scholarly journals Age of Speech Onset in Autism Relates to Structural Connectivity in the Language Network

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Elise B Barbeau ◽  
Denise Klein ◽  
Isabelle Soulières ◽  
Michael Petrides ◽  
Boris Bernhardt ◽  
...  
Keyword(s):  
Structural Connectivity ◽  
Autism Spectrum ◽  
White Matter Tract ◽  
Arcuate Fasciculus ◽  
Brain Organization ◽  
Autistic Group ◽  
Categorical Diagnosis ◽  
Onset Delays ◽  
Brain Reorganization ◽  
Language Network

Abstract Speech onset delays (SOD) and language atypicalities are central aspects of the autism spectrum (AS), despite not being included in the categorical diagnosis of AS. Previous studies separating participants according to speech onset history have shown distinct patterns of brain organization and activation in perceptual tasks. One major white matter tract, the arcuate fasciculus (AF), connects the posterior temporal and left frontal language regions. Here, we used anatomical brain imaging to investigate the properties of the AF in adolescent and adult autistic individuals with typical levels of intelligence who differed by age of speech onset. The left AF of the AS group showed a significantly smaller volume than that of the nonautistic group. Such a reduction in volume was only present in the younger group. This result was driven by the autistic group without SOD (SOD−), despite their typical age of speech onset. The autistic group with SOD (SOD+) showed a more typical AF as adults relative to matched controls. This suggests that, along with multiple studies in AS-SOD+ individuals, atypical brain reorganization is observable in the 2 major AS subgroups and that such reorganization applies mostly to the language regions in SOD− and perceptual regions in SOD+ individuals.

scholarly journals Cross-species cortical alignment identifies different types of neuroanatomical reorganization in the temporal lobe of higher primates

2019 ◽  
Author(s):  
Nicole Eichert ◽  
Emma C. Robinson ◽  
Katherine L. Bryant ◽  
Saad Jbabdi ◽  
Mark Jenkinson ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Parietal Cortex ◽  
Connectivity Pattern ◽  
Arcuate Fasciculus ◽  
Computational Neuroanatomy ◽  
Brain Organization ◽  
Cortical Organization ◽  
Connectivity Patterns ◽  
Different Types ◽  
Brain Reorganization

AbstractEvolutionary modifications of the temporo-parietal cortex are considered to be a critical adaptation of the human brain. Cortical adaptations, however, can affect different aspects of brain architecture, including areal expansion or changes in connectivity profiles. We propose to distinguishing different types of brain reorganization using a computational neuroanatomy approach. We investigate the extent to which between-species alignment based on cortical myelin can predict changes in connectivity patterns across macaque, chimpanzee and human. We show that expansion and relocation of brain areas are sufficient to predict terminations of several white matter tracts in temporo-parietal cortex, including the middle and superior longitudinal fasciculus, but not of the arcuate fasciculus. This demonstrates that the arcuate fasciculus underwent additional evolutionary modifications affecting the connectivity pattern of the temporal lobe. The presented approach can flexibly be extended to include other features of cortical organization and other species, allowing direct tests of comparative hypotheses of brain organization.

scholarly journals MÓZGOWE PODŁOŻE ROZWOJU MOWY W AUTYZMIE

2021 ◽  
pp. 39-51
Author(s):  
Krystyna Rymarczyk
Keyword(s):  
Early Stage ◽  
Autism Spectrum ◽  
Speech Development ◽  
The Other ◽  
Arcuate Fasciculus ◽  
Foetal Life ◽  
Behavioural Research ◽  
Speech Development Disorders ◽  
Structure And Activity ◽  
Atypical Brain Development

Although in a majority of cases, autistic children face difficulties communicating verbally, the valid diagnostic classifi cations do not identify them as the main symptoms of the disorder. The adoption of such a position has been supported by results of (mainly behavioural) research, which imply that language and speech development in the autism spectrum disorder (ASD) is extremely variable and individually diversifi ed and the observed delay of its development is not unique to autism. On the other hand, the research conducted by means of neuroimaging methods shows that an atypical structure and activity of Broca’s and Wernicke’s areas, which are important for language processes, exist in the ASD. A weak structural and functional connectivity in the arcuate fasciculus, which connects these structures, has also been discovered. It is assumed that the changes arise from neurodevelopmental irregularities occurring at an early stage of foetal life and their causes are probably genetic. This study characterises speech development disorders and atypical brain development in autism referring to results of both behavioural and neuroimaging research.

scholarly journals Reduced Volume of the Arcuate Fasciculus in Adults with High-Functioning Autism Spectrum Conditions

