刺激模拟量的空间表征:面积和亮度的类SNARC效应

在数字比较任务中的SNARC效应表明心理数字线具有空间上从左到右的方向性。本研究在两个实验中分别用面积和亮度作为比较刺激来探讨SNARC效应是否存在于面积比较任务和亮度比较任务中。实验结果显示,面积比较和亮度比较任务中存在类SNARC效应。     

Simon效应对空间-数字反应编码联合效应的抑制作用

采用Simon效应研究范式,以阿拉伯数字为实验材料,三个实验分别要求被试判断呈现数字的空间位置、颜色和大小,系统考察Simon效应、空间-数字反应编码联合效应的加工特点以及两者之间的关系。结果发现:(1)三个实验中,不管采用何种判断标准,被试总是对左侧的数字按左键反应更快,对右侧的数字按右键反应更快,数字加工中出现Simon效应;而对不同大小的数字按左键和按右键的反应时差异均不显著,数字加工中均未出现SNARC效应。(2)Simon效应和SNARC效应不同质,两者的加工机制也互不相同,而且Simon效应对SNARC效应具有抑制作用。(3)Simon效应与SNARC效应相比,Simon效应相对更稳固,SNARC效应则相对更灵活,易受知觉信息变化的影响。     

数字的空间特性

当要求被试对数字进行奇偶判断时,左手对小数的反应较快,而右手对大数的反应较快,该现象被称为空间数字反应编码联合效应（SNARC效应）。大量研究证实了SNARC效应的存在,该效应表明人类对数字的加工受空间表征和空间注意的影响。该文系统地回顾了SNARC效应存在及其发生阶段的证据,对比了Simon效应与SNARC效应,最后尝试着从空间注意的角度挖掘数字和空间的本质联     

书写习惯对数字空间表征SNARC效应的影响

本文设计两个实验,采用大小判断任务,选取读写习惯相反的维、汉大学生为研究对象,探讨两类被试对阿拉伯数字和母语数字空间表征的一致性与差异性。结果发现：（1）维、汉被试均表现出对阿拉伯小数反应左手快于右手,对大数反应右手快于左手,即出现正向SNARC效应;（2）维吾尔族被试表现出对母语小数反应右手快于左手,对大数反应左手快于右手,即对母语数字出现反向SNARC效应;汉族被试表现出对母语小数反应左手快于右手,对大数反应右手快于左手,即对母语数字出现正向SNARC效应。结论：（1）维、汉被试对于阿拉伯数字的SNARC效应存在一致性;（2）维、汉被试母语数字的SNARC效应存在差异性;（3）数字空间对应性与书写习惯是导致结果的重要因素。     

不同注意提示线索条件下汉字数字加工的SNARC效应

采用Ponser的实验范式.以判断"壹"到"玖"的汉字数字奇偶为任务,探讨不同提示线索时在注意条件与非注意条件下的空间数字反应编码联合效应(SNARC效应).实验结果发现: (1)当有效提示线索为80%时,注意条件下汉字数字出现了SNARC效应,而非注意条件下对汉字数字的加工没有出现SNARC效应; (2)当有效提示线索为50%时,在注意和非注意条件下汉字数字都出现了明显的SNARC效应.结果表明注意水平对SNARC效应产生了影响.     

不同注意条件下的空间－数字反应编码联合效应

考察在无线索、内源性线索与外源性线索时不同符号数字在注意与非注意条件下的空间－数字的反应编码联合效应（Spatial Numerical Association of Response Codes,简称SNARC效应）。采用1到9的中文与阿拉伯数字为材料,以判断数字奇偶为任务。实验结果表明：⑴无线索时注意条件下阿拉伯和中文数字都出现了SNARC效应,而非注意条件下则都没有出现,并且受影响的主要是较大的数字（8、9）;⑵外源性线索和内源性线索时,我们得到一个逐渐递减的SNARC效应,受影响的也主要是较大的数字（8、9）。在内源性线索的注意条件阿拉伯和中文数都有SNARC效应,而在非注意条件只有阿拉伯数有SNARC效应;在外源性线索的注意条件只有阿拉伯数有SNARC效应,而在非注意条件阿拉伯和中文都没有SNARC效应,说明外源性注意的影响比内源性注意更大,中文数字所受的影响比阿拉伯数字更大。     

