Publications

Abstract

Speech segmentation procedures may differ in speakers of different languages. Earlier work based on French speakers listening to French words suggested that the syllable functions as a segmentation unit in speech processing. However, while French has relatively regular and clearly bounded syllables, other languages, such as English, do not. No trace of syllabifying segmentation was found in English listeners listening to English words, French words, or nonsense words. French listeners, however, showed evidence of syllabification even when they were listening to English words. We conclude that alternative segmentation routines are available to the human language processor. In some cases speech segmentation may involve the operation of more than one procedure

Abstract

One of a listener's major tasks in understanding continuous speech is segmenting the speech signal into separate words. When listening conditions are difficult, speakers can help listeners by deliberately speaking more clearly. In four experiments, we examined how word boundaries are produced in deliberately clear speech. In an earlier report we showed that speakers do indeed mark word boundaries in clear speech, by pausing at the boundary and lengthening pre-boundary syllables; moreover, these effects are applied particularly to boundaries preceding weak syllables. In English, listeners use segmentation procedures which make word boundaries before strong syllables easier to perceive; thus marking word boundaries before weak syllables in clear speech will make clear precisely those boundaries which are otherwise hard to perceive. The present report presents supplementary data, namely prosodic analyses of the syllable following a critical word boundary. More lengthening and greater increases in intensity were applied in clear speech to weak syllables than to strong. Mean F0 was also increased to a greater extent on weak syllables than on strong. Pitch movement, however, increased to a greater extent on strong syllables than on weak. The effects were, however, very small in comparison to the durational effects we observed earlier for syllables preceding the boundary and for pauses at the boundary.

Abstract

In a 50,000-word corpus of spoken British English the occurrence of words embedded within other words is reported. Within-word embedding in this real speech sample is common, and analogous to the extent of embedding observed in the vocabulary. Imposition of a syllable boundary matching constraint reduces but by no means eliminates spurious embedding. Embedded words are most likely to overlap with the beginning of matrix words, and thus may pose serious problems for speech recognisers.

Abstract

Participants' eye movements to four objects displayed on a computer screen were monitored as the participants clicked on the object named in a spoken instruction. The display contained pictures of the referent (e.g., a snake), a competitor that shared features with the visual representation associated with the referent's concept (e.g., a rope), and two distractor objects (e.g., a couch and an umbrella). As the first sounds of the referent's name were heard, the participants were more likely to fixate the visual competitor than to fixate either of the distractor objects. Moreover, this effect was not modulated by the visual similarity between the referent and competitor pictures, independently estimated in a visual similarity rating task. Because the name of the visual competitor did not overlap with the phonetic input, eye movements reflected word-object matching at the level of lexically activated perceptual features and not merely at the level of preactivated sound forms.

Abstract

Listening to speech is difficult in noisy environments, and is even harder when the interfering noise consists of intelligible speech as compared to unintelligible sounds. This suggests that the competing linguistic information interferes with the neural processing of target speech. Interference could either arise from a degradation of the neural representation of the target speech, or from increased representation of distracting speech that enters in competition with the target speech. We tested these alternative hypotheses using magnetoencephalography (MEG) while participants listened to a target clear speech in the presence of distracting noise-vocoded speech. Crucially, the distractors were initially unintelligible but became more intelligible after a short training session. Results showed that the comprehension of the target speech was poorer after training than before training. The neural tracking of target speech in the delta range (1–4 Hz) reduced in strength in the presence of a more intelligible distractor. In contrast, the neural tracking of distracting signals was not significantly modulated by intelligibility. These results suggest that the presence of distracting speech signals degrades the linguistic representation of target speech carried by delta oscillations.

Abstract

Background

Variation in the longitudinal course of childhood attention deficit/hyperactivity disorder (ADHD) coincides with neurodevelopmental maturation of brain structure and function. Prior work has attempted to determine how alterations in white matter (WM) relate to changes in symptom severity, but much of that work has been done in smaller cross-sectional samples using voxel-based analyses. Using standard diffusion-weighted imaging (DWI) methods, we previously showed WM alterations were associated with ADHD symptom remission over time in a longitudinal sample of probands, siblings, and unaffected individuals. Here, we extend this work by further assessing the nature of these changes in WM microstructure by including an additional follow-up measurement (aged 18 – 34 years), and using the more physiologically informative fixel-based analysis (FBA).
Methods

Data were obtained from 139 participants over 3 clinical and 2 follow-up DWI waves, and analyzed using FBA in regions-of-interest based on prior findings. We replicated previously reported significant models and extended them by adding another time-point, testing whether changes in combined ADHD and hyperactivity-impulsivity (HI) continuous symptom scores are associated with fixel metrics at follow-up.
Results

Clinical improvement in HI symptoms over time was associated with more fiber density at follow-up in the left corticospinal tract (lCST) (tmax = 1.092, standardized effect[SE] = 0.044, pFWE = 0.016). Improvement in combined ADHD symptoms over time was associated with more fiber cross-section at follow-up in the lCST (tmax = 3.775, SE = 0.051, pFWE = 0.019).
Conclusions

Aberrant white matter development involves both lCST micro- and macrostructural alterations, and its path may be moderated by preceding symptom trajectory.

Abstract

Speech comprehension is resistant to acoustic distortion in the input, reflecting listeners' ability to adjust perceptual processes to match the speech input. For noise-vocoded sentences, a manipulation that removes spectral detail from speech, listeners' reporting improved from near 0% to 70% correct over 30 sentences (Experiment 1). Learning was enhanced if listeners heard distorted sentences while they knew the identity of the undistorted target (Experiments 2 and 3). Learning was absent when listeners were trained with nonword sentences (Experiments 4 and 5), although the meaning of the training sentences did not affect learning (Experiment 5). Perceptual learning of noise-vocoded speech depends on higher level information, consistent with top-down, lexically driven learning. Similar processes may facilitate comprehension of speech in an unfamiliar accent or following cochlear implantation.

Abstract

This paper argues that inter-individual and inter-group variation in language acquisition, perception, processing and production, rooted in our biology, may play a largely neglected role in sound change. We begin by discussing the patterning of these differences, highlighting those related to vocal tract anatomy with a foundation in genetics and development. We use our ArtiVarK database, a large multi-ethnic sample comprising 3D intraoral optical scans, as well as structural, static and real-time MRI scans of vocal tract anatomy and speech articulation, to quantify the articulatory strategies used to produce the North American English /r/ and to statistically show that anatomical factors seem to influence these articulatory strategies. Building on work showing that these alternative articulatory strategies may have indirect coarticulatory effects, we propose two models for how biases due to variation in vocal tract anatomy may affect sound change. The first involves direct overt acoustic effects of such biases that are then reinterpreted by the hearers, while the second is based on indirect coarticulatory phenomena generated by acoustically covert biases that produce overt “at-a-distance” acoustic effects. This view implies that speaker communities might be “poised” for change because they always contain pools of “standing variation” of such biased speakers, and when factors such as the frequency of the biased speakers in the community, their positions in the communicative network or the topology of the network itself change, sound change may rapidly follow as a self-reinforcing network-level phenomenon, akin to a phase transition. Thus, inter-speaker variation in structured and dynamic communicative networks may couple the initiation and actuation of sound change.

