Neuroscience of second language acquisition: Opportunities and challenges

Abstract:

Understanding the cognitive mechanisms of second language (L2) acquisition is central to the field of applied linguistics. The neural mechanisms of first language and L2 acquisition have also become increasingly important to mainstream cognitive neuroscience today. Extensively debated topics include the effects of the age of acquisition in the multilingual brain, bilingual language control in the brain, the neural plasticity of L2 learning, and individual learner differences in the brain. This invited colloquium highlights for applied linguists what and how cognitive neuroscientists have attempted to reveal neural mechanisms of L2 acquisition. This colloquium brings together three cognitive neuroscientists who focus on L2 acquisition and bilingualism in the brain. Arturo E. Hernandez presents a series of studies that systematically investigate the role of age of acquisition, language proficiency, and cognitive control in the neural representation of bilinguals. Dynamic and complex interplays among these factors will also be discussed. Ping Li presents on multimodal behavioral and imaging studies that examine the effect of learning contexts using virtual learning technologies and learner differences in the brain. Li discusses semantic representations of L1 and L2 and how functional and structural neuroplasticity occurs due to the L2 experience and the context of learning. Hyeonjeong Jeong then overviews a series of collaborative studies with applied linguists to examine major research topics in their field (e.g., corrective feedback, learner differences, explicit and implicit knowledge). A major goal of this symposium is to bring together cognitive neuroscientists and applied linguists for future collaboration on issues of mutual concern and interest.

Bilingualism, brain and development: A Neuroemergentist perspective
Arturo E. Hernandez, University of Houston

For over 100 years, researchers have suggested that age of acquisition, language proficiency and cognitive control play a role in the neural representation of two languages. Work in the Laboratory for the Neural Bases of Bilingualism at the University of Houston has looked at the effects of all three factors on brain activity in child and adult Spanish-English bilinguals. This work has considered the role of age of acquisition and language proficiency on the brain activity in tasks involving speech sounds as well as the processing of grammar and meaning. Although the first studies of neural activity in bilinguals occurred over twenty years ago, researchers have once again taken up the relationship between bilingualism and cognitive control. Work in my laboratory suggest a complex and dynamic relationship between age of acquisition, language proficiency and cognitive control. These results fit nicely within a Neuroemergentist framework. In this view, language and cognitive development are characterized by non-linear waves of combination and recombination of simple parts into more and more complex forms of processing across the lifespan. Because of the non-linear nature of language exposure in bilinguals, it is particularly well suited to dynamical models such as Neuroemergentism.

Neuroplasticity, individual differences, and the context of learning in second language acquisition
Ping Li, The Hong Kong Polytechnic University

Both folk wisdom and scientific evidence point to the positive effect of study abroad experiences for second language (L2) learning. This effect is attributed to the context that enables the L2 learner to directly interact with the environment in which the target language is used and spoken by native speakers. However, the specific features of this interaction and their impact on the mind and the brain of the learner have remained under-examined in the literature. In this talk, I suggest that we can study the effects of learning context by using virtual learning technologies, especially virtual reality (VR), and comparing VR learning with non-virtual classroom-based learning. The context of learning effects could be examined with respect to both behavioral performance and experience-dependent neuroplasticity. In several studies, we demonstrate that virtual learning and non-virtual learning differentially impact speed of learning, working memory, and structural and functional brain changes (Lan et al., 2015; Legault et al., 2018). Using immersive VR (Legault et al., 2019), we recently have found that the degree of direct interaction, including embodied motion and other physical experiences, directly affect learning performance. Our data also show significant individual differences in not only traditional classroom-learning (e.g., Grant et al., 2015; Yang et al., 2015) but also in immersive VR; preliminary evidence suggests that virtual learning benefits mostly struggling L2 learners but less so highly successful learners. These data suggest, on the one hand, that current theories based on monolingual and bilingual conceptual semantic representations need to be revised and, on the other hand, a good account of individual differences in L2 learning needs to take into account variables such as learning and learner features in the learning context and mechanisms under which behavioral and neurocognitive changes might occur.

Cognitive neuroscientists working with second language acquisition researchers
Hyeonjeong Jeong, Tohoku University

In this talk, I demonstrate that neuroscience and second language acquisition (SLA) researchers can and should work together to deepen our understanding of cognitive mechanisms involved in second language (L2) teaching and learning. To do so, I provide three exemplary studies I have collaborated on with SLA researchers to investigate major topics: (a) corrective feedback, (b) learner differences, and (c) explicit and implicit knowledge. SLA researchers claim that receiving corrective feedback and responding to such feedback play an important role in promoting L2 acquisition. Using fMRI, I have investigated these neural mechanisms when L2 learners modify their ill-formed speech following corrective feedback. According to SLA research, L2 communication is affected by learner differences such as anxiety, aptitude, and L2 proficiency level. Using fMRI, I have investigated how neural mechanisms of L2 communication are associated with L2 proficiency, anxiety, and aptitude. Furthermore, SLA researchers argue that it is important to distinguish explicit knowledge from implicit knowledge. The major differences between explicit knowledge and implicit knowledge lie in whether learners are aware of linguistic knowledge or not. Using fMRI, I have examined the neural activities of L2 learners performing various tasks that are believed to tap into explicit and implicit knowledge. This talk concludes with opportunities and challenges for neuroscientists to work with SLA researchers, calling for further interdisciplinary collaboration.