Frederick William Damen1,2, Longchuan Li1, William D. Hopkins3, Todd M. Preuss4, James K. Rilling3,5, Govind Nair1, Xiaodong Zhang4, Susan Kramer1, Xiaoping Hu1,2
1Biomedical Imaging Technology Center, School of Medicine, Emory University, Atlanta, GA, United States; 2Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, GA, United States; 3Division of Developmental & Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, United States; 4Division of Neuropharmacology & Neurological Diseases, Yerkes National Primate Research Center, Atlanta, GA, United States; 5Department of Anthropology, Emory University, Atlanta, GA, United States
The homologues of Brocas and Wernickes areas have been identified in chimpanzees using histological methods. However, the white-matter pathways linking these two areas and their hemispheric asymmetry have not yet been extensively explored. In this study, we reconstructed the white-matter pathways connecting the inferior frontal gyrus and superior temporal gyrus in chimpanzees using probabilistic tractography. Our results support previous findings of tracts connecting these regions through the ventral external/extreme capsule, in addition to the dorsal arcuate fasciculus with a trend of rightward asymmetry. The results suggest that leftward asymmetry of the arcuate may be a distinctive human attribute.