Abstract

Linguistic diversity is affected by multiple factors, but it is usually assumed that variation in the anatomy of our speech organs
plays no explanatory role. Here we use realistic computer models of the human speech organs to test whether inter-individual
and inter-group variation in the shape of the hard palate (the bony roof of the mouth) affects acoustics of speech sounds. Based
on 107 midsagittal MRI scans of the hard palate of human participants, we modelled with high accuracy the articulation of a set
of five cross-linguistically representative vowels by agents learning to produce speech sounds. We found that different hard
palate shapes result in subtle differences in the acoustics and articulatory strategies of the produced vowels, and that these
individual-level speech idiosyncrasies are amplified by the repeated transmission of language across generations. Therefore,
we suggest that, besides culture and environment, quantitative biological variation can be amplified, also influencing language.

Abstract

Attention deficit/hyperactivity disorder (ADHD) is a highly heritable childhood behavioral disorder affecting 5% of children and 2.5% of adults. Common genetic variants contribute substantially to ADHD susceptibility, but no variants have been robustly associated with ADHD. We report a genome-wide association meta-analysis of 20,183 individuals diagnosed with ADHD and 35,191 controls that identifies variants surpassing genome-wide significance in 12 independent loci, finding important new information about the underlying biology of ADHD. Associations are enriched in evolutionarily constrained genomic regions and loss-of-function intolerant genes and around brain-expressed regulatory marks. Analyses of three replication studies: a cohort of individuals diagnosed with ADHD, a self-reported ADHD sample and a meta-analysis of quantitative measures of ADHD symptoms in the population, support these findings while highlighting study-specific differences on genetic overlap with educational attainment. Strong concordance with GWAS of quantitative population measures of ADHD symptoms supports that clinical diagnosis of ADHD is an extreme expression of continuous heritable traits.

Abstract

This chapter discusses the genetic foundations of the human capacity for language. It reviews the molecular structure of the genome and the complex molecular mechanisms that allow genetic information to influence multiple levels of biology. It goes on to describe the active regulation of genes and their formation of complex genetic pathways that in turn control the cellular environment and function. At each of these levels, examples of genes and genetic variants that may influence the human capacity for language are given. Finally, it discusses the value of using animal models to understand the genetic underpinnings of speech and language. From this chapter will emerge the complexity of the genome in action and the multidisciplinary efforts that are currently made to bridge the gap between genetics and language.

Abstract

Do interlocutors adjust their conversational strategies to the specific contextual demands of a given situation? Prior studies have yielded conflicting results, making it unclear how strategies vary with demands. We combine insights from qualitative and quantitative approaches in a within-participant experimental design involving two different contexts: spontaneously occurring conversations (SOC) and task-oriented conversations (TOC). We systematically assess backchanneling, other-repair and linguistic alignment. We find that SOC exhibit a higher number of backchannels, a reduced and more generic repair format and higher rates of lexical and syntactic alignment. TOC are characterized by a high number of specific repairs and a lower rate of lexical and syntactic alignment. However, when alignment occurs, more linguistic forms are aligned. The findings show that conversational strategies adapt to specific contextual demands.

Abstract

This paper investigates when and how children figure out the force of modals: that possibility modals (e.g., can/might) express possibility, and necessity modals (e.g., must/have to) express necessity. Modals raise a classic subset problem: given that necessity entails possibility, what prevents learners from hypothesizing possibility meanings for necessity modals? Three solutions to such subset problems can be found in the literature: the first is for learners to rely on downward-entailing (DE) environments (Gualmini and Schwarz in J. Semant. 26(2):185–215, 2009); the second is a bias for strong (here, necessity) meanings; the third is for learners to rely on pragmatic cues stemming from the conversational context (Dieuleveut et al. in Proceedings of the 2019 Amsterdam colloqnium, pp. 111–122, 2019a; Rasin and Aravind in Nat. Lang. Semant. 29:339–375, 2020). This paper assesses the viability of each of these solutions by examining the modals used in speech to and by 2-year-old children, through a combination of corpus studies and experiments testing the guessability of modal force based on their context of use. Our results suggest that, given the way modals are used in speech to children, the first solution is not viable and the second is unnecessary. Instead, we argue that the conversational context in which modals occur is highly informative as to their force and sufficient, in principle, to sidestep the subset problem. Our child results further suggest an early mastery of possibility—but not necessity—modals and show no evidence for a necessity bias.

Abstract

To investigate how orthography and semantics interact during bilingual visual word recognition, Dutch–English bilinguals made lexical decisions in two masked priming experiments. Dutch primes and English targets were presented that were either neighbour cognates (boek – BOOK), noncognate translations (kooi – CAGE), orthographically related neighbours (neus – NEWS), or unrelated words (huid - COAT). Prime durations of 50 ms (Experiment 1) and 83 ms (Experiment 2) led to similar result patterns. Both experiments reported a large cognate facilitation effect, a smaller facilitatory noncognate translation effect, and the absence of inhibitory orthographic neighbour effects. These results indicate that cognate facilitation is in large part due to orthographic-semantic resonance. Priming results for each condition were simulated well (all r's >.50) by Multilink+, a recent computational model for word retrieval. Limitations to the role of lateral inhibition in bilingual word recognition are discussed.

Abstract

Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Consortium to examine age‐related trajectories inferred from cross‐sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3–90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter‐individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age‐related morphometric patterns.

Abstract

Continuers —words like mm, mmhm, uhum and the like— are among the most frequent types of responses in conversation. They play a key role in joint action coordination by showing positive evidence of understanding and scaffolding narrative delivery. Here we investigate the hypothesis that their functional importance along with their conversational ecology places selective pressures on their form and may lead to cross-linguistic similarities through convergent cultural evolution. We compare continuer tokens in linguistically diverse conversational corpora and find languages make available highly similar forms. We then approach the causal mechanism of convergent cultural evolution using exemplar modelling, simulating the process by which a combination of effort minimization and functional specialization may push continuers to a particular region of phonological possibility space. By combining comparative linguistics and computational modelling we shed new light on the question of how language structure is shaped by and for social interaction.

Abstract

Informal social interaction is the primordial home of human language. Linguistically diverse conversational corpora are an important and largely untapped resource for computational linguistics and language technology. Through the efforts of a worldwide language documentation movement, such corpora are increasingly becoming available. We show how interactional data from 63 languages (26 families) harbours insights about turn-taking, timing, sequential structure and social action, with implications for language technology, natural language understanding, and the design of conversational interfaces. Harnessing linguistically diverse conversational corpora will provide the empirical foundations for flexible, localizable, humane language technologies of the future.

