[Pain words activate pain-processing neural structures].

Previous studies suggested that areas of the neural"pain matrix" are activated by the processing of pain-related environmental cues such as pain-related pictures or descriptors of pain. However, it is still sketchy whether these activations are specific to the pain-relevant content of the stimuli or simply reflect a general effect of negative emotional valence or increased arousal. The present study addressed this question by investigating the neural mechanisms underlying the processing of pain-related, negative (non-pain-related), positive and neutral words. When subjects were instructed to image a situation associated with the word presented (imagination task), we found increased activation within the dorsolateral prefrontal cortex (DLPFC) and inferior parietal cortex (IPC) when processing pain-related words compared to other words. When attention was focused on a distracting task (distraction task), we found a decrease in activation within the dorsal anterior cingulum (dACC) and a relative increase in activation within the subgenual anterior cingulum (sACC) when processing pain-related words compared to other words. These results indicate that the differences in processing pain-related words compared to non-pain-related words are specific to the content of the words and cannot simply be explained by emotional valence or arousal. Additionally, we showed that the specific activations to pain-related words are substantially modulated by the attention demands of the task.