Open research questions in Neurobiology of Language and Bilingualism

What the literature leaves open

• Short-term recall is strongly influenced by lexical organisation, but it remains unclear whether co-activation of orthographic neighbours primarily facilitates recall or produces competition and interference.

  Do High-Frequency Neighbours Help or Hurt Short-Term Recall? Evidence From French, English, and Spanish · 2026 · DOI

• Learning to read a second language requires the brain to incorporate a new writing system into an already established native-language reading network, yet how this process reshapes the Visual Word Form Area (VWFA) remains poorly understood.

  Learning to read a second language establishes a parallel L2 representation alongside the native one in the VWFA · 2026 · DOI

• These findings indicate that item-level psycholinguistic properties alone are insufficient to differentiate HP from LC, whereas sequential word frequency variation provides a potential index of cognitive impairment, reflecting underlying differences in semantic retrieval and memory organisation.

  Sequential Word Properties in Verbal Fluency: Detecting High-Proficiency Cognitive Impairment · 2026 · DOI

• Transformer-based language models have demonstrated sensitivity to a range of linguistic dependencies, yet it remains unclear how they represent information-structural focus and integrate discourse and lexical focus cues during ellipsis resolution.

  Focus shifts in contextual and lexical cue interactions in GPT models · 2026 · DOI

• Although word production engages a frontal-temporal-parietal network, no studies have tested how lesions to temporal and parietal lobe areas that represent semantic and phonological knowledge dampen neural responses in the left pars triangularis and the left pars opercularis, two adjacent regions in the left inferior frontal gyrus implicated in word search and retrieval.

  Causal dependencies between frontal and temporal lobe regions underlying word search and retrieval · 2026 · DOI

• The present study has several limitations that could be addressed in future work. First, we elected to use a self-paced reading task given previous reports that it might be an important variable for understanding prediction and sorting LFP responses (Payne and Federmeier, 2017). However, reading time did not much relate to ERPs in the present study. Instead, using a self-paced task might have introduced more noise, influencing our ability to detect LFP effects—especially given their protracted nature and the fact that their timecourse overlaps with the (variable) onset time of presentation for the word following the critical word. More generally, the variability of reading times across all of the words in the second sentence of our materials might have contributed additional noise to our data, potentially making it harder to detect ERP effects overall. We therefore plan to conduct an extension of this work using rapid serial visual presentation (RSVP) to ensure that all participants receive materials on the same time course. In addition, compared to many of our previous ERP studies investigating effects of domain knowledge on word-by-word reading, we used relatively fewer words per condition (30 here compared to ∼50 in most previous studies). This choice was made so that we could include the same number of Control as HP sentences without requiring an overly lengthy experimental session for participants. Future work investigating prediction/LFPs as a function of domain knowledge could benefit from a more specific focus on the domain of interest, thus allowing experimenters to increase the number of stimuli per condition. The combination of self-paced reading and smaller trial numbers may have meant that we were underpowered to detect small effects of HP knowledge on LFP effects. Our study tested a number of participants (N = 48) equivalent to or larger than the number of participants in our previous HP studies, which have repeatedly shown robust effects of domain (HP) knowledge on N400 effects of contextual support and other semantic manipulations, and we again found robust effects of individual differences on the N400. However, there was not the same breadth of knowledge on which to base our sample size for LFP effects, which, different from N400s, are non-obligatory, being apparent in moments where individuals are engaged in active prediction, and which can thus fluctuate over the course of an experiment (e.g., Payne and Federmeier, 2017; Jongman et al., 2023). We therefore aim to include a larger sample size in future work investigating individual differences in LFPs. Nonetheless, our results present novel evidence that domain knowledge can influence the predictive processes underlying realtime language comprehension.

  Shifting expectations: when knowledge-based predictions and linguistic context collide · 2026 · DOI

• The presence of an early RT effect of target-distractor mismatch is a key prediction of representational accounts, but it remains unclear why and how this effect interacts with the secondary task (Laurinavichyute and von der Malsburg, 2024).

