Animal Physiology, Institute of Neurobiology, University Tübingen, Tübingen 72076, Germany.
Proc Natl Acad Sci U S A. 2012 Jul 17;109(29):11860-5. doi: 10.1073/pnas.1204580109. Epub 2012 Jul 3.
Numerosity, the number of elements in a set, is a most abstract quantitative category. As such, it is independent of the sensory modality of its elements, i.e., supramodal. Because neuronal numerosity selectivity had never been compared directly across different sensory modalities, it remained elusive if and where single neurons encode numerosity irrespective of the items' modality. Here, monkeys were trained to discriminate both the number of auditory sounds and visual items within the same session. While the monkeys performed this task, the activity of neurons was recorded in the lateral prefrontal cortex and ventral intraparietal sulcus, structures critically involved in numerical cognition. Groups of neurons in both areas encoded either the number of auditory pulses, visual items, or both. The finding of neurons responding to numerosity irrespective of the sensory modality supports the idea of a nonverbal, supramodal neuronal code of numerical quantity in the primate brain.
数量，即集合中元素的数量，是一个非常抽象的定量类别。因此，它独立于其元素的感觉模态，即超模态。由于神经元数量选择性从未在不同感觉模态之间直接进行比较，因此仍然不清楚是否以及在何处单个神经元可以对数量进行编码，而与项目的模态无关。在这里，猴子在同一会议中接受了辨别听觉声音和视觉项目数量的训练。当猴子执行此任务时，记录了外侧前额叶皮层和腹侧顶内沟的神经元活动，这些结构对于数字认知至关重要。这两个区域的神经元组编码听觉脉冲的数量、视觉项目的数量或两者兼而有之。对与感觉模态无关的数量作出反应的神经元的发现支持了灵长类动物大脑中存在非语言、超模态神经元数量编码的想法。
