Yao Yuzhao, Jia Xiuqin, Luo Jun, Chen Feiyan, Liang Peipeng
Bio-X Laboratory, Department of Physics, Zhejiang University, Hangzhou, China.
Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
Front Hum Neurosci. 2020 Dec 23;14:566675. doi: 10.3389/fnhum.2020.566675. eCollection 2020.
Numerical inductive reasoning has been considered as one of the most important higher cognitive functions of the human brain. Importantly, previous behavioral studies have consistently reported that one critical component of numerical inductive reasoning is checking, which often occurs when a discrepant element is discovered, and reprocessing is needed to determine whether the discrepancy is an error of the original series. However, less is known about the neural mechanism underlying the checking process. Given that the checking effect involves cognitive control processes, such as the incongruent resolution, that are linked to the right dorsolateral prefrontal cortex (DLPFC), this study hypothesizes that the right DLPFC may play a specific role in the checking process. To test the hypothesis, this study utilized the transcranial direct current stimulation (tDCS), a non-invasive brain stimulation method that could modulate cortical excitability, and examined whether and how the stimulation of the right DLPFC tDCS could modulate the checking effect during a number-series completion problem task. Ninety healthy participants were allocated to one of the anodal, cathodal, and sham groups. Subjects were required to verify whether number sequences formed rule-based series, and checking effect was assessed by the difference in performance between invalid and valid conditions. It was found that significantly longer response times (RTs) were exhibited in invalid condition compared with valid condition in groups of anodal, cathodal, and sham tDCS. Furthermore, the anodal tDCS significantly shortened the checking effect than those of the cathodal and sham groups, whereas no significantly prolonged checking effect was detected in the cathodal group. The current findings indicated that anodal tDCS affected the process of checking, which suggested that the right DLPFC might play a critical role in the checking process of numerical inductive reasoning by inhibiting incongruent response.
数字归纳推理被认为是人类大脑最重要的高级认知功能之一。重要的是，先前的行为研究一致报告称，数字归纳推理的一个关键组成部分是检查，这通常在发现不一致元素时发生，并且需要重新处理以确定该差异是否是原始序列的错误。然而，对于检查过程背后的神经机制知之甚少。鉴于检查效应涉及认知控制过程，如与右侧背外侧前额叶皮质（DLPFC）相关的不一致解决，本研究假设右侧DLPFC可能在检查过程中发挥特定作用。为了验证这一假设，本研究采用了经颅直流电刺激（tDCS），一种可以调节皮层兴奋性的非侵入性脑刺激方法，并研究了右侧DLPFC的tDCS刺激是否以及如何在数字序列完成问题任务中调节检查效应。90名健康参与者被分配到阳极、阴极和假刺激组之一。受试者被要求验证数字序列是否形成基于规则的系列，并通过无效和有效条件下表现的差异来评估检查效应。结果发现，在阳极、阴极和假tDCS组中，与有效条件相比，无效条件下的反应时间（RTs）显著更长。此外，与阴极和假刺激组相比，阳极tDCS显著缩短了检查效应，而在阴极组中未检测到显著延长的检查效应。目前的研究结果表明，阳极tDCS影响了检查过程，这表明右侧DLPFC可能通过抑制不一致反应在数字归纳推理的检查过程中发挥关键作用。
