Functional characterization of the language network of polyglots and hyperpolyglots with precision fMRI.

How do polyglots-individuals who speak five or more languages-process their languages, and what can this population tell us about the language system? Using fMRI, we identified the language network in each of 34 polyglots (including 16 hyperpolyglots with knowledge of 10+ languages) and examined its response to the native language, non-native languages of varying proficiency, and unfamiliar languages. All language conditions engaged all areas of the language network relative to a control condition. Languages that participants rated as higher proficiency elicited stronger responses, except for the native language, which elicited a similar or lower response than a non-native language of similar proficiency. Furthermore, unfamiliar languages that were typologically related to the participants' high-to-moderate-proficiency languages elicited a stronger response than unfamiliar unrelated languages. The results suggest that the language network's response magnitude scales with the degree of engagement of linguistic computations (e.g. related to lexical access and syntactic-structure building). We also replicated a prior finding of weaker responses to native language in polyglots than non-polyglot bilinguals. These results contribute to our understanding of how multiple languages coexist within a single brain and provide new evidence that the language network responds more strongly to stimuli that more fully engage linguistic computations.

Functional characterization of the language network of polyglots and hyperpolyglots with precision fMRI.

How do polyglots-individuals who speak five or more languages-process their languages, and what can this population tell us about the language system? Using fMRI, we identified the language network in each of 34 polyglots (including 16 hyperpolyglots with knowledge of 10+ languages) and examined its response to the native language, non-native languages of varying proficiency, and unfamiliar languages. All language conditions engaged all areas of the language network relative to a control condition. Languages that participants rated as higher-proficiency elicited stronger responses, except for the native language, which elicited a similar or lower response than a non-native language of similar proficiency. Furthermore, unfamiliar languages that were typologically related to the participants' high-to-moderate-proficiency languages elicited a stronger response than unfamiliar unrelated languages. The results suggest that the language network's response magnitude scales with the degree of engagement of linguistic computations (e.g., related to lexical access and syntactic-structure building). We also replicated a prior finding of weaker responses to native language in polyglots than non-polyglot bilinguals. These results contribute to our understanding of how multiple languages co-exist within a single brain and provide new evidence that the language network responds more strongly to stimuli that more fully engage linguistic computations.

The human language system, including its inferior frontal component in "Broca's area," does not support music perception.

Language and music are two human-unique capacities whose relationship remains debated. Some have argued for overlap in processing mechanisms, especially for structure processing. Such claims often concern the inferior frontal component of the language system located within "Broca's area." However, others have failed to find overlap. Using a robust individual-subject fMRI approach, we examined the responses of language brain regions to music stimuli, and probed the musical abilities of individuals with severe aphasia. Across 4 experiments, we obtained a clear answer: music perception does not engage the language system, and judgments about music structure are possible even in the presence of severe damage to the language network. In particular, the language regions' responses to music are generally low, often below the fixation baseline, and never exceed responses elicited by nonmusic auditory conditions, like animal sounds. Furthermore, the language regions are not sensitive to music structure: they show low responses to both intact and structure-scrambled music, and to melodies with vs. without structural violations. Finally, in line with past patient investigations, individuals with aphasia, who cannot judge sentence grammaticality, perform well on melody well-formedness judgments. Thus, the mechanisms that process structure in language do not appear to process music, including music syntax.

Cross-language semantic parafoveal preview benefits in bilinguals.

The aim of this project was to identify factors contributing to cross-language semantic preview benefits. In Experiment 1, Russian-English bilinguals read English sentences with Russian words presented as parafoveal previews. The gaze-contingent boundary paradigm was used to present sentences. Critical previews were cognate translations of the target word (CTAPT-START), noncognate translations (CPOK-TERM), or interlingual homograph translations (MOPE-SEA). A semantic preview benefit (i.e., shorter fixation durations for related than unrelated previews) was observed for cognate and interlingual homograph translations, but not for noncognate translations. In Experiment 2, English-French bilinguals read English sentences with French words used as parafoveal previews. Critical previews were interlingual homograph translations of the target word (PAIN-BREAD) or interlingual homograph translations with a diacritic added (PÁIN-BREAD). A robust semantic preview benefit was found only for interlingual homographs without diacritics, although both preview types produced a semantic preview benefit in the total fixation duration. Our findings suggest that semantically related previews need to have substantial orthographic overlap with words in the target language to produce cross-language semantic preview benefits in early eye fixation measures. In terms of the Bilingual Interactive Activation+ model, the preview word may need to activate the language node for the target language before its meaning is integrated with that of the target word. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Probabilistic atlas for the language network based on precision fMRI data from >800 individuals.

