Functional changes during visuo-spatial working memory in autism spectrum disorder: 2-year longitudinal functional magnetic resonance imaging study / V. M. VOGAN in Autism, 23-3 (April 2019)  

Public ISBD [article]  inAutism > 23-3 (April 2019) . - p.639-652 Titre : Functional changes during visuo-spatial working memory in autism spectrum disorder: 2-year longitudinal functional magnetic resonance imaging study Type de document : Texte imprimé et/ou numérique Auteurs : V. M. VOGAN, Auteur ; B. R. MORGAN, Auteur ; M. L. SMITH, Auteur ; M. J. TAYLOR, Auteur Article en page(s) : p.639-652 Langues : Anglais (eng) Mots-clés : adolescents  autism spectrum disorders  cognitive load  functional magnetic resonance imaging  longitudinal  school-age children  working memory Index. décimale : PER Périodiques Résumé : This study examined functional changes longitudinally over 2 years in neural correlates associated with working memory in youth with and without autism spectrum disorder, and the impact of increasing cognitive load. We used functional magnetic resonance imaging and a visuo-spatial 1-back task with four levels of difficulty. A total of 14 children with autism spectrum disorder and 15 typically developing children (ages 7-13) were included at baseline and followed up approximately 2 years later. Despite similar task performance between groups, differences were evident in the developmental trajectories of neural responses. Typically developing children showed greater load-dependent activation which intensified over time in the frontal, parietal and occipital lobes and the right fusiform gyrus, compared to those with autism spectrum disorder. Children with autism spectrum disorder showed minimal age-related changes in load-dependent activation, but greater longitudinal load-dependent deactivation in default mode network compared to typically developing children. Results suggest inadequate modulation of neural activity with increasing cognitive demands in children with autism spectrum disorder, which does not mature into adolescence, unlike their typically developing peers. Diminished ability for children with autism spectrum disorder to modulate neural activity during this period of maturation suggests that they may be more vulnerable to the increasing complexity of social and academic demands as they progress through adolescence than their peers. En ligne : http://dx.doi.org/10.1177/1362361318766572 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=392 [article] Functional changes during visuo-spatial working memory in autism spectrum disorder: 2-year longitudinal functional magnetic resonance imaging study [Texte imprimé et/ou numérique] / V. M. VOGAN, Auteur ; B. R. MORGAN, Auteur ; M. L. SMITH, Auteur ; M. J. TAYLOR, Auteur . - p.639-652. Langues : Anglais (eng) in Autism > 23-3 (April 2019) . - p.639-652 Mots-clés : adolescents  autism spectrum disorders  cognitive load  functional magnetic resonance imaging  longitudinal  school-age children  working memory Index. décimale : PER Périodiques Résumé : This study examined functional changes longitudinally over 2 years in neural correlates associated with working memory in youth with and without autism spectrum disorder, and the impact of increasing cognitive load. We used functional magnetic resonance imaging and a visuo-spatial 1-back task with four levels of difficulty. A total of 14 children with autism spectrum disorder and 15 typically developing children (ages 7-13) were included at baseline and followed up approximately 2 years later. Despite similar task performance between groups, differences were evident in the developmental trajectories of neural responses. Typically developing children showed greater load-dependent activation which intensified over time in the frontal, parietal and occipital lobes and the right fusiform gyrus, compared to those with autism spectrum disorder. Children with autism spectrum disorder showed minimal age-related changes in load-dependent activation, but greater longitudinal load-dependent deactivation in default mode network compared to typically developing children. Results suggest inadequate modulation of neural activity with increasing cognitive demands in children with autism spectrum disorder, which does not mature into adolescence, unlike their typically developing peers. Diminished ability for children with autism spectrum disorder to modulate neural activity during this period of maturation suggests that they may be more vulnerable to the increasing complexity of social and academic demands as they progress through adolescence than their peers. En ligne : http://dx.doi.org/10.1177/1362361318766572 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=392

