Fig. 4.

Pain measurements before and after NFB training for participants with high and low NFB training efficacy. Graphs show pain measurements in both pre- and post-NFB sessions, including the pain threshold (A), pain intensity (B) and unpleasantness (C) ratings to suprahthreshold painful stimuli for two groups of participants with high and low NFB training efficacy. Bars represent Mean ± SEM; symbols represent individual repeated-measures data (12 participants for each group). n.s.: p > 0.05; *: p < 0.05; **: p < 0.01; ***: p < 0.001; paired-sample t-test between pre- and post-NFB sessions.