Figure 3. Human imaging during acute nociceptive stimulation.

A. Summary of peak activation sites in 40 studies during noxious thermal stimulation of the skin and noxious hypertonic saline or visceral distention (References provided online). Cutaneous activations were almost homogeneous throughout MCC with somewhat fewer in the rostral part of aMCC and most in the dorsal and rostral part of pMCC, while visceral activity was greatest in pACC and some in rostral aMCC. The two yellow circles are for activations associated with the opioid placebo (1.⁵⁵) and the acupuncture placebo (2.⁵⁷). B./C. Activation sites for two studies were coregistered to the postmortem control case because two different noxious stimulation paradigms were applied to the same subjects providing a more accurate differentiation of the topography of activation sites. As a rule, noxious cutaneous stimulation evoked small and more caudal activity in pMCC, while noxious esophageal distention (B.³⁶) or electrical stimulation of muscle (C.³⁷) evoked larger and more rostral activity in aMCC. Differential activation of parts of MCC likely reflects the differential recruitment of the caudal and rostral cingulate motor areas and their associated cognitive functions.