13 hours ago, Eise said:

our consciousness is an emergent property of the nervous system as a whole

I’m far more comfortable with this claim than the one asserting a cortex is prerequisite to consciousness, but I believe it too is mistaken.

Jellyfish, for example, also don’t have a CNS but very much seem conscious. Slime molds are another potential example of conscious behavior in the absence of a CNS, though this one is admittedly easier to argue against despite the way they solve mazes and respond “intelligently” to multiple complex stimuli.

4 hours ago, iNow said:

Jellyfish, for example, also don’t have a CNS but very much seem conscious. Slime molds are another potential example of conscious behavior in the absence of a CNS, though this one is admittedly easier to argue against despite the way they solve mazes and respond “intelligently” to multiple complex stimuli.

First, I did not mention a CNS, I said 'the nervous system as a whole'. Secondly, it seems to me that your criterion for what behaviour counts as 'conscious behaviour' gets lower and lower. I am with you with octopuses, but jelly fish and even slime molds? I think their 'intelligent behaviour' can easily be explained by chemical or physical gradients, on which they react automatically. What about plants that 'follow the sun', or roots that 'search for water'? What about bacteria?

Can you be more explicit about what your criteria for being conscious are, maybe with some examples, especially close to the border line conscious-not conscious?

Edited August 8Aug 8 by Eise

2 hours ago, Eise said:

jelly fish and even slime molds? I think their 'intelligent behaviour' can easily be explained by chemical or physical gradients

As can those of humans

2 hours ago, Eise said:

What about plants that 'follow the sun', or roots that 'search for water'? What about bacteria?

Indeed. Hence the question I posed in my first reply to DrmDoc: Where is the threshold when drilling farther and farther down the evolutionary tree.

2 hours ago, Eise said:

Can you be more explicit about what your criteria for being conscious are

I cannot, no. I’ve not formalized my thinking on this to that level of specificity.

Criteria are tough to pin down. My five week old kittens seem to be aware of their environment, but I doubt they are aware of themselves as distinct beings that persist over time with a sense of selfhood. They do feel things, which is a lower definitional bar. And they remember and recognize me, swarming over me when I arrive in the house (memo to self: long pants, ALWAYS long pants). But they evidently are not conscious in the way that I am or that apes or Cetaceans are. It's probably easier to view consciousness as a gradient or spectrum than as a something that satisfies a specific checklist. As soon as someone tries to do that, someone else comes along with a specific set of neurological tracts and loci which are purported to be the site of consciousness.

15 hours ago, iNow said:

Indeed. Hence the question I posed in my first reply to DrmDoc: Where is the threshold when drilling farther and farther down the evolutionary tree.

Any organism, if I may follow up a bit further here, that demostratively responds to stimili possesses, by my definition of the term, consciousness. Whether that organism's measure of consciousness rises to the level of human consciousness is dependent on whether their consciousness measure enables behaviours we perceive as thought driven--essentially behaviours suggestive of intelligent awareness by human standards.

58 minutes ago, DrmDoc said:

Any organism, if I may follow up a bit further here, that demostratively responds to stimili possesses, by my definition of the term, consciousness

So even plants and possibly bacteria too then, is that correct? Just at the lower end of the robustness spectrum?

On 8/8/2025 at 11:20 AM, iNow said:

  On 8/8/2025 at 9:09 AM, Eise said:

jelly fish and even slime molds? I think their 'intelligent behaviour' can easily be explained by chemical or physical gradients

As can those of humans

Sure, we can also explain life and consciousness on the level of elementary particles, no?

On 8/8/2025 at 11:20 AM, iNow said:

  On 8/8/2025 at 9:09 AM, Eise said:

Can you be more explicit about what your criteria for being conscious are

I cannot, no. I’ve not formalized my thinking on this to that level of specificity.

Well, at least I have some suggestions. One of them is when it turns out that we can only explain the behaviour of an organism by assuming that it has a mental picture of its environment and its position in it. Automatic reactions like 'swim away because some unpleasant environmental substance is around me' doesn't count. Elephants making a detour, because they know there is water on that way certainly would. Bacteria and jelly fish do not do that.

So this is definitively not enough:

9 hours ago, DrmDoc said:

Any organism, if I may follow up a bit further here, that demostratively responds to stimili possesses, by my definition of the term, consciousness.

A thermostat would fit that definition.

