| for maintenance | 12 | purpose |
| for the life of nerve cells | 8 | purpose |
| for survival | 5 | purpose |
| ngf → be → essential | 11 |
| ngf → be → critical | 11 |
| ngf → be → important | 6 |
| negative | neutral | positive |
| 0.048 | 0.654 | 0.298 |
| Raw frequency | 28 |
| Normalized frequency | 1.000 |
| Modifier score | 0.500 |
| Perplexity | 111.955 |