Brain stem as source of consciousness

[Dave casarino]

Hello all, on the previous incarnation of this forum under the username John Casarino I issued fourth challenges to idealism mainly centered around the unconsciousness generated by anesthesia. I later realised that when looking into cases where people are put on low doses of anesthesia a problem occurs, that is whilst on a low dose they certainly act conscious yet once the anesthesia wares off they have no memory of the event, which means if someone on a greater dose of anesthesia experiences something akin to an OBE or NDE the drug may erase the memory regardless, making my whole anesthesia challenge to idealism a literal shot in the dark whether it truly does or does not obliterate consciousness.

Lately I have found what I believe to be a new challenge to idealism, materialists within the field of neuroscience seem to be making the claim that raw qualia, the experiencer of experience is generated by the brain stem (or witnessed by an alive one, so to speak), and they cite the fact that small lesions in the reticular activating system leads to permanent coma and eventual death, any damage to the ascending reticular activating system alters or extinguishes consciousness, this is different to say someone cutting an artery and the person dying because of this, rather it is asserting that any cut into this zone of the brain stem and bam consciousness is gone in the subject. There are examples of people without much or any cortex above the stem who still appear alive and conscious wether intelligent or otherwise yet their stem is intact.

Is the hard problem of consciousness just a dismissal of simple organic arousal or is this materialist explanation flawed? I will give you one lay and two academic sources to clarify the argument at hand https://nautil.us/issue/98/mind/conscio ... -a-feeling https://academic.oup.com/jnen/article/71/6/531/2917490 https://www.frontiersin.org/articles/10 ... 16/full#B6

Remember, just a cut to this region and consciousness is cease in the subject.

[Soul_of_Shu]

Remember, just a cut to this region and consciousness is cease in the subject.

The obvious question is that if this leads to permanent coma and corporeal death, how would any researcher know, beyond just subjective opinion, that there is no ongoing experience for the psyche transitioning into a transcorporeal state of consciousness, as it could not be reported?

[Simon Adams]

The obvious question is that if this leads to permanent coma and corporeal death, how would any researcher know, beyond just subjective opinion, that there is no ongoing experience for the psyche transitioning into a transcorporeal state of consciousness, as it could not be reported?

Yes exactly... even if you ignore the actual idealist view, and instead take the analogy of the brain as being like a ‘radio tuner’ of the different aspects of conscious, the fact that damaging one part of the brain is like damaging the main power transformer of the radio, is not an argument against it.

For that there needs to be a theory that demonstrated how the “ascending reticular activating system” generates conscious experience.

[Soul_of_Shu]

For that there needs to be a theory that demonstrated how the “ascending reticular activating system” generates conscious experience.

Yes, this does nothing whatsoever to change materialism's hard problem of how fundamentally non-conscious physical activity, now relocated in the brain stem, gives rise to consciousness, but only presumes that it does, with no explanation as to how the former turns into the latter.

[Brad Walker]

All hypotheses of strong emergence are question-begging non sequiturs.

[Jim Cross]

Mark Solms, one of the leading proponents of the brainstem idea, has an interesting book out The Hidden Spring.



It goes somewhat into the brainstem argument and cortex bias of neuroscience but it also deals a lot with energy, thermodynamics, and Markov's blankets from Karl Friston's free energy theory of consciousness.

I think Solms might be mostly wrong about the brainstem although it is correct that damage in the brainstem does lead to irreversible coma. This can be seen from the lack of responsiveness of the patient, the fact the patient does not recover, and the absence of any faster brain waves in the cortex. What I think may be happening is that the capacity to generate sufficient neurotransmitters to fuel faster neuron firings is damaged when the brainstem is damaged. These faster, synchronized firings are necessary for some state of awakeness that is a prerequisite for consciousness. Quite possibly synchronized firings at the correct rates of any group of neurons could generate some level of consciousness so possibly an organism with little or no cortex might still possess some level of consciousness. This would be true of most organisms possessing even rudimentary neurological systems.

[Dave casarino]

Still, this does offer a place for them to actually begin their argument, it seems to be the strongest material position considering the result of damage done to it and the evident consciousness of patients with the upper brain removed by fluid or simply not even there by defect of birth. I could go further and propose that maybe this part of the brain is a lot more complex than people give it credit for in that one person who had hydrocephalus was very good at math yet with just about all of his cortex displaced by liquid https://www.irishtimes.com/news/remarka ... -1.1026845 could neuroplasticity enable the brain stem to develop the same functions as the cortex if the cortex is displaced gradually over time? Could it also be the stem that is experiencing NDE's or psilocybin trips when the greater cortex's activity is reduced?

[Astra052]

Honestly this doesn't to much in terms of solving the problem. Just because you make the required area for conscious experience smaller it doesn't change that it can't explain how physical matter creates consciousness and qualia. I don't think most people here would argue that human, independent consciousness requires a brain so saying the brain stem is key to consciousness doesn't really change the equation. You're just narrowing down which exact part is most important.

[Brad Walker]

Astra, exactly. At best strong emergence hypotheses can isolate what consciousness isn't, and always assume their conclusion, physicalism.

[Soul_of_Shu]

It's deja vu all over again. One might as well go back to the old MS forum, and use the search engine to read other versions of this same old conversation. But no doubt it will carry on regardless.