言语与空间任务指令对数字-空间联结编码的影响

以1～9除5外的阿拉伯数字和汉字标签“左”“右”为实验材料,采用数字奇偶判断任务,探讨任务指令对数字-空间联结编码的影响。结果发现：言语任务指令条件下,词语一致性与物理一致性的交互作用显著,且词语一致和不一致时均未发现空间-数字联合反应编码效应（SNARC）,表明言语-空间编码在数字-空间联结中更有优势;空间任务指令条件下,物理一致性主效应显著,且词语一致和不一致时均出现了SNARC效应,表明视觉空间编码更有优势。说明数字-空间联结编码受实验任务指令的影响,被试会根据任务指令设置的情景选择视觉空间编码或言语-空间编码对数字进行空间联结。     

数字-空间联结SNARC效应的编码：视觉空间和言语空间

采用Gevers等的实验范式,以判断数字大小并选择不同言语符号方向信息左右为任务。材料为阿拉伯数字（1、2、8、9）和汉字、英文单词符号（“左”、“右”、“left”、“m#t”）。考察在不同语言符号方向信息下数字-空间联结SANBC效应的编码方式,结果发现：（1）在汉字和英文符号信息下,被试在数字大小比较任务中都表现出SNARC效应;（2）在汉字符号方向信息下。SNARC效应的编码方式主要存在视觉空间和言语空间编码,且以言语空间编码为主;（3）在英文符号方向信息下。SNARC效应的鳊码方式主要是视觉空间编码。     

数字空间表征的在线建构：来自干扰情境中数字SNARC效应的证据

尽管已有研究发现数字以空间方式表征在人类记忆系统, 但是人脑如何完成数字的空间表征尚存争议。本研究两个实验在不同比例的数字字母(实验1)和不同比例的数字汉字(实验2)混合情境中考察了数字空间表征特点及其机制, 对上述争议进行了深入研究。结果发现：(1)当数字字母比例为“1 : 1”时, 数字加工中不出现SNARC效应。当数字字母比例为“1 : 6”和“6 : 1”时, 数字加工中均出现SNARC效应。即数字字母比例与数字SNARC效应之间呈倒“U”型关系。(2)数字汉字混合情境中数字汉字比例与数字SNARC效应之间同样呈倒“U”型关系。结果说明：(1)干扰刺激与数字混合呈现会影响数字SNARC效应。(2)干扰刺激加工对数字SNARC效应的影响受到数字与干扰刺激比例的调节, 且具有跨干扰材料的稳定性。研究结果意味着数字的空间表征是人类通过统计学习在线建构的, 支持了工作记忆理论。     

在亮度对比和颜色对比下立体视知觉的定量研究

研究了在亮度对比与等亮度颜色对比的条件下,受试者分辨随机点阵立体图对的立体视敏度（最小视差）．结果表明：（１）在亮度对比条件下,立体视敏度随对比度的增加而增加,１０％的对比度即可引起立体视知觉,对比度大于３０％时达到饱和;（２）在亮度对比与等亮度颜色对比两种不同的条件下,受试者的立体视敏度不存在有统计学意义的差异;（３）当双眼分别接受不同颜色的等亮度立体图刺激时,与亮度对比条件相比,受试者的立体视敏度无明显差异;（４）当受试者双眼分别接受由亮度对比和颜色对比形成的立体图刺激时,只有当颜色对比图中图形与背景间的对比度超过等亮度值３８％以上时,才能形成立体视知觉．以上结果提示,大、小细胞系统（包括斑点系统与斑点间系统）均参与立体视知觉信息的传递．     

Implicit response-irrelevant number information triggers the SNARC effect: Evidence using a neural overlap paradigm

