Monday, August 26, 2013

Rat nirvana

I'm going to comment on this article:
Although the experiments were done in rats, Borjigin thinks they have implications for the near-death experiences (NDEs) reported by one in five people who are resuscitated after their hearts stop. Although they were unconscious, unresponsive and clinically dead at the time, they come back with stories of bright lights, “realer than real” memories, and meetings with people they knew. Some scientists have dismissed these accounts outright. Others have taken NDEs as proof of a religious afterlife or a consciousness that lives on outside the body, as popularised in a recent bestseller of dubious provenance.
But Borjigin’s research suggests that these experiences could just be a natural product of a dying brain. That doesn’t make them any less real, but it does root them in the natural world, without the need for a “super-“ prefix.

Before proceeding, let's clarify the scope of my comments. I'm not going to comment on whether NDEs are evidence for the afterlife. Rather, I'm going to comment on whether these experiments are evidence that there is no afterlife. Is mind reducible to detectible neurological activity? 
Here's my problem with this sort of evidence. 

i) This isn't comparable to humans who were clinically dead, resuscitated, and describe their "postmortem" experience. Rats don't report back to us. 

ii) Tracking general brain activity doesn't explain the specific content of NDEs. 

iii) Likewise, a scientific 3rd-person description doesn't give us the 1st-person viewpoint. 

iv) We can't get inside the "minds" of rats, assuming they have minds. We don't know what they visualize, if anything, at the moment of death.

v) This leaves the "hard problem of consciousness" unsolved.

vi) I don't rule out that some animals may have rational souls. What do dogs dream about? I don't know, but I don't think dualism has to stop with humans. 

Suppose we had very sensitive neuroimaging techniques to scan brain states. Suppose we hooked up a test subject and scanned his brain states while he was having the following experiences:

1) Listening to music.

2) Dreaming.

3) Spontaneously remembering something.

4) Deliberately retrieving a memory.

5) Deliberately imagining something. 

Now, unless I'm mistaken, all of these experiences would show up on the neuroscan. The scan would reveal "heightened" activity "in" the brain. They'd all be very similar. 

Yet these neurological outputs have very different inputs. 

In the case of (1), that brain state is caused by an external stimulus.

In the case of (2), we might say that's caused by the brain.

In the case of (3), we might say that's "inside" the brain. Yet it's a brain state that corresponds to an external event, not just a neurological event. He's remembering something from the past. Something that really happened. And that's the source of the memory. The brain is not the source of the memory, but the past event.

In the case of (4), that could be the same memory as (3). But there's a difference. In the case of (3), the recollection was involuntary. He had a spontaneous flashback. In the case of (4), he willed himself to access that memory. He deliberately retrieved that memory. 

Does that mean his brain caused his brain state? But what's the difference between cause and effect if both are brain states?

Moreover, how does reducing all this to activity in the brain distinguish voluntary recollection from involuntary recollection? Both are (allegedly) brain states, but in the case of voluntary recollection, what causes that memory to surface in consciousness is the mental act of willing it. 

Likewise, dreaming and imagining are both said to be brain states. And they are both subjective. Figments of the imagination.  They don't correspond to objective reality.

Yet dreaming is involuntary whereas imagining is voluntary. If the test subject imagines something, he will cause a brain state that registers on the neuroscan. And that seems dualistic. It suggests a certain independence, where his mind causes a brain state. 

Of course, a physicalist would deny it, but in that case, how does a physicalist distinguish between two internal brain states where one is the effect of volition while the other is spontaneous? 

In addition, wouldn't all these different brain states simply register as heightened neurological activity on the scans, even though they are clearly distinguishable in terms of their sources and causes? 

Another simple example is pain:

If I'm hooked up to the scanners when a bee stings me, the scanners will register heightened brain activity. But even if the effect (pain) is a brain event, that doesn't mean the cause (bee sting) is a brain event. 


  1. Why do you think that brain activity is heightened during NDEs? I'm not very familiar with NDEs, but I take it that they usually are reported as occuring outside of the body, and if so, why is there any brain activity reported at all?

    1. i) Well, this particular experiment has reference to rats. But we have no direct evidence that dying rats experience NDEs.

      ii) NDEs allegedly involve a transitional phase between clinical death and irreversible death. They aren't the same as OBEs, although they are related.