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.

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.

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.

Judgments of auditory-visual affective congruence in adolescents with and without autism: a pilot study of a new task using fMRI.

One of the most widely reported developmental deficits associated with autism is difficulty perceiving and expressing emotion appropriately. Brain activation associated with performance on a new task, the Emotional Congruence Task, requires judging affective congruence of facial expression and voice, compared with their sex congruence. Participants in this pilot study were adolescents with normal IQ (n = 5) and autism or without (n = 4) autism. In the emotional congruence condition, as compared to the sex congruence of voice and face, controls had significantly more activation than the Autism group in the orbitofrontal cortex, the superior temporal, parahippocampal, and posterior cingulate gyri and occipital regions. Unlike controls, the Autism group did not have significantly greater prefrontal activation during the emotional congruence condition, but did during the sex congruence condition. Results indicate the Emotional Congruence Task can be used successfully to assess brain activation and behavior associated with integration of auditory and visual information for emotion. While the numbers in the groups are small, the results suggest that brain activity while performing the Emotional Congruence Task differed between adolescents with and without autism in fronto-limbic areas and in the superior temporal region. These findings must be confirmed using larger samples of participants.

A comparison of behavioral and emotional functioning in children and adolescents with Autistic Disorder and PDD-NOS.

Behavioral symptomatology was compared in 26 children and adolescents with Autistic Disorder ("autism") and 25 children and adolescents with Pervasive Developmental Disorder, Not Otherwise Specified ("PDD-NOS"). Relative to individuals with PDD-NOS, those with autism had more symptoms of depression, social withdrawal, atypical behavior, and immature social skills--and fewer family problems. These differences remained even when group differences in intellectual ability were statistically controlled. No group differences emerged in somatization, anxiety, or hyperactivity. Findings suggest that although both groups demonstrate considerable evidence of behavioral and emotional problems, those with autism are at particularly high risk for comorbid behavioral and emotional disabilities.