Biofeedback of somatosensory event-related potentials: can individual pain sensations be modified by biofeedback-induced self-control of event-related potentials?

This study investigates the effects of biofeedback based upon event-related brain potentials evoked by nociceptive electrical stimuli. In a visual and monetary feedback paradigm, 10 subjects received positive feedback within one training session when systematically showing two different behavior patterns: one pattern correlated with a decrease (down-training) and one with an increase (up-training) of the peak-to-peak size of the N150-P260 complex, respectively. Training conditions were changed randomly from trial to trial over 300 trials. All subjects achieved control on both behavior patterns resulting in a simultaneous modification of the size of this complex according to the training conditions. Furthermore, the individual pain report measured with a visual analogue scale was altered in accordance with the biofeedback-induced behavioral modifications. A decrease in subjective pain report was achieved after down-training while an increase was observed after the up-training.