Table 1.
Group characteristics by age and race.
| Measure | Young | Old | |||||
|---|---|---|---|---|---|---|---|
| Black (n = 11) | White (n = 9) | Black (n = 9) | White (n = 21) | 1 | 2 | 3 | |
| Age | 25.09 (1.71) | 22.89 (1.36) | 63.33 (1.65) | 69.42 (0.97) | ∗∗ | ∗∗∗ | |
| Gender (Women/Men) | 6/5 | 6/3 | 4/5 | 12/9 | |||
| Education | 15.00 (0.38) | 15.44 (2.79) | 15.22 (0.70) | 15.29 (0.46) | |||
| High Confidence d’ | 1.69 (0.20) | 1.65 (0.77) | 1.33 (0.23) | 1.04 (0.17) | ∗ | ||
| High Confidence Trials | 0.67 (0.05) | 0.64 (0.03) | 0.73 (0.05) | 0.75 (0.04) | |||
| List Recognition | 11.75 (0.16) | 12.00 (0.00) | 11.50 (0.27) | 12.00 (0.00) | ∗ | ||
| Visual Recognition | 16.82 (1.27) | 17.67 (1.27) | 13.11 (1.86) | 15.43 (0.92) | ∗ | ||
| Verbal Span | 12.64 (0.62) | 11.33 (1.00) | 9.22 (0.74) | 10.95 (0.55) | ∗ | ||
| Trials A (seconds) | 25.62 (2.51) | 22.85 (1.92) | 35.19 (3.00) | 35.63 (2.71) | ∗ | ||
| Trials B (seconds) | 66.91 (9.77) | 54.45 (5.86) | 101.50 (13.01) | 67.67 (2.85) | ∗ | ∗ | |
| MOCA | 27.55 (0.37) | 28.00 (0.55) | 23.33 (1.01) | 27.40 (0.41) | ∗∗∗ | ∗∗∗ | ∗∗ |
| DASS-Stress | 3.00 (1.12) | 4.78 (1.28) | 2.78 (0.98) | 3.52 (0.71) | |||
| IRRS-B Cultural | 28.75 (5.12) | 21.25 (3.12) | 28.00 (7.08) | 14.33 (2.20) | ∗∗ | ||
| IRRS-B Institutional | 10.50 (2.40) | 9.75 (2.17) | 12.25 (3.54) | 6.50 (0.50) | ∗ | ||
| IRRS-B Individual | 11.25 (3.35) | 7.50 (1.50) | 13.33 (2.40) | 6.44 (0.44) | ∗ | ||
| Income | 33434.67 (4851.62) | 59856.71 (4013.46) | ∗∗ | ||||
| TST-M | 397.93 (20.32) | 417.89 (17.92) | 350.95 (15.04) | 411.37 (11.39) | ∗ | ||
| TST-V | 12706.23 (4561.47) | 5047.56 (1200.78) | 5046.26 (1552.16) | 3889.18 (978.34) | ∗ | ||
| Number of Awakenings-M | 15.70 (2.15) | 16.16 (2.42) | 17.96 (2.71) | 13.23 (0.97) | |||
| Number of Awakenings-V | 43.31 (9.00) | 23.70 (4.40) | 25.28 (6.22) | 20.20 (4.20) | |||
| Sleep Efficiency-M | 87.27 (1.51) | 88.65 (2.84) | 82.55 (3.90) | 89.64 (0.90) | ∗ | ||
| Sleep Efficiency-V | 29.94 (8.41) | 25.71 (16.22) | 34.22 (15.88) | 21.01 (4.24) | |||
| WASO-M | 49.14 (6.43) | 47.53 (13.84) | 74.17 (19.49) | 43.80 (4.48) | |||
| WASO-V | 841.74 (290.19) | 557.76 (367.69) | 596.88 (139.94) | 660.88 (181.70) | |||
| SFI-M | 29.48 (3.01) | 24.03 (4.03) | 40.26 (5.16) | 24.67 (1.25) | ∗∗ | ||
| SFI-V | 134.31 (31.57) | 90.43 (18.42) | 169.09 (33.03) | 114.24 (18.28) | |||
| Sleep Discontinuity Component - M | 0.06 (0.28) | -0.03 (0.34) | 0.57 (0.51) | -0.26 (0.13) | |||
| Sleep Time Component- M | 0.05 (0.31) | 0.47 (0.34) | -0.63 (0.22) | 0.23 (0.17) | ∗ | ||
| Sleep Discontinuity Component-V | 0.39 (0.35) | -0.20 (0.25) | -0.32 (0.22) | -0.30 (0.22) | |||
| Sleep Time Component - V | 0.32 (0.46) | -0.33 (0.21) | 0.35 (0.43) | -0.14 (0.17) | |||
The standard error of the mean is in parentheses. Mean differences between old Black and old White are in column 1; age group main effects are marked in column 2; and racial group main effects are in column 3. There were no significant differences between young Black and young White participants. The IRRS-B measures are based on a smaller subset of participants. TST = Total Sleep Time; WASO = Wake After Sleep Onset; SFI = sleep fragmentation index; M = mean; V = variance. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.