Abstract

This chapter makes the case for ‘ideophone’ as a comparative concept: a notion that captures a recurrent typological pattern and provides a template for understanding language-specific phenomena that prove similar. It revises an earlier definition to account for the observation that ideophones typically form an open lexical class, and uses insights from canonical typology to explore the larger typological space. According to the resulting definition, a canonical ideophone is a member of an open lexical class of marked words that depict sensory imagery. The five elements of this definition can be seen as dimensions that together generate a possibility space to characterise cross-linguistic diversity in depictive means of expression. This approach allows for the systematic comparative treatment of ideophones and ideophone-like phenomena. Some phenomena in the larger typological space are discussed to demonstrate the utility of the approach: phonaesthemes in European languages, specialised semantic classes in West-Chadic, diachronic diversions in Aslian, and depicting constructions in signed languages.

Abstract

Under what circumstances do languages die? Why has their “mortality rate” increased dramatically in the recent past? What “causes of death” can be identified for historical cases, to what extent are these generalizable, and how can they be captured in an explanatory theory? In pursuing these questions, it becomes apparent that in typical cases of language death various causes tend to interact in multiple ways. Speakers’ attitudes towards their language play a critical role in all of this. Existing categorial taxonomies do not succeed in modeling the complex relationships between these factors. Therefore, an alternative, dimensional approach is called for to more adequately address (and counter) the causes of language death in a given scenario.

Abstract

Relationships among laurasiatherian clades represent one of the most highly disputed topics in mammalian phylogeny. In this study, we attempt to disentangle laurasiatherian interordinal relationships using two independent genome-level approaches: (1) quantifying retrotransposon presence/absence patterns, and (2) comparisons of exon datasets at the levels of nucleotides and amino acids. The two approaches revealed contradictory phylogenetic signals, possibly due to a high level of ancestral incomplete lineage sorting. The positions of Eulipotyphla and Chiroptera as the first and second earliest divergences were consistent across the approaches. However, the phylogenetic relationships of Perissodactyla, Cetartiodactyla, and Ferae, were contradictory. While retrotransposon insertion analyses suggest a clade with Cetartiodactyla and Ferae, the exon dataset favoured Cetartiodactyla and Perissodactyla. Future analyses of hitherto unsampled laurasiatherian lineages and synergistic analyses of retrotransposon insertions, exon and conserved intron/intergenic sequences might unravel the conflicting patterns of relationships in this major mammalian clade.

Abstract

People readily generalize knowledge to novel domains and stimuli. We present a theory, instantiated in a computational model, based on the idea that cross-domain generalization in humans is a case of analogical inference over structured (i.e., symbolic) relational representations. The model is an extension of the Learning and Inference with Schemas and Analogy (LISA; Hummel & Holyoak, 1997, 2003) and Discovery of Relations by Analogy (DORA; Doumas et al., 2008) models of relational inference and learning. The resulting model learns both the content and format (i.e., structure) of relational representations from nonrelational inputs without supervision, when augmented with the capacity for reinforcement learning it leverages these representations to learn about individual domains, and then generalizes to new domains on the first exposure (i.e., zero-shot learning) via analogical inference. We demonstrate the capacity of the model to learn structured relational representations from a variety of simple visual stimuli, and to perform cross-domain generalization between video games (Breakout and Pong) and between several psychological tasks. We demonstrate that the model’s trajectory closely mirrors the trajectory of children as they learn about relations, accounting for phenomena from the literature on the development of children’s reasoning and analogy making. The model’s ability to generalize between domains demonstrates the flexibility afforded by representing domains in terms of their underlying relational structure, rather than simply in terms of the statistical relations between their inputs and outputs.

Abstract

Reading and writing are crucial life skills but roughly one in ten children are affected by dyslexia, which can persist into adulthood. Family studies of dyslexia suggest heritability up to 70%, yet few convincing genetic markers have been found. Here we performed a genome-wide association study of 51,800 adults self-reporting a dyslexia diagnosis and 1,087,070 controls and identified 42 independent genome-wide significant loci: 15 in genes linked to cognitive ability/educational attainment, and 27 new and potentially more specific to dyslexia. We validated 23 loci (13 new) in independent cohorts of Chinese and European ancestry. Genetic etiology of dyslexia was similar between sexes, and genetic covariance with many traits was found, including ambidexterity, but not neuroanatomical measures of language-related circuitry. Dyslexia polygenic scores explained up to 6% of variance in reading traits, and might in future contribute to earlier identification and remediation of dyslexia.

Abstract

Visual information conveyed by iconic hand gestures and visible speech can enhance speech comprehension under adverse listening conditions for both native and non‐native listeners. However, how a listener allocates visual attention to these articulators during speech comprehension is unknown. We used eye‐tracking to investigate whether and how native and highly proficient non‐native listeners of Dutch allocated overt eye gaze to visible speech and gestures during clear and degraded speech comprehension. Participants watched video clips of an actress uttering a clear or degraded (6‐band noise‐vocoded) action verb while performing a gesture or not, and were asked to indicate the word they heard in a cued‐recall task. Gestural enhancement was the largest (i.e., a relative reduction in reaction time cost) when speech was degraded for all listeners, but it was stronger for native listeners. Both native and non‐native listeners mostly gazed at the face during comprehension, but non‐native listeners gazed more often at gestures than native listeners. However, only native but not non‐native listeners' gaze allocation to gestures predicted gestural benefit during degraded speech comprehension. We conclude that non‐native listeners might gaze at gesture more as it might be more challenging for non‐native listeners to resolve the degraded auditory cues and couple those cues to phonological information that is conveyed by visible speech. This diminished phonological knowledge might hinder the use of semantic information that is conveyed by gestures for non‐native compared to native listeners. Our results demonstrate that the degree of language experience impacts overt visual attention to visual articulators, resulting in different visual benefits for native versus non‐native listeners.

Abstract

We here demonstrate that face-to-face spatial orientation induces a special ‘social mode’ for neurocognitive processing during conversation, even in the absence of visibility. Participants conversed face-to-face, face-to-face but visually occluded, and back-to-back to tease apart effects caused by seeing visual communicative signals and by spatial orientation. Using dual-EEG, we found that 1) listeners’ brains engaged more strongly while conversing in face-to-face than back-to-back, irrespective of the visibility of communicative signals, 2) listeners attended to speech more strongly in a back-to-back compared to a face-to-face spatial orientation without visibility; visual signals further reduced the attention needed; 3) the brains of interlocutors were more in sync in a face-to-face compared to a back-to-back spatial orientation, even when they could not see each other; visual signals further enhanced this pattern. Communicating in face-to-face spatial orientation is thus sufficient to induce a special ‘social mode’ which fine-tunes the brain for neurocognitive processing in conversation.

