| Group | Right | Left |
| Control | 0.3675 ± 0.0156 | 0.2938 ± 0.0231 |
| ALS | 0.1547 ± 0.0291 | 0.1351 ± 0.0124 |
| Parkinson | 0.2462 ± 0.0093 | 0.2378 ± 0.0274 |
| Huntington | 0.2954 ± 0.0682 | 0.3006 ± 0.0293 |