  Representation distortion contributes to agreement attraction in comprehension · 2026 · DOI

• Future research could address this by incorporating a behavioral pre-test, such as a ‘word-likeness’ rating task, to empirically validate the phonotactic naturalness of the stimuli. A potential limitation of the current study concerns the assessment of phonotactic legality, which was controlled strictly through position-specific bigram frequency.

  The Effect of Orthographic Neighbourhood and Semantics on Lexical Processing in a Transparent Orthographic Language: A Pupilometry Study · 2026 · DOI

• Future work could address this by collecting larger discourse samples, by refining the treatment of Mixed errors (e. The model was fit to discourse samples from a single elicitation task (Cinderella story retelling), and it remains to be seen whether the parameter estimates generalize across different discourse genres or more structured production tasks. Several limitations of the present study should be noted.

  From structure to sequence: a Multinomial Processing Tree model of syntactic encoding · 2026 · DOI

• Future research should address the limitations identi- fied, such as the lack of control data and the need for a standardized word-finding test. Given that previous studies show that word finding may be impaired long after surgery, future studies may focus on how psycholinguistic processing skills underly- ing word finding may change in response to radio- and/or chemotherapy as shown in other cognitive skills [120] or how intervention in speech-language therapy may shape psycholinguistic processing in this population, as shown in other clinical groups [121].

  Language Processing in Posterior Fossa Tumour Patients: Psycholinguistic Insights into the Word-Finding Ability · 2026 · DOI

• The current study did not have control data to compare the word-finding ability of PFT patients. This limited the inter- pretation of the linguistic levels that significantly impacted accuracy and reaction times in terms of their contribution to the impairment status. Future studies should recruit age- matched controls and replicate the current study to find if their word-finding ability is influenced by the same linguis- tic levels as the PFT sample. The approach used in previ- ous studies for narrative data can also be employed to check whether principal component analysis with the psycholin- guistic variables and word-finding ability helps differenti- ate between controls and patients [92]. Moreover, a larger sample size is required to establish whether the effect of psycholinguistic properties on word-finding performance changes due to surgery. With the limited sample size of the current study, we can merely read the null interactions as absence of evidence for such a change. Wordrace needs to be standardized in English and other languages, adding to the construct validity of the test. An even better approach would be to rethink the test design, balancing items on visual complexity and psycholinguistic properties of the target words. Potentially significant factors, such as the selection of stimuli and their order, are usually overlooked in picture naming tests [117]. For instance, the effect of seman- tic categories can obscure performance [118]. Lastly, more assessment points should be investigated to examine the trajectory of word-finding ability over time after surgery in terms of improvement or worsening. As reported in a recent systematic review [4], some studies that tested language ability longitudinally in the PFT sample, revealed inconsistent results, with some finding no impairment shortly after surgery but finding phonological and pragmatic deficits at one-year follow-up [119], while others reported persistent lexical-semantic difficulties at all assessment points after sur- gery [39]. A longitudinal study would also help pinpoint how radiotherapy affects word retrieval abilities and how this evo- lution might differ depending on specific patient characteris- tics such as age, sex, language background (i.e., monolingual/ bilingual), and/or socioeconomic status.

  Language Processing in Posterior Fossa Tumour Patients: Psycholinguistic Insights into the Word-Finding Ability · 2026 · DOI

• It is important to consider the limitations of our study. First, our sample size was rela- tively small, resulting in reduced statistical power and potentially limiting the ability to detect possible relationships. Increasing the number of participants in future research will be essential to improve the reliability and robustness of the findings. Additionally, our sample consisted exclusively of college students, most of whom were female. Future studies should aim to include learners with more diverse educational backgrounds, age ranges, and gender distributions to enhance the generalizability of the findings. Second, the AJT was administered using a Rapid Serial Visual Presentation (RSVP) format due to EEG recording requirements. This format does not reflect a fully natural reading process, and although there is evidence that RSVP with normal reading rate does not impact comprehension (Ricciardi & Di Nocera, 2017) or alter reading pro- cesses (Juola et al., 1982), future work may benefit from incorporating more naturalistic or multimodal comprehension measures. Lastly, the target stimuli in this study were intentionally limited to inanimate nouns with canonical -o/-a endings; future work that is interested in exploring additional aspects of grammatical gender agreement, includ- ing unmarked and deceptively marked nouns, would need to develop a less restrictive stimuli set.