There is evidence from the SNARC (spatial–numerical association of response codes) effect and NDE (numerical distance effect) that number activates spatial representations. Most of this evidence comes from tasks with explicit reference to number, whether through presentation of Arabic digits (SNARC) or through magnitude decisions to nonsymbolic representations (NDE). Here, we report four studies that use the neural overlap paradigm developed by Fias, Lauwereyns, and Lammertyn (2001) to examine whether the presentation of implicit and task-irrelevant numerosity information (nonsymbolic arrays and auditory numbers) is enough to activate a spatial representation of number. Participants were presented with either numerosity arrays (1–9 circles or triangles) to which they made colour (Experiment 1) or orientation (Experiment 2) judgements, or auditory numbers coupled with an on-screen stimulus to which they made a colour (Experiment 3) or orientation (Experiment 4) judgement. SNARC effects were observed only for the orientation tasks. Following the logic of Fias et al., we argue that this SNARC effect occurs as a result of overlap in parietal processing for number and orientation judgements irrespective of modality. Furthermore, we found stronger SNARC effects in the small number range (1–4) than in the larger number range (6–9) for both nonsymbolic displays and auditory numbers. These results suggest that quantity is extracted (and interferes with responses in the orientation task) but this is not exact for the entire number range. We discuss a number of alternative models and mechanisms of numerical processing that may account for such effects.     

Implicit response-irrelevant number information triggers the SNARC effect: Evidence using a neural overlap paradigm

There is evidence from the SNARC (spatial-numerical association of response codes) effect and NDE (numerical distance effect) that number activates spatial representations. Most of this evidence comes from tasks with explicit reference to number, whether through presentation of Arabic digits (SNARC) or through magnitude decisions to nonsymbolic representations (NDE). Here, we report four studies that use the neural overlap paradigm developed by Fias, Lauwereyns, and Lammertyn (2001) to examine whether the presentation of implicit and task-irrelevant numerosity information (nonsymbolic arrays and auditory numbers) is enough to activate a spatial representation of number. Participants were presented with either numerosity arrays (1-9 circles or triangles) to which they made colour (Experiment 1) or orientation (Experiment 2) judgements, or auditory numbers coupled with an on-screen stimulus to which they made a colour (Experiment 3) or orientation (Experiment 4) judgement. SNARC effects were observed only for the orientation tasks. Following the logic of Fias et al., we argue that this SNARC effect occurs as a result of overlap in parietal processing for number and orientation judgements irrespective of modality. Furthermore, we found stronger SNARC effects in the small number range (1-4) than in the larger number range (6-9) for both nonsymbolic displays and auditory numbers. These results suggest that quantity is extracted (and interferes with responses in the orientation task) but this is not exact for the entire number range. We discuss a number of alternative models and mechanisms of numerical processing that may account for such effects.     

Spatial structure of quantitative representation of numbers: Evidence from the SNARC effect

Dehaene, Bossini, and Giraux (1993) revealed that subjects responded to large numbers faster with the choice on the right than with the choice on the left, whereas the reverse held true for small numbers (SNARC effect). According to Dehaene et al. (1993), the SNARC effect depends on the quantitative representation of number, such as a left-to-right-oriented analog number line. The main goal of the present study was twofold: first, to investigate whether the vertical SNARC effect could be observed, and, second, to verify whether Dehaene et al.'s (1993) explanation of the SNARC effect is correct. Experiments 2A and 2B showed the vertical SNARC effect in a parity judgment task. Subjects responded to large numbers faster with the top choice than with the bottom choice, whereas the reverse held true for small numbers. However, Experiment 3 failed to show the SNARC effect in a number magnitude judgment task, suggesting that the quantitative representation could be dissociated from the spatial code that produces the SNARC effect.     

