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Sakai Sharleen Sakai
Ph.D. Psychology/Neuroscience Program, Michigan State University 0
Masters Psychology, Claremont Graduate School 0
Bachelors Psychology, California State University, Humboldt 0
Primary Program: Behavioral Neuroscience
218 Giltner
(517) 353-8889

Research Statement
Our lab is interested in the factors that led to the evolution of large brains. One tenet of comparative neurology is the idea that species that exhibit behavioral specializations have correspondingly enhanced brain representations. We are currently evaluating the social brain hypothesis which proposes that the cognitive abilities resulting from social living are related to the evolution of large brains including the expansion of the frontal lobes. We can now examine this idea by evaluating a large number of carnivore species using computed tomography (CT) to create virtual three-dimensional endocasts from skull specimens. This analysis yields detailed external brain morphology as well as quantitative data including total and regional brain volumes. These data are used to evaluate factors that may selectively influence the evolution of the brain.

Related Research Websites
Sakai Lab Our lab is interested in the factors that led to the evolution of large brains. We are evaluating if brain size varies with such factors as sociality, ecological complexity and life style variables among carnivores.

Research Publications    
2012Arsznov, BM and Sakai, ST 2012 "Pride diaries: Sex, brain size and sociality in the African lion (Panthera leo) and cougar (Puma concolor)". Brain Behavior and Evolution, 79: 275-289.
2012Swanson EM, Holekamp KE, Lundrigan BL, Arsznov BM, Sakai ST 2012 Multiple Determinants of Whole and Regional Brain Volume among Terrestrial Carnivorans. PLoS ONE 7(6): e38447. doi:10.1371/journal.pone.0038447
2011Sakai, S.T., B.M. Arsznov, B.L. Lundrigan & K.E. Holekamp, 2011 Brain size and social complexity: A computed tomography study in Hyaenidae. Brain Behav. Evol 77: 91-104.
2011Sakai S.T., Arsznov B.N., Lundrigan B.L. & Holekamp K.H., 2011 Virtual endocasts: an application of computed tomography in the study of brain variation among hyenas. Ann. N.Y. Acad. Sci. 1225: E160–E170.
2010Arsznov, B.M., B.L. Lundrigan, K.E. Holekamp & S.T. Sakai 2010 Sex and the frontal cortex: A developmental CT study in the spotted hyena. Brain Behav. Evol. 76:185-97.
2009S.T. Sakai A.G. Davidson and J.A. Buford. (2009) Reticulospinal neurons in the pontomedullary reticular formation of the monkey (Macaca fascicularis) Neuroscience 163: 1158–1170
2008J. B. Tanner, E. R. Dumont, S. T. Sakai, B. L. Lundrigan, and K. E. Holekamp. (2008) Of Arcs and Vaults: The Biomechanics of Bone-Cracking in Spotted Hyenas (Crocuta crocuta). Biological Journal of the Linnean Society 95: 246–255.
2007Kay E. Holekamp, Sharleen T. Sakai, and Barbara L. Lundrigan. (2007) The Spotted Hyena (Crocuta crocuta) as a Model System for Study of the Evolution of Intelligence. Journal of Mammalogy 88(3):545–554,
2007Kay E. Holekamp, Sharleen T. Sakai, and Barbara L. Lundrigan. (2007) Social intelligence in the spotted hyena (Crocuta crocuta). Philos Trans R Soc Lond B Biol Sci., 362(1480):523-38.