In brain surgery, a mistake can mean a disability or death. So how do you teach a neurosurgeon without mistakes? Dr. Jaime Gasco uses a 3-D brain simulator. UTMB in Galveston has one of five simulators in the United States. In the first two UTMB studies, they found that medical students who were going into neurosurgery were 30 percent to 50 percent more accurate if they trained on the computer brain simulator.