How Do Various States and Forms of Consciousness Differ?

[candydude357]

OK, what is the difference between the experiences of
1. A person in a dreamless sleep.
2. An organism without a brain, ie plant or bacteria
3. A dead person or a rock.
I asked this on another forum, they told me sleeping people feel everything but don't think about it/remember it, plants and bacteria are similar except they feel much less and dead people don't feel anything but I want more opinions.
Also are sleeping people/bacteria aware of time?
Is it different experience to be a sleeping person than a rock? What about a bacteria as opposed to a rock? If all living things feel do sleeping people feel? What about people in a coma?
Also one thing that's worrying me is that if you are your consciousness, if you become unconscious you wouldn't be you when you wake up, ie, when your conscious experience ends, the conscious experience that follows is experienced by a different consciousness. Or are there always gaps in conscious experience in daily life as well?

 

[1MileCrash]

I disagree entirely with what those other people told you. A plant feels absolutely no consciousness, and bacteria are little more than a phospholipid bilayer that sucks **** up.

 

[Ryan_m_b]

Ok this issue needs some definitions, I propose that (btw these are just definitions that I think are useful here, they may not be 100% accurate)

-Consciousness is a process by which an intelligence compares it's sensory input to memory and can create predictive models in order to plan it's actions
-Feeling is to ambiguous a word, we should use sensing instead
-Perceiving is when a conscious entity examines sensory input.

With that out of the way let's address some specifics;

A person in a dreamless sleep

They are unconscious. They can still sense but they cannot perceive. A sleeping (dreamless) person can still react to you touching them but they do not perceive it, they may move away from your touch or scratch the area but there's no consciousness analyzing that input therefore no experience.

An organism without a brain, ie plant or bacteria

Plants and bacteria can sense but without a central nervous system there is no consciousness and therefore no perception. Any sensory input directly causes the behavioral output. Again no experience

A dead person or a rock

No sensory input, no consciousness, no perception = totally no experience

the conscious experience that follows is experienced by a different consciousness.

Consciousness is an emergent property of the brain. The brain hasn't changed so the consciousness wont, it's a bit like saying if my kindle turns off and on again has the story changed?

 

[candydude357]

Another question, can you define experience?
I always define ANY sort of sensing as experience since you sense something.

 

[Ryan_m_b]

Another question, can you define experience?
I always define ANY sort of sensing as experience since you sense something.

I wouldn't agree, a coma patient is still sensing but they have no experience of it. In a similar vein I sense things whilst asleep yet I have no experience of them.

My definition of "experience" would have to be similar to perception. An experience would be the effect on my consciousness from perception of defined sensory input. For example

I sense sound
I perceive a song
I experience emotions

But experience would require consciousness and therefore within the discussed definitions would require perception, not just sensing.

 

[candydude357]

So coma patients still hear sounds, they just hear them as random sounds without memory of them?

 

[Ryan_m_b]

So coma patients still hear sounds, they just hear them as random sounds without memory of them?

A coma patient still has functioning ears, they sense the sound, that information is processed by the brain but there's no consciousness to deal with that information.

Perhaps an analogy will be useful;

-Picture a building
-Couriers constantly come in and hand envelopes to the receptionist
-The receptionist immediately hands those envelopes to the clerk
-The clerk opens all the letters, reads them all and write summaries of the information in the letters.
-The clerk then hands them over to the manager who reads the summaries and gives orders on what is to be done.

In this analogy the building is the body, the couriers are the sensory stimulus (e.g light, sound, heat), the receptionist is a sensory organ (e.g. eye, ear, nose), the clerk is the section of the brain that processes that sensory information (e.g occipital lobe) and the manager is the consciousness.

A coma patient or sleeping person has all of those staff working except the manager. The body senses the stimuli, the brain processes this stimuli but there's nothing there to analyse that information and make decisions on what to do.

 

[candydude357]

A coma patient still has functioning ears, they sense the sound, that information is processed by the brain but there's no consciousness to deal with that information.

Perhaps an analogy will be useful;

-Picture a building
-Couriers constantly come in and hand envelopes to the receptionist
-The receptionist immediately hands those envelopes to the clerk
-The clerk opens all the letters, reads them all and write summaries of the information in the letters.
-The clerk then hands them over to the manager who reads the summaries and gives orders on what is to be done.

In this analogy the building is the body, the couriers are the sensory stimulus (e.g light, sound, heat), the receptionist is a sensory organ (e.g. eye, ear, nose), the clerk is the section of the brain that processes that sensory information (e.g occipital lobe) and the manager is the consciousness.

A coma patient or sleeping person has all of those staff working except the manager. The body senses the stimuli, the brain processes this stimuli but there's nothing there to analyse that information and make decisions on what to do.

