Piazza Manuela, Pinel Philippe, Le Bihan Denis, Dehaene Stanislas
Institut National de la Santé et de la Recherche Médicale (INSERM), Cognitive Neuroimaging Unit, Service Hospitalier Frédéric Joliot, F-91401 Orsay, France.
Neuron. 2007 Jan 18;53(2):293-305. doi: 10.1016/j.neuron.2006.11.022.
Activation of the horizontal segment of the intraparietal sulcus (hIPS) has been observed in various number-processing tasks, whether numbers were conveyed by symbolic numerals (digits, number words) or by nonsymbolic displays (dot patterns). This suggests an abstract coding of numerical magnitude. Here, we critically tested this hypothesis using fMRI adaptation to demonstrate notation-independent coding of numerical quantity in the hIPS. Once subjects were adapted either to dot patterns or to Arabic digits, activation in the hIPS and in frontal regions recovered in a distance-dependent fashion whenever a new number was presented, irrespective of notation changes. This remained unchanged when analyzing the hIPS peaks from an independent localizer scan of mental calculation. These results suggest an abstract coding of approximate number common to dots, digits, and number words. They support the idea that symbols acquire meaning by linking neural populations coding symbol shapes to those holding nonsymbolic representations of quantities.
在各种数字处理任务中，均观察到顶内沟水平段（hIPS）的激活，无论数字是通过符号数字（数字、数字词）还是非符号显示（点阵图案）来传达。这表明存在数字大小的抽象编码。在此，我们通过功能磁共振成像适应技术对这一假设进行了严格测试，以证明hIPS中数字量的符号无关编码。一旦受试者适应了点阵图案或阿拉伯数字，每当呈现新数字时，hIPS和额叶区域的激活会以距离依赖的方式恢复，而与符号变化无关。当从独立的心理计算定位扫描中分析hIPS峰值时，这一结果保持不变。这些结果表明，点、数字和数字词存在共同的近似数字抽象编码。它们支持这样一种观点，即符号通过将编码符号形状的神经群体与持有数量非符号表征的神经群体相联系来获得意义。
