Flat EEG and Neural activity

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Frank Matera

#5
The point Craig, is there's brain activity where people some of which hang out here claim there is not.
LOL. Forgive me if I am wrong... but didn't the Science community also believe that lack of EEG means no significant brain activity? That I imagine is one of the reasons why this study was conducted... to find out if EEG's were telling the whole story or if Science had to admit they only got half the story again.

If NDE researchers are using EEG's as evidence of no brain activity... it is only because that's what Science told us. It appears for those involved with any kind of "non-mainstream" research, that they are damned if they do and damned if they don't either way.
 
F

Frank Matera

#6
The point Craig, is there's brain activity where people some of which hang out here claim there is not.
Oh and by the way Craig is correct. You also have no evidence that there is brain activity in NDE's because up until now they had been using EEG's to measure brain activity.... you know... like the rest of Medical Science had been doing.

Now we may know more. You can't move the goalposts and then say "Look! The woo merchants are practising Pseudo-Science! with their claims of no brain activity!".

As Craig rightfully points out, seeing brain activity in a drug induced coma does not equal brain activity in an NDE.
 
#8
LOL. Forgive me if I am wrong... but didn't the Science community also believe that lack of EEG means no significant brain activity? That I imagine is one of the reasons why this study was conducted... to find out if EEG's were telling the whole story or if Science had to admit they only got half the story again.
It' doesn't matter because neuroscience wasn't and isn't looking to prove life after death.

If NDE researchers are using EEG's as evidence of no brain activity... it is only because that's what Science told us. It appears for those involved with any kind of "non-mainstream" research, that they are damned if they do and damned if they don't either way.
It's not if and it's not damned if you do and damned if you don't. The argument presented that NDE's are evidence is the idea that when EEG's show a flatline, therefore the only right interpretation is NDE's can't be hallucinations, but must be evidence of a non-local consciousness [that's how the thinking goes]. Now that there appears to be good evidence of deep brain activity, the NDE crowd will have to rethink their ideas and come up with a new strategy for explaining NDE or abandon the idea a flat EEG confirms the NDE.
 
#9
Oh and by the way Craig is correct. You also have no evidence that there is brain activity in NDE's because up until now they had been using EEG's to measure brain activity.... you know... like the rest of Medical Science had been doing.
The only thing I know is typical EEG's can't detect deep within the brain activity.

Now we may know more. You can't move the goalposts and then say "Look! The woo merchants are practising Pseudo-Science! with their claims of no brain activity!".
No one is moving any goal posts. However, that is the claim. I've always suspected the claim of no brain activity was jumping the gun.

As Craig rightfully points out, seeing brain activity in a drug induced coma does not equal brain activity in an NDE.
This is not the argument.
 
#10
The argument presented that NDE's are evidence is the idea that when EEG's show a flatline, therefore the only right interpretation is NDE's can't be hallucinations, but must be evidence of a non-local consciousness [that's how the thinking goes]. Now that there appears to be good evidence of deep brain activity, the NDE crowd will have to rethink their ideas and come up with a new strategy for explaining NDE or abandon the idea a flat EEG confirms the NDE.
The survivalist position never has relied solely on that argument. The facts that coherent experiences occur when brain activity is very committed and is not sufficient to cause these experiences and extrasensory and veridical experiences are also evidence for survivalism.
 
#11
The survivalist position never has relied solely on that argument. The facts that coherent experiences occur when brain activity is very committed and is not sufficient to cause these experiences and extrasensory and veridical experiences are also evidence for survivalism.
I don't know what you mean by committed. But I do know this. There appears to be ample brain activity and possibly some level of outside environmental awareness which could account for the near death experience. The authors of this study also conclude:
Moreover, the discovery of this novel brain state and its underlying mechanisms draw attention to the difficulties in establishing clinical brain death [my emphasis] and could thus revive discussions about the usefulness of depth recordings as an additional assessment criteria for brain death, as suggested by Walker in 1977
What I'm suggesting is this. Before anyone can argue effectively the near death experience is evidence of survival of the consciousness this work has to be factored into the near death experience.
 
