Brain Imaging

A Quantitative Link between Face Discrimination Deficits and Neuronal Selectivity for Faces in Autism

Source: 
NeuroImage: Clinical
Date Published: 
March 15, 2013
Abstract: 

In this fMRI study of adults with ASD, reduced neuronal selectivity for faces was linked to greater behavioral deficits in face recognition.

Differences in White Matter Fiber Tract Development Present from 6 to 24 Months in Infants with Autism.

Source: 
American Journal of Psychiatry
Date Published: 
June 2012
Abstract: 

Research suggests that aberrant development of white matter pathways may precede the manifestation of autistic symptoms in the first year of life.

The Geometric Structure of the Brain Fiber Pathways

Source: 
Science
Date Published: 
March 30, 2012
Abstract: 

Using diffusion magnetic resonance imaging, researchers found cerebral fiber pathways formed a rectilinear three-dimensional grid and Cortico-cortical pathways formed parallel sheets of interwoven paths in four nonhuman primate species and in humans.

Special Report: Connectivity

Source: 
SFARI
Date Published: 
March 25, 2013
Abstract: 

This special report from the Simons Foundation looks at neural connectivity theories of autism.

Developmental Meta-Analysis of the Functional Neural Correlates of Autism Spectrum Disorders

Source: 
Journal of the American Academy of Child and Adolescent Psychiatry
Date Published: 
December 26, 2012
Abstract: 

According to this recent meta-analysis of fMRI studies, autism-related changes in brain activity may continue to develop with age.

Impaired Coordination of Brain Activity in Autism Involves Local, as Well as Long-Range, Signaling

Source: 
Science Daily
Date Published: 
January 14, 2013
Abstract: 

MEG study finds diminished long-range and local functional connectivity as individuals with ASD viewed faces. The study challenges the popular assumption that only long-range connectivity is reduced in ASD.

Impaired Language Pathways in Tuberous Sclerosis Complex Patients with Autism Spectrum Disorders

Source: 
Cerebral Cortex
Date Published: 
June 1, 2012
Abstract: 

"The purpose of this study was to examine the relationship between language pathways and autism spectrum disorders (ASDs) in patients with tuberous sclerosis complex (TSC). "

Fractionation of Social Brain Circuits in Autism Spectrum Disorders

Source: 
Brain
Date Published: 
September 2012
Abstract: 

"Here, we evaluate the hypothesis that decreased connectivity in high-functioning adolescents with an autism spectrum disorder relative to typically developing adolescents is concentrated within domain-specific circuits that are specialized for social processing. Using a novel whole-brain connectivity approach in functional magnetic resonance imaging, we found that not only are decreases in connectivity most pronounced between regions of the social brain but also they are selective to connections between limbic-related brain regions involved in affective aspects of social processing from other parts of the social brain that support language and sensorimotor processes."

A Stable Pattern of EEG Spectral Coherence Distinguishes Children with Autism From Neuro-typical Controls - A Large Case Control Study

Source: 
BMC Medicine
Date Published: 
June 26, 2012
Abstract: 

"BACKGROUND: The autism rate has recently increased to 1 in 100 children. Genetic studies demonstrate poorly understood complexity. Environmental factors apparently also play a role. Magnetic resonance imaging (MRI) studies demonstrate increased brain sizes and altered connectivity. Electroencephalogram (EEG) coherence studies confirm connectivity changes. However, genetic-, MRI- and/or EEG-based diagnostic tests are not yet available. The varied study results likely reflect methodological and population differences, small samples and, for EEG, lack of attention to group-specific artifact.

RESULTS: Total sample PCA [principal components analysis] of coherence data identified 40 factors which explained 50.8% of the total population variance. For the 2- to 12-year-olds, the 40 factors showed highly significant group differences (P < 0.0001). Ten randomly generated split half replications demonstrated high-average classification success (C, 88.5%; ASD, 86.0%). Still higher success was obtained in the more restricted age sub-samples using the jackknifing technique: 2- to 4-year-olds (C, 90.6%; ASD, 98.1%); 4- to 6-year-olds (C, 90.9%; ASD 99.1%); and 6- to 12-year-olds (C, 98.7%; ASD, 93.9%). Coherence loadings demonstrated reduced short-distance and reduced, as well as increased, long-distance coherences for the ASD-groups, when compared to the controls. Average spectral loading per factor was wide (10.1 Hz)."