Macnamara Anne, Keage Hannah A D, Loetscher Tobias
School of Psychology, Social Work and Social Policy, University of South Australia, Adelaide, Australia.
Exp Brain Res. 2018 Feb;236(2):335-346. doi: 10.1007/s00221-017-5154-6. Epub 2017 Dec 26.
The spatial numerical association of response code (SNARC) effect is characterized by low numbers mapped to the left side of space and high numbers mapped to the right side of space. In addition to numbers, SNARC-like effects have been found in non-numerical magnitude domains such as time, size, letters, luminance, and more, whereby the smaller/earlier and larger/later magnitudes are typically mapped to the left and right of space, respectively. The purpose of this systematic and meta-analytic review was to identify and summarise all empirical papers that have investigated horizontal (left-right) SNARC-like mappings using non-numerical stimuli. A systematic search was conducted using EMBASE, Medline, and PsycINFO, where 2216 publications were identified, with 57 papers meeting the inclusion criteria (representing 112 experiments). Ninety-five of these experiments were included in a meta-analysis, resulting in an overall effect size of d = .488 for a SNARC-like effect. Additional analyses revealed a significant effect size advantage for explicit instruction tasks compared with implicit instructions, yet yielded no difference for the role of expertise on SNARC-like effects. There was clear evidence for a publication bias in the field, but the impact of this bias is likely to be modest, and it is unlikely that the SNARC-like effect is a pure artefact of this bias. The similarities in the response properties for the spatial mappings of numerical and non-numerical domains support the concept of a general higher order magnitude system. Yet, further research will need to be conducted to identify all the factors modulating the strength of the spatial associations.
反应编码的空间数字关联（SNARC）效应的特点是较小的数字映射到空间的左侧，较大的数字映射到空间的右侧。除了数字之外，在诸如时间、大小、字母、亮度等非数字量级领域也发现了类似SNARC的效应，其中较小/较早和较大/较晚的量级通常分别映射到空间的左侧和右侧。本系统综述和荟萃分析的目的是识别和总结所有使用非数字刺激研究水平（左右）类似SNARC映射的实证论文。使用EMBASE、Medline和PsycINFO进行了系统检索，共识别出2216篇出版物，其中57篇论文符合纳入标准（代表112项实验）。其中95项实验被纳入荟萃分析，得出类似SNARC效应的总体效应量d = 0.488。进一步分析显示，与内隐指令相比，外显指令任务的效应量优势显著，但专业知识对类似SNARC效应的作用没有差异。该领域存在明显的发表偏倚证据，但这种偏倚的影响可能较小，而且类似SNARC效应不太可能是这种偏倚的纯粹人为产物。数字和非数字领域空间映射的反应特性相似性支持了一般高阶量级系统的概念。然而，还需要进一步的研究来确定所有调节空间关联强度的因素。