Abstract

Listeners are often challenged by adverse listening conditions during language comprehension induced by external factors, such as noise, but also internal factors, such as being a non-native listener. Visible cues, such as semantic information conveyed by iconic gestures, can enhance language comprehension in such situations. Using magnetoencephalography (MEG) we investigated whether spatiotemporal oscillatory dynamics can predict a listener's benefit of iconic gestures during language comprehension in both internally (non-native versus native listeners) and externally (clear/degraded speech) induced adverse listening conditions. Proficient non-native speakers of Dutch were presented with videos in which an actress uttered a degraded or clear verb, accompanied by a gesture or not, and completed a cued-recall task after every video. The behavioral and oscillatory results obtained from non-native listeners were compared to an MEG study where we presented the same stimuli to native listeners (Drijvers et al., 2018a). Non-native listeners demonstrated a similar gestural enhancement effect as native listeners, but overall scored significantly slower on the cued-recall task. In both native and non-native listeners, an alpha/beta power suppression revealed engagement of the extended language network, motor and visual regions during gestural enhancement of degraded speech comprehension, suggesting similar core processes that support unification and lexical access processes. An individual's alpha/beta power modulation predicted the gestural benefit a listener experienced during degraded speech comprehension. Importantly, however, non-native listeners showed less engagement of the mouth area of the primary somatosensory cortex, left insula (beta), LIFG and ATL (alpha) than native listeners, which suggests that non-native listeners might be hindered in processing the degraded phonological cues and coupling them to the semantic information conveyed by the gesture. Native and non-native listeners thus demonstrated similar yet distinct spatiotemporal oscillatory dynamics when recruiting visual cues to disambiguate degraded speech.

Abstract

Este trabalho descreve e fundamenta a ortografia da língua Awetí (Tupí, Alto Xingu/mt), com base na análise da estrutura fonológica e gramatical do Awetí. A ortografia é resultado de um longo trabalho colaborativo entre os três autores, iniciado em 1998. Ela não define apenas um alfabeto (a representação das vogais e das consoantes da língua), mas também aborda a variação interna, ressilabificação, lenição, palatalização e outros processos (morfo‑)fonológicos. Tanto a representação escrita da oclusiva glotal, quanto as consequências ortográficas da harmonia nasal receberam uma atenção especial. Apesar de o acento lexical não ser ortograficamente marcado em Awetí, a grande maioria dos afixos e partículas é abordada considerando o acento e sua interação com morfemas adjacentes, ao mesmo tempo determinando as palavras ortográficas. Finalmente foi estabelecida a ordem alfabética em que dígrafos são tratados como sequências de letras, já a oclusiva glotal ⟨ʼ⟩ é ignorada, facilitando o aprendizado do Awetí. A ortografia tal como descrita aqui tem sido usada por aproximadamente dez anos na escola para a alfabetização em Awetí, com bons resultados obtidos. Acreditamos que vários dos argumentos aqui levantados podem ser produtivamente transferidos para outras línguas com fenômenos semelhantes (a oclusiva glotal como consoante, harmonia nasal, assimilação morfo-fonológica, etc.).

Abstract

The number of individuals affected by traumatic brain injury (TBI) is growing globally. TBIs may cause a range of physical, cognitive, and psychiatric deficits that can negatively impact employment, academic attainment, community independence, and interpersonal relationships. Although there has been a significant decrease in the number of injury related deaths over the past several decades, there has been no corresponding reduction in injury related disability over the same time period. We propose that patient registries with large, representative samples and rich multidimensional and longitudinal data have tremendous value in advancing basic and translational research and in capturing, characterizing, and predicting individual differences in deficit profile and outcomes. Patient registries, together with recent theoretical and methodological advances in analytic approaches and neuroscience, provide powerful tools for brain injury research and for leveraging the heterogeneity that has traditionally been cited as a barrier inhibiting progress in treatment research and clinical practice. We report on our experiences, and challenges, in developing and maintaining our own patient registry. We conclude by pointing to some future opportunities for discovery that are afforded by a registry model.

Abstract

Motricity is the most commonly affected ability after a stroke. While many clinical studies attempt to predict motor symptoms at different chronic time points after a stroke, longitudinal acute-to-chronic studies remain scarce. Taking advantage of recent advances in mapping brain disconnections, we predict motor outcomes in 62 patients assessed longitudinally two weeks, three months, and one year after their stroke. Results indicate that brain disconnection patterns accurately predict motor impairments. However, disconnection patterns leading to impairment differ between the three-time points and between left and right motor impairments. These results were cross-validated using resampling techniques. In sum, we demonstrated that while some neuroplasticity mechanisms exist changing the structure–function relationship, disconnection patterns prevail when predicting motor impairment at different time points after stroke.

Abstract

Understanding cetacean distribution is essential for conservation planning and decision-making, particularly in regions subject to rapid environmental changes. Nevertheless, information on their spatiotemporal distribution is commonly limited, especially from remote areas. Species distribution models (SDMs) are powerful tools, relating species occurrences to environmental variables to predict the species' potential distribution. This study aims at using presence-only SDMs (MaxEnt) to identify suitable habitats for fin whales (Balaenoptera physalus) on their Nordic and Barents Seas feeding grounds. We used spatial-block cross-validation to tune MaxEnt parameters and evaluate model performance using spatially independent testing data. We considered spatial sampling bias correction using four methods. Important environmental variables were distance to shore and sea ice edge, variability of sea surface temperature and sea surface salinity, and depth. Suitable fin whale habitats were predicted along the west coast of Svalbard, between Svalbard and the eastern Norwegian Sea, coastal areas off Iceland and southern East Greenland, and along the Knipovich Ridge to Jan Mayen. Results support that presence-only SDMs are effective tools to predict cetacean habitat suitability, particularly in remote areas like the Arctic Ocean. SDMs constitute a cost-effective method for targeting future surveys and identifying top priority sites for conservation measures.

Abstract

It is often argued that narratives improve social cognition, either by appealing to social-cognitive abilities as we engage with the story world and its characters, or by conveying social knowledge. Empirical studies have found support for both a correlational and a causal link between exposure to (literary, fictional) narratives and social cognition. However, a series of failed replications has cast doubt on the robustness of these claims. Here, we review the existing empirical literature and identify open questions and challenges. An important conclusion of the review is that previous research has given too little consideration to the diversity of narratives, readers, and social-cognitive processes involved in the social-cognitive potential of narratives. We therefore establish a research agenda, proposing that future research should focus on (1) the specific text characteristics that drive the social-cognitive potential of narratives, (2) the individual differences between readers with respect to their sensitivity to this potential, and (3) the various aspects of social cognition that are potentially affected by reading narratives. Our recommendations can guide the design of future studies that will help us understand how, for whom, and in what respect exposure to narratives can advantage social cognition.

