Department of Neurological Surgery, Division of Optical Brain Engineering, Nihon University School of Medicine, 30-1 Oyaguchi-Kamimachi, Itabashi-ku, Tokyo 173-8610, Japan.
Neuroimage. 2011 Sep 15;58(2):640-6. doi: 10.1016/j.neuroimage.2011.06.076. Epub 2011 Jul 2.
This study used off-line repetitive transcranial magnetic stimulation (rTMS) to examine the roles of the superior parietal lobule (SPL) and inferior frontal gyrus (IFG) in a deductive reasoning task. Subjects performed a categorical syllogistic reasoning task involving congruent, incongruent, and abstract trials. Twenty four subjects received magnetic stimulation to the SPL region prior to the task. In the other 24 subjects, TMS was administered to the IFG region before the task. Stimulation lasted for 10min, with an inter-pulse frequency of 1Hz. We found that bilateral SPL (Brodmann area (BA) 7) stimulation disrupted performance on abstract and incongruent reasoning. Left IFG (BA 45) stimulation impaired congruent reasoning performance while paradoxically facilitating incongruent reasoning performance. This resulted in the elimination of the belief-bias. In contrast, right IFG stimulation only impaired incongruent reasoning performance, thus enhancing the belief-bias effect. These findings are largely consistent with the dual-process theory of reasoning, which proposes the existence of two different human reasoning systems: a belief-based heuristic system; and a logic-based analytic system. The present findings suggest that the left language-related IFG (BA 45) may correspond to the heuristic system, while bilateral SPL may underlie the analytic system. The right IFG may play a role in blocking the belief-based heuristic system for solving incongruent reasoning trials. This study could offer an insight about functional roles of distributed brain systems in human deductive reasoning by utilizing the rTMS approach.
本研究采用离线重复经颅磁刺激（rTMS）技术，考察顶叶上回（SPL）和额下回（IFG）在演绎推理任务中的作用。受试者完成了涉及一致、不一致和抽象试验的类别三段论推理任务。24 名受试者在任务前接受 SPL 区的磁刺激。在另外 24 名受试者中，TMS 在前任务前施加于 IFG 区。刺激持续 10 分钟，脉冲间隔频率为 1Hz。我们发现双侧 SPL（Brodmann 区 7）刺激破坏了抽象和不一致推理的表现。左 IFG（BA45）刺激损害了一致推理表现，而反常地促进了不一致推理表现。这导致了信念偏差的消除。相比之下，右 IFG 刺激仅损害了不一致推理表现，从而增强了信念偏差效应。这些发现与推理的双加工理论基本一致，该理论提出了两种不同的人类推理系统的存在：基于信念的启发式系统；以及基于逻辑的分析系统。本研究表明，左语言相关 IFG（BA45）可能对应于启发式系统，而双侧 SPL 可能是分析系统的基础。右 IFG 可能在解决不一致推理试验时阻止基于信念的启发式系统。通过利用 rTMS 方法，本研究可以深入了解分布式脑系统在人类演绎推理中的功能作用。
