Table 1. Stimulus conditions used in Experiments 2 and 3.
| Condition | Stimulus intensity | ||||
|---|---|---|---|---|---|
| CS100 | CCS5 | CS10 | CS2 | TS | |
| 2 A | — | — | — | — | 0.5 mV |
| 2B | — | — | — | 0.8MT | 0.5 mV |
| 2C | — | — | 0.8MT | — | 0.5 mV |
| 2D | — | AMT–5% | — | — | 0.5 mV |
| 2E | — | — | — | — | 0.5 mVCCS5 |
| 2F | — | — | — | 0.8MT | 0.5 mVCCS5 |
| 2G | — | — | 0.8MT | — | 0.5 mVCCS5 |
| 2H | — | AMT–5% | — | — | 0.5 mVCCS5 |
| 2I | — | AMT–5% | — | 0.8MT | 0.5 mVCCS5 |
| 2J | — | AMT–5% | 0.8MT | — | 0.5 mVCCS5 |
| 3A | — | — | — | — | 0.5 mV |
| 3B | — | AMT–5% | — | — | 0.5 mV |
| 3C | 1 mV | — | — | — | 0.5 mV |
| 3D | — | — | — | — | 0.5 mVCS100 |
| 3E | — | AMT–5% | — | — | 0.5 mVCS100 |
| 3F | 1 mV | — | — | — | 0.5 mVCS100 |
| 3G | 1 mV | AMT–5% | — | — | 0.5 mVCS100 |
CS100 represents a conditioning stimulus delivered 100 ms before TS (Experiment 3), CCS5 is a contralateral conditioning stimulus delivered 5 ms before test stimulus and an intensity at 5% of the stimulator output below the active motor threshold (AMT–5%), CS10 is a conditioning stimulus delivered 10 ms before TS (Experiment 2), CS2 is a conditioning stimulus delivered 2 ms before TS (Experiment 2), MT represents the resting motor threshold and TS is the test stimulus. See Methods for definition of TS intensity.