Detecting social and non-social changes in natural scenes: performance of children with and without autism spectrum disorders and typical adults.

We probed differences in the ability to detect and interpret social cues in adults and in children and young adolescents with and without autism spectrum disorders (ASD) by investigating the effect of various social and non-social contexts on the visual exploration of pictures of natural scenes. Children and adolescents relied more on social referencing cues in the scene as compared to adults, and in the presence of such cues, were less able to use other kinds of cues. Typically developing children and adolescents were no better than those with ASD at detecting changes within the various social contexts. Results suggest children and adolescents with ASD use relevant social cues while searching a scene just as typical children do.

How somatic cortical maps differ in autistic and typical brains.

The comorbidity of 'core characteristics' and sensorimotor abnormalities in autism implies abnormalities in brain development of a general and pervasive nature and atypical organization of sensory cortex. By using magnetoencephalography, we examined the cortical response to passive tactile stimulation of the thumb and index finger of the dominant hand and lip of the individuals with autism spectrum disorder and typically developing persons. The distance between the cortical representations of thumb and the lip was significantly larger in the autism group than in typicals. Moreover, in cortex, the thumb is typically closer to the lip than the index finger. This was not observed in persons with autism. Our findings are arguably the first demonstration of abnormality in sensory organization in the brains of persons with autism.

Increased response variability in autistic brains?

One of the key ideas regarding atypical connectivity in autistic brains is the hypothesis of noisier networks. The systems level version of this hypothesis predicts reduced reliability or increased variability in the evoked responses of individuals with autism. Using magnetoencephalography, we examined the response of individuals with autism spectrum disorder versus matched typically developing persons to passive tactile stimulation of the thumb and index finger of the dominant (right) hand. A number of different analyses failed to show higher variability in the evoked response to the thumb or to the index finger in the autism group as compared with typicals. Our results argue against the hypothesis that the brain networks in autism are noisier than normal.