Data Sheet 1_Multidimensional EEG mechanisms and explainable prediction of responsiveness to posterior parietal HD-tDCS in chronic disorders of consciousness.pdf

In R+ only, the aperiodic exponent decreased at four centro-parietal electrodes, power in the 20–35 Hz window increased at nine electrodes, RQA metrics decreased across 13–18 electrodes, LZc increased at 11 electrodes, and NSC in the 20–35 Hz window increased significantly (p = 0.0222). No corresponding changes were detected in R−. Relief-based feature selection identified the aperiodic exponent and the 20–35 Hz NSC feature from eight candidate biomarkers for training a Bayesian-optimized support vector machine.

SHapley Additive exPlanations indicated comparable contributions from both features. These findings identify responder-specific changes in periodic and aperiodic spectral parameters and in nonlinear EEG descriptors following Pz-targeted HD-tDCS. They are consistent with modulation of cortical state and large-scale dynamics, but do not by themselves demonstrate excitation–inhibition rebalancing or thalamocortical loop reinforcement, and the single-arm design without sham stimulation precludes attribution of the observed changes specifically to HD-tDCS.</p>