How words impact on pain.
INTRODUCTION: The wording used before and during painful medical procedures might significantly affect the painfulness and discomfort of the procedures. Two theories might account for these effects: the motivational priming theory (Lang, 1995, American Psychologist, 50, 372) and the theory of neural networks (Hebb, 1949, The organization of behavior. New York, NY: Wiley; Pulvermuller, 1999, Behavioral and Brain Sciences, 22, 253; Pulvermuller and Fadiga, 2010, Nature Reviews Neuroscience, 11, 351). METHODS: Using fMRI, we investigated how negative, pain-related, and neutral words that preceded the application of noxious stimuli as priming stimuli affect the cortical processing and pain ratings of following noxious stimuli. RESULTS: Here, we show that both theories are applicable: Stronger pain and stronger activation were observed in several brain areas in response to noxious stimuli preceded by both, negative and pain-related words, respectively, as compared to preceding neutral words, thus supporting motivational priming theory. Furthermore, pain ratings and activation in somatosensory cortices, primary motor cortex, premotor cortex, thalamus, putamen, and precuneus were even stronger for preceding pain-related than for negative words supporting the theory of neural networks. CONCLUSION: Our results explain the influence of wording on pain perception and might have important consequences for clinical work.