Study Reveals Faulty Connections Deep Within Autistic Brains
April Flowers for redOrbit.com – Your Universe Online
New light is being shed on the effects autism has on the brain by a group of researchers from San Diego State University’s Brain Development Imaging Laboratory.
According to the findings, the connection between the thalamus – a deep brain structure critical to sensory and motor functions – and the brain’s outer layer known as the cerebral cortex is impaired in children with autism spectrum disorders (ASD).
This first of its kind study combined functional and anatomical magnetic resonance imaging (fMRI) techniques with diffusion tensor imaging (DTI) to examine connections between the cerebral cortex and the thalamus. Aarti Nair, a student in the SDSU/UCSD Joint Doctoral Program in Clinical Psychology, worked with Dr. Ralph-Axel Müller, an SDSU professor of psychology, to examine more than 50 children. Some of the children had autism and some did not. The results of this study were published in the journal BRAIN.
The thalamus is critical for many functions, including vision, hearing, movement control and attention. The researchers found in children with ASD the pathways that normally connect the cerebral cortex and thalamus were affected. This suggests the two parts of the brain are not communicating well with each other in these children.
“This impaired connectivity suggests that autism is not simply a disorder of social and communicative abilities, but also affects a broad range of sensory and motor systems,” Müller said.
The scientists believe disturbances in the development of both the structure and function of the thalamus could play a role in the emergence of social and communicative impairments. These impairments are among the most distressing and prevalent symptoms of autism.
The study’s results are novel, but they are in line with a growing body of evidence on sensory and motor abnormalities in autism. The findings suggest the diagnostic criteria for autism, which emphasize social and communicative impairment, may fail to take into account the broad spectrum of problems experienced by children with autism.