#12
I don't know what you mean by committed. But I do know this. There appears to be ample brain activity and possibly some level of outside environmental awareness which could account for the near death experience. The authors of this study also conclude:
What I'm suggesting is this. Before anyone can argue effectively the near death experience is evidence of survival of the consciousness this work has to be factored into the near death experience.
Or at least, attempts shouldn't be made to argue from an overly simplistic "EEG activity = brain activity" perspective in order to 'prove' that mind /= brain.

Linda
 
#13
Or at least, attempts shouldn't be made to argue from an overly simplistic "EEG activity = brain activity" perspective in order to 'prove' that mind /= brain.
Exactly. I wonder whether survival proponents are prepared to abandon the claim that some NDEs occur when there is no possibility of brain function.

Pat
 
#14
There appears to be ample brain activity and possibly some level of outside environmental awareness which could account for the near death experience.
The argument is that although there is neuronal activity, it is an activity so degraded that according to all we know it could not cause lucid and coherent experiences as NDEs.
 
#15
Exactly. I wonder whether survival proponents are prepared to abandon the claim that some NDEs occur when there is no possibility of brain function.

Pat
If there is no possibility of brain function, then a person is irreversibly dead. If you want to know what they experienced, you'll need the help of a good medium.
 
#16
The argument is that although there is neuronal activity, it is an activity so degraded that according to all we know it could not cause lucid and coherent experiences as NDEs.
Yes although there is some evidence of activity that can reach the cortex this is not to suggest that the activity caused by quasi-rhythmic waves emanating from the hippocampus could possibly produce the highly lucid and complex activity we find in an NDE.
Also the study seems to suggest this is not something that can occur straight away when someone enters a flat-brain state (at least as far as cortex activity is concerned) as granule cells prevent ripples spreading until a threshold of activity is achieved (at least that's how I'm reading the bit quoted below):

"Therefore, marginally synchronized ripple events will not be relayed to the cortex by the EC but will be directed towards the hippocampal DG via the perforant pathway. As mentioned above, DG granule cells show very low excitability and have been described as “gate” or “filter” for hippocampal afferent signals [35], [36]. Thus the relatively unsynchronized EPSPs of ripples are filtered out by granule cells and their propagation within the hippocampus stops at the DG gate (Fig. 8A). However, since the intra-hippocampal synchrony steadily increases in successive ripple events, the continuous excitation of the granule cell gate by ever increasing volleys leads to a decreasing activation threshold, as granule cells appear to be highly sensitive to preceding signaling activity [37]. Also, CA3 synchronization may have to undergo a certain threshold behavior before single-cell bursting activity leads to a truly synchronous population burst [38]. When this threshold is reached, DG activation is achieved. The divergent connectivity of granule cells [39] ensures their synchronous activation, which in turn results in highly concurrent propagation of the signal towards the rest of the hippocampus via the CA3: a ν-complex is generated (Fig. 8B). This event is then carried through CA2, CA1 and subiculum further towards the EC, where it now activates the deep V–VI layers instead of superficial layers due to the νC’s high frequency signal. Consequently, the νC event is further directed towards neocortical targets (Fig. 8C) from where it spreads into virtually the whole brain"

Its unclear the timescale involved here - however this may also be an issue in using this data to explain ndes as ndes can occur very quickly following flatline in cardiac arrest.

But hey I'm not a neuroscientist so feel free to shoot me down!

D
 
#17
If there is no possibility of brain function, then a person is irreversibly dead. If you want to know what they experienced, you'll need the help of a good medium.
It depends on how you interpret the phrase "no possibility".

If it simply means there was no possibility of brain function at the point in time when the NDE was deemed to have occurred, that is a very different matter from there being no possibility of brain function ever again.

In addition, the whole concept of what is meant by "irreversibly dead" is very ill-defined, as it can only ever be decided in retrospect. It doesn't have any specific meaning in and of itself.
 
#18
If there is no possibility of brain function, then a person is irreversibly dead. If you want to know what they experienced, you'll need the help of a good medium.
OK, I'll rephrase:

I wonder whether survival proponents are prepared to abandon the claim that some NDEs occur during periods of time in which there is no possibility of brain function.

Pat
 
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