Jeffrey Berman
The auditory radiation is the gateway to the brain for sound sensation. However this functionally important tract is not easily delineated with traditional DTI tractography. Other sensory input pathways such as the somatosensory and optic radiations have been extensively studied with traditional DTI because they comprise relatively simple single-fiber architectures. The auditory radiation is relatively small and crosses other white matter tracts. The complex architecture of the auditory radiation necessitates the use of advanced diffusion methods like high angular resolution diffusion imaging (HARDI) to pick apart the crossing fiber populations and delineate the tract.
This work enables future studies to directly assess the microstructure of the auditory radiation in an objective and accurate way. HARDI can be acquired in a clinically feasible time span and discerns multiple crossing fibers. This will improve our understanding of the biological basis of autism spectrum disorder (ASD), which is known to have deficits in the latency of the auditory evoked response. The relationship between abnormal structure and function of the auditory radiation also has ramifications for language processing impairments common in autism. This work may lead to targeted treatments designed to compensate for alterations in the auditory system.
This work enables investigation of an important sensory tract that was previously inaccessible. Other researchers and clinicians have suggested applications to other neurological and neuropsychiatric conditions that involve the auditory system and may benefit from either quantifying the tract’s microstructure or simply delineating its position.
My focus will be on examining the relationship between structure and function of the auditory radiation in ASD. HARDI tractography creates an opportunity to assess changes in white matter microstructure within the language and auditory networks in ASD. It is hypothesized that HARDI is sensitive to microstructural changes within the auditory radiation in ASD. It is further hypothesized that the white matter abnormalities will be associated with alterations in brain electrophysiology, detected using magnetoencephalography.