9 hours ago, iNow said:

So even plants and possibly bacteria too then, is that correct? Just at the lower end of the robustness spectrum?

Yes! Most assuredly so--IMO

27 minutes ago, Eise said:

A thermostat would fit that definition.

Is a thermostat an organism? Consider, if you will, the wording in my comments. You might find my meaning a bit more nuanced than your perception here. Consciousness alone isn't some unique or grand quality as some misguidedly, in my view, believe. What makes consciousness grand is how that attribute is expressed through an organism's behaviours--because our observations of behavioral reactions are the only measures by which we may assess that attribute.

Edited August 9Aug 9 by DrmDoc
Rewording and additional comments.

35 minutes ago, DrmDoc said:

Is a thermostat an organism? Consider, if you will, the wording in my comments. You might find my meaning a bit more nuanced than your perception here.

Granted, I exaggerated. But otherwise, yes, a bit more nuanced. But not much. Assigning consciousness to plants and bacteria is a few steps too far. Yes, there are rationales for how plants, bacteria and jelly fish behave. But it is us that recognise these rationales. Plants, bacteria, and jelly fish do not behave the way they do by recognising there rationales them selves. The do not behave because of these rationales, but we do.

Edited August 9Aug 9 by Eise

2 minutes ago, Eise said:

Granted, I exaggerated. But otherwise, yes, a bit more nuanced. But not much. Assigning consciousness to plants and bacteria is a few steps too far. Yes, there are rationales for how plants, bacteria and jelly fish behave. But it is us that recognise these rationales. Plants, bacteria, and jelly fish do not behave the way they do by recognising there rationales them selves. But we do.

You appear to be assessing consciousness solely by a human standard. What you appear to be saying here is that if an organism doesn't behave the way we do, that organism doesn't possess consciousness. If true, all you're suggesting is that plants, bacteria, and jellyfish doesn't possess human consciousness. In fact, these organisms may possess plants, bacteria, and jellyfish consciousness. When we remove classification bias from our perspective, we should find that consciousness is relative.

Edited August 9Aug 9 by DrmDoc
additional comments.

2 hours ago, Eise said:

we can also explain life and consciousness on the level of elementary particles, no?

Precisely, which is partially why finding thresholds gets so maddeningly muddy.

2 hours ago, Eise said:

when it turns out that we can only explain the behaviour of an organism by assuming that it has a mental picture of its environment and its position in it. Automatic reactions like 'swim away because some unpleasant environmental substance is around me' doesn't count.

Except I’d pushback that here yet again humans are no different in that regard. We too are simply a more complex aggregation of automatic reactions.

You and I have many times walked this path together though, in context of freewill, and my own automatic reactions lead me to conclude it has already been trodden quite enough.

2 hours ago, DrmDoc said:

You appear to be assessing consciousness solely by a human standard.

Nope. I am assessing it by what mental capabilities would be needed to explain the organism's behaviour. I already mentioned elephants. I could add delphins, wales, crows, parrots etc. (and iNow mentioned octopuses, which I at least not disagree with.) In short: all animals that show behaviour, for which it is needed to have a cognitive map of their environment, and the possible alternative for their actions in the environment (sometimes known as planning). And capable of learning, of course.

When the behaviour of an organism can be fully explained by simple 1 to 1 reactions on changes in their physical and chemical environment, where such a 'cognitive map' is not necessary, I assume it has no consciousness.

2 hours ago, iNow said:

Except I’d pushback that here yet again humans are no different in that regard. We too are simply a more complex aggregation of automatic reactions.

And then I would ask: what kind of complexity? This 'simply' (an example of the 'just-operator') and this added 'complexity' do not fit well in your sentence. In fact, if you would leave out that 'simply', we are not that far apart in our conceptions. For me consciousness arises in at least some minimal kind of complexity of underlying automatons. Science that wants to understand consciousness is worth nothing when it stops understanding consciousness before explaining why exactly these automatic reactions lead to consciousness. You are not wrong: but you are just giving up to understand consciousness, seeing the complexity in front of you.

And of course 'just' homeostasis' doesn't do the job either...

Edited August 9Aug 9 by Eise

2 hours ago, Eise said:

Nope. I am assessing it by what mental capabilities would be needed to explain the organism's behaviour. I already mentioned elephants. I could add delphins, wales, crows, parrots etc. (and iNow mentioned octopuses, which I at least not disagree with.) In short: all animals that show behaviour, for which it is needed to have a cognitive map of their environment, and the possible alternative for their actions in the environment (sometimes known as planning). And capable of learning, of course.

