64 Because fMRI requires minimal motion from research subjects, cognitive manifestations of restricted and repetitive behaviors have been the focus of fMRI research. Such studies have mostly relied on tasks requiring cognitive control because of linkages between deficits on neuropsychological
cognitive control tasks and symptoms of restricted and repetitive behaviors and interests in ASDs.65 Animal lesion and nonclinical Inhibitors,research,lifescience,medical human neuroimaging studies indicate that cognitive control is mediated by frontostriatal brain systems, including the lateral prefrontal cortex, the inferior frontal cortex (including the insular cortex), the anterior cingulate cortex, the intraparietal sulcus, and the striatum.66 nearly Functional MRI studies of cognitive control in ASDs have revealed anomalous activation in frontostriatal brain regions (Table III), including inferior and middle frontal gyri, dorsal anterior Inhibitors,research,lifescience,medical cingulate cortex, and the basal ganglia during cognitive Inhibitors,research,lifescience,medical control tasks. Such findings have been reported using go/no-go, Stroop, and switching tasks,67 tasks that require interference inhibition,68-72 response
monitoring,73 novelty detection,74-75 spatial attention,68 working memory,76,77 and saccadic eye movements.78 These findings have been read this interpreted to reflect deficits in behavioral inhibition and/or generation of adaptive behaviors linked to the
expression of restricted and repetitive behavior and interests. Although the direction of effects has varied across studies (ie, frontostriatal hyperactivation vs hypoactivation), Inhibitors,research,lifescience,medical likely due to task demands and analysis methods, anomalous frontostriatal activation during tasks requiring cognitive control has been a consistent result in ASD samples, Inhibitors,research,lifescience,medical with the majority of findings indicating frontostriatal hyperactivation that has been interpreted to reflect a neurof unctional compensatory mechanisms to overcome cortical inefficiency.70 Table III Studies investigating cognitive control in autism spectrum disorders. ASD: Autism Spectrum Disorder; TYP: Neurotypical; †ASD refers to the entire Brefeldin_A autism sample in a particular study, including high functioning autism, Asperger’s syndrome, and … Communication Investigations of communication deficits in ASDs have focused predominantly on brain regions mediating language perception, comprehension, and generation. The left hemisphere is typically language-dominant, and speech production is mediated by Broca’s area at the junction of the frontal, parietal, and temporal lobes, whereas speech comprehension is mediated by Wernicke’s area in the posterior temporal lobe.