Load matters: neural correlates of verbal working memory in children with autism spectrum disorder / V. M. VOGAN in Journal of Neurodevelopmental Disorders, 10-1 (December 2018)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 10-1 (December 2018) . - 19 p. Titre : Load matters: neural correlates of verbal working memory in children with autism spectrum disorder Type de document : Texte imprimé et/ou numérique Auteurs : V. M. VOGAN, Auteur ; K. E. FRANCIS, Auteur ; B. R. MORGAN, Auteur ; M. L. SMITH, Auteur ; M. J. TAYLOR, Auteur Année de publication : 2018 Article en page(s) : 19 p. Langues : Anglais (eng) Mots-clés : Autism spectrum disorder  Cognitive load  Executive functioning  Verbal working memory  fMRI Index. décimale : PER Périodiques Résumé : BACKGROUND: Autism spectrum disorder (ASD) is a pervasive neurodevelopmental disorder characterised by diminished social reciprocity and communication skills and the presence of stereotyped and restricted behaviours. Executive functioning deficits, such as working memory, are associated with core ASD symptoms. Working memory allows for temporary storage and manipulation of information and relies heavily on frontal-parietal networks of the brain. There are few reports on the neural correlates of working memory in youth with ASD. The current study identified the neural systems underlying verbal working memory capacity in youth with and without ASD using functional magnetic resonance imaging (fMRI). METHODS: Fifty-seven youth, 27 with ASD and 30 sex- and age-matched typically developing (TD) controls (9-16 years), completed a one-back letter matching task (LMT) with four levels of difficulty (i.e. cognitive load) while fMRI data were recorded. Linear trend analyses were conducted to examine brain regions that were recruited as a function of increasing cognitive load. RESULTS: We found similar behavioural performance on the LMT in terms of reaction times, but in the two higher load conditions, the ASD youth had lower accuracy than the TD group. Neural patterns of activations differed significantly between TD and ASD groups. In TD youth, areas classically used for working memory, including the lateral and medial frontal, as well as superior parietal brain regions, increased in activation with increasing task difficulty, while areas related to the default mode network (DMN) showed decreasing activation (i.e., deactivation). The youth with ASD did not appear to use this opposing cognitive processing system; they showed little recruitment of frontal and parietal regions across the load but did show similar modulation of the DMN. CONCLUSIONS: In a working memory task, where the load was manipulated without changing executive demands, TD youth showed increasing recruitment with increasing load of the classic fronto-parietal brain areas and decreasing involvement in default mode regions. In contrast, although they modulated the default mode network, youth with ASD did not show the modulation of increasing brain activation with increasing load, suggesting that they may be unable to manage increasing verbal information. Impaired verbal working memory in ASD would interfere with the youths' success academically and socially. Thus, determining the nature of atypical neural processing could help establish or monitor working memory interventions for ASD. En ligne : http://dx.doi.org/10.1186/s11689-018-9236-y Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=386 [article] Load matters: neural correlates of verbal working memory in children with autism spectrum disorder [Texte imprimé et/ou numérique] / V. M. VOGAN, Auteur ; K. E. FRANCIS, Auteur ; B. R. MORGAN, Auteur ; M. L. SMITH, Auteur ; M. J. TAYLOR, Auteur . - 2018 . - 19 p. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 10-1 (December 2018) . - 19 p. Mots-clés : Autism spectrum disorder  Cognitive load  Executive functioning  Verbal working memory  fMRI Index. décimale : PER Périodiques Résumé : BACKGROUND: Autism spectrum disorder (ASD) is a pervasive neurodevelopmental disorder characterised by diminished social reciprocity and communication skills and the presence of stereotyped and restricted behaviours. Executive functioning deficits, such as working memory, are associated with core ASD symptoms. Working memory allows for temporary storage and manipulation of information and relies heavily on frontal-parietal networks of the brain. There are few reports on the neural correlates of working memory in youth with ASD. The current study identified the neural systems underlying verbal working memory capacity in youth with and without ASD using functional magnetic resonance imaging (fMRI). METHODS: Fifty-seven youth, 27 with ASD and 30 sex- and age-matched typically developing (TD) controls (9-16 years), completed a one-back letter matching task (LMT) with four levels of difficulty (i.e. cognitive load) while fMRI data were recorded. Linear trend analyses were conducted to examine brain regions that were recruited as a function of increasing cognitive load. RESULTS: We found similar behavioural performance on the LMT in terms of reaction times, but in the two higher load conditions, the ASD youth had lower accuracy than the TD group. Neural patterns of activations differed significantly between TD and ASD groups. In TD youth, areas classically used for working memory, including the lateral and medial frontal, as well as superior parietal brain regions, increased in activation with increasing task difficulty, while areas related to the default mode network (DMN) showed decreasing activation (i.e., deactivation). The youth with ASD did not appear to