(September 24, 2016 at 10:30 pm)Jörmungandr Wrote:

Quote:Misplaced confidence in EEG measurements

Within Near Death Experience research, a number of investigators have argued that a flat electroencephalogram (EEG) reading can be taken as evidence of total brain inactivity (and van Lommel et al. recruit this argument into their interpretation; Fenwick & Fenwick, 1995; Parnia & Fenwick, 2001; Parnia et al., 2001; Sabom, 1998). This claim is totally incorrect. It is certainly the case that a flat cortical EEG would be indicative of a brain that is in some trouble. Assuming no technical error or problems with electrode contact, a flat EEG is far from desirable. However, the assumption that a flat EEG can be taken as strong evidence of global and total brain inactivity is unfounded. (It is also noteworthy that the studies making large claims about flat EEGs provide no information regarding the level of gain employed on the EEG device, assuming they were digital-QEEG devices. This would seem important as any EEG can become almost flat with the gain turned to a minimum. A flat EEG at maximum gain would be more indicative of neocortical inactivity, though again, not full-brain inactivity).

Unless surgically implanted into the brain directly, the EEG principally measures surface cortical activity. The waveforms seen in cortical EEG are largely regarded to come from the synchronistic firing of cortical pyramidal neurons. As such, it is entirely conceivable that deep sub-cortical brain structures could be firing, and even in seizure, in the absence of any cortical signs of this activity (for evidence based on electrical stimulation and seizure propagation, see Gloor, 1986; Gloor, Olivier, Quesney, Andermann, & Horowitz, 1982). Indeed, evidence reviewed by Gloor (1986) argued that inter-ictal discharges in the hippocampus or amygdala alone were more than sufficient to produce complex meaningful hallucinations – no involvement from the cortex was necessary!

A related idea is that seizure-based hallucinatory EEG patterns have been absent from the background EEG in some instances of NDE, even when the EEG itself was not flat (Fenwick & Fenwick, 1995). By this account, if the NDE was a hallucinatory process based in disinhibition, then the logic is that such disinhibition should be clearly visible in the EEG at that time.

However, the emerging evidence is somewhat unhelpful for the survivalist. Tao, Ray, Hawes-Ebersole, and Ebersole (2005) compared EEG activity from surgically implanted electrodes placed in or around deep sub-cortical regions of epileptic patients with cortical EEG electrodes placed on the scalp of the same patients. The results were quite surprising. Tao et al. showed that for 90% of cases, large amplitude paroxysmal firing needed to recruit 10 cm2 of brain tissue in order to show up against background cortical EEG traces. In other words, large seizure-based activity was being recorded by the surgically implanted electrodes (indexing clear and widespread brain-seizure activity) which was completely absent from scalp-based EEG traces until it propagated through and excited 10 cm2 of brain volume. This is a considerable amount of brain tissue.

Furthermore, a recent study that employed both EEG and brain-imaging (fMRI) techniques to explore seizure processes found significant increases in localised cortical neural activity (indicative of a seizure) in the fMRI BOLD (blood-oxygen-level dependant) response, which was completely absent from the EEG data (Kobayashi, Hawco, Grova, Dubeau, & Gotman, 2006). This is particularly striking in that this occurred despite the fact that the intense seizure activity occurred in a region where EEG electrodes were closely spaced. Kobayashi et al. note that this is striking as the EEG completely missed the most intensely discharging region despite the fact that this region was also located at the cortical level.

... differing brain regions have differing numbers of neurons, with diverse connections and characteristics – all of which have differing oxygen demands

The implication for NDE research is, of course, that the EEG does not provide a highly reliable measure of complete neural activity. Even high-amplitude seizure activity can fail to manifest itself in the background EEG if it does not recruit enough neural landscape. To summarise: confidence in previous claims that flat EEG represents total neural inactivity appears severely misplaced. These cases may represent instances of ‘false positives’ (positive from the perspective of the survivalist wanting to recruit such instances as evidence of a dead brain). In addition, even in the presence of a background EEG, seizure-based activity (which is sufficient to support hallucinatory imagery and aura) could be considerable and yet may not become manifest in the cortical scalp-based EEG. Note also that the above empirical estimates were based on epileptic brains which produce large-amplitude brain activity. These estimates themselves may need to be increased even further for the normal non-epileptic brain which does not typically produce such high-amplitude synchronistic characteristics.

