Table 1.
Demographic Characteristics as a Function of Sample
| Full Sample | Ability Discrepancy > 0 |
Ability Discrepancy > 0 with PET |
Ability Discrepancy ≤ 0 |
|
|---|---|---|---|---|
| N | 112 (75 with PET) |
60 | 43 | 52 (32 with PET) |
| Age (years) | 75.58 (7.1) | 76.28 (7.2) | 76.14 (7.0) | 74.77 (7.0) |
| Age Range | 65–89 | 65–89 | 65–89 | 65–88 |
| Sex (M/F) | 41/71 | 29/31a | 23/20 | 12/40 |
| Education (years) | 16.13 (2.5) | 16.75 (2.5)a | 16.93 (2.5) | 15.41 (2.4) |
| Education Range | 12–21 | 12–21 | 12–21 | 12–21 |
| MMSE Score | 27.75 (1.3) | 27.78 (1.2) | 27.84 (1.2) | 27.71 (1.3) |
| MMSE Range | 26–30 | 26–30 | 26–30 | 26–30 |
| Mean Cortical Thickness |
2.69 (0.16) | 2.70 (0.16) | 2.71 (0.13) | 2.68 (0.17) |
| Mean Cortical Thickness Range |
2.00–3.03 | 2.00–3.03 | 2.39–3.03 | 2.15–2.95 |
| Mean Cortical Aβ | 1.23 (0.18) | − | 1.25 (0.19) | 1.22 (0.17) |
| Mean Cortical Aβ Range |
0.97–1.77 | − | 1.07–1.77 | 0.97–1.58 |
| N Aβ+ (%) | 31 (41%) | − | 17 (40%) | 14 (44%) |
| Discrepancy Score | −0.01 (1.0) | 0.69 (0.6) | 0.69 (0.6) | −0.82 (0.7) |
| Discrepancy Score Range |
−2.97–2.32 | 0.01–2.32 | 0.01–2.32 | −2.97–−0.03 |
Notes. Standard deviation is in parentheses; Mean cortical thickness and Aβ deposition is calculated across all regions of interest;
a
Subjects with an ability discrepancy score greater than zero were more educated and were more likely to be male than those with a score zero or less (p’s < .01).