As published in the last issue of JAMA (The Journal of the American Medical Association) by Irene Tracey (Oxford University) emotions and motivations play an important role in the mechanisms of the perception of pain in the human brain. Using brain imaging techniques with patients suffering chronic pain neuroscientists have discovered that pain perception areas are activated at the same time as expectation areas. In one hand, anxiety and anticipation can worsen a pain experience. On the other hand, positive experiences can relieve the pain perception.
Cognition and consciousness mechanisms obviously greatly affect the amount of perceived pain. As Tracey argues, pain requires much attention. She has demonstrated that inattentive or amused subjects feel less discomfort when applying heat in the hand. In fact, distraction techniques are being evaluated as painkillers.
Other conscious pain inhibitors are motivations. When a harmful stimulus appears, the perception of the pain can be reduced if there is a reason to ignore the pain. For instance, during the search for food, endogenous opioids are released to eliminate the pain feeling, Tracey explains in her paper.