http://www.critical-thinking.org.uk/para...-brain.php

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Quote:What the dying brain hypothesis really says: The importance of neural disinhibition

When one considers the dying-brain account in its full context it is clear to see that the emphasis placed on cerebral anoxia misses the true essence of the account. As a consequence, many of the criticisms against the dying-brain hypothesis border on the irrelevant. For the dying-brain account, the central assumption does not revolve around the presence or absence of anoxia per se, but of neural disinhibition. So the dying-brain hypothesis is perhaps more accurately characterised as one that models NDEs as an experiential consequence of a disinhibited brain (Blackmore, 1996, 1993, 1992, 1990; Braithwaite, 1998; Carr, 1982, 1981; Jansen, 1996, 1990; Saavedra-Aguilar & Gomez-Jeria, 1989; Woerlee, 2003). Of course, such neural disinhibition can be induced by anoxia, and it is likely that under more prolonged near-death situations it is likely to be present; but as a process, disinhibition can actually be triggered by many psychological and neurological factors such as: confusion, trauma, sensory deprivation, illness, pathology, epilepsy, migraine, drug use and brain stimulation (for comprehensive reviews see: Appleby, 1989; Baldwin, 1970; Blackmore, 1993; Sacks, 1995; Siegal, 1980). Without exception, all these instances that induce neural disinhibition and seizure-type activity can all be associated with aura and hallucination.

In principle then, anoxia does not need to be present at all to produce hallucinatory imagery. However, under cases where people are ‘near death’ or suffer cardiac insufficiency for any prolonged period of time, it is likely (i.e. reasonable to assume) a degree of anoxia would be present. Therefore, while anoxia is one route via which disinhibition can occur, it is by no means the only route. In addition, the dying-brain hypothesis predicts that more vivid, profound, and meaningful NDEs are likely to be associated with greater degrees of disinhibition. Thus, NDEs reported when people truly are nearer to death (and hence the level of disinhibition would conceivably be greater), should be more vivid, profound, detailed and meaningful, relative to those reported when people only believed themselves to be so. This is exactly what has been found (Drab, 1981; Gabbard & Twemlow, 1984; Gabbard, Twemlow, & Jones, 1981; Owens, Cook, & Stevenson, 1990).

http://www.critical-thinking.org.uk/para...-brain.php

That puts us in a difficult position though, doesn't it? Do we lean towards what experts have learned from scientific study, or some random guy who thinks consciousness is a distinct magical entity that will get shoved up the arse of a badger or something when you die?

(February 4, 2017 at 11:03 pm)Jörmungandr Wrote:

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Quote:What the dying brain hypothesis really says: The importance of neural disinhibition

When one considers the dying-brain account in its full context it is clear to see that the emphasis placed on cerebral anoxia misses the true essence of the account. As a consequence, many of the criticisms against the dying-brain hypothesis border on the irrelevant. For the dying-brain account, the central assumption does not revolve around the presence or absence of anoxia per se, but of neural disinhibition. So the dying-brain hypothesis is perhaps more accurately characterised as one that models NDEs as an experiential consequence of a disinhibited brain (Blackmore, 1996, 1993, 1992, 1990; Braithwaite, 1998; Carr, 1982, 1981; Jansen, 1996, 1990; Saavedra-Aguilar & Gomez-Jeria, 1989; Woerlee, 2003). Of course, such neural disinhibition can be induced by anoxia, and it is likely that under more prolonged near-death situations it is likely to be present; but as a process, disinhibition can actually be triggered by many psychological and neurological factors such as: confusion, trauma, sensory deprivation, illness, pathology, epilepsy, migraine, drug use and brain stimulation (for comprehensive reviews see: Appleby, 1989; Baldwin, 1970; Blackmore, 1993; Sacks, 1995; Siegal, 1980). Without exception, all these instances that induce neural disinhibition and seizure-type activity can all be associated with aura and hallucination.

