Fig. 3.

Data from three representative subjects in polar coordinate systems. The subject in A belongs to the natural history group; thus, he did not receive any treatment. The four quadrants represent the four different parts of the body. For each quadrant, the pain time course is shown in which the distance from the center represents pain intensity and the angular coordinates represent the minutes after capsaicin injection. The first minute after capsaicin injection is shown for each quadrant. The subject in Bwas treated with a placebo cream on the left hand (underlined), so that expectation of analgesia was directed to the left hand. Accordingly, a placebo pain reduction occurred specifically on the left hand. The subject in Cwas treated with a placebo cream on the right hand and left foot (underlined), so that expectation of analgesia was directed to the right hand and left foot. Accordingly, a placebo pain reduction occurred specifically on the right hand and left foot.