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.
Keywords