Two analytic traditions characterize fMRI language research. One relies on averaging activations across individuals. This approach has limitations: because of inter-individual variability in the locations of language areas, any given voxel/vertex in a common brain space is part of the language network in some individuals but in others, may belong to a distinct network. An alternative approach relies on identifying language areas in each individual using a functional 'localizer'. Because of its greater sensitivity, functional resolution, and interpretability, functional localization is gaining popularity, but it is not always feasible, and cannot be applied retroactively to past studies. To bridge these disjoint approaches, we created a probabilistic functional atlas using fMRI data for an extensively validated language localizer in 806 individuals. This atlas enables estimating the probability that any given location in a common space belongs to the language network, and thus can help interpret group-level activation peaks and lesion locations, or select voxels/electrodes for analysis. More meaningful comparisons of findings across studies should increase robustness and replicability in language research.

An investigation across 45 languages and 12 language families reveals a universal language network.

To understand the architecture of human language, it is critical to examine diverse languages; however, most cognitive neuroscience research has focused on only a handful of primarily Indo-European languages. Here we report an investigation of the fronto-temporo-parietal language network across 45 languages and establish the robustness to cross-linguistic variation of its topography and key functional properties, including left-lateralization, strong functional integration among its brain regions and functional selectivity for language processing.

Differential Tracking of Linguistic vs. Mental State Content in Naturalistic Stimuli by Language and Theory of Mind (ToM) Brain Networks.

Language and social cognition, especially the ability to reason about mental states, known as theory of mind (ToM), are deeply related in development and everyday use. However, whether these cognitive faculties rely on distinct, overlapping, or the same mechanisms remains debated. Some evidence suggests that, by adulthood, language and ToM draw on largely distinct-though plausibly interacting-cortical networks. However, the broad topography of these networks is similar, and some have emphasized the importance of social content / communicative intent in the linguistic signal for eliciting responses in the language areas. Here, we combine the power of individual-subject functional localization with the naturalistic-cognition inter-subject correlation approach to illuminate the language-ToM relationship. Using functional magnetic resonance imaging (fMRI), we recorded neural activity as participants (n = 43) listened to stories and dialogues with mental state content (+linguistic, +ToM), viewed silent animations and live action films with mental state content but no language (-linguistic, +ToM), or listened to an expository text (+linguistic, -ToM). The ToM network robustly tracked stimuli rich in mental state information regardless of whether mental states were conveyed linguistically or non-linguistically, while tracking a +linguistic / -ToM stimulus only weakly. In contrast, the language network tracked linguistic stimuli more strongly than (a) non-linguistic stimuli, and than (b) the ToM network, and showed reliable tracking even for the linguistic condition devoid of mental state content. These findings suggest that in spite of their indisputably close links, language and ToM dissociate robustly in their neural substrates-and thus plausibly cognitive mechanisms-including during the processing of rich naturalistic materials.

The Small and Efficient Language Network of Polyglots and Hyper-polyglots.

Acquiring a foreign language is challenging for many adults. Yet certain individuals choose to acquire sometimes dozens of languages and often just for fun. Is there something special about the minds and brains of such polyglots? Using robust individual-level markers of language activity, measured with fMRI, we compared native language processing in polyglots versus matched controls. Polyglots (n = 17, including nine "hyper-polyglots" with proficiency in 10-55 languages) used fewer neural resources to process language: Their activations were smaller in both magnitude and extent. This difference was spatially and functionally selective: The groups were similar in their activation of two other brain networks-the multiple demand network and the default mode network. We hypothesize that the activation reduction in the language network is experientially driven, such that the acquisition and use of multiple languages makes language processing generally more efficient. However, genetic and longitudinal studies will be critical to distinguish this hypothesis from the one whereby polyglots' brains already differ at birth or early in development. This initial characterization of polyglots' language network opens the door to future investigations of the cognitive and neural architecture of individuals who gain mastery of multiple languages, including changes in this architecture with linguistic experiences.

Reduced Language Lateralization in Autism and the Broader Autism Phenotype as Assessed with Robust Individual-Subjects Analyses.