In principle then, anoxia does not need to be present at all to produce hallucinatory imagery. However, under cases where people are ‘near death’ or suffer cardiac insufficiency for any prolonged period of time, it is likely (i.e. reasonable to assume) a degree of anoxia would be present. Therefore, while anoxia is one route via which disinhibition can occur, it is by no means the only route. In addition, the dying-brain hypothesis predicts that more vivid, profound, and meaningful NDEs are likely to be associated with greater degrees of disinhibition. Thus, NDEs reported when people truly are nearer to death (and hence the level of disinhibition would conceivably be greater), should be more vivid, profound, detailed and meaningful, relative to those reported when people only believed themselves to be so. This is exactly what has been found (Drab, 1981; Gabbard & Twemlow, 1984; Gabbard, Twemlow, & Jones, 1981; Owens, Cook, & Stevenson, 1990).

http://www.critical-thinking.org.uk/para...-brain.php

Gee, I am so excited yog.  
After reading all that crap interested report that say that a brain is not dead even if it show a flat electroencephalogram (EEG) reading and despite also that the blood and oxygen do not flow in the brain anymore I thought to call these experts to my house so they can make my car running without any fuel.
I am quite sure that these expert can do this.  
I will never stop thanking you yog for letting me know about these experts.  

Oh, by the way yog I need your expert help.  
When people who have an OBE see their bodies from above does this means that their brain is still active or it means that the consciousness has separated from a dead body-brain?  

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(February 5, 2017 at 3:21 am)robvalue Wrote: That puts us in a difficult position though, doesn't it? Do we lean towards what experts have learned from scientific study, or some random guy who thinks consciousness is a distinct magical entity that will get shoved up the arse of a badger or something when you die?

Not at all Roberto.  
Consciousness is the real YOU not ..........a distinct magical entity .........but the so called experts that yog keep on calling up do not understand yet what is the difference between you and your brain.
For them it is the same thing.  
No distinction of whatsoever.  
They still do not understand that inside a moving vehicle there is a driver.  
Luckily that you are not a fool like them.
We all know Roberto that you are very smart.  

I had a thought about all this:

Let's assume for a second that a person really does "die" temporarily, whatever that means, and their consciousness "leaves" their body. They have a NDE/OBE, then come to life to tell us all about it.

Now. Why didn't the consciousness fly off to be reincarnated in some other animal? Or get sent off to heaven, hell or whatever else place it's supposed to go? Did the consciousness know the future, that the host would come back to life, so it hung around? Or is there like a certain amount of time it has to wait just to check the person doesn't reanimate before hopping off?

I look forward to ad hoc explanations regarding this problem.

Anytime someone tries to show where he's going wrong he flails his arms around and is like:





but the moment he is presented with evidence, he dismisses it as "crap".

Meanwhile he gets to throw around all the shit he likes without even so much as a note from home?

(February 5, 2017 at 8:24 am)Little Rik Wrote: Oh, by the way yog I need your expert help.  
When people who have an OBE see their bodies from above does this means that their brain is still active or it means that the consciousness has separated from a dead body-brain?  

Already answered.  https://atheistforums.org/thread-47356-p...pid1496393

Like I said, you just suck at listening.

As Chas informed you.  Death is a process, not an event.  And parts of that process linger on after the blood is no longer flowing.  If it weren't, the cells would all be dead the moment that blood flow stops and there would be no returning.  But as we've seen, the cells don't all at once stop working merely because there's no more blood flow to them.  They keep working, sometimes for fairly long periods of time.

https://en.wikipedia.org/wiki/Lazarus_syndrome

Despite your protestations, the brain isn't truly dead until it's truly dead.

Quote:The brain can survive for up to about six minutes after the heart stops.  The reason to learn cardiopulmonary resuscitation (CPR) is that if CPR is started within six minutes of cardiac arrest, the brain may survive the lack of oxygen. After about six minutes without CPR, however, the brain begins to die. (See How CPR Works to learn more about the procedure.) Prompt resuscitation allows the physician time to assess and treat the damaged brain. Medication and mechanical ventilation permit tissue oxygenation, but severe brain damage or a prolonged period without oxygen or glucose causes the death of the brain.

