Fig. 5.

Effect of capsaicin on the ERPs elicited by pinprick stimulation applied in the area of secondary hyperalgesia (n = 19). Left and center: group-level average ERP waveforms of the signals measured from Fz, Cz, and Pz vs. A1A2, before capsaicin injection (T0; left) and 30 min after capsaicin treatment (T1; center) for both the control arm and the capsaicin-treated arm (black) and averaged across pinprick intensities. Right: group-level average subtracted (post − pre) waveforms for the 2 arms (capsaicin treated and control). Gray shading indicates the time window for which the 2 arms significantly differ after capsaicin treatment.