2016 ◽  
Vol 10 ◽  
Author(s):  
Rachel L. Moseley ◽  
Marta M. Correia ◽  
Simon Baron-Cohen ◽  
Yury Shtyrov ◽  
Friedemann Pulvermüller ◽  
...  
Keyword(s):  
High Functioning Autism ◽  
Autism Spectrum ◽  
Autism Spectrum Conditions ◽  
Arcuate Fasciculus ◽  
High Functioning ◽  
Reduced Volume

Handedness and White Matter Networks

2020 ◽  
pp. 107385842093765
Author(s):  
Sanja Budisavljevic ◽  
Umberto Castiello ◽  
Chiara Begliomini
Keyword(s):  
White Matter ◽  
Motor Behavior ◽  
Genetic Research ◽  
Structural Connectivity ◽  
Population Level ◽  
Neural Basis ◽  
Brain Organization ◽  
Recent Developments ◽  
Commissural Pathway ◽  
Functional Brain Organization

The development and persistence of laterality is a key feature of human motor behavior, with the asymmetry of hand use being the most prominent. The idea that asymmetrical functions of the hands reflect asymmetries in terms of structural and functional brain organization has been tested many times. However, despite advances in laterality research and increased understanding of this population-level bias, the neural basis of handedness remains elusive. Recent developments in diffusion magnetic resonance imaging enabled the exploration of lateralized motor behavior also in terms of white matter and connectional neuroanatomy. Despite incomplete and partly inconsistent evidence, structural connectivity of both intrahemispheric and interhemispheric white matter seems to differ between left and right-handers. Handedness was related to asymmetry of intrahemispheric pathways important for visuomotor and visuospatial processing (superior longitudinal fasciculus), but not to projection tracts supporting motor execution (corticospinal tract). Moreover, the interindividual variability of the main commissural pathway corpus callosum seems to be associated with handedness. The review highlights the importance of exploring new avenues for the study of handedness and presents the latest state of knowledge that can be used to guide future neuroscientific and genetic research.

scholarly journals Functional brain organization for visual search in ASD

2008 ◽  
Vol 14 (6) ◽  
pp. 990-1003 ◽  
Author(s):  
BRANDON KEEHN ◽  
LAURIE BRENNER ◽  
ERICA PALMER ◽  
ALAN J. LINCOLN ◽  
RALPH-AXEL MÜLLER
Keyword(s):  
Visual Search ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Neural Mechanisms ◽  
Search Efficiency ◽  
Typically Developing ◽  
Brain Organization ◽  
Activation Patterns ◽  
Set Size ◽  
Functional Brain Organization

AbstractAlthough previous studies have shown that individuals with autism spectrum disorder (ASD) excel at visual search, underlying neural mechanisms remain unknown. This study investigated the neurofunctional correlates of visual search in children with ASD and matched typically developing (TD) children, using an event-related functional magnetic resonance imaging design. We used a visual search paradigm, manipulating search difficulty by varying set size (6, 12, or 24 items), distractor composition (heterogeneous or homogeneous) and target presence to identify brain regions associated with efficient and inefficient search. While the ASD group did not evidence accelerated response time (RT) compared with the TD group, they did demonstrate increased search efficiency, as measured by RT by set size slopes. Activation patterns also showed differences between ASD group, which recruited a network including frontal, parietal, and occipital cortices, and the TD group, which showed less extensive activation mostly limited to occipito-temporal regions. Direct comparisons (for both homogeneous and heterogeneous search conditions) revealed greater activation in occipital and frontoparietal regions in ASD than in TD participants. These results suggest that search efficiency in ASD may be related to enhanced discrimination (reflected in occipital activation) and increased top-down modulation of visual attention (associated with frontoparietal activation). (JINS, 2008, 14, 990–1003.)

scholarly journals Autism spectrum heterogeneity: fact or artifact?

2020 ◽  
Vol 25 (12) ◽  
pp. 3178-3185 ◽  
Author(s):  
Laurent Mottron ◽  
Danilo Bzdok
Keyword(s):  
Autistic Traits ◽  
Fold Increase ◽  
Autism Spectrum ◽  
Machine Learning Algorithms ◽  
Qualitative Properties ◽  
Diagnostic Practices ◽  
Clinical Intuition ◽  
Dsm 5 ◽  
Diagnostic Threshold ◽  
Categorical Diagnosis

