Extended Broca’s Area in the Connectome of Language in Adults: Subcortical Single-Subject Analysis Using DTI Tractography

• Published in: Brain topography Vol. 26; no. 3; pp. 428 - 441
• Main Authors: Lemaire, Jean-Jacques, Golby, Alexandra, Wells, William M, Pujol, Sonia, Tie, Yanmei, Rigolo, Laura, Yarmarkovich, Alexander, Pieper, Steve, Westin, Carl-Fredrik, Jolesz, Ferenc, Kikinis, Ron
• Format: Journal Article
• Language: English
• Published: 22.09.2012
• ISSN: 0896-0267; 1573-6792
• DOI: 10.1007/s10548-012-0257-7

Traditional models of the human language circuitry encompass three cortical areas, Broca's, Geschwind's and Wernicke's, and their connectivity. In an effort to expand current knowledge, we used diffusion tensor imaging (DTI) to explore subject-specific structural macroscopic connectivity, focusing on Broca’s area. Fascicles were studied using diffusion tensor imaging fiber tracking seeded from volumes placed manually within the white matter. White matter fascicles were co-registered with 3-D renderings of the brain in 12 healthy subjects. We discovered a connectome divisible into three systems --anterior, superior and inferior-- around the insula, more complex than previously thought. The extended Broca’s area involves two new fascicles: the operculo-premotor fascicle comprised of well-organized U-shaped fibers that connect the pars opercularis with the premotor region; and (2) the triangulo-orbitaris system comprised of intermingled U-shaped fibers that connect the pars triangularis with the pars orbitaris. The findings enhance our understanding of human language.