near to death episodes: latest study (Endings)

by David Turell , Sunday, October 29, 2017, 14:01 (2580 days ago) @ dhw

DAVID: Sorry you are confused. The cortex stops functioning within 20 seconds, not 4-6 minutes. From my original entry:
"Dr Sam Parnia said: “Technically, that's how you get the time of death – it's all based on the moment when the heart stops.
“'Once that happens, blood no longer circulates to the brain, which means brain function halts almost instantaneously.
“'You lose all your brain stem reflexes – your gag reflex, your pupil reflex, all that is gone.'”

dhw: He also wrote: "They saw activity patterns which are linked to a “hyper-alerted state” in the brief period after clinical death.” (My bold)

Clearly there is a problem with what he describes as the technical time of death. Why should it be the stoppage of the heart? But I am indeed confused. This was your further explanation:

DAVID: To explain further the brain death I'm describing after 4-6 minutes (15 minutes in very young children) is the whole cortex. (My bold)

dhw: This is confirmed by various websites (unless I have badly misunderstood their message and your post): oxygen continues to reach the brain FOR SOME MINUTES after the heart stops. The physical reflexes are gone, but it would seem from these accounts that consciousness remains for those few minutes. So the cortex as the “seat of awareness” DOES still function for 4-6 minutes.

Wrong! When blood flow stops, consciousness disappears in 4-20 seconds. There is no further oxygen delivery but the living, non-functioning cortex has residual oxygen which permits it, in the adult to survive about four minutes before complete death of those cells. This is why resuscitation can work. However, the EEG is flat, no electrical activity present, obviously it is not functional.. Consciousness obviously continues, based on NDE's, while the cortex is demonstrably non-functional. The 'hyperactivity' is an agonal burst from a distressed cortex and is over in a few seconds.

dhw: How does that prove that it is not the source of consciousness? Again: once the cortex is well and truly dead, you can use experiences as evidence for dualism.

At this point the patient is permanently brain dead, and consciousness has gone to the afterlife. In the 4-6 minute period after blood and oxygen delivery is stopped, before neuron death, you are correct. Consciousness could be received there, but how would a non-functioning network of neurons handle it? You are saying it an function without evidence of function, either physically or by EEG.

DAVID: But from what patients tell physicians they are able to experience events around them for the minutes it takes to fully resuscitate them. I've had courses is resuscitation and resuscitated patients. I've had patients tell me abut out of body experiences during surgery. The cortex is the only seat of awareness known, and its not functioning. But consciousness is! Dualism is supported.

dhw: The cortex is not functioning as the motor for physical reflexes, but the brain activity the researchers have recorded after the stoppage of the heart and the experiences that coincide with that brief period show that it is still functioning as the “seat of awareness”, which suggests that it is the SOURCE of consciousness.

The brief agonal burst is just for a few seconds. You are trying to stretch it. Resuscitation events can last 20-30 minutes (I've been there), and revived patients can then tell us about the NDE.