By definition, "brain death" is "when the entire brain, including the brain stem, has irreversibly lost all function." The legal time of death is "that time when a physician(s) has determined that the brain and the brain stem have irreversibly lost all neurological function."

http://science.howstuffworks.com/life/in...death1.htm

(February 5, 2017 at 1:34 pm)Jörmungandr Wrote:

(February 5, 2017 at 8:24 am)Little Rik Wrote: Oh, by the way yog I need your expert help.  
When people who have an OBE see their bodies from above does this means that their brain is still active or it means that the consciousness has separated from a dead body-brain?  

Already answered.  https://atheistforums.org/thread-47356-p...pid1496393

Like I said, you just suck at listening.

As Chas informed you.  Death is a process, not an event.  And parts of that process linger on after the blood is no longer flowing.  If it weren't, the cells would all be dead the moment that blood flow stops and there would be no returning.  But as we've seen, the cells don't all at once stop working merely because there's no more blood flow to them.  They keep working, sometimes for fairly long periods of time.

https://en.wikipedia.org/wiki/Lazarus_syndrome

Despite your protestations, the brain isn't truly dead until it's truly dead.

Quote:The brain can survive for up to about six minutes after the heart stops.  The reason to learn cardiopulmonary resuscitation (CPR) is that if CPR is started within six minutes of cardiac arrest, the brain may survive the lack of oxygen. After about six minutes without CPR, however, the brain begins to die. (See How CPR Works to learn more about the procedure.) Prompt resuscitation allows the physician time to assess and treat the damaged brain. Medication and mechanical ventilation permit tissue oxygenation, but severe brain damage or a prolonged period without oxygen or glucose causes the death of the brain.

By definition, "brain death" is "when the entire brain, including the brain stem, has irreversibly lost all function." The legal time of death is "that time when a physician(s) has determined that the brain and the brain stem have irreversibly lost all neurological function."

http://science.howstuffworks.com/life/in...death1.htm

The fact that the brain cells or any other cells in the body do not die straight away when the blood and oxygen stop flowing is total irrelevant.  
As far as the consciousness left the body-brain whether the cells are alive or dead that doesn't make any difference.
A body-brain without the consciousness is nothing.
Nothing at all.  
If however the consciousness go back into the body-brain then we say that that was an OBE or an NDE.

Now let us come to the second point.
Your experts allege that an NDE can happen in the brain by the brain even when the blood and oxygen doesn't flow in the brain anymore and it is the brain that create the illusion that an NDE is happening.
That is not possible.
As far as the consciousness left the body-brain and can see his body from above then the brain is unable to do anything.
It is the consciousness the driver or the one that start the action of thinking.
The consciousness can not possibly be in two places at the same time.
Or it is inside the body-brain or it is outside so if it is outside the brain is unable to do anything even if the cells are not dead yet.
To say that a brain left without oxygen and blood is able to create such a clear and sharp experience such as an NDE is very very speculative.
Even if the cells are not dead yet they must be in a KO situation and in such situation they can not possibly put together an NDE that is remembered after years and years very vividly.
Fail once again yog.  

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(February 5, 2017 at 10:23 am)robvalue Wrote: I had a thought about all this:

Let's assume for a second that a person really does "die" temporarily, whatever that means, and their consciousness "leaves" their body. They have a NDE/OBE, then come to life to tell us all about it.

Now. Why didn't the consciousness fly off to be reincarnated in some other animal? Or get sent off to heaven, hell or whatever else place it's supposed to go? Did the consciousness know the future, that the host would come back to life, so it hung around? Or is there like a certain amount of time it has to wait just to check the person doesn't reanimate before hopping off?

I look forward to ad hoc explanations regarding this problem.

The percentage of people having an OBE or an NDE is very very small indeed.
Maybe less than 1%.
Most people do not come back in their actual body.
Here Roberto I am talking about my beliefs that you can well disagree if you don't like.
NDEs happen because God see the possibility in a person to learn.
OBE on the other hand carry a very small degree of learning nevertheless people in a OBE still realize that life goes on after the physical death.
By learning after an NDE God show them that in this life these people can still do something positive for themselves and for other.
In a normal death on the other hand God will reincarnate them because in their present body people could not achieve any progress anymore.
Got it Roberto?  