Abstract

Previous studies have shown that speakers align their speech to each other at multiple linguistic levels. This study investigates whether alignment is mostly the result of priming from the immediately preceding
speech materials, focussing on pitch and articulation rate (AR). Native Dutch speakers completed sentences, first by themselves (pre-test), then in alternation with Confederate 1 (Round 1), with Confederate 2 (Round 2), with Confederate 1 again
(Round 3), and lastly by themselves again (post-test). Results indicate that participants aligned to the confederates and that this alignment lasted during the post-test. The confederates’ directly preceding sentences were not good predictors for the participants’ pitch and AR. Overall, the results indicate that alignment is more of a global effect than a local priming effect.

Abstract

We present a dataset of behavioural and fMRI observations acquired in the context of humans involved in multimodal referential communication. The dataset contains audio/video and motion-tracking recordings of face-to-face, task-based communicative interactions in Dutch, as well as behavioural and neural correlates of participants’ representations of dialogue referents. Seventy-one pairs of unacquainted participants performed two interleaved interactional tasks in which they described and located 16 novel geometrical objects (i.e., Fribbles) yielding spontaneous interactions of about one hour. We share high-quality video (from three cameras), audio (from head-mounted microphones), and motion-tracking (Kinect) data, as well as speech transcripts of the interactions. Before and after engaging in the face-to-face communicative interactions, participants’ individual representations of the 16 Fribbles were estimated. Behaviourally, participants provided a written description (one to three words) for each Fribble and positioned them along 29 independent conceptual dimensions (e.g., rounded, human, audible). Neurally, fMRI signal evoked by each Fribble was measured during a one-back working-memory task. To enable functional hyperalignment across participants, the dataset also includes fMRI measurements obtained during visual presentation of eight animated movies (35 minutes total). We present analyses for the various types of data demonstrating their quality and consistency with earlier research. Besides high-resolution multimodal interactional data, this dataset includes different correlates of communicative referents, obtained before and after face-to-face dialogue, allowing for novel investigations into the relation between communicative behaviours and the representational space shared by communicators. This unique combination of data can be used for research in neuroscience, psychology, linguistics, and beyond.

Abstract

The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures (word reading, nonword reading, spelling, phoneme awareness, and nonword repetition) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 × 10−8) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.

Abstract

Genetic investigations of people with impaired development of spoken language provide windows into key aspects of human biology. Over 15 years after FOXP2 was identified, most speech and language impairments remain unexplained at the molecular level. We sequenced whole genomes of nineteen unrelated individuals diagnosed with childhood apraxia of speech, a rare disorder enriched for causative mutations of large effect. Where DNA was available from unaffected parents, we discovered de novo mutations, implicating genes, including CHD3, SETD1A and WDR5. In other probands, we identified novel loss-of-function variants affecting KAT6A, SETBP1, ZFHX4, TNRC6B and MKL2, regulatory genes with links to neurodevelopment. Several of the new candidates interact with each other or with known speech-related genes. Moreover, they show significant clustering within a single co-expression module of genes highly expressed during early human brain development. This study highlights gene regulatory pathways in the developing brain that may contribute to acquisition of proficient speech.

Abstract

We conducted four experiments to investigate the specificity of perceptual adjustments made to unusual speech sounds. Dutch listeners heard a female talker produce an ambiguous fricative [?] (between [f] and [s]) in [f]- or [s]-biased lexical contexts. Listeners with [f]-biased exposure (e.g., [witlo?]; from witlof, “chicory”; witlos is meaningless) subsequently categorized more sounds on an [εf]–[εs] continuum as [f] than did listeners with [s]-biased exposure. This occurred when the continuum was based on the exposure talker's speech (Experiment 1), and when the same test fricatives appeared after vowels spoken by novel female and male talkers (Experiments 1 and 2). When the continuum was made entirely from a novel talker's speech, there was no exposure effect (Experiment 3) unless fricatives from that talker had been spliced into the exposure talker's speech during exposure (Experiment 4). We conclude that perceptual learning about idiosyncratic speech is applied at a segmental level and is, under these exposure conditions, talker specific.

Abstract

The most basic question for the study of morphology and the mental lexicon is whether or not words are _decomposed_: informally, this is the question of whether words are represented (and processed) in terms of some kind of smaller units; that is, broken down into constituent parts. Formally, what it means to represent or process a word as decomposed or not turns out to be quite complex. One of the basic lines of division in the field classifies approaches according to whether they decompose all “complex” words (“Full Decomposition”), or none (“Full Listing”), or some but not all, according to some criterion (typical of “Dual-Route” models). However, if we are correct, there are at least three senses in which an approach might be said to be decompositional or not, with the result that ongoing discussions of what appears to be a single large issue might not always be addressing the same distinction. Put slightly differently, there is no single question of decomposition. Instead, there are independent but related questions that define current research. Our goal here is to identify this finer-grained set of questions, as they are the ones that should assume a central place in the study of morphological and lexical representation.

Abstract

Central to cultural, social, and conceptual life are cognitive arti-facts, the perceptible structures which populate our world and mediate our navigation of it, complementing, enhancing, and altering available affordances for the problem-solving challenges of everyday life. Much work in this domain has concentrated on technological artifacts, especially manual tools and devices and the conceptual and communicative tools of literacy and diagrams. Recent research on hand gestures and other bodily movements which occur during speech shows that the human body serves a number of the functions of "cognitive technologies," affording the special cognitive advantages claimed to be associated exclusively with enduring (e.g., printed or drawn) diagrammatic representations. The issue is explored with reference to extensive data from video-recorded interviews with speakers of Lao in Vientiane, Laos, which show integration of verbal descriptions with complex spatial representations akin to diagrams. The study has implications both for research on cognitive artifacts (namely, that the body is a visuospatial representational resource not to be overlooked) and for research on ethnogenealogical knowledge (namely, that hand gestures reveal speakers' conceptualizations of kinship structure which are of a different nature to and not necessarily retrievable from the accompanying linguistic code).

Abstract

How do people answer polar questions? In this fourteen-language study of answers to questions in conversation, we compare the two main strategies; first, interjection-type answers such as uh-huh (or equivalents yes, mm, head nods, etc.), and second, repetition-type answers that repeat some or all of the question. We find that all languages offer both options, but that there is a strong asymmetry in their frequency of use, with a global preference for interjection-type answers. We propose that this preference is motivated by the fact that the two options are not equivalent in meaning. We argue that interjection-type answers are intrinsically suited to be the pragmatically unmarked, and thus more frequent, strategy for confirming polar questions, regardless of the language spoken. Our analysis is based on the semantic-pragmatic profile of the interjection-type and repetition-type answer strategies, in the context of certain asymmetries inherent to the dialogic speech act structure of question–answer sequences, including sequential agency and thematic agency. This allows us to see possible explanations for the outlier distributions found in ǂĀkhoe Haiǁom and Tzeltal.

