Table 1.
Demographic and neuropsychological measures (mean ± SD)
| Variable | Young (sleep; n = 20) | Young (wake; n = 20) | Older (sleep; n = 31) | Older (wake; n = 20) |
|---|---|---|---|---|
| Age (y) | 20.4 ± 2.0 | 21.7 ± 2.9 | 73.5 ± 5.2 | 74.1 ± 7.1 |
| Gender | 12 Female | 9 Female | 22 Female | 17 Female |
| MMSE | 29.6 ± 0.9 | 29.4 ± 1.0 | 29.5 ± 1.0 | 29.4 ± 0.9 |
| Mean prestudy bed time | 0:20 ± 0:54 | 23:43 ± 1:01 | 22:50 ± 1:15 | 22:56 ± 1:06 |
| Mean prestudy wake time | 8:26 ± 0:52 | 7:34 ± 0:53 | 7:16 ± 1:11 | 6:41 ± 1:09 |
| Mean prestudy time in bed (h) | 8.11 ± 0.58 | 8.01 ± 0.67 | 8.42 ± 0.73 | 7.83 ± 0.84 |
| Mean prestudy sleep time (h) | 7.75 ± 0.61 | 7.52 ± 0.85 | 7.14 ± 1.00 | 7.28 ± 1.00 |
| Mean prestudy sleep latency (min) | 15.7 ± 9.2 | 22.5 ± 26.4 | 35.7 ± 42.2 | 17.6 ± 19.1 |
| Mean prestudy sleep efficiency (%) | 95.6 ± 3.4 | 93.8 ± 6.8 | 86.0 ± 11.5 | 92.9 ± 6.7 |
| Neuropsychological measures | ||||
| CVLT (long delay, # free recalled) | 11.0 ± 3.1 | 12.9 ± 2.8 | ||
| WMS (visual reproduction %) | 75.0 ± 17.0 | 83.9 ± 21.7 | ||
| Trailmaking B (seconds) | 72.2 ± 34.5 | 80.0 ± 33.3 | ||
| Stroop (# correct in 60 s) | 50.2 ± 14.2 | 50.1 ± 11.8 |
MMSE, Mini Mental State Examination; CVLT, California Verbal Learning Test (number recalled after 20 min delay); WMS, Wechsler Memory Scale-Revised.