Many studies of autism delve into specific areas of the brain known to govern a particular function. One reason for the limited field of study is the complex nature of the autism spectrum disorder (ASD). Another limitation has been the equipment available to study the brain but an international multi-disciplinary team of scientists has solved that problem.

They’ve developed a breakthrough technology that allowed them to produce the first ever 3-dimensional (3D) maps of the entire brains of autistic and non-autistic individuals. The maps were created from more than one trillion data points.

The team included:

• Wei Cheng, Jie Zhang, Jianfeng Feng — Center for Computational Systems Biology, Fudan University, Shanghai, PR China.
• Edmond T. Rolls — Department of Computer Science, University of Warwick, Coventry, and Oxford Centre for Computational Neuroscience, Oxford, United Kingdom (Feng is also affiliated with the Oxford Centre for Computational Neuroscience).
• Huaguang Gu — School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai, PR China.

The team developed a methodology they call Brain-Wide Association Analysis (BWAS) they used to identify the parts of the brain that create symptoms of autism. The first phase of the study involved taking functional magnetic resonance images (fMRIs) of the brains of:

• 418 subjects (people with ASD)
• 509 controls (people who did not have autism but were demographically similar to the subjects)

The fMRIs were taken while each study participant was in a resting state.

From the fMRI data, the research team identified 47,636 voxels. Voxel is a computer modeling term that combines the words volume and pixel. Voxels are used to produce a 3-D representation of something that is not geometric (the highly-contoured brain versus a stack of dominoes or house of cards, for example). Voxels are widely used to create 3-D graphic images for games, movies, and similar applications.

Once all voxels were defined, each of the 47,000+ voxels in the autistic study participants was compared to the corresponding voxels in the non-autistic participants.

The research team discovered the autistic study participants had reduced connectivity between areas of the brain associated with three elements that are affected by ASD:

• Interpretation of the facial expressions of others in order to generate social and emotional interaction.
• Theory of mind, or the ability to properly identify oneself in an environment that includes people, place, and things within the environment.
• The sense of self, or the ability to integrate facial expressions with the theory of mind to establish one’s place in a society (family, classroom, workplace, etc.)

The research suggests reduced connectivity within and between the brain regions that govern these elements of producing the symptoms of ASD.

Feng said, “BWAS tests for differences between patients and controls in the connectivity of every pair of voxels at a whole brain level.” Unlike studies limited to smaller, isolated areas of the brain, the BWAS method “has the great advantage of being fully unbiased in that the connectivity of all brain voxels can be compared, not just selected brain regions.”

The researchers expect the BWAS method can be applied to the more in-depth study of other cognitive disorders such as attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), and schizophrenia.


Sources:

1. Cheng, Wei, et al. "Autism: reduced connectivity between cortical areas involved in facial expression, the theory of mind, and the sense of self." Brain: A Journal of Neurology. Guarantors of Brain, 20 Mar. 2015. Oxford University Press. Web. 2 Apr. 2015.
2. "Brain Basics: Know Your Brain." NIH / National Institute of Neurological Disorders and Stroke. US Department of Health & Human Services, 28 2014. Web. 2 Apr. 2015.