Neural substrates underlying decision making based on free will

大脑有能力进入大脑中的各种处理过程，并以自上而下的方式操纵它。人类的能力无论是在数量上还是质量上都是其他动物无法比拟的。我假设了“自由意志”的存在，并研究了自上而下的信号如何在决策过程中发挥作用。我在人类前额叶皮层上应用了经颅磁刺激（TMS），并评估了前额叶皮层有效连接的动力学。我们发现TMS-EP的变化依赖于任务难度和行为表现。结果表明，从前额叶皮层的信号传输的效率动态变化取决于自下而上的信号的强度。

The brain has an ability to access to various processing in the brain and to manipulate it in top-down manner. The ability of human being is overwhelming relative to the other animals both in quantitative and qualitative aspects. I hypothesized an existence of 'free will' and studied how top-down signals come into effect in the process of decision making. I applied transcranial magnetic stimulation (TMS) over the human prefrontal cortex and evaluated dynamics of effective connectivity from the prefrontal cortex. We found a change in TMS-EP dependent of task difficulty and behavioral performance. The results suggest that the efficiency of signal transmission from the prefrontal cortex changes dynamically depending on the strength of bottom-up signals.