Institute of Neurobiology, Animal Physiology, University of Tuebingen, Germany.
Eur J Neurosci. 2010 Oct;32(8):1380-7. doi: 10.1111/j.1460-9568.2010.07427.x.
The primate prefrontal (PFC) and posterior parietal cortices (PPC) have been shown to be cardinal structures in processing abstract absolute magnitudes, such as numerosity or length. The neuronal representation of quantity relations, however, remained largely elusive. Recent functional imaging studies in humans showed that blood flow changes systematically both in the PFC and the PPC as a function of relational distance between proportions. We investigated the response properties of single neurons in the lateral PFC and the inferior parietal lobule (IPL, area 7) in rhesus monkeys performing a lengths-proportion-discrimination task. Neurons in both areas shared many characteristics and showed peaked tuning functions with preferred proportions. However, a significantly higher percentage of neurons coding proportions was found in the PFC compared with the IPL. In agreement with human studies, our study shows that proportions are represented in the fronto-parietal network that has already been implicated for absolute magnitude processing.
灵长类动物的前额叶皮层（PFC）和顶后皮质（PPC）已被证明是处理抽象绝对大小的关键结构，例如数量或长度。然而，数量关系的神经元表示在很大程度上仍然难以捉摸。最近在人类中的功能成像研究表明，血流变化在 PFC 和 PPC 中都系统地发生，这是比例之间关系距离的函数。我们在执行长度-比例辨别任务的猕猴中研究了外侧 PFC 和下顶叶小叶（IPL，区域 7）中单神经元的反应特性。两个区域的神经元具有许多共同特征，并显示出具有最佳比例的峰值调谐功能。然而，与 IPL 相比，在 PFC 中编码比例的神经元比例明显更高。与人类研究一致，我们的研究表明，比例在已经涉及到绝对大小处理的额顶网络中得到了表示。
