Fig. 2: Neurofeedback training and experimental design.

a Each experiment consisted of the following tasks: first, MEG resting-state data were recorded for 5 min. Then, the subject’s pain threshold was measured. Neurofeedback training was performed 2 times for 10 min each. Two types of modulation were used to control the feedback picture, one for each experiment. After the pain threshold was measured, the MEG resting-state data were recorded again for 5 min. b Neurofeedback training. The subjects were instructed to intentionally try to enlarge the size of the black disk on the screen.