Table 2.
Multilevel anlaysis of the training data (n-back task).
| MODEL 1 |
MODEL 2 |
MODEL 3 |
MODEL 4 |
MODEL 5 |
MODEL 6 |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| + change in time in Nback task | + age as a predictor | + sex as a predictor | + education level score as a predictor | + occupational activity as a predictor | + Initial OSPAN | |||||||
| b | (s.e.) | b | (s.e.) | b | (s.e.) | b | (s.e.) | b | (s.e.) | b | (s.e.) | |
| Fixed effects | ||||||||||||
| Intercept | 2.165 | (0.088)*** | 2.162 | (0.093)*** | 2.216 | (0.151)*** | 2.238 | (0.111)*** | 2.278 | (0.158)*** | 1.928 | (0.143)*** |
| Time – linear (centered at 1st day) | 0.031 | (0.005)*** | 0.028 | (0.005)*** | 0.036 | (0.008)*** | 0.035 | (0.006)*** | 0.037 | (0.008)*** | 0.016 | (0.007)* |
| Ageˆ | — | — | 0.010 | (0.018) n.s. |
— | — | — | — | — | — | — | — |
| Sex∼ | — | — | — | — | –0.008 | (0.188) n.s. |
— | — | — | — | — | — |
| Education level∼ | — | — | — | — | — | — | –0.204 | (0.186) n.s. |
— | — | — | — |
| Occupational activity∼ | — | — | — | — | — | — | — | — | –0.131 | (0.191) n.s. |
— | — |
| Initial OSPAN score ∼ (high/low) | — | — | — | — | — | — | — | — | — | — | 0.038 | (0.183)* |
| Time × age | — | — | –0.002 | (0.001)° | — | — | — | — | — | — | — | — |
| Time × sex | — | — | — | — | –0.008 | (0.009) n.s. |
— | — | — | — | — | — |
| Time × education level | — | — | — | — | — | — | –0.011 | (0.009) n.s. |
— | — | — | — |
| Time × occupational activity | — | — | — | — | — | — | — | — | –0.008 | (0.010) n.s. |
— | — |
| Time × initial OSPAN score | — | — | — | — | — | — | — | — | — | — | 0.026 | (0.008)** |
| Random effects ([co-]variances) | ||||||||||||
| Level 2 (between-person) | ||||||||||||
| Intercept | 0.285 | (0.073)*** | 0.301 | (0.079)*** | 0.300 | (0.006)*** | 0.292 | (0.076)*** | 0.283 | (0.075)*** | 0.286 | (0.075)*** |
| Time – linear | 0.001 | (0.001)*** | 0.001 | (0.001)*** | 0.001 | (0.001)*** | 0.001 | (0.001)*** | 0.001 | (0.001)*** | 0.001 | (0.001)*** |
| Intercept and time | 0.006 | (0.003)* | 0.006 | (0.003)* | 0.006 | (0.003)* | 0.006 | (0.003)* | 0.005 | (0.003)° | 0.004 | (0.002)° |
| Level 1 (within-person) | ||||||||||||
| Residual | 0.151 | (0.009)*** | 0.149 | (0.009)*** | 0.150 | (0.009)*** | 0.151 | (0.009)*** | 0.153 | (0.009)*** | 0.149 | (0.009)*** |
| Autocorrelation | 0.339 | (0.039)*** | 0.336 | (0.040)*** | 0.338 | (0.039)*** | 0.338 | (0.039)*** | 0.336 | (0.039)*** | 0.328 | (0.040)*** |
| Model fit | ||||||||||||
| –2 log likelihood (y2) | 1069.32 | 1063.69 | 1089.51 | 1088.24 | 1077.91 | 1046.37 | ||||||
| Akaike’s Information Criterion (AIC) | 1083.32 | 1073.69 | 1099.51 | 1098.24 | 1087.91 | 1056.37 | ||||||
Results from multilevel modeling. Unstandardized regression coefficients listed with standard errors in parenthesis, °p = 0.1, *p < 0.05, **p < 0.01, and ***p < 0.001. All p-Values are two-tailed except in the case of variances, where one-tiled p-Values are used (because variances are constrained to be non-negative). ∧The predictors are mean centered. ∼The predictors are dichotomous.