Fig. 2: Experiment 4: 10-Hz RVS strengthens the ERPs.
From: Frequency-dependent photic modulation of wakeful consolidation in visual learning
a EEG (electroencephalogram) and VEOG (vertical electrooculogram) signals were recorded during the ODT (orientation discrimination task) using a 64-channel cap. EEG signals were referenced at FCz and grounded at AFz (blue). Electrodes P5 and P6 were selected for ERP (event-related potential) analyses (green). Depicted are data from a representative participant. Dashed and solid curves are ERPs from the ipsilateral and contralateral hemispheres, respectively. b Learning curves in Experiment 4. Error bars are SEMs. N (number of participants) = 45. c Simple main effects analyses from the repeated-measures ANOVA were conducted for each group to compare pre- and post-stimulation performance (two-sided, Bonferroni-adjusted: 10-Hz: F(1,41) = 6.036, p = 0.018, partial η2 = 0.128, 95% CI = [0.003 0.328]; 1-Hz (F(1,41) = 12.790, p = 0.001, partial η2 = 0.238, 95% CI = [0.049 0.439]; 0-Hz: (F(1,41) = 3.426, p = 0.071, partial η2 = 0.077, 95% CI = [0.000 0.265]). Discrimination thresholds decreased after the 10-Hz RVS, increased after the 1-Hz RVS, and remained unchanged after the 0-Hz RVS. Filled circles are individual participants, violins are kernel density estimates, and black horizontal lines are means. N = 45. d ERP waveforms under 12 combinations (2 hemispheres × 3 groups × 2 sessions). Upper and lower panels show ERPs from the ipsilateral (IPS) and contralateral (CON) electrodes. Vertical lines at 0 ms indicate stimulus onset. ERPs exhibited an enhanced negative peak at around 160 or 190 ms at the CON and IPS electrodes after the 10-Hz RVS. Error bands are SEMs. N = 45. e Simple main effects analyses from the repeated-measures ANOVA were conducted for each group to compare pre- and post-stimulation N1 amplitude (two-sided, Bonferroni-adjusted: 10-Hz: F(1,42) = 12.063, p = 0.001, partial η2 = 0.223, 95% CI = [0.042 0.423]; 1-Hz: F(1,42) = 0.879, p = 0.354, partial η2 = 0.021, 95% CI = [0.000 0.167]; 0-Hz: F(1,42) = 0.168, p = 0.684, partial η2 = 0.004, 95% CI = [0.000 0.113]). The N1 amplitude was enhanced only by the 10-Hz RVS. N = 45. f In the 10-Hz group, Pearson correlation was performed between changes in behavioral performance and changes in N1 amplitude (two-sided: r = −0.542, p = 0.037, 95% CI = [−0.723 −0.292]). The center line shows the best-fit linear regression for the Pearson correlation. Shaded areas represent 95% confidence intervals (CIs). N = 15. *p < 0.05, **p < 0.01. Source data are provided as a Source Data file.