Abstract

Over the decades, high-intensity language learners scattered over the globe referred to as “hyperpolyglots” have undertaken a natural experiment into the limits of learning and acquiring proficiencies in multiple languages. This chapter details several ways in which hyperpolyglots are relevant to research on aptitude. First, historical hyperpolyglots Cardinal Giuseppe Mezzofanti, Emil Krebs, Elihu Burritt, and Lomb Kató are described in terms of how they viewed their own exceptional outcomes. Next, I draw on results from an online survey with 390 individuals to explore how contemporary hyperpolyglots consider the explanatory value of aptitude. Third, the challenges involved in studying the genetic basis of hyperpolyglottism (and by extension of language aptitude) are discussed. This mosaic of data is meant to inform the direction of future aptitude research that takes hyperpolyglots, one type of exceptional language learner and user, into account.

Abstract

Previous research has shown that the production of morphologically complex words in isolation is affected by the properties of morphologically, phonologically, or semantically similar words stored in the mental lexicon. We report five experiments with Dutch speakers that show that reading an inflectional word form in its linguistic context is also affected by analogical sets of formally similar words. Using the self-paced reading technique, we show in Experiments 1-3 that an incorrectly spelled suffix delays readers less if the incorrect spelling is in line with the spelling of verbal suffixes in other inflectional forms of the same verb. In Experiments 4 and 5, our use of the self-paced reading technique shows that formally similar words with different stems affect the reading of incorrect suffixal allomorphs on a given stem. These intra- and interparadigmatic effects in reading may be due to online processes or to the storage of incorrect forms resulting from analogical effects in production.

Abstract

The oldest of the Celtic language family, Irish differs considerably from English, notably with respect to word order and case marking. In spite of differences in surface constituent structure, less restricted accounts of bilingual shared syntax predict that processing datives and passives in Irish should prime the production of their English equivalents. Furthermore, this cross-linguistic influence should be sensitive to L2 proficiency, if shared structural representations are assumed to develop over time. In Experiment 1, we investigated cross-linguistic structural priming from Irish to English in 47 bilingual adolescents who are educated through Irish. Testing took place in a classroom setting, using written primes and written sentence generation. We found that priming for prepositional-object (PO) datives was predicted by self-rated Irish (L2) proficiency, in line with previous studies. In Experiment 2, we presented translations of the materials to an English-educated control group (n=54). We found a within-language priming effect for PO datives, which was not modulated by English (L1) proficiency. Our findings are compatible with current theories of bilingual language processing and L2 syntactic acquisition.

Abstract

This paper shows that the dictation task, a well-
known testing instrument in language education, has
untapped potential as a research tool for studying
speech perception. We describe how transcriptions
can be scored on measures of lexical, orthographic,
phonological, and semantic similarity to target
phrases to provide comprehensive information about
accuracy at different processing levels. The former
three measures are automatically extractable,
increasing objectivity, and the middle two are
gradient, providing finer-grained information than
traditionally used. We evaluate the measures in an
English dictation task featuring phonetically reduced
continuous speech. Whereas the lexical and
orthographic measures emphasize listeners’ word
identification difficulties, the phonological measure
demonstrates that listeners can often still recover
phonological features, and the semantic measure
captures their ability to get the gist of the utterances.
Correlational analyses and a discussion of practical
and theoretical considerations show that combining
multiple measures improves the dictation task’s
utility as a research tool.

Abstract

Lexically guided perceptual learning has traditionally been studied with ambiguous consonant sounds to which native listeners are exposed in a purely receptive listening context. To extend previous research, we investigate whether lexically guided learning applies to a vowel shift encountered by non-native listeners in an interactive dialogue. Dutch participants played a two-player game in English in either a control condition, which contained no evidence for a vowel shift, or a lexically constraining condition, in which onscreen lexical information required them to re-interpret their interlocutor’s /ɪ/ pronunciations as representing /ε/. A phonetic categorization pre-test and post-test were used to assess whether the game shifted listeners’ phonemic boundaries such that more of the /ε/-/ɪ/ continuum came to be perceived as /ε/. Both listener groups showed an overall post-test shift toward /ɪ/, suggesting that vowel perception may be sensitive to directional biases related to properties of the speaker’s vowel space. Importantly, listeners in the lexically constraining condition made relatively more post-test /ε/ responses than the control group, thereby exhibiting an effect of lexically guided adaptation. The results thus demonstrate that non-native listeners can adjust their phonemic boundaries on the basis of lexical information to accommodate a vowel shift learned in interactive conversation.

Abstract

When speaking in any language, speakers must conceptualize what they want to say before they can formulate and articulate their message. We present two experiments employing a novel experimental paradigm in which the formulating and articulating stages of speech production were kept identical across conditions of differing conceptualizing difficulty. We tracked the effect of difficulty in conceptualizing during the generation of speech (Experiment 1) and during the abandonment and regeneration of speech (Experiment 2) on speaking fluency by Dutch native speakers in their first (L1) and second (L2) language (English). The results showed that abandoning and especially regenerating a speech plan taxes the speaker, leading to disfluencies. For most fluency measures, the increases in disfluency were similar across L1 and L2. However, a significant interaction revealed that abandoning and regenerating a speech plan increases the time needed to solve conceptual difficulties while speaking in the L2 to a greater degree than in the L1. This finding supports theories in which cognitive resources for conceptualizing are shared with those used for later stages of speech planning. Furthermore, a practical implication for language assessment is that increasing the conceptual difficulty of speaking tasks should be considered with caution.

Abstract

The brain has the extraordinary capacity to construct predictive models of the environment by internalizing statistical regularities in the sensory inputs. The resulting sensory expectations shape how we perceive and react to the world; at the neural level, this relates to decreased neural responses to expected than unexpected stimuli (‘expectation suppression’). Crucially, expectations may need revision as context changes. However, existing research has often neglected this issue. Further, it is unclear whether contextual revisions apply selectively to expectations relevant to the task at hand, hence serving adaptive behaviour. The present fMRI study examined how contextual visual expectations spread throughout the cortical hierarchy as participants update their beliefs. We created a volatile environment with two state spaces presented over separate contexts and controlled by an independent contextualizing signal. Participants attended a training session before scanning to learn contextual temporal associations among pairs of object images. The fMRI experiment then tested for the emergence of contextual expectation suppression in two separate tasks, respectively with task-relevant and task-irrelevant expectations. Behavioural and neural effects of contextual expectation emerged progressively across the cortical hierarchy as participants attuned themselves to the context: expectation suppression appeared first in the insula, inferior frontal gyrus and posterior parietal cortex, followed by the ventral visual stream, up to early visual cortex. This applied selectively to task-relevant expectations. Taken together, the present results suggest that an insular and frontoparietal executive control network may guide the flexible deployment of contextual sensory expectations for adaptive behaviour in our complex and dynamic world.

