Brain and Language最新文献

Pragmatic impairment is diffused in schizophrenia spectrum disorders, but the literature still debates its neurocognitive underpinnings. This systematic review and meta-analysis aimed to investigate the neurocognitive correlates of pragmatic disorders in schizophrenia and determine the weight of social cognition and executive functioning on such disorders. Of the 2,668 records retrieved from the literature, 16 papers were included in the systematic review, mostly focused on non-literal meanings and discourse production in schizophrenia. Ten studies were included in the meta-analysis: pragmatics was moderately associated with both social cognition and executive functions (especially inhibition), but the link with social cognition was stronger. The mediation analysis showed that social cognition mediated the relationship between executive functions and pragmatics. Based on this, we proposed a hierarchical neurocognitive model where pragmatics stems from social cognition, while executive functions are the fertile ground supporting the other two domains, and we discuss its theoretical and clinical implications.

This review examines whether and how the “default mode” network (DMN) contributes to semantic processing. We review evidence implicating the DMN in the processing of individual word meanings and in sentence- and discourse-level semantics. Next, we argue that the areas comprising the DMN contribute to semantic processing by coordinating and integrating the simultaneous activity of local neuronal ensembles across multiple unimodal and multimodal cortical regions, creating a transient, global neuronal ensemble. The resulting ensemble implements an integrated simulation of phenomenological experience – that is, an embodied situation model – constructed from various modalities of experiential memory traces. These situation models, we argue, are necessary not only for semantic processing but also for aspects of cognition that are not traditionally considered semantic. Although many aspects of this proposal remain provisional, we believe it provides new insights into the relationships between semantic and non-semantic cognition and into the functions of the DMN.

Procedural circuit Deficit Hypothesis (PDH) of Developmental Language Disorder (DLD) predicts problems with learning and retention of grammar. Twenty 7- to 9-year-old Cantonese-speaking children with DLD and their typically developing (TD) age peers participated in a syntactic priming task that was given in two sessions one week apart. Production of Indirect Object Relative Clause (IORC) was tested using a probe test before and after the priming task, and one week later. The study involved two cycles of learning and retention, and two levels of prior knowledge. Bayesian linear mixed effects modelling was used for data analysis. Children with DLD learned, and possibly retained, IORC less well than TD children after age, working memory and general grammatical knowledge were controlled for. No interaction effects were significant, meaning that cycle and prior knowledge affected both groups similarly in learning and retention. Results were discussed in relation to PDH and the Complementary Learning Systems Theory.

Recent work has focussed on how patterns of functional change within the temporal lobe relate to whole-brain dimensions of intrinsic connectivity variation (Margulies et al., 2016). We examined two such ‘connectivity gradients’ reflecting the separation of (i) unimodal versus heteromodal and (ii) visual versus auditory-motor cortex, examining visually presented verbal associative and feature judgments, plus picture-based context and emotion generation. Functional responses along the first dimension sometimes showed graded change between modality-tuned and heteromodal cortex (in the verbal matching task), and other times showed sharp functional transitions, with deactivation at the extremes and activation in the middle of this gradient (internal generation). The second gradient revealed more visual than auditory-motor activation, regardless of content (associative, feature, context, emotion) or task process (matching/generation). We also uncovered subtle differences across each gradient for content type, which predominantly manifested as differences in relative magnitude of activation or deactivation.

In this EEG study, we examined the ability of French listeners to perceive and use the position of stress in a discrimination task. Event-Related-Potentials (ERPs) were recorded while participants performed a same-different task. Different stimuli diverged either in one phoneme (e.g., /ʒy'ʁi/-/ʒy'ʁɔ̃/) or in stress position (e.g., /ʒy'ʁi/-/'ʒyʁi/). Although participants reached 93% of correct responses, ERP results indicated that a change in stress position was not detected while a change in one phoneme elicited a MisMatchNegativity (MMN) response. It results that in the early moments of speech processing, stimuli that are phonemically identical but that differ in stress position are perceived as being strictly similar. We concluded that the good performance observed in behavioral responses on stress position contrasts are due to attentional/decisional processes linked to discrimination tasks, and not to automatic and unconscious processes involved in stress position processing.

