Hierarchical auditory processing integrating macroscopic and mesoscopic neural networks

Motivation: The invasive microscopic research on the brain can only be widely conducted in animal models. Detecting signals in laminar level using noninvasive MRI helps us bridge knowledge between macro- and micro-research. Goal(s): To understand the neural mechanism of hierarchical auditory processing in both macroscopic and mesoscopic brain cortex in-vivo. Approach: We used the 7T MRI to perform the whole-brain-fMRI and layer-fMRI with ultra-high-resolution when human was listening to a hierarchical auditory sequence paradigm. Results: The responses to the hierarchical auditory processing are not only along a pathway from auditory to frontal cortices, but also various across laminar cortex. Impact: We used the layer-fMRI to find that the auditory processing is distributed across cortical layers in a hierarchical manner. The detection of auditory processing in both macroscopic and mesoscopic levels allows us to build predictive coding model in multiple dimensions.