Grey area: When is a dead person really dead?
Did you know that even after someone has been declared dead, the brain can continue to remain active for 10 minutes?
The concept of death has always intrigued human beings. The debate on what happens after death has been a source of myths which have fascinated people, altered their religious beliefs and challenged the scientific community. But the answer still eludes us.
The subject of near-death or after-death experiences have been featured even in ancient history in some form in all cultures. Books describing the writers’ near-death experiences have all been best-sellers. Everyone is eager to know what happens once you “go there” and to go there and come back makes you somebody special!
The scientific community too is just as fascinated as the rest of the world by this after-death phenomenon.
The first large-scale scientific effort to delve deeper into this was made by the University of Southampton (2014) with a mass experiment on more than 2000 people who had suffered cardiac arrest in 15 hospitals in UK, Australia, US. Nearly 40 per cent of the patients who had survived, recalled some awareness during the period of arrest when their hearts stopped. Medically, it is a well-known fact that the brain cannot function for more than 30 seconds to 60 seconds after the heart stops.
Scientifically speaking, the brain is supposed to be a network of electrical circuits with some chemical messengers added. EEG is a test which shows this electrical activity of the brain. After the patient has passed away, it normally stops showing any activity after one to five minutes. In the latest case study published in a Canadian Journal of Neurosciences, continued EEG activity was noticed in one patient till 30 minutes after cardiac and circulatory arrest!
The activity which registered on the machine was very similar to that which showed during deep sleep. Of course, the question remains — how do we interpret this EEG activity? The only correct answer is, nobody knows as yet. That’s because the EEG is an electrical study which shows myriad waves and patterns which have still not been correlated with any specific brain function, even in a live individual. There are too many “artefacts” or technical interferences from external as well as internal sources. These sources can be as wide-ranging as pulse, heartbeat, muscle movement to even AC in the room. So it becomes hard to explain a single EEG finding. Even if it is an accurate EEG result, doctors may view it as a residual spurt of activity in dying neurons, just like in the ECG.
The way in which this activity can be interpreted is a topic for future research. Also, a single unusual case should always be treated with caution. A startling finding should stimulate us to look for more scientific answers in this direction, but nothing concrete can be inferred at this point.
In the final analysis, the fact remains that human beings are nothing but a bundle of cells which are connected electrically, mechanically and chemically and that’s all we know till now.