Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, USA.
Am J Primatol. 2013 May;75(5):441-9. doi: 10.1002/ajp.22120. Epub 2013 Jan 8.
In developing human children, joint attention (JA) is an important preverbal skill fundamental to the development of language. Poor JA skills have been described as a behavioral risk factor for some neurodevelopmental disorders, such as autism spectrum disorder. It has been hypothesized that the anterior cingulate cortex (ACC) plays an important role in the development of JA in human children. Here, we tested whether the morphometry and lateralization of the ACC differed between chimpanzees that were classified as either consistently or inconsistently engaging in JA with a human experimenter. Results showed that chimpanzees that performed poorly on the JA task had larger gray matter (GM) volumes in the ACC compared to apes that performed well on the task. In addition, both population-level asymmetries and sex differences in the volume of GM were found within the ACC. Specifically, females had relatively larger GM volumes in two of the three subregions of the ACC compared to males, and significant leftward asymmetries were found for two of the subregions whereas a rightward bias was observed in the third. Based on these findings, we suggest that the ACC plays an important role in mediating JA, not just in humans, but also chimpanzees. We further suggest that the differences found between groups may reflect inherent differences in the amount of white matter within the ACC, thereby suggesting reduced connectivity between the ACC and other cortical regions in chimpanzees with poor JA skills.
在人类儿童的发展过程中，共同注意力（Joint Attention，JA）是一种重要的前言语技能，是语言发展的基础。共同注意力技能较差被描述为一些神经发育障碍（如自闭症谱系障碍）的行为风险因素。有人假设，前扣带皮层（Anterior Cingulate Cortex，ACC）在人类儿童共同注意力的发展中起着重要作用。在这里，我们测试了在与人类实验者进行 JA 时被归类为始终或不一致地参与 JA 的黑猩猩中，ACC 的形态和侧化是否存在差异。结果表明，在 JA 任务中表现不佳的黑猩猩的 ACC 中的灰质（GM）体积大于在任务中表现良好的黑猩猩。此外，还发现了 GM 体积在 ACC 内的群体水平不对称和性别差异。具体来说，与男性相比，雌性在 ACC 的三个亚区中的两个亚区中具有相对较大的 GM 体积，并且在两个亚区中发现了显著的左偏，而在第三个亚区中观察到了右偏。基于这些发现，我们认为 ACC 不仅在人类中，而且在黑猩猩中也起着重要作用，调节 JA。我们进一步建议，群体之间发现的差异可能反映了 ACC 内白质数量的固有差异，从而表明具有较差 JA 技能的黑猩猩的 ACC 与其他皮质区域之间的连通性降低。
