Functional roles of the thalamus for language capacities

Intuitive physical reasoning is not mediated by linguistic nor exclusively domain-general abstract representations

The ability to reason about the physical world is a critical tool in the human cognitive toolbox, but the nature of the representations that mediate physical reasoning remains debated. Here, we use fMRI to illuminate this question by investigating the relationship between the physical-reasoning system and two well-characterized systems: a) the domain-general Multiple Demand (MD) system, which supports abstract reasoning, including mathematical and logical reasoning, and b) the language system, which supports linguistic computations and has been hypothesized to mediate some forms of thought. We replicate prior findings of a network of frontal and parietal areas that are robustly engaged by physical reasoning and identify an additional physical-reasoning area in the left frontal cortex, which also houses components of the MD and language systems. Critically, direct comparisons with tasks that target the MD and the language systems reveal that the physical-reasoning system overlaps with the MD system, but is dissociable from it in fine-grained activation patterns, which replicates prior work. Moreover, the physical-reasoning system does not overlap with the language system. These results suggest that physical reasoning does not rely on linguistic representations, nor exclusively on the domain-general abstract reasoning that the MD system supports.

Severity of Germinal Matrix-Intraventricular Hemorrhage Impacts Thalamic Growth and Neurodevelopmental Outcomes in Preterm Infants: A Longitudinal Magnetic Resonance Study

BACKGROUND

Preterm birth and germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) can significantly affect neurodevelopment in very-low-birth-weight infants (VLBWI). This study examined the impact of GMH-IVH on thalamic volume (TV) during the neonatal period and its relationship with cognitive, motor, and language outcomes at two years corrected age.

METHODS

Preterm infants admitted to the neonatal intensive care unit at Hospital Puerta del Mar underwent early (<36 weeks postmenstrual age) and term-equivalent magnetic resonance imaging to assess thalamic growth. Neurodevelopmental outcomes were evaluated using the Bayley Scales of Infant and Toddler Development.

RESULTS

The severity of GMH-IVH correlated with greater reductions in TV. At term, infants without GMH-IVH had a mean TV of 3.72 ± 0.65 cm3, compared with 2.76 ± 0.55 cm3 in those with grade III GMH-IVH (P = 0.0001). Grade III GMH-IVH and parenchymal hemorrhagic infarction were linked to significantly lower cognitive (P = 0.024), language (P = 0.001), and motor scores (P = 0.006) at two years, with reduced TV contributing to poorer language outcomes (β = 9.857; P = 0.028). Our findings suggest that GMH-IVH negatively affects thalamic growth, which in turn leads to neurodevelopmental delays in preterm infants.

CONCLUSIONS

The severity of GMH-IVH is associated with decreased TV and adverse cognitive, language, and motor outcomes, highlighting the need for early identification and targeted interventions in this vulnerable population. Further research should explore additional brain structures affected by GMH-IVH to better understand the mechanisms driving these impairments.

Acoustic Inspired Brain-to-Sentence Decoder for Logosyllabic Language

Recent advances in brain-computer interfaces (BCIs) have demonstrated the potential to decode language from brain activity into sound or text, which has predominantly focused on alphabetic languages, such as English. However, logosyllabic languages, such as Mandarin Chinese, present marked challenges for establishing decoders that cover all characters, due to its unique syllable structures, extended character sets (e.g., over 50,000 characters for Mandarin Chinese), and complex mappings between characters and syllables, thus hindering practical applications. Here, we leverage the acoustic features of Mandarin Chinese syllables, constructing prediction models for syllable components (initials, tones, and finals), and decode speech-related stereoelectroencephalography (sEEG) signals into coherent Chinese sentences. The results demonstrate a high sentence-level offline decoding performance with a median character accuracy of 71.00% over the full spectrum of characters in the best participant. We also verified that incorporating acoustic-related features into the design of prediction models substantially enhances the accuracy of initials, tones, and finals. Moreover, our findings revealed that effective speech decoding also involves subcortical structures like the thalamus in addition to traditional language-related brain regions. Overall, we established a brain-to-sentence decoder for logosyllabic languages over full character set with a large intracranial electroencephalography dataset.

Structural brain network in relation to language in school-aged extremely preterm children: A diffusion tensor imaging study

Between 22 and 45 % of children born preterm experience difficulties with expressive and receptive language when they reach school age. Little is currently known about the neural mechanisms behind their linguistic performance. This study investigates the brain areas and white matter connections that form the structural language network in extremely preterm-born children who have reached school age. Structural brain connectivity was quantified using diffusion-weighted imaging (DWI) and tractography in n = 58 (62 % female) extremely preterm-born children aged 8-12 years. Language outcomes were assessed using the CELF-4-NL Recalling Sentences subtest. Language scores were below average in n = 13 (22 %) children. Language outcomes related significantly to a subnetwork of 16 brain regions (p = 0.012). The network comprised brain regions from the left hemisphere including the pars orbitalis, middle and superior frontal gyrus, frontal pole, pre- and postcentral gyrus, superior temporal gyrus, insula, caudate nucleus, thalamus, and putamen. In the right hemisphere, the anterior cingulate was part of the network. These findings suggest that extremely preterm children rely mostly on their left hemisphere during language processing, which is similar to typically developing children. However, they seem to use compensatory neural pathways that include brain areas right next to the areas typically involved in language processing. These areas include the pars orbitalis (adjacent to Broca's area) and the putamen and caudate nucleus (adjacent to the limbic system). It is important to note that language difficulties were not necessarily related to brain injury around birth.

Benefits of horseback riding for neurotypical children and adolescents: a scoping review

PURPOSE

To investigate evidence of horse riding in the development of language, cognition, social, emotional, and behavioral aspects in neurotypical children and adolescents.

RESEARCH STRATEGIES

Search in the databases of LILACS, MEDLINE, Web of Science, EMBASE, Scopus, and grey literature, without date or language restrictions. Registration in the Open Science Framework (OSF), under number DOI 10.17605/OSF.IO/32ETZ. For search strategies: "Equine-Assisted Therapy", "Child or Adolescent Development", Cognition, Socialization, and "Child Behavior".

SELECTION CRITERIA

Randomized clinical trials and non-randomized experimental before-and-after studies, case series, and prospective observational studies of neurotypically developing people up to 18 years old. Studies with people with disabilities and neurodevelopmental disorders were excluded. Interventions researched: horse riding and animal-assisted therapy.

DATA ANALYSIS

Two judges identified primary studies independently by reading the titles and abstracts, considering the inclusion criteria; a third judge was consulted to resolve divergences. The risk of bias was assessed using the ROBINS-I and ROBINS 2 tools.

RESULTS

Altogether, 131 studies were obtained, and duplicates (27) were removed. Subsequently, 104 studies were analyzed and 77 were excluded. Of the 27 studies evaluated in full text, 21 were excluded. Six studies were eligible for this review - four non-randomized clinical studies and two randomized clinical trials.

CONCLUSION

The non-randomized studies showed significant improvements in cognitive functions and behavioral and emotional aspects. The randomized studies, on the other hand, found significant gains in social competence.

Whole-brain dynamics of articulatory, acoustic and semantic speech representations

Speech production is a complex process that traverses several representations, from the meaning of spoken words (semantic), through the movement of articulatory muscles (articulatory) and, ultimately, to the produced audio waveform (acoustic). In this study, we identify how these different representations of speech are spatially and temporally distributed throughout the depth of the brain. Intracranial neural data is recorded from 15 participants, across 1647 electrode contacts, while overtly speaking 100 unique words. We find a bilateral spatial distribution for all three representations, with a more widespread and temporally dynamic distribution in the left compared to the right hemisphere. The articulatory and acoustic representations share a similar spatial distribution surrounding the Sylvian fissure, while the semantic representation is more widely distributed across the brain in a mostly distinct network. These results highlight the distributed nature of the speech production neural process and the potential of non-motor representations for speech brain-computer interfaces.

