Fig. 3
Changes in EEG power of VS patients with sleep cycles before and after treatments. A Topographical distribution of alpha, beta and gamma power on the scalp in the sham group. Red and blue indicate maximum and minimum EEG power (10*log10(μv2/Hz)), respectively. B Topographical distribution of alpha, beta and gamma power on the scalp in tDCS group. Red and blue indicate maximum and minimum EEG power (10*log10(μv2/Hz)) at each time point, respectively. C–E Comparison of EEG power in parietooccipital region before and after treatment both in sham group and tDCS group (Electrode number: 5,6,7,8,18,19,20,21,22,23,24,25,26,27,30,31,32,33,36,37,38,39,44,45,46,47,57), including alpha power (C), beta power (D) and gamma power (E). *P < 0.05, n.s: no significant difference; P values were determined using analysis of covariance (ANCOVA) and age was included as a covariate; tDCS: transcranial direct current stimulation; VS: vegetative state