Fig. 3.

A–C Regions that have been shown to covary in activity with factors of respiration (A), factors of heart activity (B), and levels of CO₂ (C). D Summary of regions that have been shown to covary with all three respiration, heart activity, and CO₂. Abbreviations: PCC, posterior cingulate cortex; MCC, middle cingulate cortex; ACC, anterior cingulate cortex; STG, superior temporal gyrus; SSC, somatosensory cortex; SMG, supramarginal gyrus; SMA, supplementary motor area; DLPFC, dorsolateral prefrontal cortex; VLPFC, ventrolateral prefrontal cortex; OFPFC, orbitofrontal prefrontal cortex; PMC, primary motor cortex; SFG, superior frontal gyrus; MFG, middle frontal gyrus; DMPFC, dorsomedial prefrontal cortex; SPL, superior parietal lobule; aINS, anterior insula; mINS, middle insula; pINS, posterior insula; Caud, caudate; Thal, thalamus; LPFC, lateral prefrontal cortex; Cereb, cerebellum; amyg, amygdala; hipp, hippocampus; FG, fusiform gyrus; pOP, parietal operculum; AG, angular gyrus.