Radboud University Nijmegen.
J Cogn Neurosci. 2014 Apr;26(4):768-76. doi: 10.1162/jocn_a_00518. Epub 2013 Nov 4.
A dominant hypothesis on how the brain processes numerical size proposes a spatial representation of numbers as positions on a "mental number line." An alternative hypothesis considers numbers as elements of a generalized representation of sensorimotor-related magnitude, which is not obligatorily spatial. Here we show that individuals' relative use of spatial and nonspatial representations has a cerebral counterpart in the structural organization of the posterior parietal cortex. Interindividual variability in the linkage between numbers and spatial responses (faster left responses to small numbers and right responses to large numbers; spatial-numerical association of response codes effect) correlated with variations in gray matter volume around the right precuneus. Conversely, differences in the disposition to link numbers to force production (faster soft responses to small numbers and hard responses to large numbers) were related to gray matter volume in the left angular gyrus. This finding suggests that numerical cognition relies on multiple mental representations of analogue magnitude using different neural implementations that are linked to individual traits.
一种关于大脑如何处理数字大小的主导假设提出，数字在“心理数字线”上的位置是一种空间表示。另一种假设则认为数字是与感觉运动相关的大小的广义表示的元素，而不一定是空间的。在这里，我们表明，个体在空间和非空间表示之间的相对使用在大脑后顶叶皮层的结构组织中具有对应物。在数字和空间反应之间的联系（对小数字的左反应快，对大数字的右反应快；反应代码的空间-数字关联效应）的个体间可变性与右楔前叶周围的灰质体积变化相关。相反，将数字与力产生联系的倾向（对小数字的软反应快，对大数字的硬反应快）的差异与左角回的灰质体积有关。这一发现表明，数字认知依赖于使用不同神经实现的模拟大小的多种心理表示，这些表示与个体特征相关。
