Department of Anthropology, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA 30322, USA.
Soc Cogn Affect Neurosci. 2012 Apr;7(4):369-79. doi: 10.1093/scan/nsr017. Epub 2011 Apr 5.
Our two closest living primate relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), exhibit significant behavioral differences despite belonging to the same genus and sharing a very recent common ancestor. Differences have been reported in multiple aspects of social behavior, including aggression, sex, play and cooperation. However, the neurobiological basis of these differences has only been minimally investigated and remains uncertain. Here, we present the first ever comparison of chimpanzee and bonobo brains using diffusion tensor imaging, supplemented with a voxel-wise analysis of T1-weighted images to specifically compare neural circuitry implicated in social cognition. We find that bonobos have more gray matter in brain regions involved in perceiving distress in both oneself and others, including the right dorsal amygdala and right anterior insula. Bonobos also have a larger pathway linking the amygdala with the ventral anterior cingulate cortex, a pathway implicated in both top-down control of aggressive impulses as well as bottom-up biases against harming others. We suggest that this neural system not only supports increased empathic sensitivity in bonobos, but also behaviors like sex and play that serve to dissipate tension, thereby limiting distress and anxiety to levels conducive with prosocial behavior.
我们最近的两种灵长类近亲，黑猩猩（Pan troglodytes）和倭黑猩猩（Pan paniscus），尽管属于同一属，拥有非常近的共同祖先，但表现出显著的行为差异。在多个方面的社会行为中都有报道差异，包括攻击性、性别、游戏和合作。然而，这些差异的神经生物学基础仅得到了最小程度的研究，仍然不确定。在这里，我们使用弥散张量成像首次比较了黑猩猩和倭黑猩猩的大脑，并结合 T1 加权图像的体素分析，专门比较了涉及社会认知的神经回路。我们发现，倭黑猩猩在大脑中与感知自身和他人痛苦相关的区域有更多的灰质，包括右背侧杏仁核和右前岛叶。倭黑猩猩还有一个更大的通路，将杏仁核与腹侧前扣带皮层连接起来，这个通路不仅与攻击性冲动的自上而下的控制有关，也与避免伤害他人的自下而上的偏见有关。我们认为，这个神经系统不仅支持倭黑猩猩的同理心敏感性增加，还支持性行为和游戏等行为，这些行为可以消除紧张，从而将压力和焦虑限制在有利于亲社会行为的水平。
