Slide Slam I16
The patterns and pathways of structural connectivity in the human language network
Ya-Ning Chang1, Ajay D. Halai1, Matthew Lambon Ralph1; 1MRC Cognition and Brain Sciences Unit, University of Cambridge, UK
Advanced tractography research has demonstrated the neuroanatomical basis of the dual pathway streams for language processing including a dorsal pathway subserving repetition and a ventral pathway subserving comprehension. Most previous research has focused on structural connectivity within the perisylvian language regions. However, some brain regions, such as the anterior temporal lobe (ATL) that is crucial for semantic processing and the ventral occipitotemporal regions that are crucial for orthographic processing, have not yet been well integrated into the language structural connectome. Therefore, by utilising probabilistic tractography, this study generated an anatomical map extending out the classical perisylvian language network to include the lateral/ventral ATLs and the occipitotemporal cortex. Crucially, we developed a novel approach to compute average streamlines as representative pathways connecting brain regions. The results replicated and extended previous tractography studies by demonstrating that most brain regions were linked via a single pathway. However, some brain regions especially the frontal and occipitotemporal regions were linked via dual pathways with different weights. The connectivity patterns revealed regional specific connectivity changes. The resultant neuroanatomical map of the language network provided detailed information about, not only whether the language regions connected to each other, but also how they connected. The result provides a neuroanatomical basis for establishing the relationship between functionally associated regions and their structural connections within the language network.