Neural correlates of lexical, sublexical and motor processes in word handwriting

Writing recruits a vast neural network underpinning both linguistic and motor processes. Previous studies have tried to identify which brain areas underpin both the linguistic and motor aspects of writing. However, little is known about the neural substrate of the lexical and sublexical "routes" for spelling. In this fMRI study, participants (n = 25) copied or saw/read symbols or words. Words varied in lexical frequency and phonology-to-orthography (P-O) consistency. Anterior parts of the inferior frontal gyrus were selectively recruited when copying P-O inconsistent words, while the right Heschl's gyrus was recruited only when copying consistent words. Non-specific motor and linguistic areas were also identified. Our results contribute to our knowledge of the neural substrate of the lexical and sublexical spelling routes and suggest that different brain areas might be involved in the lexical processing of input (reading) and output (writing) orthography.

Contributions of the left and right thalami to language: A meta-analytic approach

BACKGROUND

Despite a pervasive cortico-centric view in cognitive neuroscience, subcortical structures including the thalamus have been shown to be increasingly involved in higher cognitive functions. Previous structural and functional imaging studies demonstrated cortico-thalamo-cortical loops which may support various cognitive functions including language. However, large-scale functional connectivity of the thalamus during language tasks has not been examined before.

METHODS

The present study employed meta-analytic connectivity modeling to identify language-related coactivation patterns of the left and right thalami. The left and right thalami were used as regions of interest to search the BrainMap functional database for neuroimaging experiments with healthy participants reporting language-related activations in each region of interest. Activation likelihood estimation analyses were then carried out on the foci extracted from the identified studies to estimate functional convergence for each thalamus. A functional decoding analysis based on the same database was conducted to characterize thalamic contributions to different language functions.

RESULTS

The results revealed bilateral frontotemporal and bilateral subcortical (basal ganglia) coactivation patterns for both the left and right thalami, and also right cerebellar coactivations for the left thalamus, during language processing. In light of previous empirical studies and theoretical frameworks, the present connectivity and functional decoding findings suggest that cortico-subcortical-cerebellar-cortical loops modulate and fine-tune information transfer within the bilateral frontotemporal cortices during language processing, especially during production and semantic operations, but also other language (e.g., syntax, phonology) and cognitive operations (e.g., attention, cognitive control).

CONCLUSION

The current findings show that the language-relevant network extends beyond the classical left perisylvian cortices and spans bilateral cortical, bilateral subcortical (bilateral thalamus, bilateral basal ganglia) and right cerebellar regions.

Lexical inhibition after semantic violations recruits a domain-general inhibitory control mechanism

Language processing is incremental. As language signals-for example, words in a sentence-unfold, humans predict and activate likely upcoming input to facilitate comprehension. Prediction not only accelerates understanding but also prompts reassessment in the case of prediction error, fostering learning and refining comprehension skills. Therefore, it is paramount to understand what happens when linguistic predictions are violated-for example, when a sentence ends in an unpredicted word. One theory, which we test here, is that the originally predicted word is actively inhibited after semantic violations. Furthermore, we tested whether this purported lexical inhibition process is achieved by a domain-general mechanism-that is, one that also inhibits other processes (e.g., movement). We combined a semantic violation task, in which highly constrained sentences primed specific words but sometimes continued otherwise, with a motoric stop-signal task. Across two experiments, semantic violations significantly impaired simultaneous action-stopping. This implies that lexical and motor inhibition share the same process. In support of this view, multivariate decoding of electroencephalographic recordings showed early overlap in neural processing between action-stopping (motor inhibition) and semantic violations (lexical inhibition). Moreover, a known signature of motor inhibition (the stop-signal P3) was reduced after this initial overlap period, further suggesting the presence of a bottleneck due to shared processing. These findings show that semantic violations trigger inhibitory processing and suggest that this lexical inhibition recruits a domain-general inhibitory control mechanism. This provides a new perspective on long-standing debates in psycholinguistics, extends the range of a well-characterized cognitive control mechanism into the linguistic domain, and offers support for recent neurobiological models of domain-general inhibitory control. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Expanding the molecular landscape of childhood apraxia of speech: evidence from a single-center experience

Background

Childhood apraxia of speech (CAS) is a genetically heterogeneous pediatric motor speech disorder. The advent of whole exome sequencing (WES) and whole genome sequencing techniques has led to increased identification of pathogenic variants in CAS genes. In an as yet uncharacterized Italian cohort, we aimed both to identify new pathogenic gene variants associated with CAS, and to confirm the disease-related role of genes already reported by others. We also set out to refine the clinical and neurodevelopmental characterization of affected children, with the aim of identifying specific, gene-related phenotypes.

Methods

In a single-center study aiming to explore the genetic etiology of CAS in a cohort of 69 Italian children, WES was performed in the families of the 34 children found to have no copy number variants. Each of these families had only one child affected by CAS.

Results

High-confidence (HC) gene variants were identified in 7/34 probands, in two of whom they affected KAT6A and CREBBP, thus confirming the involvement of these genes in speech impairment. The other probands carried variants in low-confidence (LC) genes, and 20 of these variants occurred in genes not previously reported as associated with CAS. UBA6, ZFHX4, and KAT6A genes were found to be more enriched in the CAS cohort compared to control individuals. Our results also showed that most HC genes are involved in epigenetic mechanisms and are expressed in brain regions linked to language acquisition processes.

Conclusion

Our findings confirm a relatively high diagnostic yield in Italian patients.

Machine learning decoding of single neurons in the thalamus for speech brain-machine interfaces

Objective. Our goal is to decode firing patterns of single neurons in the left ventralis intermediate nucleus (Vim) of the thalamus, related to speech production, perception, and imagery. For realistic speech brain-machine interfaces (BMIs), we aim to characterize the amount of thalamic neurons necessary for high accuracy decoding.Approach. We intraoperatively recorded single neuron activity in the left Vim of eight neurosurgical patients undergoing implantation of deep brain stimulator or RF lesioning during production, perception and imagery of the five monophthongal vowel sounds. We utilized the Spade decoder, a machine learning algorithm that dynamically learns specific features of firing patterns and is based on sparse decomposition of the high dimensional feature space.Main results. Spade outperformed all algorithms compared with, for all three aspects of speech: production, perception and imagery, and obtained accuracies of 100%, 96%, and 92%, respectively (chance level: 20%) based on pooling together neurons across all patients. The accuracy was logarithmic in the amount of neurons for all three aspects of speech. Regardless of the amount of units employed, production gained highest accuracies, whereas perception and imagery equated with each other.Significance. Our research renders single neuron activity in the left Vim a promising source of inputs to BMIs for restoration of speech faculties for locked-in patients or patients with anarthria or dysarthria to allow them to communicate again. Our characterization of how many neurons are necessary to achieve a certain decoding accuracy is of utmost importance for planning BMI implantation.

Language Impairment in Vascular Dementia: A Clinical Review

Vascular cognitive impairment (VCI) encompasses a wide range of conditions, including cognitive impairment associated with stroke or vascular brain injury, mild vascular cognitive impairment, and vascular dementia (VD). Knowledge of language impairment associated with VD is far less extensive than that of Alzheimer's disease. Although not prevalent in VD, impairment in language skills has been reported. A better understanding of the neurolinguistic features associated with the different presentations of VD could facilitate medical diagnosis. In this article, we report data on language impairment in VD, with particular attention to their primary or secondary functional origin. To better appreciate this functional origin, we also outline the main characteristics of impairment in other cognitive functions. Key elements that should be considered in the speech-language assessment of individuals with possible or proven VD are also highlighted.

Speech decoding using cortical and subcortical electrophysiological signals

Introduction

Language impairments often result from severe neurological disorders, driving the development of neural prosthetics utilizing electrophysiological signals to restore comprehensible language. Previous decoding efforts primarily focused on signals from the cerebral cortex, neglecting subcortical brain structures' potential contributions to speech decoding in brain-computer interfaces.

Methods

In this study, stereotactic electroencephalography (sEEG) was employed to investigate subcortical structures' role in speech decoding. Two native Mandarin Chinese speakers, undergoing sEEG implantation for epilepsy treatment, participated. Participants read Chinese text, with 1-30, 30-70, and 70-150 Hz frequency band powers of sEEG signals extracted as key features. A deep learning model based on long short-term memory assessed the contribution of different brain structures to speech decoding, predicting consonant articulatory place, manner, and tone within single syllable.

