Longchuan Li1, Todd M. Preuss2, James K. Rilling3, William D. Hopkins4, Matthew F. Glasser5, Bhargav Kumar6, Roger Nana6, Xiaodong Zhang2, Xiaoping Hu6
1Biomedical Imaging Technology Center, School of Medicine, Georgia Institute of Technology/Emory University, Atlanta, GA, United States; 2Division of Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, United States; 3Center for Behavioral Neuroscience, Emory University, Atlanta, GA, United States; 4Division of Psychobiology, Yerkes National Primate Research Center, Atlanta, GA, United States; 5Department of Anthropology, Emory University, Atlanta, GA, United States; 6Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, GA, United States
Recent studies indicate that chimpanzees show a population-level bias for the use of the right hand for certain tasks. Here we studied the chimpanzees hemispheric asymmetry in the precentral corticospinal tracts (pCST) using diffusion magnetic resonance imaging and its association with handedness. The depth of the central sulcus was also measured and their relationship with handedness and the asymmetry of the pCST were studied. The results show that handedness has an effect on the asymmetry of the central sulcus depth, but not the asymmetry of the pCST fractional anisotropy (FA). It is likely that the asymmetries of central sulcus depth and that of corticospinal FA are largely functionally independent in chimpanzees and hand dominance is related more strongly to interhemispheric differences in cortical gray matter volume than to interhemispheric differences of the corticospinal tract white matter indexed by FA.