Table 4. Model Output for SEM Analyses Investigating Plausibility of Mediationa.
| Factor | Path a, NP and brain factors | Path b, brain factors and cognitive tasks | Path a × b, indirect effect | Path c, NP and cognitive tasks with brain factors in model | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Estimate (SE) | z | P value | Estimate (SE) | z | P value | Estimate (SE) | z | P value | Estimate (SE) | z | P value | |
| Picture vocabulary | ||||||||||||
| NP | NA | NA | NA | NA | NA | NA | NA | NA | NA | –0.15 (0.02) | –10.26 | <.001 |
| Prefrontal factor | –0.23 (0.01) | –21.27 | <.001 | 0.15 (0.02) | 7.41 | <.001 | –0.03 (0.01) | –7.02 | <.001 | NA | NA | NA |
| Hippocampal factor | –0.19 (0.01) | –16.15 | <.001 | 0.07 (0.02) | 3.87 | <.001 | –0.01 (0.004) | –3.77 | <.001 | NA | NA | NA |
| Oral reading | ||||||||||||
| NP | NA | NA | NA | NA | NA | NA | NA | NA | NA | –0.06 (0.02) | –3.61 | <.001 |
| Prefrontal Factor | –0.23 (0.01) | –21.27 | <.001 | 0.08 (0.02) | 3.82 | <.001 | –0.02 (0.01) | –3.75 | <.001 | NA | NA | NA |
| Hippocampal factor | –0.19 (0.01) | –16.15 | <.001 | 0.07 (0.02) | 3.68 | <.001 | –0.01 (0.004) | –3.52 | <.001 | NA | NA | NA |
| Dimensional card sort | ||||||||||||
| NP | NA | NA | NA | NA | NA | NA | NA | NA | –0.1 (0.02) | –6.75 | <.001 | |
| Prefrontal factor | –0.23 (0.01) | –21.27 | <.001 | 0.07 (0.02) | 3.33 | <.01 | –0.02 (0.01) | –3.27 | .001 | NA | NA | NA |
| Hippocampal factor | –0.19 (0.01) | –16.15 | <.001 | 0.04 (0.02) | 1.9 | .06 | –0.01 (0.004) | –1.89 | .06 | NA | NA | NA |
| Flanker inhibitory control | ||||||||||||
| NP | NA | NA | NA | NA | NA | NA | NA | NA | NA | –0.08 (0.02) | –4.63 | <.001 |
| Prefrontal factor | –0.23 (0.01) | –21.27 | <.001 | 0.06 (0.02) | 2.64 | .01 | –0.01 (0.01) | –2.62 | .01 | NA | NA | NA |
| Hippocampal factor | –0.19 (0.01) | –16.15 | <.001 | 0.04 (0.02) | 1.85 | .06 | –0.01 (0.004) | –1.84 | .07 | NA | NA | NA |
| List sorting | ||||||||||||
| NP | NA | NA | NA | NA | NA | NA | NA | NA | NA | –0.12 (0.02) | –7.63 | <.001 |
| Prefrontal factor | –0.23 (0.01) | –21.27 | <.001 | 0.12 (0.02) | 5.73 | <.001 | –0.03 (0.01) | –5.56 | <.001 | NA | NA | NA |
| Hippocampal factor | –0.19 (0.01) | –16.15 | <.001 | 0.02 (0.02) | 0.92 | .36 | –0.01 (0.004) | –0.92 | .36 | NA | NA | NA |
| Pattern comparison | ||||||||||||
| NP | NA | NA | NA | NA | NA | NA | NA | NA | NA | –0.07 (0.02) | –4.5 | <.001 |
| Prefrontal factor | –0.23 (0.01) | –21.27 | <.001 | 0.04 (0.02) | 1.83 | .07 | –0.01 (0.01) | –1.82 | .07 | NA | NA | NA |
| Hippocampal factor | –0.19 (0.01) | –16.15 | <.001 | 0.02 (0.02) | 1.16 | .25 | –0.01 (0.004) | –1.15 | .25 | NA | NA | NA |
| Picture sequence | ||||||||||||
| NP | NA | NA | NA | NA | NA | NA | NA | NA | NA | –0.07 (0.02) | –4.32 | <.001 |
| Prefrontal factor | –0.23 (0.01) | –21.27 | <.001 | 0.06 (0.02) | 2.97 | .008 | –0.02 (0.01) | –2.93 | <.001 | NA | NA | NA |
| Hippocampal factor | –0.19 (0.01) | –16.15 | <.001 | 0.07 (0.02) | 3.49 | <.001 | –0.01 (0.004) | –3.42 | <.001 | NA | NA | NA |
Abbreviations: NA, not applicable; NP, neighborhood poverty.
a
Covariates included: age, sex, household income, and intracranial volume. Fit indices suggest that models were a good fit for the data: Prefrontal models (CFI = 0.936, RMSEA = 0.087, SRMR = 0.071); Hippocampal models (CFI = 0.940, RMSEA = 0.084, SRMR = 0.053). NP was modeled as the predictor with prefrontal and hippocampal factors as mediators, with separate cognitive tasks as the outcome (7 models total).