use this opposing cognitive processing system; they showed little recruitment of frontal and parietal regions across the load but did show similar modulation of the DMN. CONCLUSIONS: In a working memory task, where the load was manipulated without changing executive demands, TD youth showed increasing recruitment with increasing load of the classic fronto-parietal brain areas and decreasing involvement in default mode regions. In contrast, although they modulated the default mode network, youth with ASD did not show the modulation of increasing brain activation with increasing load, suggesting that they may be unable to manage increasing verbal information. Impaired verbal working memory in ASD would interfere with the youths' success academically and socially. Thus, determining the nature of atypical neural processing could help establish or monitor working memory interventions for ASD. En ligne : http://dx.doi.org/10.1186/s11689-018-9236-y Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=386

The neural correlates of visuo-spatial working memory in children with autism spectrum disorder: effects of cognitive load / V. M. VOGAN in Journal of Neurodevelopmental Disorders, 6-1 (December 2014)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 6-1 (December 2014) . - p.19 Titre : The neural correlates of visuo-spatial working memory in children with autism spectrum disorder: effects of cognitive load Type de document : Texte imprimé et/ou numérique Auteurs : V. M. VOGAN, Auteur ; B. R. MORGAN, Auteur ; W. LEE, Auteur ; T. L. POWELL, Auteur ; M. L. SMITH, Auteur ; M. J. TAYLOR, Auteur Article en page(s) : p.19 Langues : Anglais (eng) Mots-clés : Autism spectrum disorder  Cognitive load  Executive function  Frontal lobe  Functional magnetic resonance imaging  Parietal lobe  Working memory Index. décimale : PER Périodiques Résumé : BACKGROUND: Research on the neural bases of cognitive deficits in autism spectrum disorder (ASD) has shown that working memory (WM) difficulties are associated with abnormalities in the prefrontal cortex. However, cognitive load impacts these findings, and no studies have examined the relation between WM load and neural underpinnings in children with ASD. Thus, the current study determined the effects of cognitive load on WM, using a visuo-spatial WM capacity task in children with and without ASD with functional magnetic resonance imaging (fMRI). METHODS: We used fMRI and a 1-back colour matching task (CMT) task with four levels of difficulty to compare the cortical activation patterns associated with WM in children (7-13 years old) with high functioning autism (N = 19) and matched controls (N = 17) across cognitive load. RESULTS: Performance on CMT was comparable between groups, with the exception of one difficulty level. Using linear trend analyses, the control group showed increasing activation as a function of difficulty level in frontal and parietal lobes, particularly between the highest difficulty levels, and decreasing activation as a function of difficulty level in the posterior cingulate and medial frontal gyri. In contrast, children with ASD showed increasing activation only in posterior brain regions and decreasing activation in the posterior cingulate and medial frontal gyri, as a function of difficulty level. Significant differences were found in the precuneus, dorsolateral prefrontal cortex and medial premotor cortex, where control children showed greater positive linear relations between cortical activity and task difficulty level, particularly at the highest difficulty levels, but children with ASD did not show these trends. CONCLUSIONS: Children with ASD showed differences in activation in the frontal and parietal lobes-both critical substrates for visuo-spatial WM. Our data suggest that children with ASD rely mainly on posterior brain regions associated with visual and lower level processing, whereas controls showed activity in frontal lobes related to the classic WM network. Findings will help guide future work by localizing areas of vulnerability to developmental disturbances. En ligne : http://dx.doi.org/10.1186/1866-1955-6-19 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=346 [article] The neural correlates of visuo-spatial working memory in children with autism spectrum disorder: effects of cognitive load [Texte imprimé et/ou numérique] / V. M. VOGAN, Auteur ; B. R. MORGAN, Auteur ; W. LEE, Auteur ; T. L. POWELL, Auteur ; M. L. SMITH, Auteur ; M. J. TAYLOR, Auteur . - p.19. