Nieder Andreas, Miller Earl K
Picower Center for Learning and Memory, and Department of Brain and Cognitive Sciences, RIKEN-Massachusetts Institute of Technology Neuroscience Research Center, Cambridge, MA 02139, USA.
Proc Natl Acad Sci U S A. 2004 May 11;101(19):7457-62. doi: 10.1073/pnas.0402239101. Epub 2004 May 3.
Recent electrophysiological studies in monkeys have implicated the prefrontal cortex (PFC) and posterior parietal cortex (PPC) in numerical judgments. The functional organization and respective contributions of these (and other) cortical areas, however, are unknown; their neural activity during numerical judgments has not been directly compared. We surveyed activity in the PPC and the anterior inferior temporal cortex while monkeys performed a visual numerosity judgment task and compared it with a population of PFC neurons. In the PPC, the proportion of numerosity-selective neurons was highest in the fundus of the intraparietal sulcus; only few numerosity-selective neurons were found in other PPC areas or the anterior inferior temporal cortex. Further, neurons in the fundus of the intraparietal sulcus responded and conveyed numerosity earlier than PFC neurons, suggesting that numerosity information flows from the PPC to the lateral PFC. This finding suggests a parieto-frontal network for numerosity in monkeys and establishes homologies between the monkey and human brain.
最近对猴子进行的电生理研究表明，前额叶皮层（PFC）和顶叶后皮层（PPC）参与数字判断。然而，这些（以及其他）皮层区域的功能组织和各自的作用尚不清楚；它们在数字判断过程中的神经活动尚未得到直接比较。我们在猴子执行视觉数字判断任务时，测量了PPC和颞下回前部皮层的活动，并将其与一群PFC神经元进行了比较。在PPC中，表示数字选择性的神经元比例在顶内沟底部最高；在其他PPC区域或颞下回前部皮层中，仅发现很少的数字选择性神经元。此外，顶内沟底部的神经元比PFC神经元更早做出反应并传递数字信息，这表明数字信息从PPC流向外侧PFC。这一发现揭示了猴子大脑中数字处理的顶叶-额叶网络，并建立了猴子和人类大脑之间的同源性。
