WISE-2B Brain Study (Weight Loss Intervention Surgical Effects on Brain Function)

There will be one group of study participants. The group will (independently of this research study) have weight loss surgery to help them with weight loss. All research participants in this group will be tested on thinking and memory processes at the start of the study, after 12 weeks, and again at 18 months. They will also undergo a non-invasive transcutaneous vagal nerve stimulation (tVNS) intervention days post-surgery, for 30 days at home with the device that is provided. The group will have an MRI Brain Scan at each time-point to study the changes in the structure and function of the brain tissue. Blood tests will be done to measure the sugar levels in the blood, and other proteins that may act as markers for disease.