When the behaviour of an organism can be fully explained by simple 1 to 1 reactions on changes in their physical and chemical environment, where such a 'cognitive map' is not necessary, I assume it has no consciousness.

The idea that an organism must demonstrate "mental capabilities" or form some mental construct such as a "cognitive map" to be possessing of consciousness is a human standard. I dare say, it's also flawed because it infers no distinction between attributes of mind and consciousness--it's the idea that one attribute cannot exist without the other.

Consciousness can certainly exist without the sophistication of a mind because consciousness, at its most basic and primal level, is merely awareness. The sophistication of having a mind suggest a level of consciousness based wholely on a human standard, which is the only standard by which we can assess that quality in other organisms. In previous comments I said that "consciousness is relative" but, in my view, mind is not. Mind, from my perspective, is shown by non-instinctive behaviours--behaviours that suggest a thought process, which are behaviours we can readily determine based on our standards for that process.

Edited August 9Aug 9 by DrmDoc

11 hours ago, Eise said:

leave out that 'simply', we are not that far apart in our conceptions

Sounds good

21 hours ago, Eise said:

And of course 'just' homeostasis' doesn't do the job either...

I disagree; homeostasis explains everything about emergences of brain function--it's the engine propelling that function.

On 8/10/2025 at 4:56 AM, iNow said:

  On 8/9/2025 at 5:29 PM, Eise said:

leave out that 'simply', we are not that far apart in our conceptions

Sounds good

OK, but beware of 'greedy reductionism'. And I think your 'simply' also appears in that (short) Wikipedia article as 'nothing-buttery'. In Intuition Pumps and Other Tools for Thinking Dennet calls it the 'just-operator'.

And the same for you, @DrmDoc, many times worse than for iNow. This same 'engine propelling that function' is also propelling the liver, kidneys, etc. But we had that argument already, and I will not dive into that again.

Edited August 11Aug 11 by Eise

10 hours ago, Eise said:

OK, but beware of 'greedy reductionism'. And I think your 'simply' also appears in that (short) Wikipedia article as 'nothing-buttery'. In Intuition Pumps and Other Tools for Thinking Dennet calls it the 'just-operator'.

And the same for you, @DrmDoc, many times worse than for iNow. This same 'engine propelling that function' is also propelling the liver, kidneys, etc. But we had that argument already, and I will not dive into that again.

I agree; philosophy is philosophy and science is science.

7 hours ago, DrmDoc said:

I agree; philosophy is philosophy and science is science.

Yep. But see one of my disclaimers:

There is no such thing as philosophy-free science; there is only science whose philosophical baggage is taken on board without examination.

For a better understanding, I would suggest to read Dennett's Consciousness Explained. He was one of the most science oriented philosophers, and only passed away about a year ago, he definitely was not a 'freewheeling philosopher': his intellectual feet were thoroughly grounded in neurology, cognitive science and philosophy. It's a difficult (and long) read, sure, but it pays off to recognise the 'philosophical baggage' you are heavily leaning on.

17 hours ago, Eise said:

Yep. But see one of my disclaimers:

For a better understanding, I would suggest to read Dennett's Consciousness Explained. He was one of the most science oriented philosophers, and only passed away about a year ago, he definitely was not a 'freewheeling philosopher': his intellectual feet were thoroughly grounded in neurology, cognitive science and philosophy. It's a difficult (and long) read, sure, but it pays off to recognise the 'philosophical baggage' you are heavily leaning on.

Apologies, but I have very little interest in philosophy. However, if my philosophical baggage is weighted by methodologies that objectively and consistently provide and support evidence that either proves or disproves a hypothesis, then indeed I lean quite heavily on and will, unfortunately, continue to do so.

On 8/11/2025 at 11:48 PM, Eise said:

Yep. But see one of my disclaimers:

For a better understanding, I would suggest to read Dennett's Consciousness Explained. He was one of the most science oriented philosophers, and only passed away about a year ago, he definitely was not a 'freewheeling philosopher': his intellectual feet were thoroughly grounded in neurology, cognitive science and philosophy. It's a difficult (and long) read, sure, but it pays off to recognise the 'philosophical baggage' you are heavily leaning on.