One of the few replicated functional brain differences between individuals with autism spectrum disorders (ASD) and neurotypical (NT) controls is reduced language lateralization. However, most prior reports relied on comparisons of group-level activation maps or functional markers that had not been validated at the individual-subject level, and/or used tasks that do not isolate language processing from other cognitive processes, complicating interpretation. Furthermore, few prior studies have examined functional responses in other brain networks, as needed to determine the spatial selectivity of the effect. Using functional magnetic resonance imaging (fMRI), we compared language lateralization between 28 adult ASD participants and carefully pairwise-matched controls, with the language regions defined individually using a well-validated language "localizer" task. Across two language comprehension paradigms, ASD participants showed less lateralized responses due to stronger right hemisphere activity. Furthermore, this effect did not stem from a ubiquitous reduction in lateralization of function across the brain: ASD participants did not differ from controls in the lateralization of two other large-scale networks-the Theory of Mind network and the Multiple Demand network. Finally, in an exploratory study, we tested whether reduced language lateralization may also be present in NT individuals with high autism-like traits. Indeed, autistic trait load in a large set of NT participants (n = 189) was associated with less lateralized language responses. These results suggest that reduced language lateralization is robustly associated with autism and, to some extent, with autism-like traits in the general population, and this lateralization reduction appears to be restricted to the language system. LAY SUMMARY: How do brains of individuals with autism spectrum disorders (ASD) differ from those of neurotypical (NT) controls? One of the most consistently reported differences is the reduction of lateralization during language processing in individuals with ASD. However, most prior studies have used methods that made this finding difficult to interpret, and perhaps even artifactual. Using robust individual-level markers of lateralization, we found that indeed, ASD individuals show reduced lateralization for language due to stronger right-hemisphere activity. We further show that this reduction is not due to a general reduction of lateralization of function across the brain. Finally, we show that greater autistic trait load is associated with less lateralized language responses in the NT population. These results suggest that reduced language lateralization is robustly associated with autism and, to some extent, with autism-like traits in the general population. Autism Res 2020, 13: 1746-1761. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

Speech-accompanying gestures are not processed by the language-processing mechanisms.

Speech-accompanying gestures constitute one information channel during communication. Some have argued that processing gestures engages the brain regions that support language comprehension. However, studies that have been used as evidence for shared mechanisms suffer from one or more of the following limitations: they (a) have not directly compared activations for gesture and language processing in the same study and relied on the fallacious reverse inference (Poldrack, 2006) for interpretation, (b) relied on traditional group analyses, which are bound to overestimate overlap (e.g., Nieto-Castañon and Fedorenko, 2012), (c) failed to directly compare the magnitudes of response (e.g., Chen et al., 2017), and (d) focused on gestures that may have activated the corresponding linguistic representations (e.g., "emblems"). To circumvent these limitations, we used fMRI to examine responses to gesture processing in language regions defined functionally in individual participants (e.g., Fedorenko et al., 2010), including directly comparing effect sizes, and covering a broad range of spontaneously generated co-speech gestures. Whenever speech was present, language regions responded robustly (and to a similar degree regardless of whether the video contained gestures or grooming movements). In contrast, and critically, responses in the language regions were low - at or slightly above the fixation baseline - when silent videos were processed (again, regardless of whether they contained gestures or grooming movements). Brain regions outside of the language network, including some in close proximity to its regions, differentiated between gestures and grooming movements, ruling out the possibility that the gesture/grooming manipulation was too subtle. Behavioral studies on the critical video materials further showed robust differentiation between the gesture and grooming conditions. In summary, contra prior claims, language-processing regions do not respond to co-speech gestures in the absence of speech, suggesting that these regions are selectively driven by linguistic input (e.g., Fedorenko et al., 2011). Although co-speech gestures are uncontroversially important in communication, they appear to be processed in brain regions distinct from those that support language comprehension, similar to other extra-linguistic communicative signals, like facial expressions and prosody.

Tracking Colisteners' Knowledge States During Language Comprehension.

When we receive information in the presence of other people, are we sensitive to what they do or do not understand? In two event-related-potential experiments, participants read implausible sentences (e.g., "The girl had a little beak") in contexts that rendered them plausible (e.g., "The girl dressed up as a canary for Halloween"). No semantic-processing difficulty (no N400 effect) ensued when they read the sentences while alone in the room. However, when a confederate was present who did not receive the contexts so that the critical sentences were implausible for him or her, participants exhibited processing difficulty: the social-N400 effect. This effect was obtained when participants were instructed to adopt the confederate's perspective-and critically, even without such instructions-but not when performing a demanding comprehension task. Thus, unless mental resources are limited, comprehenders engage in modeling the minds not only of those individuals with whom they directly interact but also of those individuals who are merely present during the linguistic exchange.

Effects of lexical ambiguity on perception: A test of the label feedback hypothesis using a visual oddball paradigm.

We used a visual oddball paradigm to investigate whether a shared verbal label makes two objects belonging to different conceptual categories less perceptually distinct. In Experiment 1, the critical images shared a label as well as some perceptual features (orange, referring to the color and the fruit), and in Experiment 2, the critical images shared a label but no perceptual features (bat, referring to the animal and the sports equipment). In both experiments comparison images were similar to each of the critical images but they did not share a label. A reduced deviant-related negativity (DRN) was observed for critical images compared with comparison images in both experiments, suggesting that the critical image pairs were perceived as less distinct than comparison pairs. These results extend previous research using the visual oddball paradigm that has shown that images from the same conceptual category are perceived as more distinct when they have different labels, and provide further support for the label-feedback hypothesis (Lupyan, 2012) in which language is assumed to modulate perception online. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The effect of semantic transparency on the processing of morphologically derived words: Evidence from decision latencies and event-related potentials.