As far as I can tell you're referring to what I suggested, you can hear but it's not in your memory.
It WOULD have to be in your memory in order to be analyzed and decisions to be made right?

 

[Ryan_m_b]

As far as I can tell you're referring to what I suggested, you can hear but it's not in your memory.
It WOULD have to be in your memory in order to be analyzed and decisions to be made right?

I think we should avoid terms like "hear" and "see" as they imply some sort of perception. For conversations like this we need to have a clear divide between sensing and perceiving.

It would be pretty much impossible to make decisions without memory, if I'm trying to decide whether or not to run due to somebody shouting "theres a bomb behind you" I need a memory so that I can hold the whole sentence in my mind to gain a comprehensive understanding.

Coma patients are not unconscious because their memory isn't working though, I think we need to be conscious* to remember things.

*To make things complicated when you are a sleep your consciousness is active when you dream, it's just not conscious of the real world.

 

[candydude357]

I think we should avoid terms like "hear" and "see" as they imply some sort of perception. For conversations like this we need to have a clear divide between sensing and perceiving.

It would be pretty much impossible to make decisions without memory, if I'm trying to decide whether or not to run due to somebody shouting "theres a bomb behind you" I need a memory so that I can hold the whole sentence in my mind to gain a comprehensive understanding.

Coma patients are not unconscious because their memory isn't working though, I think we need to be conscious* to remember things.

*To make things complicated when you are a sleep your consciousness is active when you dream, it's just not conscious of the real world.

Hearing requires perception? But when you hear a "background" conversation you sense/hear every sound, but you don't really perceive it if you're not listening to the conversation.
Also is memory required for perception?
Also do coma patients actually have functioning brains?

 

[candydude357]

Also if you sleep when it's really loud and it suddenly becomes silent do you wake up?

 

[apeiron]

One way to look at it is as consciousness being made up of a bundle of faculties or cognitive processes - so sensation plus memory plus intention plus... And that some crucial component goes absent during sleep or coma.

But more accurate in my view is to see sleep and coma as states where the normal global integrative capacity of the brain goes awol. And that is what the neuroscience supports.

So during slow wave sleep/coma, neurons still fire to sensory input (though a stronger gating applies during REM). But there is a low level of integration. The brain is ticking over and not striving to form intentions and expectations, to derive sharp meaning.

If you introspect carefully enough, you should find that you are ruminating in a drowsy way even in deep non-dreaming sleep. If you wake up, you can just catch it - pay attention and so make it memorable.

But really, because this rumination is itself weakly organised, fairly meaningless, it is not memorable. And brain neurochemistry is also turned down in ways that reduce the potency of a memory fixing response.

So generally the explanation is that the brain is just broadly ticking over and not being tightly organised. You get a very low level of consciousness as a result - not no consciousness. And there is no single system or function that got turned off. The whole of the system is just less coherent than usual.

There are other stories like REM dreams and locked-in coma states. Consciousness is bright, but the path to action is broken, or external awareness is being actively gated.

But the key point is not to modularise the design of the brain too much. Sensation, perception, intention, memory are really all pretty integrated and seem more like aspects of the one single activity.

This is why neural network models, like the currently popular Bayesian brain, are more realistic than the gofai (good old fashioned artificial intelligence) approaches that tried to model brain as an assembly line that runs from sensory input to motor output via a series of memory-fetch and emotional valiance stages.

 

[SW VandeCarr]

This is why neural network models, like the currently popular Bayesian brain, are more realistic than the gofai (good old fashioned artificial intelligence) approaches that tried to model brain as an assembly line that runs from sensory input to motor output via a series of memory-fetch and emotional valiance stages.

For anyone interested in how Bayesian brain math works, here's a good introductory reference IMO.

http://books.google.com/books?hl=en...HeUyVsCDFBjV0FLsc-iQfJq4w#v=onepage&q&f=false

 

[candydude357]

So sleeping people still have a low level of consciousness...what about anaesthesized people?

 

[bobze]

So coma patients still hear sounds, they just hear them as random sounds without memory of them?

That rather depends on why there in a coma, if it is brainstem lesions that say wipe out the dorsolateral part of the brainstem (lateral lemniscus included), or an insult to the primary auditory cortex (transverse temporal gyrus, or Heschl's gyrus for those old-timers), or a part which lesions the cochlear nuclei then no they wouldn't hear sounds.

Coma is a rather "catch-all" term for a persons state following CNS injury, that state because of the size and complexity of the brain can vary greatly case to case.

 

[bobze]

Hearing requires perception? But when you hear a "background" conversation you sense/hear every sound, but you don't really perceive it if you're not listening to the conversation.
Also is memory required for perception?
Also do coma patients actually have functioning brains?

