RE: Can brain dead person breath on their own after being on a vent and if so what does this mean? by

Death is rarely a yes/no thing. The body does not die all at once all over. That's why we speak of people as being "brain dead." In the same way, the brain does not die all at once, all over the entire brain. Usually what are called the "cognitive centers" the parts of the brain that help you to "think" and make sense of the world die first. The inner portions of the brain, including the brain stem often last longer - sometimes much longer. So, you can be effectively brain dead, meaning you will never wake up and start talking, while some parts, usually the more primitive (but most important parts) keep on working. Hence, the brain dead can, in some cases, continue to breathe, sometimes swallow, sometimes get erections, sometimes (rarely) even make what are called "stereotyped movements", like walking.