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Joint Analysis of Band-Specific Functional Connectivity and Signal Complexity in Autism / Yasser GHANBARI in Journal of Autism and Developmental Disorders, 45-2 (February 2015)
[article]
Titre : Joint Analysis of Band-Specific Functional Connectivity and Signal Complexity in Autism Type de document : Texte imprimé et/ou numérique Auteurs : Yasser GHANBARI, Auteur ; Luke BLOY, Auteur ; J. CHRISTOPHER EDGAR, Auteur ; Lisa BLASKEY, Auteur ; Ragini VERMA, Auteur ; Timothy P. L. ROBERTS, Auteur Article en page(s) : p.444-460 Langues : Anglais (eng) Mots-clés : Autism Magnetoencephalography (MEG) Resting-state Connectivity Complexity Synchronization likelihood (SL) Multi-scale entropy (MSE) Index. décimale : PER Périodiques Résumé : Examination of resting state brain activity using electrophysiological measures like complexity as well as functional connectivity is of growing interest in the study of autism spectrum disorders (ASD). The present paper jointly examined complexity and connectivity to obtain a more detailed characterization of resting state brain activity in ASD. Multi-scale entropy was computed to quantify the signal complexity, and synchronization likelihood was used to evaluate functional connectivity (FC), with node strength values providing a sensor-level measure of connectivity to facilitate comparisons with complexity. Sensor level analysis of complexity and connectivity was performed at different frequency bands computed from resting state MEG from 26 children with ASD and 22 typically developing controls (TD). Analyses revealed band-specific group differences in each measure that agreed with other functional studies in fMRI and EEG: higher complexity in TD than ASD, in frontal regions in the delta band and occipital-parietal regions in the alpha band, and lower complexity in TD than in ASD in delta (parietal regions), theta (central and temporal regions) and gamma (frontal-central boundary regions); increased short-range connectivity in ASD in the frontal lobe in the delta band and long-range connectivity in the temporal, parietal and occipital lobes in the alpha band. Finally, and perhaps most strikingly, group differences between ASD and TD in complexity and FC appear spatially complementary, such that where FC was elevated in ASD, complexity was reduced (and vice versa). The correlation of regional average complexity and connectivity node strength with symptom severity scores of ASD subjects supported the overall complementarity (with opposing sign) of connectivity and complexity measures, pointing to either diminished connectivity leading to elevated entropy due to poor inhibitory regulation or chaotic signals prohibiting effective measure of connectivity. En ligne : http://dx.doi.org/10.1007/s10803-013-1915-7 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=258
in Journal of Autism and Developmental Disorders > 45-2 (February 2015) . - p.444-460[article] Joint Analysis of Band-Specific Functional Connectivity and Signal Complexity in Autism [Texte imprimé et/ou numérique] / Yasser GHANBARI, Auteur ; Luke BLOY, Auteur ; J. CHRISTOPHER EDGAR, Auteur ; Lisa BLASKEY, Auteur ; Ragini VERMA, Auteur ; Timothy P. L. ROBERTS, Auteur . - p.444-460.
Langues : Anglais (eng)
in Journal of Autism and Developmental Disorders > 45-2 (February 2015) . - p.444-460
Mots-clés : Autism Magnetoencephalography (MEG) Resting-state Connectivity Complexity Synchronization likelihood (SL) Multi-scale entropy (MSE) Index. décimale : PER Périodiques Résumé : Examination of resting state brain activity using electrophysiological measures like complexity as well as functional connectivity is of growing interest in the study of autism spectrum disorders (ASD). The present paper jointly examined complexity and connectivity to obtain a more detailed characterization of resting state brain activity in ASD. Multi-scale entropy was computed to quantify the signal complexity, and synchronization likelihood was used to evaluate functional connectivity (FC), with node strength values providing a sensor-level measure of connectivity to facilitate comparisons with complexity. Sensor level analysis of complexity and connectivity was performed at different frequency bands computed from resting state MEG from 26 children with ASD and 22 typically developing controls (TD). Analyses revealed band-specific group differences in each measure that agreed with other functional studies in fMRI and EEG: higher complexity in TD than ASD, in frontal regions in the delta band and occipital-parietal regions in the alpha band, and lower complexity in TD than in ASD in delta (parietal regions), theta (central and temporal regions) and gamma (frontal-central boundary regions); increased short-range connectivity in