Brain-Stomach Circuits in Chronic Nausea

This study will use cutaneous recordings of stomach activity (electrogastrogram, EGG) and non-invasive brain stimulation with Transcranial Magnetic Stimulation (TMS) to 1. map descending cerebral cortical-to-stomach circuitry via gastric motor-evoked potentials (GMEPs), 2. use repetitive TMS (rTMS) applied to GMEP hotspots to modulate the stomach response to a satiety task (water load or nutrient drink/meal), 3. assess differences in topography and function of cortical-to-stomach circuitry between healthy subjects and subjects suffering from chronic nausea vomiting syndrome (CNVS). Some clinical, demographic, and autonomic data (i.e. EKG) will be recorded and used as covariates to investigate any systematic impact on the outcome measures.