Because your brain does an enormous amount of sensory-perception filtering without your permission.

Sound for instance, after passing through the transverse temporal gyri, goes onto areas of association cortex. Like the upper temporal association cortex, which integrates auditory and visual information. But suppose, your attention is elsewhere and you're not looking at those having that "background" conversation. You brain, in all its wisdom, decides its not so important then for you to "acknowledge" that background conversation.

This makes a whole heap of sense from an evolutionary standpoint if you think about. The brain, being that sensory integrative organ it is, needs to let you keep attention on things that matter. Say for instance, your attention was on the tall grass over yonder that was emitting the scary growl of a lion. It would behoove your brain to filter out that "background" conversation so you can focus on passing go and collecting your 200 dollars.

 

[bobze]

One way to look at it is as consciousness being made up of a bundle of faculties or cognitive processes - so sensation plus memory plus intention plus... And that some crucial component goes absent during sleep or coma.

But more accurate in my view is to see sleep and coma as states where the normal global integrative capacity of the brain goes awol. And that is what the neuroscience supports.

So during slow wave sleep/coma, neurons still fire to sensory input (though a stronger gating applies during REM). But there is a low level of integration. The brain is ticking over and not striving to form intentions and expectations, to derive sharp meaning.

If you introspect carefully enough, you should find that you are ruminating in a drowsy way even in deep non-dreaming sleep. If you wake up, you can just catch it - pay attention and so make it memorable.

But really, because this rumination is itself weakly organised, fairly meaningless, it is not memorable. And brain neurochemistry is also turned down in ways that reduce the potency of a memory fixing response.

So generally the explanation is that the brain is just broadly ticking over and not being tightly organised. You get a very low level of consciousness as a result - not no consciousness. And there is no single system or function that got turned off. The whole of the system is just less coherent than usual.

There are other stories like REM dreams and locked-in coma states. Consciousness is bright, but the path to action is broken, or external awareness is being actively gated.

But the key point is not to modularise the design of the brain too much. Sensation, perception, intention, memory are really all pretty integrated and seem more like aspects of the one single activity.

This is why neural network models, like the currently popular Bayesian brain, are more realistic than the gofai (good old fashioned artificial intelligence) approaches that tried to model brain as an assembly line that runs from sensory input to motor output via a series of memory-fetch and emotional valiance stages.

Good explanation.

 

[candydude357]

So do anaesthesized people have a low level of consciousness like sleeping people?
Or do they at least have unstructured perception of some sort?
ALso which has the higher level of perception/sensing/consciousness, anaesthesia or coma?

 

[DaveC426913]

So do anaesthesized people have a low level of consciousness like sleeping people?
Or do they at least have unstructured perception of some sort?
ALso which has the higher level of perception/sensing/consciousness, anaesthesia or coma?

Certainly, my experience of (full) anesthesia is no dreaming and no experience of the passage of time and no perception.

 

[Evo]

So do anaesthesized people have a low level of consciousness like sleeping people?
Or do they at least have unstructured perception of some sort?
ALso which has the higher level of perception/sensing/consciousness, anaesthesia or coma?

I've had a number of operations, and woke up during two of them that I remember. Since part of the anaethesia medication contains an amnesiac, it's possible I awoke other times but don't remember.

Here's a simple wikipedia page on anaesthesia that might answer your questions about it.

http://en.wikipedia.org/wiki/General_anaesthesia

 

[DaveC426913]

I've had a number of operations, and woke up during two of them that I remember.

Yeah I was going to mention phenom such as this.

I decided that, to keep it simple, I'd address the ideal case. Cases where some perception of time, pain or of dreaming is really more of an intrusion of consciousness in an anesthetic episode that has not fully engaged, so doesn't directly address the poster's question of distinigushing between the cases.

 

[apeiron]

So do anaesthesized people have a low level of consciousness like sleeping people?
Or do they at least have unstructured perception of some sort?
ALso which has the higher level of perception/sensing/consciousness, anaesthesia or coma?

If you really need to know, there is plenty to read...
http://en.wikipedia.org/wiki/Anesthesia_awareness

Generally, I would take the view that there are only degrees of unconsciousness due to states like sleep, anathesia and coma. After that there is only irrecoverable damage or death.

This is because brain cells are firing all the time, even when nothing is doing. If they stopped firing, they would be dead. They also remain connected to each other all the time.

So brain activity can become depressed, desynchronised, and in other ways lose its normal strong integrative capacity. But because it cannot actually be turned off, we should always expect there to be some residual degree of awareness. And not be surprised when we do. It is our null hypothesis.

 

[candydude357]

So brain cells still work during a coma?

 

[DaveC426913]

So brain cells still work during a coma?

