Table 1.
Cognitive test scores, practice effects z-scores, and correlations with FDG PET composite
| Cognitive measure | Baseline | 1 week | Practice effects z-score | r (d) | pr (d) |
|---|---|---|---|---|---|
| BVMT-R Total Recall | |||||
| Intact | 18.7 (6.4) | 26.7 (6.2) | −0.2 (0.7) | .49 (1.1) | −0.21 (0.4) |
| MCI | 12.1 (7.3) | 21.3 (7.6) | −0.1 (0.9) | −.64* (1.7) | −0.09 (0.2) |
| BVMT-R Delayed Recall | |||||
| Intact | 7.7 (2.7) | 9.9 (1.7) | 0.1 (0.6) | .20 (0.4) | 0.10 (0.2) |
| MCI | 5.3 (3.3) | 7.8 (3.1) | −0.4 (1.0) | −.29 (0.6) | −0.38 (0.8) |
| HVLT-R Total Recall | |||||
| Intact | 29.2 (4.3) | 31.5 (3.5) | −0.2 (0.5) | .24 (0.5) | 0.24 (0.5) |
| MCI | 23.8 (5.4) | 27.0 (6.3) | −0.3 (0.7) | −.70* (2.0) | −0.53 (1.2) |
| HVLT-R Delayed Recall | |||||
| Intact | 9.4 (2.4) | 10.6 (1.9) | 0.0 (0.5) | .48 (1.1) | 0.16 (0.3) |
| MCI | 5.5 (3.6) | 9.1 (2.5) | 0.2 (1.0) | −.40 (0.9) | −0.51 (1.2) |
| TMTA (time to complete) | |||||
| Intact | 37.4 (12.5) | 43.9 (42.6) | 1.0 (4.5) | −.01 (0.0) | 0.31 (0.6) |
| MCI | 50.1 (23.8) | 46.8 (22.1) | 0.5 (2.8) | .12 (0.2) | −0.30 (0.6) |
| TMTB (time to complete) | |||||
| Intact | 84.8 (26.1) | 77.1 (27.5) | −0.1 (0.5) | −.44 (1.0) | 0.19 (0.4) |
| MCI | 112.1 (56.8) | 111.4 (74.1) | 0.6 (1.4) | .79* (2.6) | 0.63 (1.6) |
| SDMT (correct in 90″) | |||||
| Intact | 44.4 (6.6) | 48.0 (9.1) | 0.2 (1.0) | −.13 (0.3) | 0.12 (0.2) |
| MCI | 35.8 (9.1) | 37.7 (9.8) | −0.5 (0.9) | −.56 (1.3) | −0.52 (1.2) |
| COWAT (correct across three 60″ trials) | |||||
| Intact | 38.7 (9.5) | 41.1 (11.8) | 0.1 (1.2) | .08 (0.2) | 0.08 (0.2) |
| MCI | 34.7 (8.1) | 35.4 (12.5) | −0.3 (1.3) | −.64 (1.7) | −0.02 (0.0) |
Notes: Baseline and 1 week scores are raw scores (means and SDs), where higher scores indicate better cognitive performance for all tests except TMTA and TMTB, which is opposite. Practice effects z-scores are based on standardized regression-based change formulae (see Methods for additional details), which quantifies how much change an individual shows across 1 week on a particular test compared with 167 non-demented older adults who were also administered this battery at baseline and 1 week. For all the practice effects, z-scores, except TMTA and TMTB, higher values indicate larger practice effects compared with the peer group. For TMTA and TMTB practice effects z-scores, the opposite was true (i.e., lower values indicate larger practice effects).
r = Pearson correlation between baseline cognitive scores and FDG PET composite score. pr = partial Pearson correlation between practice effects z-score and FDG PET composite score, controlling for baseline cognitive score. d = Cohen's d effect size. MCI = mild cognitive impairment, BVMT-R = Brief Visuospatial Memory Test—Revised, HVLT-R = Hopkins Verbal Learning Test—Revised, TMTA = Trail Making Test Part A, TMTB = Trail Making Test Part B, SDMT = Symbol Digit Modalities Test, COWAT = Controlled Oral Word Association Test.
*p < .05.