Results

Cortical signals excelled in articulatory place prediction (86.5% accuracy), while cortical and subcortical signals performed similarly for articulatory manner (51.5% vs. 51.7% accuracy). Subcortical signals provided superior tone prediction (58.3% accuracy). The superior temporal gyrus was consistently relevant in speech decoding for consonants and tone. Combining cortical and subcortical inputs yielded the highest prediction accuracy, especially for tone.

Discussion

This study underscores the essential roles of both cortical and subcortical structures in different aspects of speech decoding.

Associations Between Cognitive Impairment and Neuroimaging in Patients with Multiple Sclerosis

OBJECTIVE

Multiple sclerosis (MS) is a debilitating inflammatory and neurodegenerative disease which commonly involves cognitive dysfunction. Magnetic resonance imaging (MRI) studies have shown that patients with MS (pwMS) have diffuse patterns of brain atrophy, however, the relationship between the presentation of cognitive dysfunction and brain tissue loss remains understudied. Given the integral function of thalamus as a central nervous system relay center and its involvement in various brain circuits, thalamic atrophy may play a key role in the development and progression of cognitive dysfunction. The purpose of this study is to examine the relationship between cognitive impairment in pwMS and thalamic atrophy.

METHODS

A total of 121 pwMS who had neuropsychological testing and quantitative MRI within 1 year of each were retrospectively identified. Grouped LASSO linear regression with 10-fold cross validation was used to estimate each neuropsychological test score with thalamic volume as the focal predictor and all other demographic and MRI metrics as covariates.

RESULTS

Rates of impairment ranged from 19% to 44%. Results showed notable associations between thalamic volume and Symbol Digit Modalities Test (β = 0.11), Brief Visuospatial Memory Test, delayed (β = 0.12), California Verbal Learning Test, delayed and total (β = 0.24 and β = 0.15 respectively), and Trail Making Test Part A (β = -0.01), after adjusting for covariates.

CONCLUSIONS

These findings demonstrate an independent association between thalamic volumes and processing speed and memory performance, after accounting for demographic, clinical, and other MRI variables, among pwMS.

Levodopa may modulate specific speech impairment in Parkinson's disease: an fMRI study

Hypokinetic dysarthria (HD) is a difficult-to-treat symptom affecting quality of life in patients with Parkinson's disease (PD). Levodopa may partially alleviate some symptoms of HD in PD, but the neural correlates of these effects are not fully understood. The aim of our study was to identify neural mechanisms by which levodopa affects articulation and prosody in patients with PD. Altogether 20 PD patients participated in a task fMRI study (overt sentence reading). Using a single dose of levodopa after an overnight withdrawal of dopaminergic medication, levodopa-induced BOLD signal changes within the articulatory pathway (in regions of interest; ROIs) were studied. We also correlated levodopa-induced BOLD signal changes with the changes in acoustic parameters of speech. We observed no significant changes in acoustic parameters due to acute levodopa administration. After levodopa administration as compared to the OFF dopaminergic condition, patients showed task-induced BOLD signal decreases in the left ventral thalamus (p = 0.0033). The changes in thalamic activation were associated with changes in pitch variation (R = 0.67, p = 0.006), while the changes in caudate nucleus activation were related to changes in the second formant variability which evaluates precise articulation (R = 0.70, p = 0.003). The results are in line with the notion that levodopa does not have a major impact on HD in PD, but it may induce neural changes within the basal ganglia circuitries that are related to changes in speech prosody and articulation.

Neuronal Encoding of Speech Features in the Human Thalamus in Parkinson's Disease and Essential Tremor Patients

BACKGROUND AND OBJECTIVES

The human thalamus is known, from stimulation studies and functional imaging, to participate in high-level language tasks. The goal of this study is to find whether and how speech features, in particular, vowel phonemes, are encoded in the neuronal activity of the thalamus, and specifically of the left ventralis intermediate nucleus (Vim), during speech production, perception, and imagery.

METHODS

In this cross-sectional study, we intraoperatively recorded single neuron activity in the left Vim of eight neurosurgical patients with Parkinson's disease (PD) (n = 4) or essential tremor (n = 4) undergoing implantation of deep brain stimulation (n = 3) or radiofrequency lesioning (n = 5) while patients articulated the five monophthongal vowel sounds.

RESULTS

In this article, we report that single neurons in the left Vim encode individual vowel phonemes mainly during speech production but also during perception and imagery. They mainly use one of two encoding schemes: broad or sharp tuning, with a similar percentage of units each. Sinusoidal tuning has been demonstrated in almost half of the broadly tuned units. Patients with PD had a lower percentage of speech-related units in each aspect of speech (production, perception, and imagery), a significantly lower percentage of broadly tuned units, and significantly lower median firing rates during speech production and perception, but significantly higher rates during imagery, than patients with essential tremor.

CONCLUSION

The results suggest that the left Vim uses mixed encoding schemes for speech features. Our findings explain, at the single neuron level, why deep brain stimulation and radiofrequency lesioning of the left Vim are likely to cause speech side effects. Moreover, they may indicate that speech-related units in the left Vim of patients with PD may be degraded even in the subclinical phase.

Injury patterns associated with cognitive motor dissociation

In unconscious appearing patients with acute brain injury, wilful brain activation to motor commands without behavioural signs of command following, known as cognitive motor dissociation (CMD), is associated with functional recovery. CMD can be detected by applying machine learning to EEG recorded during motor command presentation in behaviourally unresponsive patients. Identifying patients with CMD carries clinical implications for patient interactions, communication with families, and guidance of therapeutic decisions but underlying mechanisms of CMD remain unknown. By analysing structural lesion patterns and network level dysfunction we tested the hypothesis that, in cases with preserved arousal and command comprehension, a failure to integrate comprehended motor commands with motor outputs underlies CMD. Manual segmentation of T2-fluid attenuated inversion recovery and diffusion weighted imaging sequences quantifying structural injury was performed in consecutive unresponsive patients with acute brain injury (n = 107) who underwent EEG-based CMD assessments and MRI. Lesion pattern analysis was applied to identify lesion patterns common among patients with (n = 21) and without CMD (n = 86). Thalamocortical and cortico-cortical network connectivity were assessed applying ABCD classification of power spectral density plots and weighted pairwise phase consistency (WPPC) to resting EEG, respectively. Two distinct structural lesion patterns were identified on MRI for CMD and three for non-CMD patients. In non-CMD patients, injury to brainstem arousal pathways including the midbrain were seen, while no CMD patients had midbrain lesions. A group of non-CMD patients was identified with injury to the left thalamus, implicating possible language comprehension difficulties. Shared lesion patterns of globus pallidus and putamen were seen for a group of CMD patients, which have been implicated as part of the anterior forebrain mesocircuit in patients with reversible disorders of consciousness. Thalamocortical network dysfunction was less common in CMD patients [ABCD-index 2.3 (interquartile range, IQR 2.1-3.0) versus 1.4 (IQR 1.0-2.0), P < 0.0001; presence of D 36% versus 3%, P = 0.0006], but WPPC was not different. Bilateral cortical lesions were seen in patients with and without CMD. Thalamocortical disruption did not differ for those with CMD, but long-range WPPC was decreased in 1-4 Hz [odds ratio (OR) 0.8; 95% confidence interval (CI) 0.7-0.9] and increased in 14-30 Hz frequency ranges (OR 1.2; 95% CI 1.0-1.5). These structural and functional data implicate a failure of motor command integration at the anterior forebrain mesocircuit level with preserved thalamocortical network function for CMD patients with subcortical lesions. Amongst patients with bilateral cortical lesions preserved cortico-cortical network function is associated with CMD detection. These data may allow screening for CMD based on widely available structural MRI and resting EEG.

