Many argue that what separates humans from non-human animals is our consciousness. This consciousness mainly resides in the neural activity within our pre-frontal cortex, the region of our brain just behind our forehead and above our eyes. When activity in this region ceases we are not conscious even though other areas of our brain are still actively monitoring and controlling basic life functions.

So how does this relate to death? As a biologist who teaches neuroscience (note: I am not a formally-trained neuroscientist), it appears to me that if the conscious areas of the brain are shut off, even temporarily, we cease to exist.

Give me a chance to explain. Imagine that an exact copy of your body was made at the atomic level. This is not a clone. Cloning is something our cells do trillions of times every day. A process called mitosis. If a clone of you was created right now, this would result in an infant with your same genetic material nine months from now. The child would be your genetic identical twin, but would be younger than you by your current age plus nine months. Also, that “twin” would have developed in a different uterus in a different mother further decreasing the similarities. Just have a look at cats or sheep that have been cloned and how different the clone looks and acts from the original.

From a consciousness standpoint, you, the original, would not be in conscious control of the clone. The same can be said for typical identical twins originating from an embryo that split apart at the two-cell stage. Each twin only has conscious control over herself and not the other twin. If one identical twin dies, their consciousness does not go on in the living twin.  The exact same thing would occur with clones. If you died, your consciousness would not continue in your younger clone.

Now let’s get back to the copy at the atomic level. Let’s imagine that we have a technology that would allow every atom and chemical bond to be copied in exactly the same arrangement as the original. This would be an exact copy, not a twin or clone. Not only would the copies have the same genetic material, but each cell, each atom, and each chemical bond would be exactly the same in form and function.

So let’s assume that this can be done and it has been done to you. You are standing there looking at your exact copy and he is looking back at you. Now, one of you has to be killed. You, the original, has the choice. Whom are you going to choose to survive? Think about this at the visceral, the gut, level. Well I know whom I’d choose. Me! The original!  If I’m destroyed then my consciousness will cease to exist. If my copy is destroyed then I will continue to exist. It would be the same scenario with the twin or the clone. I’m not saying I’d like making this choice, but if I had to I’d always choose me.

How does this all relate to sleep? When you go to sleep you lose consciousness. I realize that some of you are thinking: what about dreams? Yes, conscious parts of your brain become active when you dream. This is during REM, or rapid eye movement, sleep. But during the other phases of your sleep cycle, about 75% of your total sleep time, you spend a large amount of time in what is called slow-wave sleep. In fact, some of the stages of slow-wave sleep have EEG (electroencephalogram) patterns that resemble patterns during vegetative states or coma. During these stages you are almost completely unresponsive to external stimuli and you are surely not conscious.

My proposition is that once the thread of consciousness, via the neural activity in the pre-frontal cortex, is broken, even for just a few seconds or minutes, you have effectively died. Essentially, once you have lost consciousness, your non-conscious body is now just an exact atomic copy of the original. Once consciousness returns, all the memories are there via the neural network architecture, but the original consciousness is lost. The new version of you would never know this because the new you could recall everything including what happened before you went to sleep and up until that point in your life. But the consciousness that was lost the night before would be gone forever, just like killing the original from which the clone or the atomic copy was produced.

Think about the consciousness that is processing this article right now. It may have only a few more hours to exist.

Sweet dreams.