Mean (SEM) performance at baseline before day shift 1, and during each shift, for the young and older subjects
| Baseline | Day shift 1 | Day shift 2 | Night shift 1 | Night shift 2 | |
| Young | 15.67 (0.27) | 15.68 (0.08) | 15.64 (0.09) | 15.62 (0.1) | 15.8 (0.1) |
| Older | 14.17 (0.35) | 13.94 (0.9) | 14.38 (0.1) | 14.03 (0.1) | 14.35 (0.1) |
| p Value, young volder | 0.002 | 0.0001 | 0.0001 | 0.0001 | 0.0001 |