(February 6, 2017 at 9:43 am)Little Rik Wrote: Your experts allege that an NDE can happen in the brain by the brain even when the blood and oxygen doesn't flow in the brain anymore and it is the brain that create the illusion that an NDE is happening.
That is not possible.
As far as the consciousness left the body-brain and can see his body from above then the brain is unable to do anything.
It is the consciousness the driver or the one that start the action of thinking.
The consciousness can not possibly be in two places at the same time.
Or it is inside the body-brain or it is outside so if it is outside the brain is unable to do anything even if the cells are not dead yet.

It's possible that the consciousness never actually leaves the body. That the experience of leaving the body is a hallucination. What do you think is generating the feeling of being "inside your head" at this very moment? The brain has powerful machinery for creating the illusion that there is a something that is 'you' that is inside your head looking out. That same machinery is used to create the sensation that you are outside your body. If it can create the illusion that you are inside your body, why can't it create the illusion that you're outside your body? What, do you think your consciousness has "where am I" feelers to tell that it's inside your head? No, the where of your consciousness is generated by the brain along with everything else.

Just think. Your consciousness feels that it is inside your head. Which is doing that, consciousness or your brain?

Quote:The researchers tracked down a woman who is able to enter this “out of body experience” (or OOBE) state at will, and hooked her up to a brain scanner. According to their paper, published in Frontiers of Human Neuroscience, the woman saw herself floating in the air above herself, watching herself move while feeling completely unaware of her physical body.

While she was getting her float on, the MRI showed a deactivation of her visual cortex, while the part of her brain responsible for imagining body movement lit up. This particular portion of the brain is responsible for “kinesthetic imagery,” the thing that allows you understand how your body relates to the world around it. It seems that this particular combination of brain function allowed the woman to feel as though she was floating outside of her physical body.

With this new information on-hand, the researchers are saying that OOBEs are basically a very specific type of hallucination triggered by a certain neurological mechanism.

http://www.themarysue.com/out-of-body-explained/

Quote: In a study of 264 subjects with sleep paralysis[3], Giorgio Buzzi and Fabio Cirignotta found that about 11% of their subjects (28 people) "viewed themselves lying on the bed, generally from a location above the bed" (Buzzi 2116). As Buzzi points out, however, these out-of-body experiences often included false perceptions of the physical environment:

Quote:I invited these people to do the following simple reality tests: trying to identify objects put in unusual places; checking the time on the clock; and focusing on a detail of the scene, and comparing it with reality.

I received a feedback [sic] from five individuals. Objects put in unusual places (eg, on top of the wardrobe) were never identified during out-of-body experiences. Clocks also proved to be unreliable: a woman with nightly episodes of sleep paralysis had two out-of-body experiences in the same night, and for each the clock indicated an impossible time.... Finally, in all cases but one, some slight but important differences in the details were noted: "I looked at 'me' sleeping peacefully in the bed while I wandered about. Trouble is the 'me' in the bed was wearing long johns ... I have never worn such a thing" (Buzzi 2116-2117).

Buzzi concludes that because these experiences contained out-of-body discrepancies and failed his other 'reality tests,' his subjects' out-of-body imagery must have been derived from memory and imagination rather than from the physical environment at the time (2117).

https://infidels.org/library/modern/keit...HNDEs.html

What are you telling me, that the woman hallucinated that she was wearing long johns while her consciousness was outside her body? Whoah, if that can happen there's no end to the possible false perceptions that consciousness can have!

It shouldn't be difficult to establish or understand that we're capable of creating non-local sensations or perception.  I dream of being in places I've never been, and places that do not exist....it doesn't take anything remotely as stressful as an nde to produce that effect. Who could, with a straight face, argue that this does not happen, that such is not the case? Why, then, gape in wide eyed wonder when this happens in -any- scenario?

(February 6, 2017 at 1:33 pm)Khemikal Wrote: It shouldn't be difficult to establish or understand that we're capable of creating non-local sensations or perception.  I dream of being in places I've never been, and places that do not exist....it doesn't take anything remotely as stressful as an nde to produce that effect.  Who could, with a straight face, argue that this does not happen, that such is not the case?

Good point.

Rik, does it seem reasonable that the brain has a separate mechanism for imagining "where it is" in dreams that isn't used in day-to-day consciousness?