Biology subjects

Blanco-Elorrieta, E.

Publications and source records attributed to Blanco-Elorrieta, E..

5 recordsLinked to original sources

bioRxiv2025

Evidence for an Integrated Bilingual Language System from Discourse Tasks in Aphasia

BackgroundThe extent to which bilingual individuals represent and process their two languages within a shared or partially distinct neural architecture remains a topic of ongoing debate. While both parallel and divergent patterns of impairment have been reported in bilingual aphasia, such findings likely reflect a spectrum of representational overlap influenced by dominance, proficiency, and task demands. Critically, few studies have examined how breakdown manifests across multiple levels of linguistic structure using ecologically valid, discourse-based tasks. AimsThis study investigates whether Spanish-English bilinguals with aphasia exhibit parallel or dissociable patterns of impairment across their two languages, focusing on naturalistic narrative production and fine-grained analysis of error types and code-switching. Methods & ProceduresThirteen bilingual individuals with aphasia following acquired brain injury produced story retellings in both languages. Speech samples were transcribed and coded for phonological, morphological, syntactic, and semantic errors, and for the word type at which they occurred. Code-switches were also identified and categorized. Analyses included generalized linear modeling and unsupervised clustering. Outcomes & ResultsWhile participants made more errors in their non-dominant language, the structure and distribution of errors were highly similar across languages. Clustering algorithms revealed that impairments were parallel across languages and did not group by language dominance. Code-switching occurred more frequently from the non-dominant to the dominant language, consistent with activation-based lexical selection. ConclusionsFindings support an integrated bilingual language system that spans multiple levels of linguistic representation, modulated by language dominance. Naturalistic discourse tasks allow for richer characterization of bilingual language breakdown and may better inform both theoretical models and clinical management of bilingual aphasia.

neuroscience↗

bioRxiv2025

A theoretically driven calculation for language dominance and degree of multilingualism

Bilingualism research has long been challenged by a lack of a unified approach to quantifying language dominance and degree of multilingualism. While numerous questionnaires (e.g., LHQ, BLP, LEAP-Q, and LUQ) provide valuable data on language background variables, they lack a standardized formula to compute key measures from it. We introduce two formulas that synthesize critical linguistic variables to efficiently calculate language dominance and a multilingualism score that ranges from perfect monolingualism to native-like proficiency in multiple languages. Validation across two large datasets shows our dominance measure closely aligns with more complex PCA methods while being simpler and more efficient.

neuroscience↗

bioRxiv2020

Neural representation of words within phrases: Temporal evolution of color-adjectives and object-nouns during simple composition

In language, stored representations of lexical items combine into an infinitude of complex expressions. While the neuroscience of composition has begun to mature, we do not yet understand how the stored representations evolve and morph during composition. New decoding techniques allow us to crack open this very hard question: we can train a model to recognize a representation in one context or time-point and assess its accuracy in another. We combined the decoding approach with magnetoencephalography recorded during a picture naming task to investigate the temporal evolution of noun and adjective representations during speech planning. We tracked word representations as they combined into simple two-word phrases, using single words and two-word lists as non-combinatory controls. We found that nouns were generally more decodable than adjectives, suggesting that noun representations were stronger and/or more consistent across trials than those of adjectives. When training and testing across contexts and times, the representations of isolated nouns were recoverable when those nouns were embedded in phrases, but not so if they were embedded in lists. Adjective representations did not show a similar consistency across isolated and phrasal contexts. Noun representations in phrases also sustained over time in a way that was not observed for any other pairing of word class and context. These findings offer a new window into the temporal evolution and context sensitivity of word representations during composition, revealing a clear asymmetry between adjectives and nouns. The impact of phrasal contexts on the decodability of nouns may be due to the nouns status as head of phrase--an intriguing hypothesis for future research.

neuroscience↗

bioRxiv2019

Neural adaptation to accented speech: prefrontal cortex aids attunement in auditory cortices

Speech is a complex and ambiguous acoustic signal that varies significantly within and across speakers. A prevalent and ubiquitous example of such variation is accented speech, to which humans adapt extremely rapidly. The goal of this study is to uncover the neurobiological bases of the attunement process that enables such fluent comprehension. Twenty-four native English participants listened to words spoken by an unaccented "canonical" American talker and two "accented" talkers, and performed a word-picture matching task, while magnetoencephalography (MEG) was recorded. Accented speech was created by including systematic phonological substitutions within the word (e.g. [s] [->] [sh]). Activity in the auditory cortex (superior temporal gyrus) was greater for accented speech, but, critically, this was not attenuated by exposure. By contrast, prefrontal regions showed an interaction between the presence of an accent and amount of exposure: while activity decreased for canonical speech over time, responses to accented speech remained consistently elevated. Grainger causality analyses further revealed that prefrontal responses serve to modulate activity in auditory regions, suggesting the recruitment of top-down processing to decode accented signal. In sum, our results show that accented speech does not elicit the same prefrontal reduction in amplitude over time that unaccented speech does, and points to a dynamic exchange of information between the prefrontal and auditory cortices in order to recalculate phonetic classification and subsequent identification of lexical items. Significance statementHuman ability to adapt to different peoples idiosyncratic pronunciations is a hallmark of speech comprehension. This study aims to address whether adaptation to speakers accents manifests itself at the perceptual level (i.e. through adaptation of low-level neural responses in the auditory cortex) or at the post-perceptual level (i.e. higher-order regions correcting the sensory signal received from auditory cortex). Our results support the post-perceptual hypothesis: we found that responses in auditory cortex emitted an error-like signal that was invariant to exposure; whereas responses in the prefrontal cortex were modulated by exposure. These findings provide initial insight into accent adaptation, and illuminate the computational stages supporting speech comprehension more generally.

neuroscience↗

bioRxiv2019

Understanding requires tracking: noise and knowledge interact in bilingual comprehension

Understanding speech in noise is a fundamental challenge for speech comprehension. This perceptual demand is amplified in a second language: it is a common experience in bars, train stations, and other noisy environments that degraded signal quality severely compromises second language comprehension. Through a novel design, paired with a carefully selected participant profile, we independently assessed signal-driven and knowledge-driven contributions to the brain bases of first versus second language processing. We were able to dissociate the neural processes driven by the speech signal from the processes that come from speakers knowledge of their first versus second languages. The neurophysiological data show that in combination with impaired access to top-down linguistic information in the second language, the locus of bilinguals difficulty in understanding second language speech in noisy conditions arises from a failure to successfully perform a basic, low-level process: cortical entrainment to speech signals above the syllabic level. Significance statementOver half of the worlds population is multilingual. Although proficiency in a second language improves over time, even to the point of reaching native-like proficiency, one persistent difficulty is understanding a second language in noisy environments (e.g. in crowds, train stations, etc.). We examined this processing impairment using a novel frequency-tagging paradigm with magnetoencephalography (MEG). We found that the reason underlying bilinguals difficulty in understanding second language speech in noisy conditions is induced by a failure to neurally track the operations reflecting structure (i.e., phrase) building.

neuroscience↗