| very | 16 | degree |
| over five decades | 8 | temporal |
| in humans | 4 | other |
| ketamine → be → safe | 33 |
| ketamine → be → safe medication | 5 |
| ketamine → be proven → safe | 5 |
| ketamine → be considered → safe | 4 |
| ketamine → be deemed → safe | 3 |
| ketamine → be → safe drug | 3 |
| negative | neutral | positive |
| 0.060 | 0.358 | 0.582 |
| Raw frequency | 53 |
| Normalized frequency | 0.831 |
| Modifier score | 0.400 |
| Perplexity | 52.438 |