Figure 2.
Individual data points for the magnitude of regional μ-opioid system activation in response to the placebo intervention. Individual data points for the change in the binding potential measure (BP; μ-opioid receptor availability in vivo; Bmax/Kd) from the pain condition to the pain plus placebo condition are shown. A threshold of 10% increase in the activation of this neurotransmitter system, evidenced as a reduction in the BP measure during the placebo condition, was used to identify individuals that responded with a robust placebo effect on the activation of this system in each of the regions (dashed line). ACing_Rostral, Rostral (pregenual) region of the anterior cingulate; DLPFC_Left, left dorsolateral prefrontal cortex; Insula_Right, right insular cortex; N.Acc._Left, left nucleus accumbens.