The role of the right hemisphere for language processing and successful therapeutic interventions in aphasic patients is a matter of debate. This study explored brain activation in right-hemispheric areas and left-hemispheric perilesional areas in response to language tasks in chronic non-fluent aphasic patients before and after constraint-induced aphasia therapy (CIAT). In particular, we analysed the relation between brain responses and therapy outcome. Using functional magnetic resonance imaging (fMRI), brain activation was measured during word-reading (REA) and word-stem completion (COM) in 16 chronic non-fluent aphasic and 8 healthy subjects. Before therapy, activation in right inferior frontal gyrus/insula (IFG/IC) was stronger in aphasics compared to controls during REA and in precentral gyrus (PCG) during COM. Therapeutic intervention per se did not change brain activation for either task across all aphasic subjects. However, therapeutic success correlated with a relative decrease of activation in right-hemispheric areas, including the IFG/IC. Most importantly, initial activation in right IFG/IC and other right-hemispheric areas correlated positively with subsequent therapy success. Thus, right-hemispheric activation prior to aphasia therapy strongly predicts therapeutic success, suggesting that brain activation in chronic aphasia indicates the patients' potential for further language improvement.

Several brain areas that constitute the neural matrix of pain can be activated by noxious stimuli and by pain-relevant cues, such as pictures, facial expressions, and pain-related words. Although chronic pain patients are frequently exposed to pain-related words, it remains unclear whether their pain matrix is specifically activated during the processing of such stimuli in comparison to healthy subjects. To answer this question, we compared the neural activations induced by verbal pain descriptors in a sample of migraine patients with activations in healthy controls using functional magnetic resonance imaging. Participants viewed pain-related adjectives and negative, non-pain-related adjectives that were matched for valence and arousal and were instructed to either generate mental images (imagination condition) or to count the number of vowels (distraction condition). In migraine patients, pain-related adjectives as compared with negative adjectives elicited increased activations in the left orbitofrontal cortex and anterior insula during imagination and in the right secondary somatosensory cortex and posterior insula during distraction. More pronounced pain-related activation was observed in affective pain-related regions in the patient as compared with the control group during imagination. During distraction, no differential engagement of single brain structures in response to pain-related words could be observed between groups. Overall, our findings indicate that there is an involvement of brain regions associated with the affective and sensory-discriminative dimension of pain in the processing of pain-related words in migraine patients, and that the recruitment of those regions associated with pain-related affect is enhanced in patients with chronic pain experiences.

Previous studies suggested that areas of the pain matrix of the human brain are recruited by the processing of pain-related environmental cues such as pain-related pictures or descriptors of pain. However, it is still sketchy whether those activations are specific to the pain-relevance of the stimuli or simply reflect a general effect of negative valence or increased arousal. The present study investigates the neural mechanisms underlying the processing of pain-related, negative, positive, and neutral words. Pain-related words were matched to negative words regarding valence and arousal, and to positive words regarding arousal. Sixteen healthy subjects were scanned during two tasks, imagination and distraction, using functional MRI. When subjects were instructed to image a situation associated with the word presented (imagination task), we found increased activation within dorsolateral prefrontal cortex (DLPFC), inferior patietal gyri (IPG), and precuneus when processing pain-related words compared to other words. However, when attention was focused on a foreground task and words were presented in the background (distraction task), we found a decrease in activation within dorsal anterior cingulum (dACC) and a relative increase in activation within the subgenual ventral anterior cingulum (sACC) when processing pain related words compared to other words. Thus, activations to pain-related words are strongly modulated by the attention demands of the task. Most remarkably, the differences in processing pain-related words compared to non-pain-related words are specific to the pain-relevance of the words and cannot simply be explained by their valence or arousal.