RecruitingDiagnostic testExplosive Synchronization of Brain Network Activity in Chronic PainThis project is being conducted to evaluate the impact of explosive synchronization (ES) and its treatment with non-invasive brain stimulation in fibromyalgia (FM). The study design has three components, however, only 2 aims are enrolling participants. The first part (Aim1) is a cross sectional assessment of brain network explosive synchronization activity, connectivity, and response to pain in healthy controls and age and sex-matched fibromyalgia patients; the third part (Aim 3) is a longitudinal assessment of fibromyalgia patients undergoing one week of sham followed by high-definition transcranial direct current stimulation (HD-tDCS) of the motor cortex (M1) or one week of ES HD-tDCS of a brain region identified from computer modelling (Aim 2).