 Over a period of 10 years we will prospectively include up to 10,000 patients visiting the hospital for elective major surgery. Data defining participants demographics, medical history and questionnaire data will be collected and stored in dedicated databases. Additional details surgery and perioperative management, pain processing phenotypes and surgical and pain outcomes will be stored. Besides Electroencephalography andor magnetoencephalography, Magnetic Resonance Imaging will be performed on a subgroup n70. 