A major objective in post-stroke aphasia research is to gain a deeper understanding of neuroplastic mechanisms that drive language recovery, with the ultimate goal of enhancing treatment outcomes. Subsequent to recent advances in neuroimaging techniques, we now have the ability to examine more closely how neural activity patterns change after a stroke. However, the way these neural activity changes relate to language impairments and language recovery is still debated. The aim of this review is to provide a theoretical framework to better investigate and interpret neuroplasticity mechanisms underlying language recovery in post-stroke aphasia. We detail two sets of neuroplasticity mechanisms observed at the synaptic level that may explain functional neuroimaging findings in post-stroke aphasia recovery at the network level: feedback-based homeostatic plasticity and associative Hebbian plasticity. In conjunction with these plasticity mechanisms, higher-order cognitive control processes dynamically modulate neural activity in other regions to meet communication demands, despite reduced neural resources. This work provides a network-level neurobiological framework for understanding neural changes observed in post-stroke aphasia and can be used to define guidelines for personalized treatment development.

Does the perisylvian language network contribute to comprehension of programming languages, like Python? Univariate neuroimaging studies find high responses to code in fronto-parietal executive areas but not in fronto-temporal language areas, suggesting the language network does little. We used multivariate-pattern-analysis to test whether the language network encodes Python functions. Python programmers read functions while undergoing fMRI. A linear SVM decoded for-loops from if-conditionals based on activity in lateral temporal (LT) language cortex. In searchlight analysis, decoding accuracy was higher in LT language cortex than anywhere else. Follow up analysis showed that decoding was not driven by presence of different words across functions, “for” vs “if,” but by compositional program properties. Finally, univariate responses to code peaked earlier in LT language-cortex than in the fronto-parietal network. We propose that the language system forms initial “surface meaning” representations of programs, which input to the reasoning network for processing of algorithms.

This study examined proprioceptive acuity and its relationship with motor function in Mandarin-speaking children with and without developmental language disorder (DLD). Fifteen children aged 9–12 years with DLD and 15 age- and sex-matched typically developing (TD) children participated in this study. Children’s motor function was assessed using the second edition of the Movement Assessment Battery for Children (MABC-2). Their proprioceptive acuity was measured based on the absolute error (i.e., proprioceptive bias) and variable error (i.e., proprioceptive precision) when performing joint position matching tasks. Compared with the TD group, the DLD group exhibited impaired motor function and poorer proprioceptive acuity, as evidenced by the lower scores on the MABC-2 and the higher rates of absolute and variable errors in the joint position matching tasks. A significant association between the proprioceptive bias (absolute error) and the MABC-2 total score was also observed in the combined cohort of children with and without DLD. We conclude that DLD is associated with proprioceptive dysfunction.

In current sensorimotor theories pertaining to speech perception, there is a notable emphasis on the involvement of the articulatory-motor system in the processing of speech sounds. Using ultra-high field diffusion-weighted imaging at 7 Tesla, we visualized the white matter tracts connected to areas activated during a simple speech-sound production task in 18 healthy right-handed adults. Regions of interest for white matter tractography were individually determined through 7T functional MRI (fMRI) analyses, based on activations during silent vocalization tasks. These precentral seed regions, activated during the silent production of a lip-vowel sound, demonstrated anatomical connectivity with posterior superior temporal gyrus areas linked to the auditory perception of phonetic sounds. Our study provides a macrostructural foundation for understanding connections in speech production and underscores the central role of the articulatory motor system in speech perception. These findings highlight the value of ultra-high field 7T MR acquisition in unraveling the neural underpinnings of speech.