How the Brain Does Consciousness: Biological Research Perspectives

rocketdodger said:
At some point, signals from the brain are also input, meaning the network goes from being feedforward to being recurrent.

Does the research give any insight into what layer of filtering that recurrence occurs?
Click to expand...

Although this paper approaches it from a sensorimotor perspective, your answer is "the first one." Motor control by sensory cortex. The whole damn thing is recurrent, there's not a single piece of the brain that doesn't touch another piece within a synapse or two.


Responding to the (fair, I believe) request for citations, it all depends on what you mean by "consciousness."

Piggy's kinda gone all over the map, but his OP tended more toward consciousness qua "being conscious," what animal researchers call "awake behaving." This is possibly the least useful definition, since all it means is, hey, you're awake. Theta rhythms and all that. Which are interesting enough in their own right, especially regarding their implications in the binding problem, (another imaginary problem, imo, though this time most of computational neuroscience would disagree) but aren't really all that related to consciousness.

So, then, how about "self-consciousness?" Well, there's that whole mirror neuron thing going on in the premotor cortex. Self-recognition (that "mirror test" you've probably heard about) tends to have a bias toward the right prefrontal cortex, though since it's studied via fMRI there's bits of significance flying everywhere, it's like thunderdome.

Then there's being conscious of something, better known as "attention." This is a pretty cool phenomenon, because it's the closest thing to a real network effect we've found so far. Attention takes the form of a surprisingly subtle priming of differential cortical areas, which can be disrupted in very specific and measurable manners (there was an even better monkey paper about this, but I can't seem to find it atm). It originates this time from the parietal cortex, though the PFC and hippocampus play roles in sustaining attention as well.

But consciousness as some kind of magical overarching organized thing? Nada. Again, it's a terrible term that ought to be left by the wayside, if not drug out into the street and shot.
 
rocketdodger said:
Except, we have those instruments. We know how neurons work. We have decades and decades of research on how biological neural networks in animals function. Heck, we can simulate a rat's neocortex. We know how vision works at the neuron level, we have promising ideas about how memory works at the neuron level, but hey -- lets just ignore all that, because it involves "computer science," and focus on the research that will never shed nearly as much light on the issue because we don't want to hurt our brains thinking about it.
Click to expand...

I'm with you up to the point where you veer onto "let's just ignore all that" because the research I'm talking about is entirely about that, with the exception that we're dealing with the actual thing rather than a simulation of it.

In any case, if you want to discuss those simulations, there are lots of other places to talk about them, but it's pretty clear by now what the topic of this thread is, and it isn't that.

I don't mean to be rude, but I mean, come on.
 
rocketdodger said:
I would like to discuss vision and recall.

The vision system can be roughly modeled as a set of filters, with each layer operating on the output of the previous one. At some point, signals from the brain are also input, meaning the network goes from being feedforward to being recurrent.

Does the research give any insight into what layer of filtering that recurrence occurs? We know it isn't at the top layer, because our recall of visual perception is not even close to the detail of actual perception. But it would be interesting to know at what layer our memory of an object starts to excite the associated filters. Is it somewhere in the LGN, or not until the visual cortex proper?
Click to expand...

Interesting topic. If there's any biological research on it, it should be worth reading.
 
Beelzebuddy said:
So, then, how about "self-consciousness?" Well, there's that whole mirror neuron thing going on in the premotor cortex. Self-recognition (that "mirror test" you've probably heard about) tends to have a bias toward the right prefrontal cortex, though since it's studied via fMRI there's bits of significance flying everywhere, it's like thunderdome.

Then there's being conscious of something, better known as "attention." This is a pretty cool phenomenon, because it's the closest thing to a real network effect we've found so far. Attention takes the form of a surprisingly subtle priming of differential cortical areas, which can be disrupted in very specific and measurable manners (there was an even better monkey paper about this, but I can't seem to find it atm). It originates this time from the parietal cortex, though the PFC and hippocampus play roles in sustaining attention as well.
Click to expand...

But all of that fits in the stipulative definition of the thread. All of that can be discussed and be on topic, as long as we're talking about what brain research has to say.

The whole point of the OP's language on that issue is that we're not restricting discussion only to one of the narrower definitions, which would exclude dreams, for example.

So discussion of any biological research in those areas would be fine. Why not?
 
Kudos to Piggy for a brave thread. My head aches from reading through it.

If human consciousness is unique, which i doubt, I'd liken it to the tail on the bird of paradise...a somewhat silly adaptation for the purpose of procreation...very fancy, and, evidently effective.

Personally, I am dis-inclined to mate with female humans that demonstrate a lack of consciousness. One of the hallmarks, to me, of the lack of consciousness, is the lack of a sense of sequence. Alzheimer's victims suffer from this, and become un-human, in a way. Terry Shiavo, even more so.

A smart dog is more 'human' than a severely brain damaged human.
 
TmoonII said:
Is it possible to influence you?
Click to expand...

Absolutely.

Although I'm not sure that's a topic for this particular thread.

Is there research on the brain which you think points in that direction?
 
ThunderChunky said:
That should read "signature brain waves associated with seeing words." Presumably these people were conscious whether they saw the masked or unmasked words.

Does your stipulative definition of consciousness include organisms other than humans? Which ones?
Click to expand...

Yes, they were conscious, but that's not the point. The brain does not involve consciousness in everything it does, including visual perception. We've known for some time that the brain can perceive, functionally remember, and learn from objects and events that are picked up by the eyes but never referred to the mechanisms responsible for conscious awareness.