The SNARC effect is not a unitary phenomenon

Models of the spatial–numerical association of response codes (SNARC) effect—faster responses to small numbers using left effectors, and the converse for large numbers—diverge substantially in localizing the root cause of this effect along the numbers’ processing chain. One class of models ascribes the cause of the SNARC effect to the inherently spatial nature of the semantic representation of numerical magnitude. A different class of models ascribes the effect’s cause to the processing dynamics taking place during response selection. To disentangle these opposing views, we devised a paradigm combining magnitude comparison and stimulus–response switching in order to monitor modulations of the SNARC effect while concurrently tapping both semantic and response-related processing stages. We observed that the SNARC effect varied nonlinearly as a function of both manipulated factors, a result that can hardly be reconciled with a unitary cause of the SNARC effect.     

Developing number–space associations: SNARC effects using a color discrimination task in 5-year-olds

Human adults’ numerical representation is spatially oriented; consequently, participants are faster to respond to small/large numerals with their left/right hand, respectively, when doing a binary classification judgment on numbers, known as the SNARC (spatial–numerical association of response codes) effect. Studies on the emergence and development of the SNARC effect remain scarce. The current study introduces an innovative new paradigm based on a simple color judgment of Arabic digits. Using this task, we found a SNARC effect in children as young as 5.5 years. In contrast, when preschool children needed to perform a magnitude judgment task necessitating exact number knowledge, the SNARC effect started to emerge only at 5.8 years. Moreover, the emergence of a magnitude SNARC but not a color SNARC was linked to proficiency with Arabic digits. Our results suggest that access to a spatially oriented approximate magnitude representation from symbolic digits emerges early in ontogenetic development. Exact magnitude judgments, on the other hand, rely on experience with Arabic digits and, thus, necessitate formal or informal schooling to give access to a spatially oriented numerical representation.     

The SNARC effect: an instance of the Simon effect?

Our aim was to investigate the relations between the Spatial-Numerical Association of Response Codes (SNARC) effect and the Simon effect. In Experiment 1 participants were required to make a parity judgment to numbers from 1 to 9 (without 5), by pressing a left or a right key. The numbers were presented to either the left or right side of fixation. Results showed the Simon effect (left-side stimuli were responded to faster with the left hand than with the right hand whereas right-side stimuli were responded to faster with the right hand), and the SNARC effect (smaller numbers were responded to faster with the left hand than with the right hand, whereas larger numbers were responded to faster with the right hand). No interaction was found between the Simon and SNARC effects, suggesting that they combine additively. In Experiment 2 the temporal distance between formation of the task-relevant non-spatial stimulus code and the task-irrelevant stimulus spatial code was increased. As in Experiment 1, results showed the presence of the Simon and SNARC effects but no interaction between them. Moreover, we found a regular Simon effect for faster RTs, and a reversed Simon effect for longer RTs. In contrast, the SNARC effect did not vary as a function of RT. Taken together, the results of the two experiments show that the SNARC effect does not simply constitute a variant of the Simon effect. This is considered to be evidence that number representation and space representation rest on different neural (likely parietal) circuits.     

SNARC效应: 现状、理论与建议

SNARC效应是当对数字进行奇偶判断时,即使数的奇偶性与数的大小无关,但右手（左手）对相对大（小）的数的反应快。首先介绍SNARC效应的起源和理论解释,然后总结SNARC效应的特性,论述SNARC效应和Simon效应以及MARC 效应的关系,并对SNARC效应的脑机制进行了概述,最后提出3个有待深入研究的问题：（1）SNARC效应的加工处理机制;（2）SANRC效应的理论探索;（3）SNARC效应的本质。     

Numbers and space: a computational model of the SNARC effect

The SNARC (spatial numerical associations of response codes) effect reflects the tendency to respond faster with the left hand to relatively small numbers and with the right hand to relatively large numbers (S. Dehaene, S. Bossini, & P. Giraux, 1993). Using computational modeling, the present article aims to provide a framework for conceptualizing the SNARC effect. In line with models of spatial stimulus-response congruency, the authors modeled the SNARC effect as the result of parallel activation of preexisting links between magnitude and spatial representation and short-term links created on the basis of task instructions. This basic dual-route model simulated all characteristics associated with the SNARC effect. In addition, 2 experiments tested and confirmed new predictions derived from the model.