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 6-1 (December 2014) . - p.19 Mots-clés : Autism spectrum disorder  Cognitive load  Executive function  Frontal lobe  Functional magnetic resonance imaging  Parietal lobe  Working memory Index. décimale : PER Périodiques Résumé : BACKGROUND: Research on the neural bases of cognitive deficits in autism spectrum disorder (ASD) has shown that working memory (WM) difficulties are associated with abnormalities in the prefrontal cortex. However, cognitive load impacts these findings, and no studies have examined the relation between WM load and neural underpinnings in children with ASD. Thus, the current study determined the effects of cognitive load on WM, using a visuo-spatial WM capacity task in children with and without ASD with functional magnetic resonance imaging (fMRI). METHODS: We used fMRI and a 1-back colour matching task (CMT) task with four levels of difficulty to compare the cortical activation patterns associated with WM in children (7-13 years old) with high functioning autism (N = 19) and matched controls (N = 17) across cognitive load. RESULTS: Performance on CMT was comparable between groups, with the exception of one difficulty level. Using linear trend analyses, the control group showed increasing activation as a function of difficulty level in frontal and parietal lobes, particularly between the highest difficulty levels, and decreasing activation as a function of difficulty level in the posterior cingulate and medial frontal gyri. In contrast, children with ASD showed increasing activation only in posterior brain regions and decreasing activation in the posterior cingulate and medial frontal gyri, as a function of difficulty level. Significant differences were found in the precuneus, dorsolateral prefrontal cortex and medial premotor cortex, where control children showed greater positive linear relations between cortical activity and task difficulty level, particularly at the highest difficulty levels, but children with ASD did not show these trends. CONCLUSIONS: Children with ASD showed differences in activation in the frontal and parietal lobes-both critical substrates for visuo-spatial WM. Our data suggest that children with ASD rely mainly on posterior brain regions associated with visual and lower level processing, whereas controls showed activity in frontal lobes related to the classic WM network. Findings will help guide future work by localizing areas of vulnerability to developmental disturbances. En ligne : http://dx.doi.org/10.1186/1866-1955-6-19 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=346

Widespread White Matter Differences in Children and Adolescents with Autism Spectrum Disorder / V. M. VOGAN in Journal of Autism and Developmental Disorders, 46-6 (June 2016)  

Public ISBD [article]  inJournal of Autism and Developmental Disorders > 46-6 (June 2016) . - p.2138-2147 Titre : Widespread White Matter Differences in Children and Adolescents with Autism Spectrum Disorder Type de document : Texte imprimé et/ou numérique Auteurs : V. M. VOGAN, Auteur ; B. R. MORGAN, Auteur ; R. C. LEUNG, Auteur ; Evdokia ANAGNOSTOU, Auteur ; K. DOYLE-THOMAS, Auteur ; M. J. TAYLOR, Auteur Article en page(s) : p.2138-2147 Langues : Anglais (eng) Mots-clés : White matter  Diffusion tensor imaging  Autism Development Index. décimale : PER Périodiques Résumé : Diffusion tensor imaging studies show white matter (WM) abnormalities in children with autism spectrum disorder (ASD). However, investigations are often limited by small samples, particularly problematic given the heterogeneity of ASD. We explored WM using DTI in a large sample of 130 children and adolescents (7–15 years) with and without ASD, whether age-related changes differed between ASD and control groups, and the relation between DTI measures and ASD symptomatology. Reduced fractional anisotropy and axial diffusivity were observed in ASD in numerous WM tracts, including the corpus callosum and thalamocortical fibres—tracts crucial for interhemispheric connectivity and higher order information processing. Widespread WM compromise in ASD is consistent with the view that ASD is a disorder of generalized complex information processing. En ligne : http://dx.doi.org/10.1007/s10803-016-2744-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=288 [article] Widespread White Matter Differences in Children and Adolescents with Autism Spectrum Disorder [Texte imprimé et/ou numérique] / V. M. VOGAN, Auteur ; B. R. MORGAN, Auteur ; R. C. LEUNG, Auteur ; Evdokia ANAGNOSTOU, Auteur ; K. DOYLE-THOMAS, Auteur ; M. J. TAYLOR, Auteur . - p.2138-2147. Langues : Anglais (eng) in Journal of Autism and Developmental Disorders > 46-6 (June 2016) . - p.2138-2147 Mots-clés : White matter  Diffusion tensor imaging  Autism Development Index. décimale : PER Périodiques Résumé : Diffusion tensor imaging studies show white matter (WM) abnormalities in children with autism spectrum disorder (ASD). However, investigations are often limited by small samples, particularly problematic given the heterogeneity of ASD. We explored WM using DTI in a large sample of 130 children and adolescents (7–15 years) with and without ASD, whether age-related changes differed between ASD and control groups, and the relation between DTI measures and ASD symptomatology. Reduced fractional anisotropy and axial diffusivity were observed in ASD in numerous WM tracts, including the corpus callosum and thalamocortical fibres—tracts crucial for interhemispheric connectivity and higher order information processing. Widespread WM compromise in ASD is consistent with the view that ASD is a disorder of generalized complex information processing. En ligne : http://dx.doi.org/10.1007/s10803-016-2744-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=288

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