Abstract

A large literature in social neuroscience has associated the medial prefrontal cortex (mPFC) with the processing of self-related information. However, only recently have social neuroscience studies begun to consider the large behavioral literature showing a strong self-positivity bias, and these studies have mostly focused on its correlates during self-related judgments and decision making. We carried out a functional MRI (fMRI) study to ask whether the mPFC would show effects of the self-positivity bias in a paradigm that probed participants’ self-concept without any requirement of explicit self-judgment. We presented social vignettes that were either self-relevant or non-self-relevant with a neutral, positive, or negative outcome described in the second sentence. In previous work using event-related potentials, this paradigm has shown evidence of a self-positivity bias that influences early stages of semantically processing incoming stimuli. In the present fMRI study, we found evidence for this bias within the mPFC: an interaction between self-relevance and valence, with only positive scenarios showing a self vs other effect within the mPFC. We suggest that the mPFC may play a role in maintaining a positively-biased self-concept and discuss the implications of these findings for the social neuroscience of the self and the role of the mPFC.

Abstract

This study focuses on the main work of Gilbert Ryle, “The concept of Mind” (1949). Here the author demolishes what he refers to as the cartesian dogma of “the ghost in the machine”, highlighting the absurdity of categorical ordering in dualist systems, where mental activities are explained as separate from physical actions. Surprisingly, the Italian translator of “The concept of Mind”, Ferruccio Rossi-Landi, missed this key aspect of Ryle’s work, writing up what resulted into a significantly misleading translation. This can be clearly noticed from the title already: “Lo spirito come comportamento” [The ghost as behavior]. This erroneous translation affected the interpretation of “The concept of Mind” as a mere study on behavioral reductionism in Italy. Here, I argue in favor of the originality of Ryle’s approach in pointing out the socio-cultural dynamics as the non - physical dimensions of the human mind, and yet, linked to the human brain. In doing so, I trace the crucial influence of Wittgenstein’s philosophy in Ryle’s interpretation of the concept of mind, which helps in grasping a better understanding of his work. Wittgenstein’s influence shows clearly in Ryle’s conceptual operation of grounding the acquisition of dispositions and competences - which ultimately define the rational subjects as rational agents – in the shared background of social and cultural dynamics. In a nutshell, this social dimension is the defining characteristic of the human mind and of all human actions in Ryle’s philosophy. As Ryle argues in “On thinking” (1979), this intrinsic quality of human actions can reveal itself in actions that one performs absent-mindendly in everyday life, as well as in more complex ones: for instance, when the mind reflects upon itself.

Abstract

Developmental disorders affecting speech and language are highly heritable, but very little is currently understood about the neuromolecular mechanisms that underlie these traits. Integration of data from diverse research areas, including linguistics, neuropsychology, neuroimaging, genetics, molecular neuroscience, developmental biology, and evolutionary anthropology, is becoming essential for unraveling the relevant pathways. Recent studies of the FOXP2 gene provide a case in point. Mutation of FOXP2 causes a rare form of speech and language disorder, and the gene appears to be a crucial regulator of embryonic development for several tissues. Molecular investigations of the central nervous system indicate that the gene may be involved in establishing and maintaining connectivity of corticostriatal and olivocerebellar circuits in mammals. Notably, it has been shown that FOXP2 was subject to positive selection in recent human evolution. Consideration of findings from multiple levels of analysis demonstrates that FOXP2 cannot be characterized as “the gene for speech,” but rather as one critical piece of a complex puzzle. This story gives a flavor of what is to come in this field and indicates that anyone expecting simple explanations of etiology or evolution should be prepared for some intriguing surprises.

Abstract

FOXP2 mutations cause a speech and language disorder, raising interest in potential roles of this gene in human evolution. A new study re-evaluates genomic variation at the human FOXP2 locus but finds no evidence of recent adaptive evolution.

Abstract

Dent's disease, an X-linked renal tubular disorder, is a form of Fanconi syndrome which is characterized by proteinuria, hypercalciuria, nephrocalcinosis, kidney stones and renal failure. Previous studies localised the gene responsible to Xp11.22, within a microdeletion involving the hypervariable locus DXS255. Further analysis using new probes which flank this locus indicate that the deletion is less than 515 kb. A 185 kb YAC containing DXS255 was used to screen a cDNA library from adult kidney in order to isolate coding sequences falling within the deleted region which may be implicated in the disease aetiology. We identified two clones which are evolutionarily conserved, and detect a 9.5 kb transcript which is expressed predominantly in the kidney. Sequence analysis of 780 bp of ORF from the clones suggests that the identified gene, termed hCIC-K2, encodes a new member of the CIC family of voltage-gated chloride channels. Genomic fragments detected by the cDNA clones are completely absent in patients who have an associated microdeletion. On the basis of the expression pattern, proposed function and deletion mapping, hCIC-K2 is a strong candidate for Dent's disease.

Abstract

Learning to talk is one of the most important milestones in human development, but we still have only a limited understanding of the way in which the process occurs. It normally takes just a few years to go from babbling newborn to fluent communicator. During this period, the child learns to produce a rich array of speech sounds through intricate control of articulatory muscles, assembles a vocabulary comprising thousands of words, and deduces the complicated structural rules that permit construction of meaningful sentences. All of this (and more) is achieved with little conscious effort.

Abstract

Event-related potentials (ERPs) provide a window into how the brain is processing language. Here, we propose a theory that argues that ERPs such as the N400 and P600 arise as side effects of an error-based learning mechanism that explains linguistic adaptation and language learning. We instantiated this theory in a connectionist model that can simulate data from three studies on the N400 (amplitude modulation by expectancy, contextual constraint, and sentence position), five studies on the P600 (agreement, tense, word category, subcategorization and garden-path sentences), and a study on the semantic P600 in role reversal anomalies. Since ERPs are learning signals, this account explains adaptation of ERP amplitude to within-experiment frequency manipulations and the way ERP effects are shaped by word predictability in earlier sentences. Moreover, it predicts that ERPs can change over language development. The model provides an account of the sensitivity of ERPs to expectation mismatch, the relative timing of the N400 and P600, the semantic nature of the N400, the syntactic nature of the P600, and the fact that ERPs can change with experience. This approach suggests that comprehension ERPs are related to sentence production and language acquisition mechanisms

Abstract

Like many Indigenous Australian languages, Murrinhpatha has flexible word order with no apparent configurational syntax. We analyzed an experimental corpus of Murrinhpatha utterances for associations between different thematic role orders, intonational phrasing patterns and pitch downtrends. We found that initial constituents (Agents or Patients) tend to carry the highest pitch targets (HiF0), followed by patterns of downstep and declination. Sentence-final verbs always have lower Hif0 values than either initial or medial Agents or Patients. Thematic role order does not influence intonational
patterns, with the results suggesting that Murrinhpatha has positional prosody, although final nominals can disrupt global
pitch downtrends regardless of thematic role.

Abstract

Cognitive functional neuroimaging has been around for over 30 years and has shed light on the brain areas relevant for reading. However, new methodological developments enable mapping the interaction between functional imaging and the underlying white matter networks. In this study, we used such a novel method, called the disconnectome, to decode the reading circuitry in the brain. We used the resulting disconnection patterns to predict a typical lesion that would lead to reading deficits after brain damage. Our results suggest that white matter connections critical for reading include fronto-parietal U-shaped fibres and the vertical occipital fasciculus (VOF). The lesion most predictive of a reading deficit would impinge on the left temporal, occipital, and inferior parietal gyri. This novel framework can systematically be applied to bridge the gap between the neuropathology of language and cognitive neuroscience.

