Fig. A1.

Frequentist multiple regression models. r² (top) and adjusted r² (bottom) for multiple regression models based on the large GABA voxel data and either exact GM volume data (left) or ROI peak voxel data (right). Note that for the exact condition as well as the ROI condition, the best model (with the highest adjusted r²) had three predictors. The models are reported in Table A2.