Resting-state functional connectivity maps between each of the left (Figure 2a) and right (Figure 2b) cingulate ROIs and the rest of the brain (pcorrected <0.05). Maps for nicotine (red) and placebo (yellow) were generated separately and then overlaid together for display purpose. Orange color indicates overlapped areas from both conditions. The boundary of the ROIs from one subject (green) is overlaid here to indicate the approximate locations and sizes of the ROIs in relationship to the corresponding functional connectivity maps. Note that while the connectivity maps from each condition were based on statistically significant connectivity, the overlap or non-overlap in this display does not imply statistically significant difference between nicotine vs. placebo conditions. See Figure 5 for nicotine vs. placebo comparisons that were statistically significant. Subcallosal ACC: This ROI showed significant BOLD synchrony with dACC, medial wall of the superior frontal and orbitofrontal cortex, caudate, middle temporal cortex, precuneus, and vPCC. Rostral ACC: This ROI showed connectivity with sACC, dACC, superior frontal cortex. middle temporal cortex, insula, caudate, ventral striatum, precentral cortex, and precuneus. Dorsal ACC: sACC, oACC, superior frontal, orbitofrontal, and dorsolateral prefrontal cortex, dorsal and ventral striatum, and thalamus. MCC: dACC, superior and middle frontal cortex, PCC, insula, superior temporal cortex, inferior parietal cortex, thalamus, precuneus/ cuneus, and precentral cortex. Dorsal PCC: PCC, precuneus, cuneus, middle frontal and orbitofrontal gyrus, and thalamus (left side only). Ventral PCC: PCC, precuneus, cuneus, lingual gyrus, angular gyrus, middle and superior temporal gyrus, and in inferior parietal gyrus, medial superior and middle frontal gyrus, and parahippocampal gyrus (right side only). RSC: PCC, postcentral cortex, precuneus, cuneus, parahippocampal /fusiform gyrus, thalamus, superior frontal gyrus (left side only), medial precentral area, left cerebellum, and superior temporal gyrus.