Mechanisms of brain activation following naming therapy in aphasia: A systematic review on task-based fMRI studies

The pattern of brain neuroplasticity after naming therapies in patients with aphasia can be evaluated using task-based fMRI. This article aims to review studies investigating brain reorganization after semantic and phonological-based anomia therapy that used picture-naming fMRI tasks. We searched for those articles that compared the activation of brain areas before and after aphasia therapies in the PubMed and the EMBASE databases from 1993 up to April 2020. All studies (single-cases or group designs) on anomia treatment in individuals with acquired aphasia were reviewed. Data were synthesized descriptively through tables to allow the facilitated comparison of the studies. A total of 14 studies were selected and reviewed. The results of the reviewed studies demonstrated that the naming improvement is associated with changes in the activation of cortical and subcortical brain areas. This review highlights the need for a more systematic investigation of the association between decreased and increased activation of brain areas related to anomia therapy. Also, more detailed information about factors influencing brain reorganization is required to elucidate the neural mechanisms of anomia therapy. Overall, regarding the theoretical and clinical aspects, the number of studies that used intensive protocol is growing, and based on the positive potential of these treatments, they could be suitable for the rehabilitation of people with aphasia.

Characterizing functional modules in the human thalamus: coactivation-based parcellation and systems-level functional decoding

The human thalamus relays sensory signals to the cortex and facilitates brain-wide communication. The thalamus is also more directly involved in sensorimotor and various cognitive functions but a full characterization of its functional repertoire, particularly in regard to its internal anatomical structure, is still outstanding. As a putative hub in the human connectome, the thalamus might reveal its functional profile only in conjunction with interconnected brain areas. We therefore developed a novel systems-level Bayesian reverse inference decoding that complements the traditional neuroinformatics approach towards a network account of thalamic function. The systems-level decoding considers the functional repertoire (i.e., the terms associated with a brain region) of all regions showing co-activations with a predefined seed region in a brain-wide fashion. Here, we used task-constrained meta-analytic connectivity-based parcellation (MACM-CBP) to identify thalamic subregions as seed regions and applied the systems-level decoding to these subregions in conjunction with functionally connected cortical regions. Our results confirm thalamic structure-function relationships known from animal and clinical studies and revealed further associations with language, memory, and locomotion that have not been detailed in the cognitive neuroscience literature before. The systems-level decoding further uncovered large systems engaged in autobiographical memory and nociception. We propose this novel decoding approach as a useful tool to detect previously unknown structure-function relationships at the brain network level, and to build viable starting points for future studies.

Dynamic networks differentiate the language ability of children with cochlear implants

Background

Cochlear implantation (CI) in prelingually deafened children has been shown to be an effective intervention for developing language and reading skill. However, there is a substantial proportion of the children receiving CI who struggle with language and reading. The current study-one of the first to implement electrical source imaging in CI population was designed to identify the neural underpinnings in two groups of CI children with good and poor language and reading skill.

Methods

Data using high density electroencephalography (EEG) under a resting state condition was obtained from 75 children, 50 with CIs having good (HL) or poor language skills (LL) and 25 normal hearing (NH) children. We identified coherent sources using dynamic imaging of coherent sources (DICS) and their effective connectivity computing time-frequency causality estimation based on temporal partial directed coherence (TPDC) in the two CI groups compared to a cohort of age and gender matched NH children.

Findings

Sources with higher coherence amplitude were observed in three frequency bands (alpha, beta and gamma) for the CI groups when compared to normal hearing children. The two groups of CI children with good (HL) and poor (LL) language ability exhibited not only different cortical and subcortical source profiles but also distinct effective connectivity between them. Additionally, a support vector machine (SVM) algorithm using these sources and their connectivity patterns for each CI group across the three frequency bands was able to predict the language and reading scores with high accuracy.

Interpretation

Increased coherence in the CI groups suggest overall that the oscillatory activity in some brain areas become more strongly coupled compared to the NH group. Moreover, the different sources and their connectivity patterns and their association to language and reading skill in both groups, suggest a compensatory adaptation that either facilitated or impeded language and reading development. The neural differences in the two groups of CI children may reflect potential biomarkers for predicting outcome success in CI children.

Examination of common and unique brain regions for atypical reading and math: a meta-analysis

The purpose of this study is to identify consistencies across functional neuroimaging studies regarding common and unique brain regions/networks for individuals with reading difficulties (RD) and math difficulties (MD) compared to typically developing (TD) individuals. A systematic search of the literature, utilizing multiple databases, yielded 116 functional magnetic resonance imaging and positron emission tomography studies that met the criteria. Coordinates that directly compared TD with either RD or MD were entered into GingerALE (Brainmap.org). An activation likelihood estimate (ALE) meta-analysis was conducted to examine common and unique brain regions for RD and MD. Overall, more studies examined RD (n = 96) than MD (n = 20). Across studies, overactivation for reading and math occurred in the right insula and inferior frontal gyrus for atypically developing (AD) > TD comparisons, albeit in slightly different areas of these regions; however, inherent threshold variability across imaging studies could diminish overlying regions. For TD > AD comparisons, there were no similar or overlapping brain regions. Results indicate there were domain-specific differences for RD and MD; however, there were some similarities in the ancillary recruitment of executive functioning skills. Theoretical and practical implications for researchers and educators are discussed.

Cerebellar and subcortical atrophy contribute to psychiatric symptoms in frontotemporal dementia

Recent studies have reported early cerebellar and subcortical impact in the disease progression of genetic frontotemporal dementia (FTD) due to microtubule-associated protein tau (MAPT), progranulin (GRN) and chromosome 9 open reading frame 72 (C9orf72). However, the cerebello-subcortical circuitry in FTD has been understudied despite its essential role in cognition and behaviors related to FTD symptomatology. The present study aims to investigate the association between cerebellar and subcortical atrophy, and neuropsychiatric symptoms across genetic mutations. Our study included 983 participants from the Genetic Frontotemporal dementia Initiative including mutation carriers and noncarrier first-degree relatives of known symptomatic carriers. Voxel-wise analysis of the thalamus, striatum, globus pallidus, amygdala, and the cerebellum was performed, and partial least squares analyses (PLS) were used to link morphometry and behavior. In presymptomatic C9orf72 expansion carriers, thalamic atrophy was found compared to noncarriers, suggesting the importance of this structure in FTD prodromes. PLS analyses demonstrated that the cerebello-subcortical circuitry is related to neuropsychiatric symptoms, with significant overlap in brain/behavior patterns, but also specificity for each genetic mutation group. The largest differences were in the cerebellar atrophy (larger extent in C9orf72 expansion group) and more prominent amygdalar volume reduction in the MAPT group. Brain scores in the C9orf72 expansion carriers and MAPT carriers demonstrated covariation patterns concordant with atrophy patterns detectable up to 20 years before expected symptom onset. Overall, these results demonstrated the important role of the subcortical structures in genetic FTD symptom expression, particularly the cerebellum in C9orf72 and the amygdala in MAPT carriers.

Analysis of the association between location and patient prognosis in spontaneous intracerebral hemorrhage in the basal ganglia and thalamus: A retrospective single-center study

Spontaneous intracerebral hemorrhage (ICH) causes profound neurological sequelae in survivors. The patient's prognosis is closely linked to the location and amount of hemorrhage. Therefore, we explored the relationship between the hemorrhage location within the basal ganglia, including the thalamus, and its clinical outcomes in patients with spontaneous intracerebral hemorrhage. A retrospective analysis of consecutively enrolled patients with basal ganglia and thalamic intracerebral hemorrhage treated conservatively at a single tertiary neurosurgical center was conducted between January 2014 and December 2020. Patients were divided into 2 groups according to the lateralization of the right or left hemisphere hemorrhage. Furthermore, baseline patient demographics, hematoma volume, location of the hemorrhage (i.e., caudate nucleus, globus palidus, putamen, internal capsule anterior limb, internal capsule posterior limb, thalamus), and clinical outcomes were evaluated. Clinical outcomes were assessed using the modified Rankin scale at the 1-year follow-up. An modified Rankin scale score between 3 and 6 was considered a poor outcome. In the analysis according to location, the prognosis was poor when the ICH was localized to the posterior limb of the internal capsule (P < .000) and globus palidus (P = .001) in the right hemisphere. Similarly, the prognosis was also poor when the ICH was localized to the posterior limb of the internal capsule (P < .000), globus palidus (P < .000), putamen (P = .018), and thalamus (P < .000) of the left hemisphere. In the spontaneous intracerebral hemorrhages of the basal ganglia and thalamus, hemorrhaging within the internal capsule and the left thalamus's bilateral posterior limbs is associated with a poor prognosis. Multivariable logistic analysis showed that hematoma volume (odds ratio [OR] = 70.85, 95% confidence interval [CI]: 1.95-60.53, P = .007) and the posterior limb of the internal capsule (OR = 10.98, 95% CI:1.02-118.49, P = .048) were independent predictors of poor outcomes in the right hemisphere, while hematoma volume (OR = 70.85, 95% CI: 1.95-60.53, P = .007), the posterior limb of the internal capsule (OR = 10.98, 95% CI:1.02-118.49, P = .048) and thalamus (OR = 10.98, 95% CI:1.02-118.49, P = .048) were independent predictors of poor outcomes in the left hemisphere.

