Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
PLoS One. 2013;8(2):e56589. doi: 10.1371/journal.pone.0056589. Epub 2013 Feb 14.
Transcranial alternating current stimulation (tACS) is a promising tool for modulating brain oscillations, as well as a possible therapeutic intervention. However, the lack of conclusive evidence on whether tACS is able to effectively affect cortical activity continues to limit its application. The present study aims to address this issue by exploiting the well-known inhibitory alpha rhythm in the posterior parietal cortex during visual perception and attention orientation. Four groups of healthy volunteers were tested with a Gabor patch detection and discrimination task. All participants were tested at the baseline and selective frequencies of tACS, including Sham, 6 Hz, 10 Hz, and 25 Hz. Stimulation at 6 Hz and 10 Hz over the occipito-parietal area impaired performance in the detection task compared to the baseline. The lack of a retinotopically organised effect and marginal frequency-specificity modulation in the detection task force us to be cautious about the effectiveness of tACS in modulating brain oscillations. Therefore, the present study does not provide significant evidence for tACS reliably inducing direct modulations of brain oscillations that can influence performance in a visual task.
经颅交流电刺激（tACS）是一种有前途的调节脑振荡的工具，也是一种可能的治疗干预手段。然而，关于 tACS 是否能够有效地影响皮质活动的证据尚不明确，这仍然限制了它的应用。本研究旨在通过利用视觉感知和注意力定向过程中后顶叶皮层的抑制性 alpha 节律来解决这个问题。四组健康志愿者接受了一个 Gabor 补丁检测和辨别任务的测试。所有参与者都在基线和选择性频率的 tACS 下进行了测试，包括假刺激、6Hz、10Hz 和 25Hz。与基线相比，枕顶区域的 6Hz 和 10Hz 刺激会降低检测任务的表现。在检测任务中缺乏与视网膜组织相关的效应和边缘频率特异性调制，这使得我们对 tACS 调节脑振荡的有效性持谨慎态度。因此，本研究没有提供可靠的证据表明 tACS 能够可靠地诱导直接调节脑振荡，从而影响视觉任务的表现。
