Validation of separate pain biomarkers using combined fMRI and TMS

Pain is a fundamentally subjective experience. As a result, subjective pain ratings have proven to be the most reliable indexes of pain. Nevertheless, pain ratings are still subjected to the same biases as other self-reported measures. The proposed experiment is part of a larger project aiming at defining brain-based biomarkers for pain that can augment self-reported pain as outcome measures. Two networks of brain regions seem to be particularly relevant for the generation of pain ratings: 1) a pain-processing network (PPN) involved in the primary perception of painful stimuli and 2) an emotional appraisal network, involved in the evaluation of emotional stimuli, including pain. The objective of the proposed project is to test the respective contribution of the PPN and EAN to the generation of pain ratings by selectively disrupting these two networks with transcranial magnetic stimulation (TMS) and measuring the resulting effects on brain activation with functional magnetic resonance imaging (fMRI). If TMS is proven effective in reducing pain, the results of this study could also support the use of TMS for pain treatment.