  Working memory and second/additional language Spanish gender agreement: Longitudinal evidence from receptive and productive abilities · 2026 · DOI

• Although this provides a clear test case, attitudinal prosody varies cross- linguistically, and future research should examine additional language combinations to assess generalizability. Future research should examine how different forms of L2 exposure – such as conversational practice, multimodal input, or targeted instruction – shape learners’ https://doi.

  Neural mechanisms of attitudinal prosody in a second language: The impact of informal exposure · 2026 · DOI

• Our focus on within-age associations limits conclusions about age-related differences. Internet-using older adults from Prolific tend to have higher education and cognitive functioning than the general population (Berner et al., 2015). However, the relation between Flanker RT and Flanker error relation differed by age, which is consistent with the well-studied speedaccuracy tradeoff (for review, see Heitz, 2014) and age-related shifts toward more accuracy-focused response strategies (e.g., Ratcliff et al., 2001; Starns and Ratcliff, 2010). Pooling across these opposing patterns would risk averaging away age-specific effects though for transparency, we report the all-age model in the Supplementary Materials.

  Mechanisms of semantic composition in older adults: control, semantic processing, and imagery · 2026 · DOI

• A rigorous assessment of limitations is essential for the proper interpretation and contextualization of any empirical study. The present investigation, despite its comprehensive design and rich findings, is subject to several important limitations that span methodological, theoretical, generalizability, and statistical dimensions. This section addresses each category of limitation with the thoroughness and honesty that the topic demands, ensuring that the study’s contributions are understood within their proper epistemic boundaries.

  Emergent Consciousness Indicators in Large Language Models: A Longitudinal Analysis of Training Dynamics · 2026 · DOI

• Several limitations of this work should be acknowledged when interpreting and generalizing our findings. First, the sample size is modest (22 CSF-verified AD cases and 22 matched controls). While this is typical for deeply phenotyped, biomarker-anchored cohorts and sufficient to support the internal cross-validated analyses reported here, it constrains inferences about robustness across the broader clinical population. Future studies will need to replicate and extend these results in larger samples that span a wider range of ages, educational backgrounds, dialects, comorbidities, and clinical stages, to establish the stability of the identified speech phenotype under more heterogeneous real-world conditions.

  Detecting CSF-validated Alzheimer’s disease from spontaneous speech in German: an interpretable end-to-end machine-learning framework · 2026 · DOI

• In the field of speech processing, although considerable studies have demonstrated that a highly predictive sentence context can facilitate the perception of forthcoming word, it remains to be examined that how this type of predictability affects the perceptual learning of speech (especially degraded speech).

  The modulating effect of lexical predictability on perceptual learning of degraded speech · 2023 · DOI

• These findings are inconsistent with the interpretation of the N400 as an index of integration, as no N400 effect emerged even in the absence of a semantically attractive alternative.

  The P600 as a continuous index of integration effort · 2023 · DOI

• Our study contributes to the understanding of multilingual cognition and sheds light into an under-researched cognitive domain known to decline in normal ageing, namely episodic memory recall.

  A longitudinal study of episodic memory recall in multilinguals · 2022 · DOI

• Aims and Objectives: The cognate facilitation effect (CFE) is a robust effect in language production and visual word comprehension, but evidence for CFE during auditory comprehension is still scarce.

  Cognate facilitation effect during auditory comprehension of a second language: A visual world eye-tracking study · 2022 · DOI

• In closing, while WM studies have shown its influence on L2 proficiency and processing, to more fully understand its dynamic nature, what is needed is further research on the reciprocal influences of bilingual development and changes in WM components, such as control of attention.

