Table 4. Structural equation modelling results.
| Influence of covariate on A | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Region | Volume | Model | A | 95% CI | C | 95% CI | E | 95% CI | Gender | Age |
| Brain | Total | AE | 0.902 | 0.78, 0.95 | 0.0980 | 0.047, 0.22 | -0.022 | -0.028 | ||
| Right | AE | 0.881 | 0.73, 0.94 | 0.119 | 0.057, 0.28 | -0.023 | -0.034 | |||
| Left | AE | 0.861 | 0.68, 0.93 | 0.139 | 0.067, 0.32 | -0.035* | -0.045* | |||
| TGM | AE | 0.912 | 0.81, 0.96 | 0.0878 | 0.043, 0.19 | -0.013 | -0.030 | |||
| RGM | AE | 0.874 | 0.87, 0.94 | 0.126 | 0.062, 0.13 | -0.015 | -0.045 | |||
| LGM | AE | 0.865 | 0.71, 0.93 | 0.135 | 0.066, 0.29 | -0.019 | -0.051 | |||
| TWM | AE | 0.843 | 0.66, 0.92 | 0.158 | 0.077, 0.34 | -0.027 | -0.011 | |||
| RWM | AE | 0.872 | 0.70, 0.94 | 0.128 | 0.061, 0.30 | -0.013 | -0.0070 | |||
| LWM | AE | 0.817 | 0.61, 0.91 | 0.183 | 0.089, 0.39 | -0.032 | -0.011 | |||
| CSF | CE | 0.681 | 0.46, 0.82 | 0.319 | 0.18, 0.54 | |||||
| Cerebrum | Total | AE | 0.875 | 0.71, 0.94 | 0.126 | 0.060, 0.29 | -0.032 | -0.042 | ||
| Right | AE | 0.870 | 0.70, 0.94 | 0.130 | 0.062, 0.30 | -0.033 | -0.044* | |||
| Left | AE | 0.869 | 0.69, 0.94 | 0.131 | 0.062, 0.31 | -0.035* | -0.045* | |||
| TGM | AE | 0.883 | 0.75, 0.94 | 0.117 | 0.058, 0.25 | -0.015 | -0.044 | |||
| RGM | AE | 0.868 | 0.72, 0.94 | 0.132 | 0.065, 0.28 | -0.016 | -0.048 | |||
| LGM | AE | 0.889 | 0.76, 0.95 | 0.111 | 0.055, 0.24 | -0.016 | -0.041 | |||
| TWM | AE | 0.850 | 0.67, 0.93 | 0.150 | 0.073, 0.33 | -0.026 | -0.0098 | |||
| RWM | AE | 0.873 | 0.72, 0.94 | 0.127 | 0.061, 0.28 | -0.022 | -0.0090 | |||
| LWM | AE | 0.822 | 0.61, 0.91 | 0.178 | 0.087, 0.39 | -0.032 | -0.010 | |||
| Cerebellum | Total | AE | 0.846 | 0.67, 0.93 | 0.154 | 0.075, 0.34 | -0.019 | -0.024 | ||
| Right | AE | 0.773 | 0.52, 0.89 | 0.227 | 0.11, 0.48 | -0.027 | -0.035 | |||
| Left | AE | 0.721 | 0.45, 0.86 | 0.279 | 0.14, 0.55 | -0.038 | -0.045 | |||
| TGM | AE | 0.812 | 0.59, 0.91 | 0.188 | 0.090, 0.41 | -0.018 | -0.043 | |||
| RGM | AE | 0.753 | 0.48, 0.88 | 0.247 | 0.12, 0.52 | -0.020 | -0.053* | |||
| LGM | AE | 0.605 | 0.27, 0.80 | 0.395 | 0.20, 0.73 | -0.041 | -0.094* | |||
| TWM | AE | 0.823 | 0.66, 0.91 | 0.177 | 0.092, 0.34 | -0.021 | -0.00070 | |||
| RWM | AE | 0.786 | 0.59, 0.89 | 0.214 | 0.11, 0.41 | -0.024 | -0.00090 | |||
| LWM | CE | 0.749 | 0.57, 0.86 | 0.251 | 0.14, 0.43 | |||||
| Frontal | Total | AE | 0.867 | 0.69, 0.94 | 0.133 | 0.063, 0.31 | -0.031 | -0.028 | ||
| Right | AE | 0.749 | 0.50, 0.87 | 0.251 | 0.13, 0.50 | -0.045* | -0.040 | |||
| Left | AE | 0.862 | 0.63, 0.94 | 0.138 | 0.062, 0.37 | -0.037 | -0.036 | |||
| TGM | AE | 0.870 | 0.79, 0.94 | 0.130 | 0.064, 0.21 | 0.015 | -0.037 | |||
| RGM | AE | 0.759 | 0.53, 0.88 | 0.241 | 0.12, 0.47 | -0.022 | -0.057* | |||
| LGM | AE | 0.907 | 0.78, 0.96 | 0.0927 | 0.044, 0.22 | -0.012 | -0.028 | |||
| TWM | AE | 0.877 | 0.71, 0.94 | 0.123 | 0.059, 0.29 | -0.034 | -0.0095 | |||
