Wu Shanshan, Hitchman Glenn, Tan Jinfeng, Zhao Yuanfang, Tang Dandan, Wang Lijun, Chen Antao
Key Laboratory of Cognition and Personality of Ministry of Education, Faculty of Psychology, Southwest University, Chongqing 400715, China.
Sci Rep. 2015 May 20;5:10240. doi: 10.1038/srep10240.
Switch costs have been constantly found asymmetrical when switching between two tasks of unequal dominance. We used a combined Stroop-task-switching paradigm and recorded electroencephalographic (EEG) signals to explore the neural mechanism underlying the phenomenon of asymmetrical switch costs. The results revealed that a fronto-central N2 component demonstrated greater negativity in word switch (cW) trials relative to word repeat (wW) trials, and both First P3 and P3b components over the parieto-central region exhibited greater positivity in color switch (wC) trials relative to color repeat (cC) trials, whereas a contrasting switch-related fronto-central SP effect was found to have an opposite pattern for each task. Moreover, the time-frequency analysis showed a right-frontal lower alpha band (9-11 Hz) modulation in the word task, whereas a fronto-central upper alpha band (11-13 Hz) modulation was exclusively found in the color task. These results provide evidence for dissociable neural processes, which are related to inhibitory control and endogenous control, contributing to the generation of asymmetrical switch costs.
当在两个优势程度不同的任务之间切换时，转换成本一直被发现是不对称的。我们采用了一种结合了斯特鲁普任务切换的范式，并记录了脑电图（EEG）信号，以探究不对称转换成本现象背后的神经机制。结果显示，相对于单词重复（wW）试验，额中央N2成分在单词切换（cW）试验中表现出更大的负性；相对于颜色重复（cC）试验，顶中央区域的首次P3和P3b成分在颜色切换（wC）试验中均表现出更大的正性，而与转换相关的额中央SP效应在每个任务中呈现出相反的模式。此外，时频分析表明，在单词任务中存在右额叶较低α波段（9 - 11赫兹）的调制，而在颜色任务中仅发现额中央较高α波段（11 - 13赫兹）的调制。这些结果为可分离的神经过程提供了证据，这些过程与抑制控制和内源性控制相关，有助于产生不对称的转换成本。
