Abstract：
Task switching refers to a set of cognitive processes involved in shifting attention from one task to another. In recent years, researchers have applied transcranial direct current stimulation (tDCS) to investigate the causal relationship between the parietal cortex and task switching. However, results from available studies are highly inconsistent. This may be due to the unclear understanding of the underlying mechanisms. Therefore, the current study utilized event-related potential (ERP) analysis to investigate the modulatory effects of tDCS on task-switching processes. Twenty-four subjects were recruited to perform both predictable and unpredictable parity/magnitude tasks under anodal (RA) and sham conditions. The results showed no significant changes in behavioral performance. However, marked tDCS-induced ERP changes were observed. Specifically, for the predictable task switching, compared with the sham condition, the target-N2 component occurred significantly earlier for switch trials than repeat trials under the RA condition in males, while no difference was found in females. For unpredictable task switching, under the sham condition, the P2 peak was significantly larger for switch trials compared with repeat trials, whereas this difference was not observed under the RA condition. These results indicated the causal relationship between the right parietal cortex and exogenous adjustment processes involved in task switching. Moreover, anodal tDCS over the right parietal cortex may lead to the manifestation of gender differences.
摘要：
任务转换是指将注意力从一个任务转移到另一个任务所涉及的一组认知过程。近年来,研究人员应用经颅直流电刺激(tDCS)来研究顶叶皮层与任务切换之间的因果关系.然而,现有研究的结果高度不一致.这可能是由于对潜在机制的不清楚理解。因此,本研究利用事件相关电位(ERP)分析来研究tDCS对任务切换过程的调节作用.招募了24名受试者，在阳极（RA）和假条件下执行可预测和不可预测的奇偶校验/幅度任务。结果显示行为表现没有显著变化。然而,观察到明显的tDCS诱导的ERP变化。具体来说,对于可预测的任务切换，与假条件相比，在男性RA条件下，转换试验的目标N2成分明显早于重复试验，而在女性中没有发现差异。对于不可预测的任务切换，在假条件下，与重复试验相比，转换试验的P2峰值明显更大，而在RA条件下没有观察到这种差异。这些结果表明，右顶叶皮层与任务转换中涉及的外源调节过程之间存在因果关系。此外，右侧顶叶皮层的阳极tDCS可能导致性别差异的表现。
