Tabikh Mireille, Quetu Tom, Maillard Louis, Colnat-Coulbois Sophie, Rossion Bruno, Koessler Laurent
Ingenierie Moleculaire, Cellulaire et Physiopathologie, UMR7365, CNRS and University of Lorraine, Nancy F-54000, France.
Epilepsy surgery unit, Neurology Department, University Hospital of Nancy, Nancy F-54000, France.
Proc Natl Acad Sci U S A. 2025 Jun 10;122(23):e2416541122. doi: 10.1073/pnas.2416541122. Epub 2025 Jun 3.
Transcranial direct current stimulation (tDCS) is an easy to use, noninvasive brain stimulation technique that gained prominence for its potential in cognitive rehabilitation. Electroencephalography (EEG), which records electrical brain activity with a high temporal resolution, is well suited to quantify tDCS-induced neuromodulation in humans. However, most studies relying on scalp EEG recordings or event-related potentials showed low reliability and only indirect correlations. Here, we combined intracranial EEG (iEEG) recordings with a sham-controlled tDCS experiment during fast periodic visual stimulation. Anodal (+2 mA) tDCS was applied over the right occipito-temporal cortex for 20 min using two small ring high-definition electrodes. Through the analysis of iEEG signals of 947 intracerebral contacts in 11 drug-resistant epileptic patients, we quantified the neuromodulation of iEEG cognitive evoked responses during (P2 phase) and after (P3 phase) tDCS by comparison to a control phase before tDCS (P1 phase). Significant neuromodulations of face-selective iEEG activity in anterior & posterior temporal lobe and in the occipital lobe were found, with amplitude increases of 3% and 4%, 16% and 13%, and 36% and 33%, during and after tDCS, respectively. Interestingly, despite a unique tDCS session, the face-selective neuromodulation in the right visual occipito-temporal cortex remained significant ( = 0.015) after tDCS (P3 vs. P1). This iEEG study demonstrates that using low intensity tDCS and small ring electrodes can induce significant electrophysiological effects on a selective cognitive function in humans.
经颅直流电刺激（tDCS）是一种易于使用的非侵入性脑刺激技术，因其在认知康复方面的潜力而备受关注。脑电图（EEG）能够以高时间分辨率记录脑电活动，非常适合用于量化人类tDCS诱导的神经调节。然而，大多数依赖头皮EEG记录或事件相关电位的研究显示可靠性较低且仅存在间接相关性。在此，我们在快速周期性视觉刺激期间，将颅内EEG（iEEG）记录与假对照tDCS实验相结合。使用两个小型环形高清电极，在右侧枕颞叶皮层施加阳极（+2 mA）tDCS，持续20分钟。通过分析11例耐药性癫痫患者947个脑内触点的iEEG信号，我们将tDCS期间（P2期）和之后（P3期）的iEEG认知诱发反应的神经调节与tDCS前的对照期（P1期）进行比较，从而进行量化。发现在颞叶前后部和枕叶中，面部选择性iEEG活动存在显著的神经调节，在tDCS期间和之后，幅度分别增加了3%和4%、16%和13%、36%和33%。有趣的是，尽管仅进行了一次tDCS治疗，但在tDCS后（P3与P1相比），右侧视觉枕颞叶皮层的面部选择性神经调节仍然显著（P = 0.015）。这项iEEG研究表明，使用低强度tDCS和小型环形电极可以对人类的选择性认知功能产生显著的电生理效应。
