Entel Olga, Tzelgov Joseph, Bereby-Meyer Yoella, Shahar Nitzan
Department of Psychology and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, P.O.B. 653, Beer Sheva, 84105, Israel.
Department of Brain and Cognitive Sciences, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel.
Psychol Res. 2015 Nov;79(6):913-27. doi: 10.1007/s00426-014-0630-0. Epub 2014 Nov 25.
In this study, we tested the proposal that the Stroop task involves two conflicts--task conflict and informational conflict. Task conflict was defined as the latency difference between color words and non-letter neutrals, and manipulated by varying the proportion of color words versus non-letter neutrals. Informational conflict was defined as the latency difference between incongruent and congruent trials and manipulated by varying the congruent-to-incongruent trial ratio. We replicated previous findings showing that increasing the ratio of incongruent-to-congruent trials reduces the latency difference between the incongruent and congruent condition (i.e., informational conflict), as does increasing the proportion of color words (i.e., task conflict). A significant under-additive interaction between the two proportion manipulations (congruent vs. incongruent and color words vs. neutrals) indicated that the effects of task conflict and informational conflict were not additive. By assessing task conflict as the contrast between color words and neutrals, we found that task conflict existed in all of our experimental conditions. Under specific conditions, when task conflict dominated behavior by explaining most of the variability between congruency conditions, we also found negative facilitation, thus demonstrating that this effect is a special case of task conflict.
在本研究中，我们检验了如下观点：斯特鲁普任务涉及两种冲突——任务冲突和信息冲突。任务冲突被定义为颜色词与非字母中性刺激之间的潜伏期差异，并通过改变颜色词与非字母中性刺激的比例来操纵。信息冲突被定义为不一致试验与一致试验之间的潜伏期差异，并通过改变一致试验与不一致试验的比例来操纵。我们重复了先前的研究结果，即增加不一致试验与一致试验的比例会减少不一致条件与一致条件之间的潜伏期差异（即信息冲突），增加颜色词的比例（即任务冲突）也会有同样的效果。两种比例操纵（一致与不一致以及颜色词与中性刺激）之间存在显著的次加性交互作用，这表明任务冲突和信息冲突的效应并非相加的。通过将任务冲突评估为颜色词与中性刺激之间的对比，我们发现在所有实验条件下都存在任务冲突。在特定条件下，当任务冲突通过解释一致性条件之间的大部分变异性而主导行为时，我们还发现了负启动效应，从而证明这种效应是任务冲突的一种特殊情况。
