Investigating individual differences in chimpanzee mirror self-recognition and cortical thickness: A vertex-based and region-of-interest analysis.

Mirror self-recognition (MSR), a recently evolved cognitive trait, is one of the most significant abilities that separate humans and great apes from more distantly related nonhuman primates. MSR may serve as the foundation for a number of related but more complex social cognitive abilities unique to humans and great apes including imitation, empathy, theory-of-mind, perspective taking and deception. However, our understanding of the neural basis of MSR in nonhuman primates remains largely unknown. The current study aimed to begin to fill this gap in the literature by investigating the neuroanatomical foundations of MSR in a sample of 67 captive chimpanzees. Vertex-based and region-of-interest analysis revealed significant differences in cortical thickness, particularly in males, in the cingulate cortex, inferior frontal gyrus and superior temporal and frontal cortex. The current study provides further evidence for the neuroanatomical foundations of mirror self-recognition abilities in chimpanzees.