111 Task-based functional connectivity The majority of task-based studies in ASDs have documented reduced functional connectivity between frontal and parietal regions75,83,112 as well as between frontal and temporal and/or occipital regions.69,113 Tasks
have included language comprehension,83,88,97 cognitive control,69,75,114 mentalizing,53,113,115 PD98059 nmr social processing,113 working memory,116 and visuospatial processing.112 A number of these studies have also indicated smaller and less synchronized cortical networks in ASDs.116-117 It should be noted, however, Inhibitors,research,lifescience,medical that some task-based studies have found long-range over-connectivity between subcortical and cortical regions118-119 Inhibitors,research,lifescience,medical as well as between frontal and temporal regions.120-122 Other studies have examined
connectivity during task-related paradigms by filtering out taskrelated activity to examine connectivity patterns that are task-independent, and found evidence of decreased123-124 and increased118-121 functional connectivity. Resting-state functional connectivity Relatively fewer studies have examined brain connectivity in ASDs during resting state fMRI scans (Table VI). Cherkassky and colleagues125 Inhibitors,research,lifescience,medical reported decreased frontalposterior default network connectivity during task-based inter-trail intervals (see also refs 126-128) while others have found lower default-mode network connectivity at rest125,128-131 in ASDs. There are also reports of decreased connectivity between the anterior and posterior insula and
a number of social Inhibitors,research,lifescience,medical processing brain regions in ASDs75,114,116 and less coherent endogenous low-frequency oscillations across multiple cortical and subcortical regions in ASDs.132 von dem Hagen and colleagues133 reported reduced functional connectivity within and between resting state networks incorporating “social brain regions” including the insula and amygdala Inhibitors,research,lifescience,medical within the default-mode and salience networks, respectively, and Di Martino and colleagues134 reported increased connectivity between multiple striatal regions and striatal hyperconnectivity with the pons. Monk and colleagues127 reported positive correlations between repetitive behavior MycoClean Mycoplasma Removal Kit symptoms and resting state connectivity between posterior cingulate cortex and the right parahippocampal gyrus in adults with ASDs, despite increased connectivity between the posterior cingulate cortex, the right temporal lobe, and the right parahippocampal gyrus, although Weng and collègues128 found correlations between social and repetitive behavior symptoms and a number of resting connectivity metrics in adolescents with ASDs. Table VI Studies investigating resting state connectivity in autism spectrum disorders. ASD: Autism Spectrum Disorder; TYP: Neurotypical; †ASD refers to the entire autism sample in a particular study, including high functioning autism, Asperger’s syndrome, …