Shichel Ido, Tzelgov Joseph
Department of Brain and Cognitive Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.
Department of Brain and Cognitive Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; Department of Psychology, Ben-Gurion University of the Negev, Arugot 79800, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel; Department of Psychology, Achva Academic College, Arugot 79800, Israel.
Acta Psychol (Amst). 2018 Sep;189:93-102. doi: 10.1016/j.actpsy.2017.10.007. Epub 2017 Nov 1.
The purpose of the current study was to evaluate the unique contribution of task conflict, semantic conflict and response conflict to the Stroop effect and to test how these conflicts are modulated by manipulating the proportion of neutral trials, known to affect the magnitude of the Stroop effect. In the first experiment, we employed the two-to-one paradigm (De Houwer, 2003) while adding neutral illegible stimuli, and in the second experiment, we employed two colors and four word colors. In both experiments, we created four congruency conditions (neutral, congruent and two kind of incongruent conditions-those that include response conflict and those that do not), which allowed decomposing the Stroop effect into three orthogonal conflicts. In both experiments, we also manipulated the proportion of neutral trials. Task conflict was defined by the contrast between illegible neutrals and color words, semantic conflict by the contrast between congruent and incongruent stimuli, and response conflict by contrasting the two kinds of incongruent stimuli. Our results showed that all conflicts contributed to the Stroop effect. Task conflict and semantic conflict were modulated by the proportion of neutrals but response conflict was not. These findings imply that task conflict and semantic conflict are part of the control loop of the Stroop effect, as conceptualized by Botvinick et al.'s (2001) conflict monitoring model. There is no clear evidence of the response conflict being part of the loop. To complete the picture, we also analyzed the conflicts in the Stroop task using the traditional dependent contrasts approach and found the basic pattern of results was similar. Thus, the main advantage of the orthogonal comparisons approach is the possibility to estimate the unique contribution of the conflicts contributing to the Stroop effect and their modulation of the Stroop phenomenon.
本研究的目的是评估任务冲突、语义冲突和反应冲突对斯特鲁普效应的独特贡献，并测试如何通过操纵已知会影响斯特鲁普效应大小的中性试验比例来调节这些冲突。在第一个实验中，我们采用了二对一范式（德休尔，2003），同时添加了中性不可读刺激；在第二个实验中，我们采用了两种颜色和四种文字颜色。在两个实验中，我们都创建了四种一致性条件（中性、一致以及两种不一致条件——包括反应冲突的和不包括反应冲突的），这使得能够将斯特鲁普效应分解为三种正交冲突。在两个实验中，我们还操纵了中性试验的比例。任务冲突通过不可读中性刺激与颜色词之间的对比来定义，语义冲突通过一致和不一致刺激之间的对比来定义，反应冲突通过对比两种不一致刺激来定义。我们的结果表明，所有冲突都对斯特鲁普效应有贡献。任务冲突和语义冲突受到中性刺激比例的调节，但反应冲突不受其调节。这些发现意味着，如博特维尼克等人（2001）的冲突监测模型所概念化的那样，任务冲突和语义冲突是斯特鲁普效应控制回路的一部分。没有明确证据表明反应冲突是该回路的一部分。为了完善情况，我们还使用传统的相关对比方法分析了斯特鲁普任务中的冲突，发现基本结果模式相似。因此，正交比较方法的主要优点是有可能估计对斯特鲁普效应有贡献的冲突的独特贡献及其对斯特鲁普现象的调节。
