The idea that physical changes in the brain enable us to store memories has been around for thousands of years. More recently, scientists started thinking that it could be possible to preserve structures in the brain that contain memories and other information representing our identity—and access them in the future. Some scientists say that provides a slim chance of someday reviving a person from their preserved brain. If we could access memories from preserved neural tissue long after someone is gone, brain preservation becomes a potential means of extending life. Survey respondents also estimate the possibility of creating a whole brain emulation from a preserved brain at 40 percent.