Attentional modulation of perceived pain intensity in capsaicin-induced secondary hyperalgesia.

Perceived pain intensity is modulated by attention. However, it is not known that how pain intensity ratings are affected by attention in capsaicin-induced secondary hyperalgesia. Here we show that perceived pain intensity in secondary hyperalgesia is decreased when attention is distracted away from the painful pinprick stimulus with a visual task. Furthermore, it was found that the magnitude of attentional modulation in secondary hyperalgesia is very similar to that of capsaicin-untreated, control condition. Our findings, showing no interaction between capsaicin treatment and attentional modulation suggest that capsaicin-induced secondary hyperalgesia and attention might affect mechanical pain through independent mechanisms.