has been understudied in this domain. How much bilingual experience is needed to affect executive control?