Viarouge Arnaud, Hubbard Edward M, McCandliss Bruce D
Laboratoire Psychologie de la Perception, CNRS/UMR8242, Université Paris Descartes, Paris, France.
Educational Neuroscience Lab, Department of Educational Psychology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
PLoS One. 2014 Apr 23;9(4):e95756. doi: 10.1371/journal.pone.0095756. eCollection 2014.
Access to mental representations of smaller vs. larger number symbols is associated with leftward vs. rightward spatial locations, as represented on a number line. The well-replicated SNARC effect (Spatial-Numerical Association of Response Codes) reveals that simple decisions about small numbers are facilitated when stimuli are presented on the left, and large numbers facilitated when on the right. We present novel evidence that the size of the SNARC effect is relatively stable within individuals over time. This enables us to take an individual differences approach to investigate how the SNARC effect is modulated by spatial and numerical cognition. Are number-space associations linked to spatial operations, such that those who have greater facility in spatial computations show the stronger SNARC effects, or are they linked to number semantics, such that those showing stronger influence of magnitude associations on number symbol decisions show stronger SNARC effects? Our results indicate a significant correlation between the SNARC effect and a 2D mental rotation task, suggesting that spatial operations are at play in the expression of this effect. We also uncover a significant correlation between the SNARC effect and the distance effect, suggesting that the SNARC is also related to access to number semantics. A multiple regression analysis reveals that the relative contributions of spatial cognition and distance effects represent significant, yet distinct, contributions in explaining variation in the size of the SNARC effect from one individual to the next. Overall, these results shed new light on how the spatial-numerical associations of response codes are influenced by both number semantics and spatial operations.
在数轴上，对数词符号大小的心理表征与空间位置的左右方向相关联。得到充分验证的SNARC效应（反应编码的空间-数字关联效应）表明，当刺激出现在左侧时，对小数的简单判断会更便利；当刺激出现在右侧时，对大数的判断会更便利。我们提供了新的证据，表明SNARC效应的大小在个体内部随时间推移相对稳定。这使我们能够采用个体差异的方法来研究SNARC效应是如何受到空间和数字认知的调节的。数字与空间的关联是与空间操作相关，即那些在空间计算方面更有能力的人表现出更强的SNARC效应，还是与数字语义相关，即那些在数字符号决策中表现出更强的数量关联影响的人表现出更强的SNARC效应？我们的结果表明，SNARC效应与二维心理旋转任务之间存在显著相关性，这表明空间操作在该效应的表现中起作用。我们还发现SNARC效应与距离效应之间存在显著相关性，这表明SNARC效应也与数字语义的获取有关。多元回归分析表明，空间认知和距离效应的相对贡献在解释个体间SNARC效应大小的差异方面，代表了显著但不同的贡献。总体而言，这些结果为反应编码的空间-数字关联如何受到数字语义和空间操作的影响提供了新的见解。