AbstractThe current diagnostic practices are linked to a 20-fold increase in the reported prevalence of ASD over the last 30 years. Fragmenting the autism phenotype into dimensional “autistic traits” results in the alleged recognition of autism-like symptoms in any psychiatric or neurodevelopemental condition and in individuals decreasingly distant from the typical population, and prematurely dismisses the relevance of a diagnostic threshold. Non-specific socio-communicative and repetitive DSM 5 criteria, combined with four quantitative specifiers as well as all their possible combinations, render limitless variety of presentations consistent with the categorical diagnosis of ASD. We propose several remedies to this problem: maintain a line of research on prototypical autism; limit the heterogeneity compatible with a categorical diagnosis to situations with a phenotypic overlap and a validated etiological link with prototypical autism; reintroduce the qualitative properties of autism presentations and of current dimensional specifiers, language, intelligence, comorbidity, and severity in the criteria used to diagnose autism in replacement of quantitative “social” and “repetitive” criteria; use these qualitative features combined with the clinical intuition of experts and machine-learning algorithms to differentiate coherent subgroups in today’s autism spectrum; study these subgroups separately, and then compare them; and question the autistic nature of “autistic traits”

NEUROBIOLOGICAL UNDERPINNINGS OF LANGUAGE IN AUTISM SPECTRUM DISORDERS

2008 ◽  
Vol 28 ◽  
pp. 128-149 ◽  
Author(s):  
Inge-Marie Eigsti ◽  
Jillian M. Schuh
Keyword(s):  
Cognitive Task ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
Behavioral Differences ◽  
Brain Organization ◽  
Communicative Skills ◽  
Complex Cognitive Task ◽  
Brain And Behavior ◽  
And Behavior ◽  
The Brain

As a neurodevelopmental disorder, autism is characterized by impairments and differences at the levels of both brain and behavior. Communicative impairments in autism are a core feature of the disorder, and a rapidly expanding literature is exploring language in autism using the tools of cognitive neuroscience, particularly electroencephalography and brain imaging. Recent research indicates consistent differences in the degree to which language-specific processes are lateralized in the brain, and it also suggests that language impairments are linked to differences in brain structure that may lead to inefficient coordination of activity between different neural assemblies to achieve a complex cognitive task, defined as functional connectivity. We review findings from current work and suggest that neurobiological data are critical in our ability to understand the mechanisms underlying behavioral differences in communicative skills. Going beyond simple dichotomies between delayed versus deviant development, we can use such data to ask whether behavior reflects processes that are merely inefficient or, instead, whether impairments at the behavioral level reflect fundamental differences in brain organization and the networks involved in various tasks.

scholarly journals The Structural Connectivity Underpinning Language Aptitude, Working Memory, and IQ in the Perisylvian Language Network

2012 ◽  
Vol 62 ◽  
pp. 110-130 ◽  
Author(s):  
Huadong Xiang ◽  
Dan Dediu ◽  
Leah Roberts ◽  
Erik van Oort ◽  
David G. Norris ◽  
...  
Keyword(s):  
Working Memory ◽  
Structural Connectivity ◽  
Language Aptitude ◽  
Language Network

Altered Resting-State Functional and White Matter Tract Connectivity in Stroke Patients With Dysphagia

2013 ◽  
Vol 28 (3) ◽  
pp. 260-272 ◽  
Author(s):  
Shasha Li ◽  
Zhenxing Ma ◽  
Shipeng Tu ◽  
Muke Zhou ◽  
Sihan Chen ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Connectivity ◽  
Fractional Anisotropy ◽  
Resting State ◽  
Structural Connectivity ◽  
White Matter Tract ◽  
Stroke Patients ◽  
Hemispheric Stroke ◽  
Swallowing Dysfunction ◽  
The Mean

Background. Swallowing dysfunction is intractable after acute stroke. Our understanding of the alterations in neural networks of patients with neurogenic dysphagia is still developing. Objective. The aim was to investigate cerebral cortical functional connectivity and subcortical structural connectivity related to swallowing in unilateral hemispheric stroke patients with dysphagia. Methods. We combined a resting-state functional connectivity with a white matter tract connectivity approach, recording 12 hemispheric stroke patients with dysphagia, 12 hemispheric stroke patients without dysphagia, and 12 healthy controls. Comparisons of the patterns in swallowing-related functional connectivity maps between patient groups and control subjects included ( a) seed-based functional connectivity maps calculated from the primary motor cortex (M1) and the supplementary motor area (SMA) to the entire brain, ( b) a swallowing-related functional connectivity network calculated among 20 specific regions of interest (ROIs), and ( c) structural connectivity described by the mean fractional anisotropy of fibers bound through the SMA and M1. Results. Stroke patients with dysphagia exhibited dysfunctional connectivity mainly in the sensorimotor-insula-putamen circuits based on seed-based analysis of the left and right M1 and SMA and decreased connectivity in the bilateral swallowing-related ROIs functional connectivity network. Additionally, white matter tract connectivity analysis revealed that the mean fractional anisotropy of the white matter tract was significantly reduced, especially in the left-to-right SMA and in the corticospinal tract. Conclusions. Our results indicate that dysphagia secondary to stroke is associated with disruptive functional and structural integrity in the large-scale brain networks involved in motor control, thus providing new insights into the neural remodeling associated with this disorder.

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