Dataset of Speech Production in intracranial.Electroencephalography

Speech production is an intricate process involving a large number of muscles and cognitive processes. The neural processes underlying speech production are not completely understood. As speech is a uniquely human ability, it can not be investigated in animal models. High-fidelity human data can only be obtained in clinical settings and is therefore not easily available to all researchers. Here, we provide a dataset of 10 participants reading out individual words while we measured intracranial EEG from a total of 1103 electrodes. The data, with its high temporal resolution and coverage of a large variety of cortical and sub-cortical brain regions, can help in understanding the speech production process better. Simultaneously, the data can be used to test speech decoding and synthesis approaches from neural data to develop speech Brain-Computer Interfaces and speech neuroprostheses.

Measurement(s)	Brain activity
Technology Type(s)	Stereotactic electroencephalography
Sample Characteristic - Organism	Homo sapiens
Sample Characteristic - Environment	Epilepsy monitoring center
Sample Characteristic - Location	The Netherlands

Chronic hematoma superimposed to a large frontotemporal arachnoid cyst: evidence against crowding of audioverbal memory

We report a patient with a chronic subdural/epidural hematoma superimposed to a large arachnoid cyst occupying the left frontotemporal region. Both were discovered accidentally because of a trigeminal neuralgia and concomitant subjective memory complaints. Patient's sudden selective audioverbal memory impairment probably links to a primary cortical tone deregulation and expressed through deficits of arousal-mediating structures subtly impacted by the hematoma's progression. This case illustrates that in early-onset asymmetrical brain damage (usually left), language, audioverbal memory in particular, should not always come to dominate intact hemisphere function. A severity-threshold may exist below which inter-hemispheric reorganization of audioverbal memory is unlikely.

The powerful brain: Neural correlates of sense of power and hope

A sense of power refers to the perception that one can control and influence others' states by providing or withholding valued resources in an asymmetrical way, and which has been associated with greater hope. However, little is known about the neural bases underlying this association. The present study aimed to examine these phenomena in 261 healthy adolescent students by assessing resting-state brain activity (i.e., the amplitude of low-frequency fluctuations, ALFF) and connectivity (i.e., resting-state functional connectivity, RSFC). Whole-brain correlation analyses revealed that higher levels of perceived power were linked with reduced ALFF in the left thalamus and increased RSFC between the left thalamus and left superior temporal gyrus. Mediation analyses further showed that perceived power mediated the influence of the left thalamus activity on hope. Our results remained significant even after controlling for the head motion, age, and gender. Our findings contribute to the neurobiological basis of a sense of power and the neural mechanism underlying the relationship between a sense of power and hope.

Relationship between cognitive profile and neuroradiographic parameters in patients with idiopathic normal pressure hydrocephalus

Background: Normal pressure hydrocephalus (NPH) is a reversible type of dementia, which affects 0.2 to 5.9 percent of elders. It manifests with triad of gait disturbances, urinary incontinence, and cognitive decline. In this study, association between cognitive and neuroradiographic parameters of idiopathic NPH (iNPH) was appraised to find out possible biomarkers for preventive intervention. Methods: In a cross-sectional study, 16 patients with iNPH were evaluated for third and fourth ventricle diameter, diameter of temporal horn of lateral ventricle, Evans index (EI), callosal angle (CA), callosal bowing, and ballooning of frontal horn. The Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG) was used to take cognitive profile. Relation between brain magnetic resonance imaging (MRI) indices and cognitive domains was extracted, using generalized linear model (GLM). Results: Patients with mild callosal bowing had better function in memory (P = 0.050) and language (P = 0.001) than those with moderate to severe callosal bowing. Negative or mild ballooning of frontal horn was also associated with higher scores in memory (P = 0.010), executive function (EF) (P = 0.029), and language (P = 0.036) than moderate to severe ballooning of frontal horn. Increased 3rd ventricle diameter was associated with decline in total cognition (P = 0.008), memory (P = 0.019), EF (P = 0.012), and language (P = 0.001). Relation between other radiographic indices and cognitive function was not significant. Conclusion: Third ventricular diameter, rounding of frontal horn of lateral ventricle, and callosal bowing are more accurate neuroradiographic parameters to predict cognitive decline in iNPH.

Effects of thalamic and basal ganglia deep brain stimulation on language-related functions - Conceptual and clinical considerations

Deep Brain Stimulation (DBS) is a therapy for various neurological movement disorders. It acts predominantly on motor symptoms, but may unfold a number of mostly subtle cognitive effects. In this regard, reports on particular language-related DBS sequels are comparably frequent, but difficult to overlook, given the heterogeneity of targeted structures in the brain, treated diseases, assessment methods and results reported. Accordingly, available knowledge was organized with respect to important aspects, such as the main DBS loci and surgical versus neuromodulatory therapy actions. Current views of biolinguistic underpinnings of the reviewed data, their clinical relevance and potential implications are discussed.

Thalamic Aphasia: a Review

PURPOSE OF REVIEW

Thalamic aphasia is a rare language disorder resulting from lesions to the thalamus. While most patients exhibit mild symptoms with a predominance of lexical-semantic difficulties, variations in phenotype have been described. Overall, the exact mechanisms of thalamic aphasia await empirical research. The article reviews recent findings regarding phenotypes and possible underlying mechanisms of thalamic aphasia.

RECENT FINDINGS

Variations in phenotype of thalamic aphasia may be related to different lesion locations. Overall, the thalamus' role in language is thought to be due to its involvement in cortico-thalamic language networks with lesioning of certain nuclei resulting in the diachisis of otherwise interconnected areas. Its possible monitoring function in such a network might be due to its different cellular firing modes. However, no specific evidence has been collected to date. While recent findings show a more distinct understanding of thalamic aphasia phenotypes and possible underlying mechanisms, further research is needed. Additionally, as standard language testing might oftentimes not pick up on its subtle symptoms, thalamic aphasia might be underdiagnosed.

Cerebral perfusion mediated by thalamo-cortical functional connectivity in non-dominant thalamus affects naming ability in aphasia

Naming is a commonly impaired language domain in various types of aphasia. Emerging evidence supports the cortico‐subcortical circuitry subserving naming processing, although neurovascular regulation of the non‐dominant thalamic and basal ganglia subregions underlying post‐stroke naming difficulty remains unclear. Data from 25 subacute stroke patients and 26 age‐, sex‐, and education‐matched healthy volunteers were analyzed. Region‐of‐interest‐wise functional connectivity (FC) was calculated to measure the strength of cortico‐subcortical connections. Cerebral blood flow (CBF) was determined to reflect perfusion levels. Correlation and mediation analyses were performed to identify the relationship between cortico‐subcortical connectivity, regional cerebral perfusion, and naming performance. We observed increased right‐hemispheric subcortical connectivity in patients. FC between the right posterior superior temporal sulcus (pSTS) and lateral/medial prefrontal thalamus (lPFtha/mPFtha) exhibited significantly negative correlations with total naming score. Trend‐level increased CBF in subcortical nuclei, including that in the right lPFtha, and significant negative correlations between naming and regional perfusion of the right lPFtha were observed. The relationship between CBF in the right lPFtha and naming was fully mediated by the lPFtha‐pSTS connectivity in the non‐dominant hemisphere. Our findings suggest that perfusion changes in the right thalamic subregions affect naming performance through thalamo‐cortical circuits in post‐stroke aphasia. This study highlights the neurovascular pathophysiology of the non‐dominant hemisphere and demonstrates thalamic involvement in naming after stroke.

