There is a haunting story from the UK Sun.
A UK study on what happens to cardiac arrest patients (where the heart stops) that "come back to life" indicates that brain activity continues after death. Specifically, a person's consciousness continues to work after the person has died. In other words, your brain knows you are dead when you die.
Dr. Sam Parnia and her team from New York University Langone School of Medicine set out to find the answer in a much less dangerous fashion, looking at studies in Europe and the US on people who experienced "out of body" death experiences.
“They’ll describe watching doctors and nurses working and they’ll describe having awareness of full conversations, of visual things that were going on, that would otherwise not be known to them,” Parnia said. Their recollections were also verified by medical staff who reported their patients could remember the details.
Death, in a medical sense, is when the heart stops beating and cuts off blood to the brain.
This means the brain’s functions also stop and can no longer keep the body alive.
Parnia explained that the brain’s cerebral cortex — the so-called “thinking part” of the brain — also slows down instantly, and flatlines, meaning that no brainwaves are visible on an electric monitor, within 2 to 20 seconds.
This study adds a factual context to several LOST theories. For those who believe that the series premise was contained inside the mind(s) of a character, then the after death experiences (which could seem to last for a long time like short REM dreams) could explain LOST's mysteries and inconsistent parts. For those who believe that LOST was staged in the after life underworld, the vivid life and death dreamscapes could be from the moments right after death - - - the brain pulling memories, fantasies and information from a still-active brain after the body has died.