Lehle Carola, Cohen Asher, Sangals Jörg, Sommer Werner, Stürmer Birgit
Humboldt-Universität zu Berlin, Germany.
Acta Psychol (Amst). 2011 Jan;136(1):42-51. doi: 10.1016/j.actpsy.2010.09.013. Epub 2010 Oct 27.
Choice reaction times are shorter when stimulus and response features are compatible rather than incompatible. Recent studies revealed that spatial compatibility effects in Simon tasks are strongly attenuated when there is temporal overlap with a different high-priority task. In contrast, non-spatial variants of the Simon task appear to be unaffected by task overlap. The present study used the lateralized readiness potential (LRP) within a dual task design to elucidate the dynamics underlying these differential effects for a color and a spatial variant of the Simon task. In the color version there was no sign of early response priming by irrelevant stimulus features in the LRP. The color compatibility effect was independent of task overlap and reflected in the LRP onset latency. In contrast, in the spatial version, priming by irrelevant stimulus location showed up and was mirrored by early LRP activation. Response priming and the corresponding Simon effect, however, were present only in case of little temporal overlap with the primary task. The absence of spatial compatibility effects at strong temporal overlap suggests that response conflicts due to stimulus-related priming depend on the availability of processing resources.
当刺激和反应特征相匹配而非不匹配时，选择反应时会更短。最近的研究表明，在西蒙任务中，当与另一个高优先级任务存在时间重叠时，空间兼容性效应会大大减弱。相比之下，西蒙任务的非空间变体似乎不受任务重叠的影响。本研究在双任务设计中使用了侧化准备电位（LRP），以阐明西蒙任务的颜色和空间变体中这些差异效应背后的动态机制。在颜色版本中，LRP中没有无关刺激特征引发早期反应的迹象。颜色兼容性效应与任务重叠无关，并反映在LRP起始潜伏期。相比之下，在空间版本中，无关刺激位置引发的效应出现了，并由早期的LRP激活反映出来。然而，只有在与主要任务的时间重叠很少的情况下，才会出现反应引发效应和相应的西蒙效应。在强烈的时间重叠时不存在空间兼容性效应，这表明与刺激相关的引发效应所导致的反应冲突取决于处理资源的可用性。
