Neurocognitive Effects of Multilingualism Throughout the Lifespan

Expertise, ecosystem, and emergentism: Dynamic developmental bilingualism

“…Specifically, late bilinguals demonstrate structural changes to areas involved in cognitive control and language processing relative to early bilinguals. Claussenius-Kalman et al (2019) showed that late bilinguals had greater gray matter density in areas involved in language planning (including the bilateral MFG, IFG, right SMG, and left SFG) as compared to early bilinguals. Late bilinguals also had greater cortical thickness in regions implicated in top-down attentional control (left SPL), prelexical speech (left STG), and integration between auditory perception and motor production (left IPL).…”

Trilingual parallel processing: Do the dominant languages grab all the attention?

“…How to account for this effect of multilingual processing? Festman (2020) suggests five effects resulting from the learning and processing of multiple languages: (a) stimulating effectchildren exposed to more than one language in the early age become sensitive and interested in phonetic contrast and are faster in disengagement of attention affecting executive function in babies even before they learn to speak (see also Claussenius-Kalman & Hernandez, 2019;D'Souza et al, 2020;Höhle et al, 2020); (b) facilitating effecta larger linguistic repertoire, with increased number of languages represented in the brain provides positive transfer both quantitatively (larger mental lexicon) and qualitatively (diverse knowledge of tonality, morphological processing etc. ); (c) catalytic effectacquisition of new information especially word learning and grammatical learning is sped up in the multilingual learners (see also Montanari, 2019;Rothman, 2010); (d) modulating effectformal instruction and literacy acquisition in heritage languages causing biliteracy, especially in typologically nonrelated languages helps in developing superior metalinguistic skills (Sanz, 2007); (e) triggering effectusing the principle of convergence (using existing structures and representation to build new ones) and adaptation (strength of connections like control circuits being changed to accommodate new processing demands), the brain extends a well-organized language network to incorporate additional languages.…”

Learning and Processing Multiple Languages: The More the Easier?

“…The earliest effects of exposure to more than one language have been revealed already in very young learners in terms of heightened and extended sensitivity to phonetic contrasts as well as increased sensitivity to and interest in novelty and faster disengagement of attention. Claussenius-Kalman and Hernandez (2019) concluded "that a bilingual environment may affect executive function even before babies learn to speak" (p. 667). They have been characterized as taking an exploratory approach to learning a new language, and as striving for new information (cf.…”