Polish norms for a set of colored drawings of 168 objects and 146 actions with predictors of naming performance

Tracking Components of Bilingual Language Control in Speech Production: An fMRI Study Using Functional Localizers

When bilingual speakers switch back to speaking in their native language (L1) after having used their second language (L2), they often experience difficulty in retrieving words in their L1. This phenomenon is referred to as the L2 after-effect. We used the L2 after-effect as a lens to explore the neural bases of bilingual language control mechanisms. Our goal was twofold: first, to explore whether bilingual language control draws on domain-general or language-specific mechanisms; second, to investigate the precise mechanism(s) that drive the L2 after-effect. We used a precision fMRI approach based on functional localizers to measure the extent to which the brain activity that reflects the L2 after-effect overlaps with the language network (Fedorenko et al., 2010) and the domain-general multiple demand network (Duncan, 2010), as well as three task-specific networks that tap into interference resolution, lexical retrieval, and articulation. Forty-two Polish-English bilinguals participated in the study. Our results show that the L2 after-effect reflects increased engagement of domain-general but not language-specific resources. Furthermore, contrary to previously proposed interpretations, we did not find evidence that the effect reflects increased difficulty related to lexical access, articulation, and the resolution of lexical interference. We propose that difficulty of speech production in the picture naming paradigm-manifested as the L2 after-effect-reflects interference at a nonlinguistic level of task schemas or a general increase of cognitive control engagement during speech production in L1 after L2.

Characterizing language production across modalities

ABSTRACTThis study investigates factors influencing lexical access in language production across modalities (signed and oral). Data from deaf and hearing signers were reanalyzed (Baus and Costa, 2015, On the temporal dynamics of sign production: An ERP study in Catalan Sign Language (LSC). Brain Research, 1609(1), 40-53. https://doi.org/10.1016/j.brainres.2015.03.013; Gimeno-Martínez and Baus, 2022, Iconicity in sign language production: Task matters. Neuropsychologia, 167, 108166. https://doi.org/10.1016/j.neuropsychologia.2022.108166) testing the influence of psycholinguistic variables and ERP mean amplitudes on signing and naming latencies. Deaf signers' signing latencies were influenced by sign iconicity in the picture signing task, and by spoken psycholinguistic variables in the word-to-sign translation task. Additionally, ERP amplitudes before response influenced signing but not translation latencies. Hearing signers' latencies, both signing and naming, were influenced by sign iconicity and word frequency, with early ERP amplitudes predicting only naming latencies. These findings highlight general and modality-specific determinants of lexical access in language production.

Domain-general and language-specific contributions to speech production in a second language: an fMRI study using functional localizers

For bilinguals, speaking in a second language (L2) compared to the native language (L1) is usually more difficult. In this study we asked whether the difficulty in L2 production reflects increased demands imposed on domain-general or core language mechanisms. We compared the brain response to speech production in L1 and L2 within two functionally-defined networks in the brain: the Multiple Demand (MD) network and the language network. We found that speech production in L2 was linked to a widespread increase of brain activity in the domain-general MD network. The language network did not show a similarly robust differences in processing speech in the two languages, however, we found increased response to L2 production in the language-specific portion of the left inferior frontal gyrus (IFG). To further explore our results, we have looked at domain-general and language-specific response within the brain structures postulated to form a Bilingual Language Control (BLC) network. Within this network, we found a robust increase in response to L2 in the domain-general, but also in some language-specific voxels including in the left IFG. Our findings show that L2 production strongly engages domain-general mechanisms, but only affects language sensitive portions of the left IFG. These results put constraints on the current model of bilingual language control by precisely disentangling the domain-general and language-specific contributions to the difficulty in speech production in L2.