Subjective ratings of tVNS/sham stimulation
| tVNS | sham | |
|---|---|---|
| I have a headache | 1.82 ± 0.20 | 1.89 ± 0.22 |
| I feel nausea | 1.67 ± 0.19 | 1.63 ± 0.19 |
| I feel dizziness | 1.82 ± 0.22 | 1.97 ± 0.25 |
| I feel neck pain | 1.87 ± 0.16 | 1.97 ± 0.19 |
| I feel muscle contraction in the neck | 2.10 ± 0.20 | 2.00 ± 0.21 |
| I feel stinging under the electrode | 2.22 ± 0.22 | 2.18 ± 0.23 |
| I feel skin irritation in the ear | 2.17 ± 0.28 | 2.15 ± 0.27 |
| I feel fluctuation in concentration | 4.02 ± 0.39 | 3.73 ± 0.36 |
| I have an unpleasant feeling | 2.52 ± 0.29 | 2.71 ± 0.31 |
| I am in a good mood | 4.82 ± 0.32 | 5.23 ± 0.27 |
| I am alert | 4.07 ± 0.32 | 4.15 ± 0.31 |
Mean subjective rating in response to questions that appeared every 2 stimulation blocks (scale 0–9; higher numbers indicate agreement with the statement). No significant differences between the tVNS and sham conditions in subjective reports were observed.