2011 - placebo

Anticipatory predictors of placebo analgesia from standard regression.

A, Surfacefigures(middle) illustrateregionswhere greater placeborelated increases(warm colors) and decreases (cool colors) during pain anticipation predicted greater placebo analgesia. Scatter plots (left) illustrate the relationship between average cluster activity during anticipation ( y-axis) and reported placebo analgesia (x-axis). Examples are shown for the left DLPFC (positive correlation) and for the right SII region (negative correlation). BOLD activity reported on they-axis ascends from top to bottom, because activity is displayed relative to placebo condition, where the contrast values were negative when P C and positive when C P. The slices (right) show in greater detail that increases predicted analgesia in the VLPFC and OFC, while decreases predicted analgesia in SII and a region encompassing the insula and superior temporal gyrus (STG).

B, Regions in which anticipatory activity was correlated with greater prescan expectations of analgesia in study 2. The scatter plot shows the negative correlation in pgACC/rmPFC, averaged across voxels.