ASD in the frontal lobe in the delta band and long-range connectivity in the temporal, parietal and occipital lobes in the alpha band. Finally, and perhaps most strikingly, group differences between ASD and TD in complexity and FC appear spatially complementary, such that where FC was elevated in ASD, complexity was reduced (and vice versa). The correlation of regional average complexity and connectivity node strength with symptom severity scores of ASD subjects supported the overall complementarity (with opposing sign) of connectivity and complexity measures, pointing to either diminished connectivity leading to elevated entropy due to poor inhibitory regulation or chaotic signals prohibiting effective measure of connectivity. En ligne : http://dx.doi.org/10.1007/s10803-013-1915-7 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=258 Lesser suppression of response to bright visual stimuli and visual abnormality in children with autism spectrum disorder: a magnetoencephalographic study / S. AOKI in Journal of Neurodevelopmental Disorders, 11-1 (December 2019)
[article]
Titre : Lesser suppression of response to bright visual stimuli and visual abnormality in children with autism spectrum disorder: a magnetoencephalographic study Type de document : Texte imprimé et/ou numérique Auteurs : S. AOKI, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur ; J. MATSUZAKI, Auteur ; R. HANAIE, Auteur ; M. NAKANISHI, Auteur ; K. TOMINAGA, Auteur ; Y. NAGAI, Auteur ; I. MOHRI, Auteur ; M. TANIIKE, Auteur Article en page(s) : 9 p. Langues : Anglais (eng) Mots-clés : Autism spectrum disorders (ASD) Bright visual stimuli Magnetoencephalography (MEG) Neural suppression Supramarginal gyrus (SMG) Visual abnormality Index. décimale : PER Périodiques Résumé : BACKGROUND: Visual abnormality is a common sensory impairment in autism spectrum disorder (ASD), which may cause behavioral problems. However, only a few studies exist on the neural features corresponding to the visual symptoms in ASD. The purpose of this study was to investigate the relationship between cortical responses to visual stimuli and visual abnormality to examine the neurophysiological mechanisms of the visual abnormality in ASD. METHODS: Twenty-two high-functioning children with ASD (10.95 +/- 2.01 years old) and 23 age-matched typically developing (TD) children (10.13 +/- 2.80 years old) participated in this study. We measured the cortical responses (i.e., activated intensity and attenuation ratio) elicited by the Original visual image and other two types of bright images (the Dot noise or Blind image, which includes overlapped particles onto the Original image or the enhanced-brightness version of the Original image, respectively) using magnetoencephalography. RESULTS: The severity of visual abnormalities was significantly associated with behavioral problems in children with ASD. In addition, we found the increased cortical activation in response to the Original image in the left supramarginal gyrus (SMG) and middle temporal gyrus in children with ASD. However, there were no inter-group differences in the primary visual and medial orbitofrontal cortices. Furthermore, when we compared cortical responses according to the type of images, children with ASD showed lesser attenuation of the activated intensities than children with TD in response to the bright images compared with the Original image in the right SMG. These attenuation ratios (Dot noise/Original and Blind/Original) were also associated with the severity of visual abnormalities. CONCLUSIONS: Our results show that dysfunction of stimulus-driven neural suppression plays a crucial role in the neural mechanism of visual abnormality in children with ASD. To the best of our knowledge, this is the first magnetoencephalography study to demonstrate the association between the severity of visual abnormality and lower attenuation ratios in children with ASD. Our results contribute to the knowledge of the mechanisms underlying visual abnormality in children with ASD, and may therefore lead to more effective diagnosis and earlier intervention. En ligne : https://dx.doi.org/10.1186/s11689-019-9266-0 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=409
in Journal of Neurodevelopmental Disorders > 11-1 (December 2019) . - 9 p.[article] Lesser suppression of response to bright visual stimuli and visual abnormality in children with autism spectrum disorder: a magnetoencephalographic study [Texte imprimé et/ou numérique] / S. AOKI, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur ; J. MATSUZAKI, Auteur ; R. HANAIE, Auteur ; M. NAKANISHI, Auteur ; K. TOMINAGA, Auteur ; Y. NAGAI, Auteur ; I. MOHRI, Auteur ; M. TANIIKE, Auteur . - 9 p.
Langues : Anglais (eng)
in Journal of Neurodevelopmental Disorders > 11-1 (December 2019) . - 9 p.
