Shahar Nitzan, Meiran Nachshon
Department of Psychology and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Be'er Sheva, Israel,
Psychol Res. 2015 Mar;79(2):259-66. doi: 10.1007/s00426-014-0569-1. Epub 2014 Apr 24.
Task switching involves switch cost (poorer performance switch trials than in task-repetition trials) and mixing cost (poorer performance in task-repetition trials than in trials from blocks without task switching). These are mainly studied with the alternating runs task-switching (ARTS) paradigm (in which the task changes every constant number of trials) or the cued task-switching (CTS) paradigm, in which the tasks change randomly. The authors tested the hypothesis that dealing with actual or potential conflicts regarding which task is currently required contribute to mixing cost in CTS more than in ARTS and contribute to switch costs more in ARTS than in CTS. This hypothesis was tested using ex-Gaussian modeling of reaction time (RT) distributions, in which the heaviness of the right tail marks task conflicts (Steinhauser and Hübner in J Exp Psychol Human Percept Perform 35:1398-1412 2009). As predicted, a heavier RT-distribution tail marked switch cost more strongly in ARTS than in CTS and marked mixing costs more strongly in CTS than in ARTS. These results indicate that switch cost and mixing cost reflect different processes in different task-switching paradigms.
任务切换涉及切换成本（切换试验中的表现比任务重复试验中的表现更差）和混合成本（任务重复试验中的表现比无任务切换的组块中的试验表现更差）。这些主要通过交替运行任务切换（ARTS）范式（其中任务每隔固定数量的试验就会改变）或线索任务切换（CTS）范式进行研究，在CTS范式中任务随机改变。作者检验了这样一个假设：处理当前所需任务的实际或潜在冲突，在CTS中对混合成本的影响比对ARTS中的影响更大，而在ARTS中对切换成本的影响比对CTS中的影响更大。该假设通过对反应时间（RT）分布进行前高斯建模来检验，其中右尾的厚重程度标志着任务冲突（Steinhauser和Hübner，《实验心理学杂志：人类感知与表现》，2009年，第35卷，第1398 - 1412页）。正如预测的那样，RT分布的较重尾部在ARTS中比在CTS中更强烈地标志着切换成本，在CTS中比在ARTS中更强烈地标志着混合成本。这些结果表明，切换成本和混合成本在不同的任务切换范式中反映了不同的过程。
