Figure 1.

DCM model space. Nodes of interest were literature-specified locations in primary auditory cortex (A1), superior temporal gyrus (STG), inferior frontal gyrus (IFG), and inferior parietal cortex (IPC). Red arrows graphically indicate what has been added to each model compared with the previous, simpler model. A, Model 1 is the original winning model from Garrido et al. (2009a). Subsequent models build from this with our alternative hypotheses based on the subsequent literature, to test our specific hypotheses. B, First, we included connections between left STG and IFG (model 2). C, Second, we alternated connections between left or bilateral IPC with STG and/or IFG (models 3–8). D, Third, we added top-down IFG inputs to all previous models (models 9–16). E, Finally, we repeated all the models with added lateral connections between STGs, IFGs, and IPCs (models 17–32).