I also recommend this.

And, for an interesting look at people who have very little brain tissue and yet lead normal lives and manifest normal intelligence, I recently read this.

https://iai.tv/articles/is-your-brain-really-necessary-for-consciousness-auid-3280

This, again, shows the holistic nature (using a clever musical analogy) of consciousness being generated throughout the nervous system.

10 hours ago, TheVat said:

I also recommend this.

And, for an interesting look at people who have very little brain tissue and yet lead normal lives and manifest normal intelligence, I recently read this.

https://iai.tv/articles/is-your-brain-really-necessary-for-consciousness-auid-3280

I believe your article references a condition known as hydrocephalus; wherein, cerebrospinal fluid fills the ventricles of the brain and compresses brain tissue into thin layers. It's disengenuous for the article's author to describe such individuals as having "no brain" because, in fact, these individuals do possess brain structures and tissue that can function as well as a normal brain when adapted sufficiently early in gestation or infancy. Therefore, cortical tissue is indeed required in these case and those of individuals with this condition who appear to lead normal, well adapted lives.

For a clearer perspective of how behavior is affected by the absence or destruction of brain structure, you may want to look into decorticate and decerebrate brain studies involving both humans and animals.The effects of decortication and decerebration can be profound but survivable depending on whether there is brainstem damage and the stage of brain development when decortication/decerebration occurs. However, neither decortication, decerebration, nor hydrocephalus deminishes what this discussion thred topic suggests about what the thalamus does for brain function.

12 hours ago, TheVat said:

This, again, shows the holistic nature (using a clever musical analogy) of consciousness being generated throughout the nervous system.

From our sensory array, to our thalamus and cortex, there is indeed a holistic nature to what our central nervous system does to produce human conscousness but that doesn't render consciousness as a unique quality or exclusive to humans--which is what science rather than philosophy most clearly evinces, IMO.

I posted the article given that Michael Gazzaniga, one of the world's foremost cognitive scientists, was lead author, and that some of the cases seemed to be cranial spaces with very unusual wiring - it was not clear to me if some of them had anything beyond a brainstem (pretty much essential to basic life functions) and a thin layer of cortical tissue. If there is a thalamus anywhere in some of those mini-brains, this article (oriented towards a general audience) did not much clarify that. I would think they do have an intact thalamic nexus, but it would be interesting to follow up and see some of the most dramatic cases mentioned in more detail. Given the importance of the thalamus (no one disputing that here, just trying to offer avenues for further developing your ideas, okay?), and in particular the role of the mediodorsal thalamus in thinking, I think it's important to see if neural plasticity in any of these normal functioning minibrain individuals allows for such functions to be assumed by other tissues. For example, could the reticular activating system assume a wider function if the thalamus does not develop normally?

14 hours ago, DrmDoc said:

I believe your article references a condition known as hydrocephalus; wherein, cerebrospinal fluid fills the ventricles of the brain and compresses brain tissue into thin layers. I

If you read the whole article, I think it's clear that the cases referenced are not arising from hydrocephalus. As Gazzaniga takes pains to note, these individuals have normal fluid pressure and circulation, and cranial volumes.

14 hours ago, DrmDoc said:

disengenuous for the article's author to describe such individuals as having "no brain" because, in fact, these individuals do possess brain structures and tissue that can function as well as a normal brain when adapted sufficiently early in gestation or infancy.

The author, Michael Gazzaniga, makes all of this quite clear and is no way seriously saying that they have "no brain." I have to wonder if you read any of this article.

14 hours ago, DrmDoc said:

For a clearer perspective of how behavior is affected by the absence or destruction of brain structure, you may want to look into decorticate and decerebrate brain studies involving both humans and animals.The effects of decortication and decerebration can be profound but survivable depending on whether there is brainstem damage and the stage of brain development when decortication/decerebration occurs.

Been there, done that. This is not my first rodeo.

