Figure 3.

Placebo Analgesia × Conditioning Group. A) Average time course of Pre-Reveal placebo analgesia [Placebo – Control] during painful stimulation. Negative values indicate reduced pain with the placebo (analgesia), whereas positive values indicate increased pain with the placebo (hyperalgesia). The solid dark grey and light grey lines represent the average of subjects within the Long and Short conditioning groups, respectively. The dashed line shows the onset and offset of the painful stimulus, as well as the duration of peak temperature. B) Average time course of Post-Reveal placebo analgesia during painful stimulation. The lines are defined as in panel A. C) Mean Pre-Reveal placebo analgesia. Analgesia scores are generated by averaging over the placebo effect [Placebo-Control] time course for each subject. Long subjects had significant placebo analgesia Pre-Reveal, but Short subjects did not. Placebo analgesia was not different between groups. D) Mean Post-Reveal placebo analgesia. Long subjects continued to demonstrate placebo analgesia Post-Reveal, and had significantly greater placebo analgesia than the Short group. There was no significant Post-Reveal placebo effect in the Short group. Error bars represent sem.