Background

A number of functional magnetic resonance imaging studies have shown that the dorsolateral prefrontal cortex (dlPFC) is a critical brain region for response inhibition. However, how it exerts this function remains unclear. This study investigated whether stimulating the right dlPFC by transcranial direct current stimulation (tDCS) affects performance on stop signal task.

Methods

A total of 92 healthy subjects were enrolled in the study and randomly divided into three groups. The anode group received anodal stimulation over the right dlPFC and cathodal stimulation over the left supraorbital; the cathode group received cathodal stimulation over the right dlPFC and anodal stimulation over the left supraorbital; and the sham group received sham tDCS. All subjects performed a computer-based stop-signal task before and after tDCS.

Result

Performance on the response inhibition task after tDCS was improved in groups with both anodal and cathodal stimulation. Specifically, there was a decrease in the stop-signal reaction time in these subjects, whereas no difference was observed in the sham group. Consistent with signal detection theory, discrimination and decision bias was improved by anode tDCS relative to the sham group, while discrimination was also improved in the cathode group.

Conclusion

Anode and cathode tDCS of the right dlPFC improves response inhibition, with the right dlPFC may playing a key role in this process.

中文翻译：

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经颅直流电刺激右侧背外侧前额叶皮层可改善反应抑制

背景

许多功能性磁共振成像研究表明，背外侧前额叶皮层 (dlPFC) 是反应抑制的关键大脑区域。然而，它如何发挥这一功能仍不清楚。本研究调查了通过经颅直流电刺激 (tDCS) 刺激正确的 dlPFC 是否会影响停止信号任务的表现。

方法

共纳入 92 名健康受试者，随机分为三组。阳极组在右侧 dlPFC 上接受阳极刺激，在左侧眶上接受阴极刺激；阴极组在右侧dlPFC上接受阴极刺激，在左侧眶上接受阳极刺激；假组接受假 tDCS。所有受试者在 tDCS 之前和之后都执行了基于计算机的停止信号任务。

结果

在接受阳极和阴极刺激的组中，tDCS 后反应抑制任务的表现得到改善。具体而言，这些受试者的停止信号反应时间有所减少，而假手术组则没有观察到差异。与信号检测理论一致，阳极 tDCS 相对于假组提高了辨别力和决策偏差，而阴极组的辨别力也得到了提高。

结论

右侧 dlPFC 的阳极和阴极 tDCS 可改善反应抑制，右侧 dlPFC 可能在此过程中起关键作用。