This study investigated whether language serves as the primary organizational axis dividing lexico-semantic representations in multilingual individuals, or whether language is a subsidiary feature to dominant organizing principles identified in monolingual individuals. To address this question, we examined the influence of two well-established principles of language organization—frequency and concreteness—on naming accuracy in a post-stroke bilingual individual with anomic aphasia (PWA). The participant, a highly proficient Basque-Spanish bilingual, underwent MRI scanning to delineate the extent and location of the lesion and completed a naming-by-definition task in both languages, along with a control group of 24 age-matched bilinguals. Stimuli were orthogonally varied by frequency (high/low) and concreteness (high/low). Generalized linear mixed models revealed main effects of both frequency and concreteness on naming accuracy. Notably, while healthy controls showed a robust concreteness effect—with concrete words yielding higher accuracy—the PWA exhibited a disproportionately larger impairment for low-frequency words. This pattern, consistent with the lesion’s location to the inferior temporal gyrus, highlights a specific vulnerability of frequency-based lexical representations following temporal lobe damage. Importantly, the bilingual PWA demonstrated strikingly similar error rates across languages, yet an item-level analysis revealed that the specific words affected differed between the two languages. These findings (i) clarify the role of the inferior temporal gyrus in lexical organization, (ii) suggest that bilinguals possess an integrated lexical system governed by general cognitive principles, and (iii) challenge the notion that language itself is the dominant axis of organization in the bilingual mind/brain.

Cortical tracking, the synchronization of brain activity to linguistic rhythms is a well-established phenomenon. However, its nature has been heavily contested: Is it purely epiphenomenal or does it play a fundamental role in speech comprehension? Previous research has used intelligibility manipulations to examine this topic. Here, we instead varied listeners’ language comprehension skills while keeping the auditory stimulus constant. To do so, we tested 22 native English speakers and 22 Spanish/Catalan bilinguals learning English as a second language (SL) in an EEG cortical entrainment experiment and correlated the responses with the magnitude of the N400 component of a semantic comprehension task. As expected, native listeners effectively tracked sentential, phrasal, and syllabic linguistic structures. In contrast, SL listeners exhibited limitations in tracking sentential structures but successfully tracked phrasal and syllabic rhythms. Importantly, the amplitude of the neural entrainment correlated with the amplitude of the detection of semantic incongruities in SLs, showing a direct connection between tracking and the ability to understand speech. Together, these findings shed light on the interplay between language comprehension and cortical tracking, to identify neural entrainment as a fundamental principle for speech comprehension.

Whether a cognitive advantage exists for bilingual individuals has been the source of heated debate in the last decade. While empirical evidence putatively in favor of or against this alleged advantage has been frequently discussed, the potential sources of enhanced cognitive control in bilinguals have only been broadly declared, with no mechanistic elaboration of where, why, and how this purported link between bilingualism and enhanced language control develops, and how this enhancement transfers to, and subsequently improves, general executive function. Here, we evaluate different potential sources for a bilingual advantage and develop the assumptions one would have to make about the language processing system to be consistent with each of these notions. Subsequently, we delineate the limitations in the generalizations from language to overall executive function, and characterize where these advantages could be identified if there were to be any. Ultimately, we conclude that in order to make significant progress in this area, it is necessary to look for advantages in theoretically motivated areas, and that in the absence of clear theories as to the source, transfer, and target processes that could lead to potential advantages, an inconsistent body of results will follow, making the whole pursuit of a bilingual advantage moot.