Mots-clés : Autism spectrum disorders (ASD) Bright visual stimuli Magnetoencephalography (MEG) Neural suppression Supramarginal gyrus (SMG) Visual abnormality Index. décimale : PER Périodiques Résumé : BACKGROUND: Visual abnormality is a common sensory impairment in autism spectrum disorder (ASD), which may cause behavioral problems. However, only a few studies exist on the neural features corresponding to the visual symptoms in ASD. The purpose of this study was to investigate the relationship between cortical responses to visual stimuli and visual abnormality to examine the neurophysiological mechanisms of the visual abnormality in ASD. METHODS: Twenty-two high-functioning children with ASD (10.95 +/- 2.01 years old) and 23 age-matched typically developing (TD) children (10.13 +/- 2.80 years old) participated in this study. We measured the cortical responses (i.e., activated intensity and attenuation ratio) elicited by the Original visual image and other two types of bright images (the Dot noise or Blind image, which includes overlapped particles onto the Original image or the enhanced-brightness version of the Original image, respectively) using magnetoencephalography. RESULTS: The severity of visual abnormalities was significantly associated with behavioral problems in children with ASD. In addition, we found the increased cortical activation in response to the Original image in the left supramarginal gyrus (SMG) and middle temporal gyrus in children with ASD. However, there were no inter-group differences in the primary visual and medial orbitofrontal cortices. Furthermore, when we compared cortical responses according to the type of images, children with ASD showed lesser attenuation of the activated intensities than children with TD in response to the bright images compared with the Original image in the right SMG. These attenuation ratios (Dot noise/Original and Blind/Original) were also associated with the severity of visual abnormalities. CONCLUSIONS: Our results show that dysfunction of stimulus-driven neural suppression plays a crucial role in the neural mechanism of visual abnormality in children with ASD. To the best of our knowledge, this is the first magnetoencephalography study to demonstrate the association between the severity of visual abnormality and lower attenuation ratios in children with ASD. Our results contribute to the knowledge of the mechanisms underlying visual abnormality in children with ASD, and may therefore lead to more effective diagnosis and earlier intervention. En ligne : https://dx.doi.org/10.1186/s11689-019-9266-0 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=409 A Spectrotemporal Correlate of Language Impairment in Autism Spectrum Disorder / Luke BLOY in Journal of Autism and Developmental Disorders, 49-8 (August 2019)
[article]
Titre : A Spectrotemporal Correlate of Language Impairment in Autism Spectrum Disorder Type de document : Texte imprimé et/ou numérique Auteurs : Luke BLOY, Auteur ; K. SHWAYDER, Auteur ; Lisa BLASKEY, Auteur ; T. P. L. ROBERTS, Auteur ; D. EMBICK, Auteur Article en page(s) : p.3181-3190 Langues : Anglais (eng) Mots-clés : Language impairment Lexical access Magnetoencephalography (MEG) Oscillation Index. décimale : PER Périodiques Résumé : This study introduces an objective neurophysiological marker of language ability, the integral of event-related desynchronization in the 5-20 Hz band during 0.2-1 seconds post auditory stimulation with interleaved word/non-word tokens. This measure correlates with clinical assessment of language function in both ASD and neurotypical pediatric populations. The measure does not appear related to general cognitive ability nor autism symptom severity (beyond degree of language impairment). We suggest that this oscillatory brain activity indexes lexical search and thus increases with increased search in the mental lexicon. While specificity for language impairment in ASD remains to be determined, such an objective index has potential utility in low functioning individuals with ASD and young children during language acquisition. En ligne : http://dx.doi.org/10.1007/s10803-019-04040-x Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=403
in Journal of Autism and Developmental Disorders > 49-8 (August 2019) . - p.3181-3190[article] A Spectrotemporal Correlate of Language Impairment in Autism Spectrum Disorder [Texte imprimé et/ou numérique] / Luke BLOY, Auteur ; K. SHWAYDER, Auteur ; Lisa BLASKEY, Auteur ; T. P. L. ROBERTS, Auteur ; D. EMBICK, Auteur . - p.3181-3190.
Langues : Anglais (eng)
in Journal of Autism and Developmental Disorders > 49-8 (August 2019) . - p.3181-3190
Mots-clés : Language impairment Lexical access Magnetoencephalography (MEG) Oscillation Index. décimale : PER Périodiques Résumé : This study introduces an objective neurophysiological marker of language ability, the integral of event-related desynchronization in the 5-20 Hz band during 0.2-1 seconds post auditory stimulation with interleaved word/non-word tokens. This measure correlates with clinical assessment of language function in both ASD and neurotypical pediatric populations. The measure does not appear related to general cognitive ability nor autism symptom severity (beyond degree of language impairment). We suggest that this oscillatory brain activity indexes lexical search and thus increases with increased search in the mental lexicon. While specificity for language impairment in ASD remains to be determined, such an objective index has potential utility in low functioning individuals with ASD and young children during language acquisition. En ligne : http://dx.doi.org/10.1007/s10803-019-04040-x Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=403