Multi-region hemispheric specialization differentiates human from nonhuman primate brain function.
The human behavioral repertoire greatly exceeds that of nonhuman primates. Anatomical specializations of the human brain include an enlarged neocortex and prefrontal cortex (Semendeferi et al. in Am J Phys Anthropol 114:224-241, 2001), but regional enlargements alone cannot account for these vast functional differences. Hemispheric specialization has long believed to be a major contributing factor to such distinctive human characteristics as motor dominance, attentional control and language. Yet structural cerebral asymmetries, documented in both humans and some nonhuman primate species, are relatively minor compared to behavioral lateralization. Identifying the mechanisms that underlie these functional differences remains a goal of considerable interest. Here, we investigate the intrinsic connectivity networks in four primate species (humans, chimpanzees, baboons, and capuchin monkeys) using resting-state fMRI to evaluate the intra- and inter- hemispheric coherences of spontaneous BOLD fluctuation. All three nonhuman primate species displayed lateralized functional networks that were strikingly similar to those observed in humans. However, only humans had multi-region lateralized networks, which provide fronto-parietal connectivity. Our results indicate that this pattern of within-hemisphere connectivity distinguishes humans from nonhuman primates.
Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, 78229, USA.
Hsiao-Ying
HY
Wey
Kimberley A
KA
Phillips
D Reese
DR
McKay
Angela R
AR
Laird
Peter
P
Kochunov
M Duff
MD
Davis
David C
DC
Glahn
John
J
Blangero
Timothy Q
TQ
Duong
Peter T
PT
Fox
D000328:Adult; D000818:Animals; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002428:Cebus; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D002679:Pan troglodytes; D010215:Papio; D010296:Parietal Lobe / Q000502:physiology; D012146:Rest; D013045:Species Specificity