Altmann Erik M
Department of Psychology, Michigan State University, East Lansing 48824, USA.
Psychol Sci. 2004 Sep;15(9):616-22. doi: 10.1111/j.0956-7976.2004.00729.x.
The preparation effect in task switching is usually interpreted to mean that a switching process makes use of the interval between task-cue onset and trial-stimulus onset (the cue-stimulus interval, or CSI) to accomplish some of its work ahead of time. This study undermines the empirical basis for this interpretation and suggests that task activation, not task switching, is the functional process in cognitive control. Experiments 1 and 2 used an explicit cuing paradigm, and Experiments 3 and 4 used a variation in which the trial after a task cue was followed by several cueless trials, requiring retention of the cue in memory. Experiments 1 and 3 replicated the preparation effect on switch cost, and Experiments 2 and 4 showed that this effect vanishes when CSI is manipulated between subjects, leaving only a main effect of CSI when the task cue is a memory load.
任务切换中的准备效应通常被解释为，切换过程利用任务提示开始到试验刺激开始之间的间隔（提示-刺激间隔，或CSI），提前完成部分工作。本研究削弱了这种解释的实证基础，并表明任务激活而非任务切换才是认知控制中的功能过程。实验1和实验2采用了明确的提示范式，实验3和实验4采用了一种变体，即任务提示后的试验之后跟随几个无提示试验，这要求在记忆中保留提示。实验1和实验3重复了切换成本上的准备效应，实验2和实验4表明，当在受试者之间操纵CSI时，这种效应消失，当任务提示是一种记忆负荷时，仅留下CSI的主效应。
