Table 1.
Demographic information
| Age groups | |||||
| Variable | Younger (20–34 y) | Middle early (35–49 y) | Middle late (50–64 y) | Older (65–89 y) | P value |
| N | 44 | 43 | 85 | 132 | NA |
| % Female | 59% | 63% | 66% | 55% | NS |
| % Minority | 34% | 21% | 12% | 4% | <0.001*** |
| SES (SD) | 0.18 (1.30) | 0.21 (1.21) | −0.11 (1.19) | −0.05 (1.22) | NS |
| Education years (SD) | 16.52 (2.46) | 16.29 (2.26) | 15.65 (2.13) | 15.50 (2.29) | 0.028* |
| Occupational socioeconomic index (SD) | 45.73 (12.96) | 47.44 (13.02) | 45.30 (12.99) | 47.20 (11.79) | NS |
| MMSE (SD) | 28.41 (1.23) | 28.67 (1.13) | 28.39 (1.13) | 28.11 (1.21) | 0.035* |
| BMI | 25.20 (4.82) | 24.99 (3.91) | 26.54 (4.00) | 25.80 (3.64) | NS |
| SF-36 PCS | 56.74 (4.88) | 56.99 (4.10) | 55.38 (6.93) | 53.05 (5.77) | <0.001*** |
| % with chronic physical health issues | 23% | 14% | 20% | 31% | NS |
| % Hypertension | 0% | 2% | 24% | 32% | <0.001*** |
| % Never smoker | 64% | 67% | 73% | 56% | NS |
| Alcohol per week (SD) | 2.88 (3.73) | 2.42 (2.74) | 2.31 (3.84) | 2.77 (3.75) | NS |
| Head motion (mean FD; SD) | 0.12 (0.03) | 0.14 (0.04) | 0.16 (0.06) | 0.18 (0.06) | <0.001*** |
Statistical tests between age groups were conducted with χ2 test for distributions of gender, minority (self-reporting as nonwhite/Caucasian), participants with chronic physical health issues, participants with hypertension, and smoker status; ANOVAs were used for SES, education years, occupational socioeconomic index, Mini-Mental State Examination (MMSE), SF-36 Physical Component Score (PCS), alcohol consumption (drinks per week), and in-scanner head motion during resting state (BOLD fMRI) scan [mean frame displacement (FD)]. Asterisks denote statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001); NS, not significant; NA, statistical test was not performed.