| in order to function | 16 | purpose |
| to organize its self | 13 | purpose |
| to consolidate memories | 8 | purpose |
| brain → need → sleep | 69 |
| brain → use → sleep | 14 |
| brain → be → sleep | 13 |
| brain → prepare for → sleep | 10 |
| brain → require → sleep | 9 |
| brain → need → adequate sleep | 7 |
| brain → allow → sleep | 4 |
| brain → handle → sleep | 3 |
| negative | neutral | positive |
| 0.257 | 0.599 | 0.144 |
| Raw frequency | 129 |
| Normalized frequency | 0.603 |
| Modifier score | 0.500 |
| Perplexity | 174.546 |