Increased sensorimotor activation in false alarm than correct rejection trials in the communicative condition
For each of the three significant results (A–C), the significant voxels over participants are indicated in turquoise in the sagittal view of the brain (for other views, please see Figures S2–S4). For the most significant voxel, the power values for every participant as well as for the mean (turquoise points and line) are illustrated in the line chart for the false alarm (FA) and correct rejection (CR) trials. In the time segment (1) before agent B’s onset (in red), a power decrease in false alarm — compared to correct rejection trials — was found in (A) the alpha frequency band (8–12 Hz) in the left frontal lobe, Brodmann Area 6, premotor cortex (peak significance at MNI coordinates: −40/0/45; p < 0.05) and in (B) the lower beta band (13–17 Hz) in the left frontal lobe, Brodmann Area 6, premotor cortex (peak significance at MNI coordinates: −45/−10/60; p < 0.05) with significant activation spreading to voxels in the adjacent primary motor cortex, Brodmann Area 4.
(C) In the time segment (3) before the response (in blue), a power decrease in false alarm — compared to correct rejection trials — reached significance in the upper beta band (18–25 Hz) in the right postcentral gyrus, Brodmann Area 3, primary somatosensory cortex (peak significance at MNI coordinates: 20/−35/55; p < 0.05). Significant voxels were also present in the Brodmann Area 2 of the primary somatosensory cortex. In addition, the significant difference spread to the adjacent right precentral gyrus, Brodmann Area 4, primary motor cortex, and to the other following right parietal regions: Brodmann Area 5 (paracentral gyrus, postcentral gyrus), Brodmann Area 7 (postcentral gyrus, superior parietal lobule, precuneus), and Brodmann Area 40 (p < 0.05). For an illustration of the control contrasts false alarm versus correct rejection trials in the individual condition and false alarm versus hit trials in the communicative condition, please refer to the Figures S5–S7.