Figure 3.

Model space. (A). Schemata of parameters that made up the base models. The mirror neuron system is driven by action observation; and the three prefrontal nodes are connected by all combinations of 2 or 3 of the bidirectional connections, which are depicted by dotted lines (see Supplementary Figure 2A for expansion of 4 possible prefrontal connection models). (B). Three variations of prefrontal-MNS interactions were included. The prefrontal network was connected to the frontal node of the mirror neuron system (IFGpo) via one of the 3 prefrontal control nodes by varying the connectivity structure as shown. This allowed us to identify which prefrontal region interacts with the MNS. (C). Variations of conflict input to the system are depicted on one single connectivity structure (fully connected prefrontal network and aINS→IFGpo connection). Solid arrows show variations in the nodes receiving conflict as a driving input (from left to right: mPFC, ACC, ACC & mPFC, IFGpo). These variations test conflict detection hypotheses. Dotted lines depict conflict as a modulator of prefrontal input to the MNS. The same models excluding the modulating input were also included creating a total of 8 variations of conflict inputs. An expanded depiction of the model space showing the factorial combinations of the models depicted here can be found in Supplementary Figure 2. ACC = anterior cingulate cortex; mPFC = medial prefrontal cortex; aINS = anterior insula; IFGpo = inferior frontal gyrus, pars opercularis; AO = action observation; C = imitative conflict.