5 hours ago, TheVat said:

I posted the article given that Michael Gazzaniga, one of the world's foremost cognitive scientists, was lead author, and that some of the cases seemed to be cranial spaces with very unusual wiring - it was not clear to me if some of them had anything beyond a brainstem (pretty much essential to basic life functions) and a thin layer of cortical tissue. If there is a thalamus anywhere in some of those mini-brains, this article (oriented towards a general audience) did not much clarify that. I would think they do have an intact thalamic nexus, but it would be interesting to follow up and see some of the most dramatic cases mentioned in more detail. Given the importance of the thalamus (no one disputing that here, just trying to offer avenues for further developing your ideas, okay?), and in particular the role of the mediodorsal thalamus in thinking, I think it's important to see if neural plasticity in any of these normal functioning minibrain individuals allows for such functions to be assumed by other tissues. For example, could the reticular activating system assume a wider function if the thalamus does not develop normally?

The ideas expressed here were not clear from your previous comments regarding your link to Mr. Gazzaniga's article, but I would suspect moderators would not want us to digress in to speculations about other neural systems beyond the focus of this thread's discussion, which is the thalamus. There is, however, substantial research regarding the reticular activating system's contribution to conscious brain function by none regards that system the way they do thalamic function in the collection and relaying of the sensory information that our cognitive sense and expression of self--relative to our sensory environment--relies on.

5 hours ago, TheVat said:

If you read the whole article, I think it's clear that the cases referenced are not arising from hydrocephalus. As Gazzaniga takes pains to note, these individuals have normal fluid pressure and circulation, and cranial volumes.

The author, Michael Gazzaniga, makes all of this quite clear and is no way seriously saying that they have "no brain." I have to wonder if you read any of this article.

Forgive my misquote; however, in the opening paragraph to Mr. Gazzaniga's article he mentioned the case of a "white-collar worker" with a link to "without a brain". Mr. Gazzaniga goes on to discribe the worker as a "normal 44-year-old" with an "acceptable IQ" and a "gaping fluid-filled cavity where a brain would normally be." Selecting Mr. Gazzaniga's "without a brain" link led me to a Lancet article discussing the case of a man who suffered from postnatal hydrocephalus--and this was not the only reference to hydrocephalus cases in the focus of Mr. Gazzaniga's article.

In fact, Mr. Gazzaniga also referenced the case of a 60 year-old male with a "head full of fluid and only a thin sheet of cortex" and the case of a 72 year-old living "largely without what we might recognize as 'a brain.'" The links to both these cases reference individuals with various types of hydrocephalus. I have to wonder if you read any of this article as Mr. Gazzaniga most certainly do reference cases arising from hydrocephalus.

6 hours ago, TheVat said:

Been there, done that. This is not my first rodeo.

My apologies if my comments inferred this as your first, but I share a similar sentiment when it comes to the depiction of hydrocephalus conditions as being "without a brain".

Edited August 16Aug 16 by DrmDoc
spelling

On 8/14/2025 at 3:26 PM, TheVat said:

I also recommend this.

And, for an interesting look at people who have very little brain tissue and yet lead normal lives and manifest normal intelligence, I recently read this.

https://iai.tv/articles/is-your-brain-really-necessary-for-consciousness-auid-3280

This, again, shows the holistic nature (using a clever musical analogy) of consciousness being generated throughout the nervous system.

I think it demonstrates the level of plasticity the nervous system is capable of to keep itself functioning.

13 hours ago, DrmDoc said:

Forgive my misquote; however, in the opening paragraph to Mr. Gazzaniga's article he mentioned the case of a "white-collar worker" with a link to "without a brain". Mr. Gazzaniga goes on to discribe the worker as a "normal 44-year-old" with an "acceptable IQ" and a "gaping fluid-filled cavity where a brain would normally be." Selecting Mr. Gazzaniga's "without a brain" link led me to a Lancet article discussing the case of a man who suffered from postnatal hydrocephalus--and this was not the only reference to hydrocephalus cases in the focus of Mr. Gazzaniga's article.

My mistake, sorry. I reread a later passage (in the no paywall version) which misled me to think these were not hydrocephalus cases. I am starting to think this article needed a bit more editing before publication. This time around, I opened the Lancet link and cleared up my misconception. I will note that reference to "without a brain" were placed in quotes, a nod to journalistic excess in popular press coverage. And the author did clarify that this meant having only a thin sheet of cortical tissue. I do see where this can also mislead readers, in that it fails to mention that brains also include a stem, thalamus, cerebellum, etc, and that such were not missing.

I have six week old kittens crawling on me a lot of the time now, which seems to be throwing distraction into almost everything I do lately. Hopefully, as the adoptions move forward and we get down to just one, I can resume something like normal cortical function. Have a good weekend.

- Paul