Bar Ilan University, Ramat Gan, Israel.
J Cogn Neurosci. 2011 Nov;23(11):3380-7. doi: 10.1162/jocn_a_00020. Epub 2011 Mar 31.
A common feature of human existence is the ability to reverse decisions after they are made but before they are implemented. This cognitive control process, termed response inhibition, refers to the ability to inhibit an action once initiated and has been localized to the right inferior frontal gyrus (rIFG) based on functional imaging and brain lesion studies. Transcranial direct current stimulation (tDCS) is a brain stimulation technique that can facilitate as well as impair cortical function. To explore whether response inhibition can be improved through rIFG electrical stimulation, we administered focal tDCS before subjects performed the stop signal task (SST), which measures response inhibition. Notably, activation of the rIFG by unilateral anodal stimulation significantly improved response inhibition, relative to a sham condition, whereas the same tDCS protocol did not affect response time in the go trials of the SST and in a control task. Furthermore, the SST was not affected by tDCS at a control site, the right angular gyrus. Our results are the first demonstration of response inhibition improvement with brain stimulation over rIFG and further confirm the rIFG involvement in this task. Although this study was conducted in healthy subjects, present findings with anodal rIFG stimulation support the use of similar paradigms for the treatment of cognitive control impairments in pathological conditions.
人类存在的一个共同特征是能够在做出决定但尚未实施之前改变决定。这种认知控制过程被称为反应抑制，它指的是一旦启动就能够抑制行动的能力，并且基于功能成像和脑损伤研究已经定位于右额下回（rIFG）。经颅直流电刺激（tDCS）是一种可以促进和损害皮质功能的脑刺激技术。为了探讨通过 rIFG 电刺激是否可以改善反应抑制，我们在受试者执行停止信号任务（SST）之前给予了焦点 tDCS，该任务测量反应抑制。值得注意的是，与假刺激相比，单侧阳极刺激 rIFG 的激活显著改善了反应抑制，而相同的 tDCS 方案不会影响 SST 的 Go 试验和对照任务中的反应时间。此外，tDCS 对控制部位右角回的 SST 没有影响。我们的结果首次证明了通过 rIFG 脑刺激改善反应抑制，进一步证实了 rIFG 在该任务中的参与。尽管这项研究是在健康受试者中进行的，但目前 rIFG 阳极刺激的发现支持在病理条件下使用类似的范式来治疗认知控制障碍。
