First and Second Language at Hand: A Chronometric Transcranial-Magnetic Stimulation Study on Semantic and Motor Resonance

Abstract

According to embodied theories, motor and language processing bidirectionally interact: Motor activation modulates behavior in lexico-semantic tasks (semantic resonance), whereas understanding motor-related words entails activation of the corresponding motor brain areas (motor resonance). Whereas many studies investigated such interaction in the first language (L1), only few did so in a second language (L2), focusing on motor resonance. Here, we directly compared L1 and a late L2, for the first time both in terms of semantic and motor resonance and both in terms of magnitude and timing, by taking advantage of single-pulse TMS. Twenty-five bilinguals judged in each language, whether hand motor-related (“grasp”) and non-motor-related verbs (“believe”), were physical or mental. Meanwhile, we applied TMS on the hand motor cortex at 125, 275, 350, and 500 msec post verb onset, and recorded behavioral responses and TMS-induced motor evoked potentials. TMS induced faster responses for L1 versus L2 motor and nonmotor verbs at 125 msec (three-way interaction β = −0.0442, 95% CI [0.0814, −0.0070]), showing a semantic resonance effect at an early stage of word processing in L1 but not in L2. Concerning motor resonance, TMS-induced motor evoked potentials at 275 msec revealed higher motor cortex excitability for L2 versus L1 processing (two-way interaction β = 0.095, 95% CI [0.017, 0.173]). These findings confirm action–language interaction at early stages of word recognition, provide further evidence that L1 and L2 are differently embodied, and call for an update of existing models of bilingualism and embodiment, concerning both language representations and processing.

Kinesthetic motor-imagery training improves performance on lexical-semantic access

“…Results revealed that semantic resonance occurred at early stages of semantic processing (TMS applied at 125 ms post-stimulus) for first-language words but not second-language words, while motor resonance induced by TMS occurred at slightly later stages of semantic processing (275 ms post-stimulus) for second-language words. These results support the notion that action and language interact at early stages of word processing, and first-language and second-language are differently embodied [86]. Nevertheless, studies show that children who acquire two languages from birth learn language in a manner comparable to monolingual children, whereas highly proficient late bilinguals seem to have a more grounded representation of their second language ([87] for a review).…”

Ecological meanings: A consensus paper on individual differences and contextual influences in embodied language

“…For instance, the use of kinematic analysis to compare embodied effects across different languages (Gianelli et al, 2017), incorporating spatial and temporal precision to understand how embodied effects vary across different stages of lexical and semantic access. Additional insights may be gained by exploring linguistic-motor crosstalk in all aspects, such as the motor-semantic resonance (Monaco et al, 2021).…”

“…One of these is the timing of embodiment effects and relative language implication. Following this recommendation, Monaco et al (2021) reported a difference in the motor language interaction between L1 and L2 at the early stages of word recognition.…”

“…They suggested that those differences can vary according to which direction of the motor language processing interaction is investigated (motor -to-language/semantic resonance or language-to-motor/motor resonance), the stage of linguistic processing manipulated (early versus late), and the consequent activation of L1 or L2 network (e.g., early coactivation of L1 and L2 vs. late activation of L2). All these methodological choices are even more important considering that greater motor cortex activation was found in L2 compared to L1, independent of the motor relatedness of the stimuli (Monaco et al, 2021;Rüschemeyer, Zysset, & Friederici, 2006;Tian et al, 2020). Recent fMRI studies showed that motor implication within the structural connectivity of L1 and L2 differs as well: similar L1 and L2 induced motor activation have been observed, but the L2 network showed less integrated embodied connections (Zhang, Yang, Wang, & Li, 2020) or a different pattern of those (Tian et al, 2020).…”

Motor imagery training to improve language processing: What are the arguments?

“…Compared to sham stimulation, verum stimulation slowed down the translation process for sensorimotor-enriched foreign words but not sensory-enriched foreign words. The specific influence of rTMS on the translation of sensorimotor foreign words suggested that M1 may be specifically implicated in the representation of these words (see also Tian et al, 2020 ; Monaco et al, 2021 , for similar results, and Adams, 2016 , for a review).…”