The Spatial-Numerical Association of Response Codes (SNARC) effect suggests that numbers are represented along a horizontal left-to-right oriented, mental number line, with small numbers on the left and large numbers on the right. Much less evidence exists for vertical (down-to-up) and sagittal (near-to-far) SNARC effects. This might be due to the employment of different experimental paradigms among studies and to the, sometimes, inexact definition of the vertical and sagittal axes. We investigated for the first time the SNARC effect along the horizontal, vertical, and sagittal axes, by means of a classic SNARC task. Our results suggest the presence of three equally-strong SNARC effects. Our findings can be considered as evidence in favor of a three-dimensional, mental representation of numbers, in the form of a mental number space, defined by Cartesian coordinates.

中文翻译：

---

笛卡尔周围的数字：预先注册的关于三维SNARC效应的研究。

响应码的空间数字关联（SNARC）效果表明，数字是沿水平的从左到右方向的心理数字线表示的，左侧为小数字，右侧为大数字。垂直（从上到下）和矢状（近到远）SNARC效应的证据很少。这可能是由于研究之间采用了不同的实验范式，有时是由于垂直轴和矢状轴的定义不准确所致。我们通过经典的SNARC任务首次研究了水平，垂直和矢状轴上的SNARC效应。我们的结果表明存在三个同样强的SNARC效应。我们的发现可被视为支持以心理数字空间的形式对数字进行三维心理表示的证据，