| RWM | AE | 0.783 | 0.55, 0.89 | 0.217 | 0.11, 0.45 | -0.050 | -0.010 | |||
| LWM | AE | 0.808 | 0.48, 0.92 | 0.192 | 0.084, 0.52 | -0.065* | -0.025 | |||
| Temporal | Total | AE | 0.923 | 0.82, 0.96 | 0.0772 | 0.0369, 0.183 | -0.021 | -0.019 | ||
| Right | AE | 0.870 | 0.69, 0.94 | 0.130 | 0.061, 0.31 | -0.036 | -0.034 | |||
| Left | AE | 0.920 | 0.81, 0.96 | 0.0801 | 0.038, 0.19 | -0.023 | -0.020 | |||
| TGM | AE | 0.886 | 0.73, 0.95 | 0.114 | 0.054, 0.27 | -0.025 | -0.040 | |||
| RGM | AE | 0.819 | 0.57, 0.92 | 0.181 | 0.084, 0.43 | -0.037 | -0.066* | |||
| LGM | AE | 0.895 | 0.75, 0.95 | 0.105 | 0.050, 0.25 | -0.025 | -0.037 | |||
| TWM | AE | 0.899 | 0.78, 0.95 | 0.101 | 0.049, 0.22 | -0.021 | -0.0059 | |||
| RWM | AE | 0.902 | 0.78, 0.95 | 0.0984 | 0.048, 0.22 | -0.019 | -0.0059 | |||
| LWM | AE | 0.844 | 0.66, 0.92 | 0.156 | 0.077, 0.34 | -0.034 | -0.0086 | |||
| Parietal | Total | AE | 0.865 | 0.70, 0.94 | 0.135 | 0.065, 0.31 | -0.031 | -0.010 | ||
| Right | AE | 0.806 | 0.57, 0.91 | 0.194 | 0.093, 0.43 | -0.050* | -0.018 | |||
| Left | AE | 0.831 | 0.62, 0.92 | 0.169 | 0.081, 0.38 | -0.038 | -0.011 | |||
| TGM | AE | 0.846 | 0.68, 0.92 | 0.154 | 0.078, 0.32 | -0.018 | -0.027 | |||
| RGM | AE | 0.809 | 0.61, 0.90 | 0.191 | 0.096, 0.39 | -0.022 | -0.035 | |||
| LGM | AE | 0.820 | 0.63, 0.91 | 0.180 | 0.0909, 0.37 | -0.020 | -0.029 | |||
| TWM | AE | 0.888 | 0.74, 0.95 | 0.112 | 0.054, 0.26 | -0.026 | -0.00030 | |||
| RWM | AE | 0.827 | 0.60, 0.92 | 0.173 | 0.082, 0.40 | -0.044 | -0.00070 | |||
| LWM | AE | 0.861 | 0.68, 0.93 | 0.139 | 0.067, 0.32 | -0.032 | 0.00010 | |||
| Occipital | Total | AE | 0.643 | 0.38, 0.82 | 0.357 | 0.18, 0.62 | -0.030 | 0.000 | ||
| Right | AE | 0.241 | 0.00, 0.61 | 0.759 | 0.39, 1.0 | -0.073 | -0.031 | |||
| Left | CE | 0.559 | 0.30, 0.75 | 0.441 | 0.26, 0.70 | |||||
| TGM | AE | 0.689 | 0.41, 0.84 | 0.311 | 0.16, 0.58 | -0.024 | -0.036 | |||
| RGM | AE | 0.449 | 0.090, 0.74 | 0.551 | 0.26, 0.99 | -0.063 | -0.13 | |||
| LGM | CE | 0.564 | 0.42, 0.75 | 0.437 | 0.25, 0.58 | |||||
| TWM | AE | 0.724 | 0.49, 0.86 | 0.276 | 0.14, 0.51 | -0.011 | -0.026 | |||
| RWM | AE | 0.455 | 0.050, 0.73 | 0.545 | 0.27, 0.95 | -0.023 | -0.031 | |||
| LWM | CE | 0.642 | 0.41, 0.80 | 0.359 | 0.20, 0.59 | |||||
| Brainstem | Total | AE | 0.742 | 0.51, 0.87 | 0.258 | 0.14, 0.49 | -0.0070 | -0.048 | ||
| Right | AE | 0.755 | 0.52, 0.87 | 0.245 | 0.13, 0.47 | -0.0050 | -0.045 | |||
| Left | AE | 0.693 | 0.44, 0.834 | 0.307 | 0.16, 0.56 | -0.0099 | -0.055 | |||
The best fit model, either AE (Additive genetics & unique environment) and CE (common environment & unique environment) are shown according to best fit based on AIC, log-likelihood ratios and p-values; influence of the covariate is expressed as the path between the covariate and A using AE models corrected only for ICV and scanner. Path estimates with possible significance are marked with * (confidence intervals not crossing zero). T = total, R = right, L = left, GM = grey matter, WM = white matter, CSF = cerebrospinal fluid.