Cavernomas cerebrales en la infancia y desarrollo atípico de la comunicación y el lenguaje

Los cavernomas cerebrales corresponden a malformaciones vasculares del sistema nervioso central, con baja prevalencia en la población pediátrica. Estas malformaciones pueden aparecer como lesiones únicas o múltiples. La manifestación sintomatológica de los cavernomas se ha asociado, principalmente, a la ubicación topográfica de las lesiones. En este artículo se reportan las habilidades de comunicación y lenguaje de un niño de 3 años 10 meses, diagnosticado con cavernomatosis cerebral múltiple, y se discute la posible relación entre las habilidades evidenciadas y el cuadro neurológico de base. La indagatoria se efectuó mediante la aplicación de los siguientes tres procedimientos: 1. compilación y análisis de antecedentes clínicos en ficha médica, 2. elaboración y análisis de muestra naturalista de comunicación y lenguaje, 3. aplicación y análisis de instrumento Inventario de Desarrollo Comunicativo MacArthur. El análisis cualitativo de los antecedentes recabados permite sugerir una asociación entre las habilidades atípicas de comunicación y lenguaje observadas y el diagnóstico de cavernomatosis cerebral múltiple, en particular, debido a la ubicación topográfica de las lesiones. A nuestro entender, este artículo representa la primera descripción de habilidades atípicas de comunicación y lenguaje, asociadas al diagnóstico de cavernomatosis cerebral múltiple en edad pediátrica.

Pre-Surgery Cognitive Performance and Voxel-Based Lesion-Symptom Mapping in Patients with Left High-Grade Glioma

(1) Background: The literature on the effects of high-grade glioma (HGG) growth on cognition is still scarce. (2) Method: A consecutive series of 85 patients with HGG involving the left hemisphere underwent an extended neuropsychological evaluation prior to surgery. Voxel-based lesion-symptom mapping (VLSM) was used to identify regions related to cognitive performance. (3) Results: The patients' mean level of pre-surgery accuracy was overall high. They showed the greatest difficulties in language with tasks such as naming (42.1% of patients impaired on nouns and 61.4% on verbs), reading (36.3% on words and 32.7% on pseudo-words), auditory lexical decisions (43.9%) and writing (41.3%) being most frequently impaired. VLSM analysis revealed anatomically separated areas along the temporal cortex and the white matter related to impairments on the different tasks, with voxels commonly shared by all tasks restricted to a small region in the ventral superior and middle temporal gyrus. (4) Conclusions: High-grade glioma affects cognition; nonetheless, lesions do not cause diffuse deficits but selectively impact the different language sub-domains along the ventral stream and the dorsal stream for language processing.

Rodent somatosensory thalamocortical circuitry: Neurons, synapses, and connectivity

As our understanding of the thalamocortical system deepens, the questions we face become more complex. Their investigation requires the adoption of novel experimental approaches complemented with increasingly sophisticated computational modeling. In this review, we take stock of current data and knowledge about the circuitry of the somatosensory thalamocortical loop in rodents, discussing common principles across modalities and species whenever appropriate. We review the different levels of organization, including the cells, synapses, neuroanatomy, and network connectivity. We provide a complete overview of this system that should be accessible for newcomers to this field while nevertheless being comprehensive enough to serve as a reference for seasoned neuroscientists and computational modelers studying the thalamocortical system. We further highlight key gaps in data and knowledge that constitute pressing targets for future experimental work. Filling these gaps would provide invaluable information for systematically unveiling how this system supports behavioral and cognitive processes.

Detecting Dynamic Community Structure in Functional Brain Networks Across Individuals: A Multilayer Approach

OBJECTIVE

We present a unified statistical framework for characterizing community structure of brain functional networks that captures variation across individuals and evolution over time. Existing methods for community detection focus only on single-subject analysis of dynamic networks; while recent extensions to multiple-subjects analysis are limited to static networks.

METHOD

To overcome these limitations, we propose a multi-subject, Markov-switching stochastic block model (MSS-SBM) to identify state-related changes in brain community organization over a group of individuals. We first formulate a multilayer extension of SBM to describe the time-dependent, multi-subject brain networks. We develop a novel procedure for fitting the multilayer SBM that builds on multislice modularity maximization which can uncover a common community partition of all layers (subjects) simultaneously. By augmenting with a dynamic Markov switching process, our proposed method is able to capture a set of distinct, recurring temporal states with respect to inter-community interactions over subjects and the change points between them.

RESULTS

Simulation shows accurate community recovery and tracking of dynamic community regimes over multilayer networks by the MSS-SBM. Application to task fMRI reveals meaningful non-assortative brain community motifs, e.g., core-periphery structure at the group level, that are associated with language comprehension and motor functions suggesting their putative role in complex information integration. Our approach detected dynamic reconfiguration of modular connectivity elicited by varying task demands and identified unique profiles of intra and inter-community connectivity across different task conditions.

CONCLUSION

The proposed multilayer network representation provides a principled way of detecting synchronous, dynamic modularity in brain networks across subjects.

Changed functional connectivity at rest in functional illiterates after extensive literacy training

Background

About 6.2 million adults in Germany cannot read and write properly despite attending school for several years. They are considered to be functional illiterates (FI). Since the ability to read and write is crucial for being employed and socially accepted, we developed a special literacy training to overcome these deficits.

Methods

In this study, we investigate training-related changes in intrinsic functional connectivity (iFC) at rest in a group of 20 FI and 20 adult normal readers using resting state functional magnetic resonance imaging (rsfMRI). We used independent component analysis (ICA) to define different networks.

Results

Before training, the between group analysis showed increased iFC in FI in a left-fronto-parietal network (LFPN; anterior insula, medial frontal cortex, lateral and frontal parietal regions) and in the Basal Ganglia network (BGN: thalamus, caudate, putamen, pallidum, amygdala, supplementary motor cortex and cingulate gyrus). Furthermore, the Visual Network-1 (VN1; temporal occipital fusiform gyrus, lateral occipital cortex, occipital pole, lingual gyrus, thalamus) showed decreased iFC in FI. After training the FI group showed reversal of the “hyperconnectivity” in middle frontal gyrus and in the frontal orbital cortex and between supramarginal gyrus and the BGN. Furthermore, functional connectivity increased in FI VN1 (lateral occipital cortex, insular cortex). These changes in connectivity correlated with gains in reading speed and spelling accuracy.

Conclusions

These findings show that poor reading and writing abilities are associated with abnormalities in iFC in several brain areas subserving cognitive processes important for reading. Intensive literacy training induces changes in the functional connectivity between and within neural networks important for literacy skills.

Selective impairment of auditory attention processing in idiopathic generalized epilepsies: Implications for their cognitive pathophysiology

The neuropsychological characteristics of Idiopathic Generalized Epilepsies (IGEs) as a wide syndrome encompassing different clinical entities have been as yet not well understood. We have studied neuropsychological performance in patients suffering Juvenile Myoclonic Epilepsy (JME) and Generalized Tonic Clonic Seizures (IGE-GTCS-only) to provide indirect-cognitive evidence on the pathophysiology of IGE-related neuropsychological dysfunction. Greater arousal-related impairments were expected for the auditory modality, by drawing on previous anatomo-clinical and neuro-evolutionary accounts. We have studied neurocognitive functioning in 26 IGE patients, suffering either JME (n = 16) or IGE-GTCS-only (n = 10), and their healthy counterparts consisted of 26 (18 females) demographically matched participants. IGE patients (JME and IGE-GTCS-only) did worse with respect to HC (healthy controls) in visual- and auditory- speed of information processing (reaction time), auditory-vigilance and -response inhibition, visuo-motor coordination, visual working memory and motor speed, delayed visual recall, immediate- and delayed verbal episodic recall, lexical access and retrieval, semantic associative processing, auditory-verbal memory span and verbal learning. Although both IGE-GTCS-only and JME patients delayed episodic recall was defective, the former did significantly worse. We believe that IGE patients' neuropsychological derailments represent indirect-secondary manifestations of a primary cortical tone deregulation inherent to IGEs' pathophysiology. In particular, IGE patients' worse-dissociated performance in auditory TOVA-also seen previously in TBI and schizophrenia-may implicate a grater vulnerability of the auditory information processing system, as well as a possibly shared cognitive pathophysiological component between IGE and the above nosologies.