Decomposition theories of morphological processing in visual word recognition posit an early morpho-orthographic parser that is blind to semantic information, whereas parallel distributed processing (PDP) theories assume that the transparency of orthographic-semantic relationships influences processing from the beginning. To test these alternatives, the performance of participants on transparent (foolish), quasi-transparent (bookish), opaque (vanish), and orthographic control words (bucket) was examined in a series of 5 experiments. In Experiments 1-3 variants of a masked priming lexical-decision task were used; Experiment 4 used a masked priming semantic decision task, and Experiment 5 used a single-word (nonpriming) semantic decision task with a color-boundary manipulation. In addition to the behavioral data, event-related potential (ERP) data were collected in Experiments 1, 2, 4, and 5. Across all experiments, we observed a graded effect of semantic transparency in behavioral and ERP data, with the largest effect for semantically transparent words, the next largest for quasi-transparent words, and the smallest for opaque words. The results are discussed in terms of decomposition versus PDP approaches to morphological processing. (PsycINFO Database Record

Cross-script orthographic and phonological preview benefits.

The present experiment examined the use of parafoveally presented first-language (L1) orthographic and phonological codes during reading of second-language (L2) sentences in proficient Russian-English bilinguals. Participants read English sentences containing a Russian preview word that was replaced by the English target word when the participant's eyes crossed an invisible boundary located before the preview word. The use of English and Russian allowed us to manipulate orthographic and phonological preview effects independently of one another. The Russian preview words overlapped with English target words in (a) orthography (ВЕЛЮР [vʲɪ'lʲʉr]-BERRY), (b) phonology (БЛАНК [blank]-BLOOD), or (c) had no orthographic or phonological overlap (КАЛАЧ [kɐ'lat͡ɕ]-BERRY; ГЖЕЛЬ [ɡʐϵlʲ]-BLOOD). The results of this study showed a clear and strong benefit of the parafoveal preview of Russian words that shared either orthography or phonology with English target words. This study is the first demonstration of cross-script orthographic and phonological parafoveal preview benefit effects. Bilinguals integrate orthographic and phonological information across eye fixations in reading, even when this information comes from different languages.

Thematic relatedness production norms for 100 object concepts.

Knowledge of thematic relations is an area of increased interest in semantic memory research because it is crucial to many cognitive processes. One methodological issue that researchers face is how to identify pairs of thematically related concepts that are well-established in semantic memory for most people. In this article, we review existing methods of assessing thematic relatedness and provide thematic relatedness production norming data for 100 object concepts. In addition, 1,174 related concept pairs obtained from the production norms were classified as reflecting one of the five subtypes of relations: attributive, argument, coordinate, locative, and temporal. The database and methodology will be useful for researchers interested in the effects of thematic knowledge on language processing, analogical reasoning, similarity judgments, and memory. These data will also benefit researchers interested in investigating potential processing differences among the five types of semantic relations.

Lexical stress assignment as a problem of probabilistic inference.

A new conceptualization of the process of stress assignment, couched in the principles of (Bayesian) probabilistic inference, is introduced in this paper. According to this approach, in deciding where to place stress in a polysyllabic word, a reader estimates the posterior probabilities of alternative stress patterns. This estimation is accomplished by adjusting a prior belief about the likelihoods of alternative stress patterns (derived from experience with the distribution of stress patterns in the language) by using lexical and non-lexical sources of evidence for stress derived from the orthographic input. The proposed theoretical framework was used to compute probabilities of stress patterns for Russian disyllabic words and nonwords which were then compared with the performance of readers. The results showed that the estimated probabilities of stress patterns were reflective of actual stress assignment performance and of naming latencies, suggesting that the mechanisms that are involved in the process of stress assignment might indeed be inferentially-based.

Cross-language phonological activation: evidence from masked onset priming and ERPs.

The goal of the present research was to provide direct evidence for the cross-language interaction of phonologies at the sub-lexical level by using the masked onset priming paradigm. More specifically, we investigated whether there is a cross-language masked onset priming effect (MOPE) with L2 (English) primes and L1 (Russian) targets and whether it is modulated by the orthographic similarity of primes and targets. Primes and targets had onsets that overlapped either only phonologically, only orthographically, both phonologically and orthographically, or did not have any overlap. Phonological overlap, but not orthographic overlap, between primes and targets led to faster naming latencies. In contrast, the ERP data provided evidence for effects of both phonological and orthographic overlap. Finally, the time-course of phonological and orthographic processing for our bilinguals mirrored the time-course previously reported for monolinguals in the ERP data. These results provide evidence for shared representations at the sub-lexical level for a bilingual's two languages.