Certainly.

Brain cells not working results in the doctor saying they're a vegetable and recommending pulling the plug.

 

[candydude357]

Do plants actually perceive if they don't have a brain?
Or do they sense?

 

[DaveC426913]

Do plants actually perceive if they don't have a brain?
Or do they sense?

No. Yes.

 

[candydude357]

What exactly do they sense? What's it like to be to be a plant compared to a rock for example.

 

[apeiron]

So brain cells still work during a coma?

Unless they have died. And in the kinds of injuries that put people into comas, cells do die.

But again, there are degrees of "work" here. And so degrees of awareness from bright and bushy to pretty much as much nothing as possible.

Do an experiment. Shut your eyes and stare. What do you see? Restless, swimming, flickers of colour and light. Not darkness as your brain cells cannot switch off. But still, just a meaningless rustle of neural activity, cells firing randomly because they have no real input to get integrative about.

 

[apeiron]

No. Yes.

Being picky, the distinction between sensation and perception is a dated one that derived from simple input-output processing models of the brain. Integration implies there is a running state (of expectation, habits, intentions, etc) to which events are being assimilated. Ideas ground the impressions.

But in the context of this thread, yes, whatever...

 

[DaveC426913]

What exactly do they sense? What's it like to be to be a plant compared to a rock for example.

It is "like to be" neither.

You wouldn't ask what it's like to be a protein would you? Plants are just complex chemical processes.

Higher forms of life have emergent properties that extend beyond their chemical processes, such as some form of memory, so that an experience yesterday is stored, so that it can alter behavour today. This is not the way plants operate.

 

[Ryan_m_b]

I thought these questions had been dealt with already. Thing's that have no consciousness have no consciousness. They do not feel or think about anything

 

[apeiron]

I thought these questions had been dealt with already. Thing's that have no consciousness have no consciousness. They do not feel or think about anything

Although also, of course, you need a good definition of the phenomenon to decide when and when it is not present.

Plants show some degree of integrative capacity. So definitions are not a simple issue here.

Plants, scientists say, transmit information about light intensity and quality from leaf to leaf in a very similar way to our own nervous systems.
These "electro-chemical signals" are carried by cells that act as "nerves" of the plants.
The researchers used fluorescence imaging to watch the plants respond
In their experiment, the scientists showed that light shone on to one leaf caused the whole plant to respond.
And the response, which took the form of light-induced chemical reactions in the leaves, continued in the dark.
This showed, they said, that the plant "remembered" the information encoded in light.

http://www.bbc.co.uk/news/10598926
http://www.scientificamerican.com/blog/post.cfm?id=plants-cannot-think-and-remember-bu-2010-07-16
http://www.plantcell.org/content/22/7/2201.full.pdf

 

[Ryan_m_b]

Although also, of course, you need a good definition of the phenomenon to decide when and when it is not present.

Plants show some degree of integrative capacity. So definitions are not a simple issue here.

Yes but to go back to an early answer in the thread

Ok this issue needs some definitions, I propose that (btw these are just definitions that I think are useful here, they may not be 100% accurate)

-Consciousness is a process by which an intelligence compares it's sensory input to memory and can create predictive models in order to plan it's actions
-Feeling is to ambiguous a word, we should use sensing instead
-Perceiving is when a conscious entity examines sensory input.

With that out of the way let's address some specifics;

An organism without a brain, ie plant or bacteria
Plants and bacteria can sense but without a central nervous system there is no consciousness and therefore no perception. Any sensory input directly causes the behavioral output. Again no experience

Sensing is something that plants do but there is no conscious perception, there is no consciousness therefore it is impossible to "feel like a plant".

 

[Pythagorean]

How do you know plant don't have subjective experience? We don't even know how we've come to have it?

Plant apices do carry active conducting channels that code information much like neurons and cam be said to be "making decisions".

Plants, in fact, must be very adaptive given their inability to move.

Whether they (or single celled eukaryotes or even prokaryotes/arch) have a subjective experience is up for grabs.

You can say emergence, but we still really don't know how subjective experience emerges.

 

[SamirS]

Well it is assumed that plants only react to inputs, at least those which do "move" (see http://en.wikipedia.org/wiki/Plant_movements ).

It is assumed because plants lack a real nervous system and also a brain or any device to actually interpret information.

If a venus flytrap reacting to something landing inside its petals amounts to subjective experience, then a button that closes a circuit and moves some mechanical part could in theory also have this kind of experience. A light sensor doesn't need subjective experience to react to light.

So because plants lack any of the known required devices for subjetive experience, and the fact that they are based on the same laws as we are, it is very very unlikely that they have a subjective experience, which is for all intents and purposes the same as for now declaring they don't have it.