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. 2017 Jan 1;12(1):37-48.
doi: 10.1093/scan/nsw159.

A Neuroanatomical Predictor of Mirror Self-Recognition in Chimpanzees

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Free PMC article

A Neuroanatomical Predictor of Mirror Self-Recognition in Chimpanzees

E E Hecht et al. Soc Cogn Affect Neurosci. .
Free PMC article

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.

Keywords: brain evolution; chimpanzees; lateralization; self-recognition; superior longitudinal fasciculus.

Figures

Fig. 1
Fig. 1
(a) Regions of interest used for quantifying SLF gray matter terminations. Target regions included ventrolateral prefrontal cortex (VLPFC, Broca’s area), DLPFC, PMd, PMv, aIPL, pIPL and SPL. (b) Broca’s area in chimpanzees (left) and humans (right), with the approximate locations of Brodmann areas 44 and 45 indicated. It should be noted that while in humans, Broca’s area\ (areas 44 + 45) occupies the pars opercularis and pars triangularis of the inferior frontal gyrus, the sulcal anatomy of inferior frontal cortex differs in chimpanzees and the homologous chimpanzee cytoarchitectonic regions occur surrounding the ‘fos’ (Schenker et al., 2008, 2010).
Fig. 2
Fig. 2
Group composites of above‐threshold SLFII and SLFIII tractography in all 60 chimpanzees.
Fig. 3
Fig. 3
AQ for SLF terminations in the gray matter of Broca’s area. MSR+ chimpanzees showed greater rightward asymmetries compared with MSR? and MSR− apes, but no significant difference was found between MSR? and MSR− individuals. Error bars: ±1 SEM. *P < 0.05.
Fig. 4
Fig. 4
Partial correlation scatter plots, showing associations between total frequency of MSR behaviors and (a) the total number of contingent behaviors and (b) AQ for SLFIII’s terminations in the gray matter of Broca’s area. Negative AQ values are more rightwardly asymmetric.
Fig. 5
Fig. 5
Right‐hemisphere SLFIII in MSR−, MSR? and MSR+ chimpanzees. (a) White matter tract cores. Crosshairs are at the same coordinates in each panel; note the extension into more anterior regions of the white matter beneath the inferior frontal gyrus in MSR+ chimpanzees (white arrow). (b) Gray matter terminations in the cortex of PMv (magenta) and Broca’s area (cyan). Note that more anterior regions of the inferior frontal gyrus receive gray matter terminations in MSR+ chimps.

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References

    1. Anderson J.R. (1983). Responses to mirror image stimulation and assessment of self-recognition in mirror- and peer-reared stumptail macaques. The Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology, 35(3), 201–12. - PubMed
    1. Anderson J.R., Gallup G.G., Jr. (2015). Mirror self-recognition: a review and critique of attempts to promote and engineer self-recognition in primates. Primates, 56(4), 317–26. - PubMed
    1. Andersson J.L.R., Jenkinson M., Smith S. (2007). Non-linear optimisation: FMRIB technical report TR07JA1 from Available: www.fmrib.ox.ac.uk/analysis/techrep.
    1. Badre D. (2008). Cognitive control, hierarchy, and the rostro-caudal organization of the frontal lobes. Trends in Cognitive Sciences, 12(5), 193–200. - PubMed
    1. Badre D., D’Esposito M. (2009). Is the rostro-caudal axis of the frontal lobe hierarchical?. Nature Reviews in Neurosciences, 10(9), 659–69. - PMC - PubMed
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