Department of Psychology, Sapienza University, Rome, Italy.
PLoS One. 2020 Feb 18;15(2):e0228541. doi: 10.1371/journal.pone.0228541. eCollection 2020.
Switching between tasks requires individuals to inhibit mental representations of the previous task demands and to activate representations of the new task demands. The inhibition of the executed task remains active for a while so that when the inhibited task set must be re-activated shortly after, the need to overcome residual task set inhibition leads to behavioral costs. In a sham-controlled balanced-order within-subjects experimental design we investigated whether applying right anodal/left cathodal transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal or parietal cortex modulated the ability to overcome persistent task inhibition during task switching. Results showed that right anodal/left cathodal tDCS over the parietal cortex improves performance selectively when switching back to a recently inhibited task that requires previous inhibition to be overcome. Right Anodal/left cathodal tDCS over the prefrontal cortex improves performance during task switching in general, either when re-engaging in a inhibited task or when engaging in a non-inhibited task. Results suggest a different contribution of prefrontal and parietal regions to task switching, with parietal cortex being selectively involved in overcoming persistent task inhibition and prefrontal cortex being more generally involved in the control of task set during task switching.
在任务之间切换需要个体抑制先前任务需求的心理表现，并激活新任务需求的表现。执行任务的抑制作用会持续一段时间，因此当被抑制的任务集在短时间后必须重新激活时，克服残留的任务集抑制的需要会导致行为成本。在一项假控制平衡顺序的被试内实验设计中，我们研究了在背外侧前额叶或顶叶皮层上施加右阳极/左阴极经颅直流电刺激（tDCS）是否会调节在任务切换期间克服持续任务抑制的能力。结果表明，当切换回最近被抑制的任务时，右阳极/左阴极 tDCS 可选择性地改善顶叶皮层的表现，而该任务需要克服先前的抑制。右阳极/左阴极 tDCS 一般可改善前额叶皮层在任务切换期间的表现，无论是重新参与抑制任务还是参与非抑制任务。结果表明，前额叶和顶叶区域对任务切换有不同的贡献，顶叶皮层选择性地参与克服持续的任务抑制，而前额叶皮层更普遍地参与任务切换期间的任务集控制。