Efficacy of spoken word comprehension therapy in patients with chronic aphasia: a cross-over randomised controlled trial with structural imaging

OBJECTIVE

The efficacy of spoken language comprehension therapies for persons with aphasia remains equivocal. We investigated the efficacy of a self-led therapy app, 'Listen-In', and examined the relation between brain structure and therapy response.

METHODS

A cross-over randomised repeated measures trial with five testing time points (12-week intervals), conducted at the university or participants' homes, captured baseline (T1), therapy (T2-T4) and maintenance (T5) effects. Participants with chronic poststroke aphasia and spoken language comprehension impairments completed consecutive Listen-In and standard care blocks (both 12 weeks with order randomised). Repeated measures analyses of variance compared change in spoken language comprehension on two co-primary outcomes over therapy versus standard care. Three structural MRI scans (T2-T4) for each participant (subgroup, n=25) were analysed using cross-sectional and longitudinal voxel-based morphometry.

RESULTS

Thirty-five participants completed, on average, 85 hours (IQR=70-100) of Listen-In (therapy first, n=18). The first study-specific co-primary outcome (Auditory Comprehension Test (ACT)) showed large and significant improvements for trained spoken words over therapy versus standard care (11%, Cohen's d=1.12). Gains were largely maintained at 12 and 24 weeks. There were no therapy effects on the second standardised co-primary outcome (Comprehensive Aphasia Test: Spoken Words and Sentences). Change on ACT trained words was associated with volume of pretherapy right hemisphere white matter and post-therapy grey matter tissue density changes in bilateral temporal lobes.

CONCLUSIONS

Individuals with chronic aphasia can improve their spoken word comprehension many years after stroke. Results contribute to hemispheric debates implicating the right hemisphere in therapy-driven language recovery. Listen-In will soon be available on GooglePlay.

TRIAL REGISTRATION NUMBER

NCT02540889.

Thalamus is a common locus of reading, arithmetic, and IQ: Analysis of local intrinsic functional properties

Neuroimaging studies of basic achievement skills - reading and arithmetic - often control for the effect of IQ to identify unique neural correlates of each skill. This may underestimate possible effects of common factors between achievement and IQ measures on neuroimaging results. Here, we simultaneously examined achievement (reading and arithmetic) and IQ measures in young adults, aiming to identify MRI correlates of their common factors. Resting-state fMRI (rs-fMRI) data were analyzed using two metrics assessing local intrinsic functional properties; regional homogeneity (ReHo) and fractional amplitude low frequency fluctuation (fALFF), measuring local intrinsic functional connectivity and intrinsic functional activity, respectively. ReHo highlighted the thalamus/pulvinar (a subcortical region implied for selective attention) as a common locus for both achievement skills and IQ. More specifically, the higher the ReHo values, the lower the achievement and IQ scores. For fALFF, the left superior parietal lobule, part of the dorsal attention network, was positively associated with reading and IQ. Collectively, our results highlight attention-related regions, particularly the thalamus/pulvinar as a key region related to individual differences in performance on all the three measures. ReHo in the thalamus/pulvinar may serve as a tool to examine brain mechanisms underlying a comorbidity of reading and arithmetic difficulties, which could co-occur with weakness in general intellectual abilities.

Emerging atypicalities in functional connectivity of language-related networks in young infants at high familial risk for ASD

Prior studies have demonstrated that infants and toddlers who later go on to develop autism spectrum disorder (ASD) show atypical functional connectivity as well as altered neural processing of language and other auditory stimuli, but the timeline underlying the emergence of these altered developmental trajectories is still unclear. Here we used resting-state fMRI (rsfMRI) during natural sleep to examine the longitudinal development of functional connectivity in language-related networks from 1.5 to 9 months of age. We found that functional connectivity of networks that underlie the integration of sensory and motor representations, which is crucial for language development, is disrupted in infants at high familial risk (HR) for developing ASD as early as 1.5 months of age. By 9 months of age, HR infants showed hyperconnectivity between auditory and somatosensory regions whereas low risk (LR) infants displayed greater intrahemispheric connectivity between auditory cortex and higher-order temporal regions as well as the hippocampus. Furthermore, while LR infants showed robust changes in functional connectivity during the first year of life with increasing long-range connectivity accompanied by decreasing short-range connectivity over time, HR infants displayed limited developmental changes. Our findings demonstrate that early disruptions in the development of language-related network connectivity may provide an early marker for the later emergence of ASD symptomatology.

Disrupted Functional and Structural Connectivity in Angelman Syndrome

BACKGROUND AND PURPOSE

This work investigated alterations in functional connectivity (FC) and associated structures in patients with Angelman syndrome (AS) by using integrated quantitative imaging analysis and connectivity measures.

MATERIALS AND METHODS

We obtained 3T brain MR imaging, including resting-state functional MR imaging, diffusion tensor imaging, and 3D T1-weighted imaging from children with AS (n = 14) and age- and sex-matched controls (n = 28). The brains of patients with AS were analyzed by measuring FC, white matter microstructural analysis, cortical thickness, and brain volumes; these were compared with brains of controls.

RESULTS

Interregional FC analysis revealed significantly reduced intra- and interhemispheric FC, especially in the basal ganglia and thalamus, in patients with AS. Significant reductions in fractional anisotropy were found in the corpus callosum, cingulum, posterior limb of the internal capsules, and arcuate fasciculus in patients with AS. Quantitative structural analysis also showed gray matter volume loss of the basal ganglia and diffuse WM volume reduction in AS compared with the control group.

CONCLUSIONS

This integrated quantitative MR imaging analysis demonstrated poor functional and structural connectivity, as well as brain volume reduction, in children with AS, which may explain the motor and language dysfunction observed in this well-characterized neurobehavioral phenotype.

Coexistence of cerebral hypometabolism and neuroinflammation in the thalamo-limbic-brainstem region in young women with functional somatic syndrome

Background

Functional somatic syndrome (FSS) is a disorder characterized by clusters of medically unexplained symptoms. Some women suffer from persistent FSS after human papillomavirus (HPV) vaccination. However, a causal relationship has not been established, and the pathophysiology of FSS remains elusive. Here, we aimed to identify the brain regions showing altered cerebral metabolism and neuroinflammation in patients with FSS and to correlate the measures of positron emission tomography (PET) with clinical data. Twelve women diagnosed with FSS following HPV vaccination (FSS group) underwent both [¹⁸F]FDG-PET to measure glucose metabolism and [¹¹C]DPA713-PET to measure neuroinflammation. [¹⁸F]FDG standardized uptake value ratio (SUVR) and [¹¹C]DPA713 binding potential (BP_ND) values were compared voxel-wise between the FSS and control groups (n = 12 for [¹⁸F]FDG, n = 16 for [¹¹C]DPA713). A region-of-interest (ROI)-based analysis was performed to correlate PET parameters with clinical scores. Statistical significance was set at p < 0.05 corrected for multiple comparisons.

Results

Statistical parametric mapping revealed a concomitant significant decrease of [¹⁸F]FDG SUVR and increase of [¹¹C]DPA713 BP_ND in the regions covering the thalamus, mesial temporal area, and brainstem in the FSS group. Correlation analysis revealed that intelligence and memory scores were significantly positively correlated with [¹⁸F]FDG SUVR and negatively so with [¹¹C]DPA713 BP_ND in these regions. A direct comparison between [¹⁸F]FDG SUVR and [¹¹C]DPA713 BP_ND revealed a significant positive correlation in the right hippocampus and amygdala.

