fMRI activation during a language task in adolescents with ASD

Abstract

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by language and communication impairments, social impairments, and repetitive behaviors or restricted interests. Previous studies of semantic functions have found differences in semantic processing and differences in the activation of the language network in adults with ASD compared to controls. The goal of this study is to examine semantic functions in adolescents with ASD compared to typically developing adolescents. We utilized f MRI with a reading version of a response-naming task to investigate activation in 12 right-handed adolescent boys with ASD and 12 typically developing boys. Both groups performed the task at ceiling levels. Boys with ASD had significantly stronger activation than controls in Broca's area, which was less left lateralized in ASD individuals. Controls had a significant correlation between frontal and temporal language area activation in the left hemisphere, whereas ASD adolescents did not. Direct group comparisons revealed additional regions activated in the ASD group relative to the control group. These results suggest differences in semantic organization, approaches to the semantic task, or efficiency in semantic processing in ASD adolescents relative to typically developing adolescents. (JINS, 2008, 14, 967-979.)

The Ontogenesis of Language Impairment in Autism: A Neuropsychological Perspective

“…Left and right are reversed here by radiological convention Tesink et al 2009). Strong activations of Broca's area in individuals with AD have also been noted on a word fluency task (Kleinhans et al 2008) and on a measure requiring semantic processing of words (Knaus et al 2008), although the degree of lateralization in both these studies was smaller than that seen in a normal control group. These investigations identify abnormalities of functional organization of language that may directly contribute to language impairment.…”

Defining language impairments in a subgroup of children with autism spectrum disorder

“…This may suggest that performance on nonword repetition requires rapid integration of processing by both frontal and temporal language regions, mediated by the arcuate fasciculus. Functional imaging studies of language processing using fMRI have found reduced activation in left inferior frontal regions and other areas in both SLI [57] and ASD [58][59][60], other atypical areas of activation (e.g., cerebellum), and in ASD, reduced functional connectivity between frontal and temporal language areas. Importantly, these atypical activation patterns vary depending on participants' handedness [61].…”

Thinking in Pictures as a Cognitive Account of Autism

“…Harris et al (2006) found similar results of reduced frontal language region activation in an ASD group compared to TD controls during a word judging task with a perceptual processing baseline, and also found that the ASD group showed more similar activation in some language regions between the semantic and perceptual tasks than did the control group. In contrast, Knaus et al (2008) used a response-naming task with a perceptual processing baseline and found that subjects with ASD had greater activation in frontal and temporal language areas than did TD controls.…”