Fig. 4.

tcVNS after mental stress: Outcomes for stimulation following two types of mental stress, public speech and mental arithmetic. Bars represent the unadjusted mean changes from baseline, error bars: 95% confidence interval (CI), values calculated from raw data, * indicates p < 0.05. β coefficients, adjusted CI, effect sizes (d), and p-values were reported in β (±CI, d, p) format. Active tcVNS group experienced the following relative to sham after adjustments: (A) SD1/SD2 increased during stimulation right after speech task by 23.1% (±21.1%, d = 0.71, p = 0.033). (B) Similar to the speech task, SD1/SD2 increased by 41.2% (±22.5%, d = 0.44, p = 0.001). (C) Pre-ejection period (83) increased following stimulation after speech task by 6.8% (±5%, d = 0.16, p = 0.009). (D) Pulse pressure (PP) decreased following stimulation after mental arithmetic by 9.6% (±9.7%, d = 0.68, p = 0.049).