In the past couple decades there has been an increased interest in what happens in the brain during the moments leading up to death, particularly as it relates to near-death experiences. In the video below, Dr. Daniel Kuebler discusses the events that occur in the brain leading up to death.
What are near-death experiences?
A near-death experience (NDE) is an event where someone becomes physiologically or psychologically close to dying. This could be after an accident or another health problem where they almost die.
There have been many studies researching NDEs. People often report seeing memories from their life flash before their eyes, or entering a place with sights, sounds and smells that they've never experienced before. They often report very clear, robust memories from an NDE that occurred right around the time their body function was declining.
Brain activity before and after death
In one study, scientists measured the cortex activity of a dying 87-year-old man. In the moments leading up to his death there was a surge in brain activity, particularly in an increase in gamma waves. The gamma waves were also interacting with the Alpha waves. Interestingly, this is the same pattern of brain wave activity that happens when healthy individuals perform high levels of mental function, including recalling memories. In this study, this increased brain activity continued after cardiac arrest as well.
Much is still unknown about what happens in the brain during death.
There are many anecdotal reports of near-death experiences, and some fascinating studies such as the one discussed above, but scientists aren't able to draw many definitive conclusions from the research we have so far, so death remains largely a mystery to those who haven't experienced it.