Optimal use of EEG recordings to target active brain areas with transcranial electrical stimulation - ScienceDirect

Fig. 1. Reciprocal stimulation produces an electric field focused on the site of neural activation. (A) Focal neural activation of the right frontocentral cortex produces a radially-symmetric pattern of electric potentials on the scalp. Inset: BEM head model employed to simulate EEG activations and electric fields during TES. (B) By patterning the stimulation currents according to the observed scalp activity (i.e., 𝐼 ∝ 𝑉 ), “naive” reciprocity generates a diffuse electric field that is strong at the site of activation but also over expansive regions of cortex. (C) Applying TES in proportion to the spatially decorrelated EEG (i.e., 𝐼 = 𝑐 ( RR 𝑇 ) − 1 𝑉 ) yields focal stimulation at the neural activation. Note that the injected reciprocal currents are both positive (“anodal”) and negative (“cathodal”) over the scalp regions marked by positive EEG potentials. Fig. 2. Localization of EEG is equivalent to targeting in TES. (A) Bilateral activation of the superior parietal lobule. (B

Fig. 1. Reciprocal stimulation produces an electric field focused on the site of neural activation. (A) Focal neural activation of the right frontocentral cortex produces a radially-symmetric pattern of electric potentials on the scalp. Inset: BEM head model employed to simulate EEG activations and electric fields during TES. (B) By patterning the stimulation currents according to the observed scalp activity (i.e., 𝐼 ∝ 𝑉 ), “naive” reciprocity generates a diffuse electric field that is strong at the site of activation but also over expansive regions of cortex. (C) Applying TES in proportion