From the Guidelines
Brain imaging findings in Autism Spectrum Disorder (ASD) consistently show differences in prefrontal and early sensory cortex activity.
Key Findings
- Differential prefrontal cortex activity: Studies have found that non-autistic control groups show greater activity in the prefrontal cortex, particularly in areas such as BA9 and BA10, during perception tasks compared to autistic individuals 1.
- Heightened occipital activity: Autistic individuals have been found to show greater recruitment of the extrastriate V2 cortex (BA18) during visual processing, which is involved in early visual processing, detecting orientation, contours/edges, and colors of objects 1.
- Abnormal white matter development: Research has also shown that ASD is associated with abnormal white matter development, including increased myelination and aberrant connectivity, particularly in frontal–subcortical circuits 1.
- Frontal–subcortical dysfunction: The prefrontal cortex plays a crucial role in higher-order stages of perception, and its dysfunction has been linked to ASD symptoms, including social attention, perseveration, and language/communication deficits 1.
Implications
These findings suggest that ASD is associated with differences in brain structure and function, particularly in regions involved in sensory processing, social cognition, and executive function. Understanding these differences can inform the development of more effective diagnostic and therapeutic strategies for ASD.
From the Research
Consistent Brain Imaging Findings in Autism Spectrum Disorder (ASD)
- Studies have consistently shown that ASD is associated with atypical brain connectivity, including both hypo- and hyperconnectivity 2, 3, 4
- Functional MRI and diffusion tensor imaging techniques suggest that volume abnormalities in ASD are associated with atypical functional and structural connectivity in the brain 3, 4
- Research has identified common loci of dysfunction in ASD, including the mid- and posterior insula, posterior cingulate cortex, and thalamus 2, 5
- Abnormal connectivity patterns in ASD brains have been observed across the lifespan, with implications for social communication and restricted and repetitive behaviors 5, 6
- Combining structural and functional MRI information can improve the detection of ASD, with classification accuracies of up to 85.06% reported in some studies 6
- The use of large-scale datasets, such as the Autism Brain Imaging Data Exchange (ABIDE), has facilitated the discovery of consistent brain imaging findings in ASD 2, 6