A neuroanatomical predictor of mirror self-recognition in chimpanzees

• Type of Material: Article
• Authors: Erin Hecht, Emory University; L.M. Mahovetz, Georgia State University; Todd Preuss, Emory University; William Hopkins, Emory University
• Language: English
• Date: 2016-11-01
• Publisher: Oxford University Press (OUP): Policy C - Option D
• Publication Version: Final Published Version
• Copyright Statement: © The Author (2016).
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1093/scan/nsw159
• Title of Journal or Parent Work: Social Cognitive and Affective Neuroscience
• ISSN: 1749-5016
• Volume: 12
• Issue: 1
• Start Page: 37
• End Page: 48
• Grant/Funding Information: This work was partially supported by the Templeton Foundation (grant 40463 to E.E.H. and T.M.P.), National Institutes of Health (grants MH-92923 to W.D.H., P01AG026423 to T.M.P., and RR-00165 to the Yerkes National Primate Research Center, superceded by Office of Research Infrastructure Programs/OD P51OD11132), and National Science Foundation (grant 1631563 to E.E.H. and T.M.P.)
• Keywords: NONHUMAN-PRIMATES; RIGHT-HEMISPHERE; Science & Technology; PAN-TROGLODYTES; lateralization; GREAT APES; FACE RECOGNITION; brain evolution; Life Sciences & Biomedicine; BRAIN IMAGES; PREFRONTAL CORTEX; chimpanzees; VON ECONOMO NEURONS; Psychology; Social Sciences; Neurosciences & Neurology; superior longitudinal fasciculus; Neurosciences; self-recognition; ASIAN ELEPHANT; BROCAS AREA; Psychology, Experimental
• Research Categories: Psychology, Behavioral; Biology, Neuroscience; Psychology, Cognitive

Abstract

The ability to recognize one's own reflection is shared by humans and only a few other species, including chimpanzees. However, this ability is highly variable across individual chimpanzees. In humans, self-recognition involves a distributed, right-lateralized network including frontal and parietal regions involved in the production and perception of action. The superior longitudinal fasciculus (SLF) is a system of white matter tracts linking these frontal and parietal regions. The current study measured mirror self-recognition (MSR) and SLF anatomy in 60 chimpanzees using diffusion tensor imaging. Successful self-recognition was associated with greater rightward asymmetry in the white matter of SLFII and SLFIII, and in SLFIII's gray matter terminations in Broca's area. We observed a visible progression of SLFIII's prefrontal extension in apes that show negative, ambiguous, and compelling evidence of MSR. Notably, SLFIII's terminations in Broca's area are not right-lateralized or particularly pronounced at the population level in chimpanzees, as they are in humans. Thus, chimpanzees with more human-like behavior show more human-like SLFIII connectivity. These results suggest that self-recognition may have co-emerged with adaptations to frontoparietal circuitry.