Fig 2. Mean amplitudes and standard errors of N140 peak amplitude (negative values) averaged across frontal (Fr), frontocentral (FrCe), central (Ce), centroparietal (CePa) and parietal (Pa) locations for the Hypoalgesia, Hyperalgesia, and Control treatments during waking and hypnosis conditions in high (top panel) and low (bottom panel) hypnotizable subjects (HHs and LHs).

The histogram in the top clearly shows that in HHs, during hypnosis, hyperalgesia, compared to the control treatment, induced an enhanced N140 negative peak at frontal, frontocentral, central, centroparietal, and parietal sites, while hypoalgesia had reduced N140 wave (positive values). The bottom panel shows that LHs did not exhibit significant N140 amplitude differences between treatments in both waking and hypnosis conditions