dlorde
Philosopher
- Joined
- Apr 20, 2007
- Messages
- 6,864
This is brain activity measured via EEG, a summation of millions or billions of neurons firing in synchrony. Not detecting neural activity via EEG doesn't necessarily mean there's no neural activity, it may mean it's too disorganised (insufficiently synchronous) to sum above background noise, or that it's too weak to be detected, or it's too deep (e.g. the cortex is not significantly active). It's conceivable that auditory input could be processed by the deep brain while the cortex is minimally active, and recalled later.So, what's the skeptical explanation for the fact that people who have these often do so when their brain wave activity has flatlined, especially those who describe externally verifiable occurrences during that time? Seems to me it's hard to explain this phenomenon in terms of anomalous brain activity when there isn't any such activity going on.
Also, as Pixel42 says, it's difficult to establish the precise temporal correspondence between reported experiences and brain activity. All NDEs are retrospective. For 'traditional' NDEs involving tunnels, lights, meeting relatives, etc., the activity that generates the recalled experience may occur before the brain becomes incapable of it (assuming it does become so incapable) as hypoxia set in, or afterwards, as the brain recovers (as the blood supply is restored, perhaps analogously to the 'pins & needles' of peripheral sensory nerves).
You say, "people who have these often do so when their brain wave activity has flatlined, especially those who describe externally verifiable occurrences during that time". I'd like to see your evidence for this - how many? how often? which descriptions of external events have really been verified? perhaps some links to examples?
I do wonder in how many emergency situations of this kind - where there may be a great deal of confusion, or well-drilled staff are busy focusing on their tasks - a sufficiently precise temporal record of events around the patient is kept to validate reports of conversation, etc., and correlate them with specific times of minimal brain activity. The AWARE study was specifically set up to investigate this in the cardiac emergency/resuscitation rooms of 25 major medical centers, and found only 2% reports of visual awareness during cardiac arrest, and just one 'verifiable period of conscious awareness during which time cerebral function was not expected' (though this expectation was based on the assumption that cerebral function is 'ordinarily absent or at best severely impaired' during cardiac arrest, and wasn't supported with EEG measurement).