Conclusions

Cerebral hypometabolism with neuroinflammation occurring in the thalamo-limbic-brainstem region may reflect the pathophysiology of FSS.

Transient Aphasia Following Resection of a Thalamic Cavernous Malformation

BACKGROUND

The thalamus has a demonstrated role in language, particularly through its connectivity to frontal language cortices.

CASE DESCRIPTION

A 59-year-old man with transient mixed aphasia following resection of a left-sided thalamic cavernous malformation is reported. No operative complications were encountered, and there was no surgical contact with cortical language areas. The patient recovered full language function within a week postoperatively.

CONCLUSIONS

The role of thalamic nuclei in language processes and other reports of transient thalamic aphasia are reviewed.

Altered resting-state functional connectivity in young children at familial high risk for psychotic illness: A preliminary study

Multiple lines of evidence suggest that illness development in schizophrenia and other psychotic disorders predates the first psychotic episode by many years. In this study, we examined a sample of 15 pre-adolescent children, ages 7 through 12 years, who are at familial high-risk (FHR) because they have a parent or sibling with a history of schizophrenia or related psychotic disorder. Using multi-voxel pattern analysis (MVPA), a data-driven fMRI analysis, we assessed whole-brain differences in functional connectivity in the FHR sample as compared to an age- and sex-matched control (CON) group of 15 children without a family history of psychosis. MVPA analysis yielded a single cluster in right posterior superior temporal gyrus (pSTG/BA 22) showing significant group-differences in functional connectivity. Post-hoc characterization of this cluster through seed-to-voxel analysis revealed mostly reduced functional connectivity of the pSTG seed to a set of language and default mode network (DMN) associated brain regions including Heschl's gyrus, inferior temporal gyrus extending into fusiform gyrus, (para)hippocampus, thalamus, and a cerebellar cluster encompassing mainly Crus I/II. A height-threshold of whole-brain p < .001 (two-sided), and FDR-corrected cluster-threshold of p < .05 (non-parametric statistics) was used for post-hoc characterization. These findings suggest that abnormalities in functional communication in a network encompassing right STG and associated brain regions are present before adolescence in at-risk children and may be a risk marker for psychosis. Subsequent changes in this functional network across development may contribute to either disease manifestation or resilience in children with a familial vulnerability for psychosis.

Modulation of tonotopic ventral medial geniculate body is behaviorally relevant for speech recognition

Sensory thalami are central sensory pathway stations for information processing. Their role for human cognition and perception, however, remains unclear. Recent evidence suggests an involvement of the sensory thalami in speech recognition. In particular, the auditory thalamus (medial geniculate body, MGB) response is modulated by speech recognition tasks and the amount of this task-dependent modulation is associated with speech recognition abilities. Here, we tested the specific hypothesis that this behaviorally relevant modulation is present in the MGB subsection that corresponds to the primary auditory pathway (i.e., the ventral MGB [vMGB]). We used ultra-high field 7T fMRI to identify the vMGB, and found a significant positive correlation between the amount of task-dependent modulation and the speech recognition performance across participants within left vMGB, but not within the other MGB subsections. These results imply that modulation of thalamic driving input to the auditory cortex facilitates speech recognition.

Functional connectivity of language networks after perinatal stroke

Successful language acquisition during development is imperative for lifelong function. Complex language networks develop throughout childhood. Perinatal stroke may cause significant language disabilities but function can also be remarkably normal. Studying such very early brain injury populations may inform developmental plasticity models of language networks. We examined functional connectivity (FC) of language networks in children with arterial and venous perinatal stroke and typically developing controls (TDC) in a population-based, controlled, cohort study. Resting state functional MRI was performed at 3 T (TR/TE = 2000/30 ms, 150 volumes, 3.6mm3 voxels). Seed-based analyses used bilateral inferior frontal and superior temporal gyri. A subset of stroke participants completed clinical language testing. Sixty-six children participated (median age: 12.85±3.8y, range 6-19; arterial N = 17; venous N = 15; TDC N = 34]. Children with left hemisphere strokes had comparable FC in their right hemispheres compared to TDC. Inter- and intra-hemispheric connectivity strengths were similar between TDC and PVI but lower for AIS. Reduced FC was associated with poorer language comprehension. Language networks can be estimated using resting-state fMRI in children with perinatal stroke. Altered connectivity may occur in both hemispheres, is more pronounced with arterial lesions, and is associated with clinical function. Our results have implications for therapeutic language interventions after early stroke.

Verbal Fluency Is Affected by Altered Brain Lateralization in Adults Who Were Born Very Preterm

Language difficulties have been reported in children and adolescents who were born very preterm (<32 weeks’ gestation) and associated with an atypical lateralization of language processing, i.e., increased right-hemispheric engagement. This study used functional magnetic resonance imaging (fMRI) and spherical deconvolution tractography to study the hemodynamic responses associated with verbal fluency processing (easy and hard letter trials) and verbal fluency-related white matter fiber tracts in 64 very preterm born adults and 36 adult controls (mean age: 30 years). Tractography of the arcuate fasciculus (AF) and frontal aslant tract (FAT) was performed. Tracts were quantified in terms of mean volume, hindrance modulated orientational anisotropy, and lateralization, assessed using a laterality index (LI) to indicate hemispheric dominance. During verbal fluency fMRI, very preterm participants displayed decreased hemodynamic response suppression in both the Easy > Rest and Hard > Rest conditions, compared to controls, in superior temporal gyrus (STG), insula, thalamus, and sensorimotor cortex, particularly in the right hemisphere. At the whole-group level, decreased hemodynamic response suppression in the right sensorimotor cortex was associated with worse on-line performance on the hard letter trials. Increased left-laterality in the AF was present alongside increased right hemispheric hemodynamic response suppression in controls. When only right-handed participants were considered, decreased hemodynamic response suppression in the right STG during hard letter trials was related to weaker left and right FAT white matter integrity in the preterm group only. These results show that verbal fluency is affected by altered functional lateralization in adults who were born very preterm.

The Understanding Capacity and Information Dynamics in the Human Brain

This article proposes a theory of neuronal processes underlying cognition, focusing on the mechanisms of understanding in the human brain. Understanding is a product of mental modeling. The paper argues that mental modeling is a form of information production inside the neuronal system extending the reach of human cognition "beyond the information given" (Bruner, J.S., Beyond the Information Given, 1973). Mental modeling enables forms of learning and prediction (learning with understanding and prediction via explanation) that are unique to humans, allowing robust performance under unfamiliar conditions having no precedents in the past history. The proposed theory centers on the notions of self-organization and emergent properties of collective behavior in the neuronal substrate. The theory motivates new approaches in the design of intelligent artifacts (machine understanding) that are complementary to those underlying the technology of machine learning.

A model-guided dissociation between subcortical and cortical contributions to word recognition

Neurocognitive studies of visual word recognition have provided information about brain activity correlated with orthographic processing. Some of these studies related the orthographic neighborhood density of letter strings to the amount of hypothetical global lexical activity (GLA) in the brain as simulated by computational models of word recognition. To further investigate this issue, we used GLA of words and nonwords from the multiple read-out model of visual word recognition (MROM) and related this activity to neural correlates of orthographic processing in the brain by using functional magnetic resonance imaging (fMRI). Words and nonwords elicited linear effects in the cortex with increasing BOLD responses for decreasing values of GLA. In addition, words showed increasing linear BOLD responses for increasing GLA values in subcortical regions comprising the hippocampus, globus pallidus and caudate nucleus. We propose that these regions are involved in the matching of orthographic input onto representations in long-term memory. The results speak to a potential involvement of the basal ganglia in visual word recognition with globus pallidus and caudate nucleus activity potentially reflecting maintenance of orthographic input in working memory supporting the matching of the input onto stored representations by selection of appropriate lexical candidates and the inhibition of orthographically similar but non-matching candidates.