Abstract

Lesion symptom mapping has revolutionized our understanding of the functioning of the human brain. Associating damaged voxels in the brain with loss of function has created a map of the brain that identifies critical areas. While these methods have significantly advanced our understanding, recent improvements have identified the need for multivariate and multimodal methods to map hidden lesions and damage to white matter networks beyond the lesion voxels. This article reviews the evolution of lesion-symptom mapping from single case studies to the human disconnectome.

Abstract

Inter-individual differences can inform treatment procedures and—if accounted for—have the potential to significantly improve patient outcomes. However, when studying brain anatomy, these inter-individual variations are commonly unaccounted for, despite reports of differences in gross anatomical features, cross-sectional, and connectional anatomy. Brain connections are essential to facilitate functional organization and, when severed, cause impairments or complete loss of function. Hence, the study of cerebral white matter may be an ideal compromise to capture inter-individual variability in structure and function. We reviewed the wealth of studies that associate cognitive functions and clinical symptoms with individual tracts using diffusion tractography. Our systematic review indicates that tractography has proven to be a sensitive method in neurology, psychiatry, and healthy populations to identify variability and its functional correlates. However, the literature may be biased, as the most commonly studied tracts are not necessarily those with the highest sensitivity to cognitive functions and pathologies. Additionally, the hemisphere of the studied tract is often unreported, thus neglecting functional laterality and asymmetries. Finally, we demonstrate that tracts, as we define them, are not correlated with one, but multiple cognitive domains or pathologies. While our systematic review identified some methodological caveats, it also suggests that tract–function correlations might still be a promising tool in identifying biomarkers for precision medicine. They can characterize variations in brain anatomy, differences in functional organization, and predicts resilience and recovery in patients.

Abstract

Purpose of review: The human brain supports acquisition mechanisms that can extract structural regularities implicitly from experience without the induction of an explicit model. Reber defined the process by which an individual comes to respond appropriately to the statistical structure of the input ensemble as implicit learning. He argued that the capacity to generalize to new input is based on the acquisition of abstract representations that reflect underlying structural regularities in the acquisition input. We focus this review of the implicit learning literature on studies published during 2004 and 2005. We will not review studies of repetition priming ('implicit memory'). Instead we focus on two commonly used experimental paradigms: the serial reaction time task and artificial grammar learning. Previous comprehensive reviews can be found in Seger's 1994 article and the Handbook of Implicit Learning. Recent findings: Emerging themes include the interaction between implicit and explicit processes, the role of the medial temporal lobe, developmental aspects of implicit learning, age-dependence, the role of sleep and consolidation. Summary: The attempts to characterize the interaction between implicit and explicit learning are promising although not well understood. The same can be said about the role of sleep and consolidation. Despite the fact that lesion studies have relatively consistently suggested that the medial temporal lobe memory system is not necessary for implicit learning, a number of functional magnetic resonance studies have reported medial temporal lobe activation in implicit learning. This issue merits further research. Finally, the clinical relevance of implicit learning remains to be determined.

Abstract

In this paper we investigate the neural correlates of syntactic classification of an acquired grammatical sequence structure in an event-related FMRI study. During acquisition, participants were engaged in an implicit short-term memory task without performance feedback. We manipulated the statistical frequency-based and rule-based characteristics of the classification stimuli independently in order to investigate their role in artificial grammar acquisition. The participants performed reliably above chance on the classification task. We observed a partly overlapping corticostriatal processing network activated by both manipulations including inferior prefrontal, cingulate, inferior parietal regions, and the caudate nucleus. More specifically, the left inferior frontal BA 45 and the caudate nucleus were sensitive to syntactic violations and endorsement, respectively. In contrast, these structures were insensitive to the frequency-based manipulation.

Abstract

Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics.

Abstract

The cognate effect refers to translation equivalents with similar form between languages—i.e., cognates, such as “band” (English) and “banda” (Spanish)—being processed faster than words with dissimilar forms—such as, “cloud” and “nube.” Substantive literature supports this claim, but is mostly based on orthographic similarity and tested in the visual modality. In a previous study, we found an inhibitory orthographic similarity effect in the auditory modality—i.e., greater orthographic similarity led to slower response times and reduced accuracy. The aim of the present study is to explain this effect. In doing so, we explore the role of the speaker's accent in auditory word recognition and whether native accents lead to a mismatch between the participants' phonological representation and the stimulus. Participants carried out a lexical decision task and a typing task in which they spelled out the word they heard. Words were produced by two speakers: one with a native English accent (Standard American) and the other with a non-native accent matching that of the participants (native Spanish speaker from Spain). We manipulated orthographic and phonological similarity orthogonally and found that accent did have some effect on both response time and accuracy as well as modulating the effects of similarity. Overall, the non-native accent improved performance, but it did not fully explain why high orthographic similarity items show an inhibitory effect in the auditory modality. Theoretical implications and future directions are discussed.

Abstract

Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large‐scale studies. In response, we used cross‐sectional data from 17,075 individuals aged 3–90 years from the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Consortium to infer age‐related changes in cortical thickness. We used fractional polynomial (FP) regression to quantify the association between age and cortical thickness, and we computed normalized growth centiles using the parametric Lambda, Mu, and Sigma method. Interindividual variability was estimated using meta‐analysis and one‐way analysis of variance. For most regions, their highest cortical thickness value was observed in childhood. Age and cortical thickness showed a negative association; the slope was steeper up to the third decade of life and more gradual thereafter; notable exceptions to this general pattern were entorhinal, temporopolar, and anterior cingulate cortices. Interindividual variability was largest in temporal and frontal regions across the lifespan. Age and its FP combinations explained up to 59% variance in cortical thickness. These results may form the basis of further investigation on normative deviation in cortical thickness and its significance for behavioral and cognitive outcomes.

Abstract

Previous research on the effect of perturbed auditory feedback in speech production has focused on two types of responses. In the short term, speakers generate compensatory motor commands in response to unexpected perturbations. In the longer term, speakers adapt feedforward motor programmes in response to feedback perturbations, to avoid future errors. The current study investigated the relation between these two types of responses to altered auditory feedback. Specifically, it was hypothesised that consistency in previous feedback perturbations would influence whether speakers adapt their feedforward motor programmes. In an altered auditory feedback paradigm, formant perturbations were applied either across all trials (the consistent condition) or only to some trials, whereas the others remained unperturbed (the inconsistent condition). The results showed that speakers’ responses were affected by feedback consistency, with stronger speech changes in the consistent condition compared with the inconsistent condition. Current models of speech-motor control can explain this consistency effect. However, the data also suggest that compensation and adaptation are distinct processes, which are not in line with all current models.