Department of African Zoology, Royal Museum for Central Africa, 3080 Tervuren, Belgium.
Cereb Cortex. 2013 Feb;23(2):411-22. doi: 10.1093/cercor/bhs029. Epub 2012 Feb 23.
A left larger than right planum temporale (PT) is a neuroanatomical asymmetry common to both humans and chimpanzees. A similar asymmetry was observed in the human parietal operculum (PO), and the convergence of PT and PO asymmetries is strongly associated with right-handedness. Here, we assessed whether this combination also exists in common chimpanzees. Magnetic resonance scans were obtained in 83 captive subjects. PT was quantified following procedures previously employed and PO was defined as the maximal linear distance between the end point of the sylvian fissure and the central sulcus. Handedness was assessed using 2 tasks that were designed to simulate termite fishing of wild chimpanzees and to elicit bimanual coordination without tool use. Chimpanzees showed population-level leftward asymmetries for both PT and PO. As in humans, these leftward asymmetries were not correlated. Handedness for tool use but not for nontool use motor actions mediated the expression of asymmetries in PT and PO, with right-handed apes showing more pronounced leftward asymmetries. Consistent PT and PO asymmetry combinations were observed in chimpanzees. The proportions of individuals showing these combinations were comparable in humans and chimpanzees; however, interaction between handedness and patterns of combined PO and PT asymmetries differed between the 2 species.
左颞平面大于右颞平面（PT）是人类和黑猩猩共有的一种神经解剖学不对称现象。人类顶下小叶（PO）也存在类似的不对称性，PT 和 PO 不对称的趋同与右利手密切相关。在这里，我们评估了这种组合是否也存在于普通黑猩猩中。对 83 只圈养的黑猩猩进行了磁共振扫描。PT 是按照以前使用的程序进行量化的，PO 被定义为从外侧裂终点到中央沟的最大线性距离。使用 2 项旨在模拟野生黑猩猩白蚁捕捞和诱发双手协调而不使用工具的任务来评估利手性。黑猩猩在 PT 和 PO 上均表现出群体水平的左偏性。与人类一样，这些左偏性没有相关性。对于工具使用而非非工具运动动作的利手性介导了 PT 和 PO 不对称性的表达，右利手的黑猩猩表现出更明显的左偏性。在黑猩猩中观察到了一致的 PT 和 PO 不对称组合。在人类和黑猩猩中，表现出这些组合的个体比例相当；然而，在这 2 个物种中，利手性和组合的 PO 和 PT 不对称模式之间的相互作用是不同的。
