Ko Yao-Ting, Miller Jeff
National Central University, <location>Taiwan</location>
University of Otago, <location>New Zealand</location>
Exp Psychol. 2014 Jan 1;61(1):30-7. doi: 10.1027/1618-3169/a000224.
Our performance on a task decreases when the task is in a dual-task situation than when it is in isolation. An important experimental setting for dual-task situation is the psychological refractory period (PRP) paradigm, and the dual-task performance decrements in the PRP paradigm are referred to as PRP interference. The standard response-selection bottleneck (RSB) models state that the response-selection stage of the second task (T2) cannot start until the response-selection stage of the first task (T1) finishes, resulting in the PRP interference. Contrary to the prediction of RSB models, several researchers have found T2's modulations on T1's performance, and have suggested that T1's selection-related processes are affected by T2's selection-related processes, referred to as backward crosstalk effects. The locus of backward crosstalk effects is not clear, however, because RTs were measured in most previous studies. By using semantically unrelated stimuli and responses and by measuring T1's lateralized readiness potential, we examined the locus of backward crosstalk effects. We found that the interval between T1's stimulus onset and the stimulus-locked LRP onset was affected, suggesting T2's response selection starts before T1's selection is complete. The present result provided electrophysiological evidence focusing on T1's changes in favor of the hypothesis of parallel response selection in the PRP paradigm.
当任务处于双重任务情境中时，我们在该任务上的表现比单独执行任务时要差。双重任务情境的一个重要实验设置是心理不应期（PRP）范式，PRP范式中的双重任务表现下降被称为PRP干扰。标准的反应选择瓶颈（RSB）模型指出，第二个任务（T2）的反应选择阶段直到第一个任务（T1）的反应选择阶段完成后才能开始，从而导致PRP干扰。与RSB模型的预测相反，一些研究人员发现T2对T1的表现有调节作用，并提出T1的选择相关过程受到T2的选择相关过程的影响，这被称为反向串扰效应。然而，由于在大多数先前的研究中测量的是反应时，反向串扰效应的位置尚不清楚。通过使用语义无关的刺激和反应，并测量T1的侧化准备电位，我们研究了反向串扰效应的位置。我们发现T1的刺激开始与刺激锁定的LRP开始之间的间隔受到影响，这表明T2的反应选择在T1的选择完成之前就开始了。目前的结果提供了电生理证据，聚焦于T1的变化，支持了PRP范式中并行反应选择的假设。