  Working memory and second language development: A complex, dynamic future? · 2020 · DOI

• Speaking (1989) inspired research on topics such as word selection, syntactic formulation, and dialogue, but an issue that remains understudied is linearisation: the question of how speakers organise a series of utterances into a coherent sequence, allowing both speaker and listener to keep track of what has been said and what will come next.

  Linearisation during language production: evidence from scene meaning and saliency maps · 2019 · DOI

• However, despite evidence for deep and shallow orthographies, little is known about the role that several orthographic, phonological and semantic variables play in visual word recognition and word production of words from intermediate-depth languages, as European Portuguese (EP).

  Psycholinguistic variables in visual word recognition and pronunciation of European Portuguese words: a mega-study approach · 2019 · DOI

• Code-switching (CS) is central to many bilingual communities and, though linguistic and sociolinguistic research has characterised different types of code-switches (alternations, insertions, dense CS), the cognitive control processes (CPs) that mediate them are not well understood.

  A control process model of code-switching · 2014 · DOI

• Early posterior negativity (EPN) effects to high-arousing words were limited to the lexical decision task, corroborating recent reports that suggested that perceptual processing as reflected in the EPN might not be as automatic as previously assumed.

  <scp>P1</scp>and beyond: Functional separation of multiple emotion effects in word recognition · 2012 · DOI

Most-cited papers in Neurobiology of Language and Bilingualism

• Unreliability of the dot probe task · European Journal of Personality · 2005 · 411 citations
• Detecting formal thought disorder by deep contextualized word representations · Psychiatry Research · 2021 · 313 citations
• Evidence of a predictive coding hierarchy in the human brain listening to speech · Nature Human Behaviour · 2023 · 267 citations
• A control process model of code-switching · Language Cognition and Neuroscience · 2014 · 215 citations
• The capacity theory of sentence comprehension: Critique of Just and Carpenter (1992). · Psychological Review · 1996 · 178 citations
• The role of working memory in syntactic ambiguity resolution: A psychometric approach. · Journal of Experimental Psychology General · 2007 · 165 citations
• Short test of semantic and phonological fluency: Normal performance, validity and test‐retest reliability · British Journal of Clinical Psychology · 2000 · 165 citations
• Lack of selectivity for syntax relative to word meanings throughout the language network · Cognition · 2020 · 158 citations
• An integrated model of word processing and eye-movement control during Chinese reading. · Psychological Review · 2020 · 141 citations
• <scp>P1</scp>and beyond: Functional separation of multiple emotion effects in word recognition · Psychophysiology · 2012 · 135 citations

Most recent work

• Functionally Relevant and Reliable Brain Stimulation Targets for Enhancement of Novel Word-Learning · bioRxiv · 2026
• An ERP Study on the Neural Mechanisms of Code-Switching Processing Among Chinese-English-Japanese Trilinguals · Journal of Psycholinguistic Research · 2026
• A Unified Neural Time Course for Words, Phrases, and Sentences: MEG Evidence from Parallel Presentation · Neurobiology of Language · 2026
• Task-dependent neural correlates of L2 emotion-label versus emotion-laden word processing: Behavioral and electrophysiological evidence · Bilingualism Language and Cognition · 2026
• When word order matters: human brains represent sentence meaning differently from large language models · bioRxiv · 2026
• Multidimensional cognitive deficit in logopenic variant primary progressive aphasia: a case report · Journal of Medical Case Reports · 2026
• The dynamic relationship between pupil dilation and neural surprise in natural language comprehension · bioRxiv · 2026
• The Impact of Respectfulness on Causal Inference During Discourse Processing · Language and Speech · 2026
• Revisiting Emotional Effects Under Lexical Control in L2 Auditory Word Recognition Memory · Journal of Psycholinguistic Research · 2026
• Single-letter (but not multi-letter) flankers produce a leftward asymmetry in the flanker lexical decision task · Language Cognition and Neuroscience · 2026

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