The point of these kinds of experiments is to set up conditions where we can look at what the brain is doing when dealing with the world in ways that do and don't engage conscious awareness.

"Being conscious" does not mean being conscious of everything, by any means.

As to whether other animals are conscious in the way described by the OP, that's much trickier to answer because communication with animals is much more difficult.

I'm not looking at much of the research into other animals' brains at the moment, but perhaps some other folks are. (My hope would be that an understanding of how the brain does it for humans will allow us to identify the presence or absence of similar structures/mechanisms in other animals.)
 
Just for clarification -- I don't want to spend too much time on this topic b/c I think it would be best discussed on its own thread -- I think there's some misunderstanding about what biological research into consciousness is, and isn't.

We simply start with a set of observations: People have conscious experiences. Not all the time, but sometimes. And we're not conscious of everything that's going on around us... and sometimes we're conscious of things that aren't really going on at all.

Very interesting, worth looking into.

It's like if we observe dazzling lights in the northern sky sometimes, but not all the time, we might ask "What is that, and what causes it?" (At this point if someone were to demand a complete definition of the phenomenon beyond some equivalent of "Those lights we see sometimes over there", there would be nothing to offer except "That's what we're trying to find out by investigating it".)

Experimental and field evidence by this point clearly indicates that the activity of the brain is what causes consciousness to stop and start, and which determines what anybody's experience actually is. I don't know of any serious objection to that idea.

So we put the brain into situations in which we know what sort of conscious experience a subject is having, and we examine what the brain is doing when that occurs.

In this way, we can start investigating the biological differences among various brain tasks that are associated with different aspects of consciousness. For example, tasting an apple, imagining tasting an apple, and imagining someone else tasting an apple. (Each of these is done in a way that uses some of the same brain parts as the others, but distinct ones as well.)

We also look at what happens when the brain perceives, responds, remembers, and learns with and without the involvement of consciousness -- e.g. recognition of facial cues for emotions by certain blind people, or immediate and delayed response to extremely brief visual input.

And then we look at the effects of various type of damage to the brain, and that sort of thing.

In other words, plain vanilla science in an attempt to figure out how a particular set of observable phenomena are caused and related.

And the problem with attempting to define consciousness in terms of functions like attention, memory, perception, learning, imagination, and so forth is that all of these can be involved in what the brain is doing when consciousness is not involved or when it is. So they fall short of providing a coherent explanation of the phenomenon of conscious awareness.

From an evolutionary point of view, there is no reason to assume that consciousness is different from everything else the brain does. We should expect it to be the result of selection, and to be enabled by physical structures evolved to that purpose.

And so far, we've gotten no surprises on that point.

The picture that's emerging is of a faculty that coordinates a wide variety of impulses in order to generate a continually shifting sense of self-in-the-world, which always lags a split-second behind the events we feel we are aware of.

Anyway, that's it in a nutshell. No magic, nothing outrageous, just scientific investigation of phenomena.
 
Beelzebuddy said:
When you do something and don't remember it, people tend to call that "unconscious' or "subconscious" action, when in fact it was just your episodic memory not giving a crap about this particular commute or brushing of your teeth. Doesn't mean you weren't "conscious" while you were doing it.
Click to expand...

Just to be clear, that's certainly not how a biologist would look at it.

I think it's safe to assume that your fellow motorists are conscious, even if some of them are impaired by drugs or lack of sleep or what have you. Entirely losing consciousness while driving quickly results in a wreck if you don't wake up very soon.

For a biologist, the interesting questions are, what are people conscious of and not conscious of (among everything bombarding our senses) at various times during the commute, and how is the brain "deciding" what's included and what's excluded, and to what degree is consciousness involved in the physical performance of the commute?
 
Piggy said:
Absolutely.

Although I'm not sure that's a topic for this particular thread.

Is there research on the brain which you think points in that direction?
Click to expand...

To be influenced is to be collectively conscious.

I believe in cellular memories. Thus with this belief, consciousness continues to exist regardless of the acknowledgement of said person. It might be possible to wipe every cellular memory chemically, but under the natural process of decay, even those under the influence of neurotoxicity still retain consciousness at a cellular level. Mad cow might be more of a maintenance challenge to cellular integrity, but all cells remain cells. And the storage of memories within the brain might not be accessible from lobe to lobe for communication, but [I believe] consciousness is possible without verbal acknowledgement.
 
Piggy said:
I'm with you up to the point where you veer onto "let's just ignore all that" because the research I'm talking about is entirely about that, with the exception that we're dealing with the actual thing rather than a simulation of it.

In any case, if you want to discuss those simulations, there are lots of other places to talk about them, but it's pretty clear by now what the topic of this thread is, and it isn't that.

I don't mean to be rude, but I mean, come on.
Click to expand...

My perception is that you would rather make vague suppositions than actually explore possible mechanics.

Because like it or not the only way to make sense of consciousness is by understanding biological neural networks, and like it or not the only way to make any sense of biological neural networks is with models and simulations.

You named the thread "how the brain DOES consciousness." It seems like you aren't as interested in the "does" as you claim.

For instance -- what does any of the research you have cited thus far lead you to conclude about the "does," piggy?
 
Piggy, you're equivocating.

Piggy said:
We simply start with a set of observations: People have conscious[1] experiences. Not all the time, but sometimes. And we're not conscious[2] of everything that's going on around us... and sometimes we're conscious[3] of things that aren't really going on at all.
Click to expand...
1 - Episodic memory
2 - Attention
3 - Perception

Experimental and field evidence by this point clearly indicates that the activity of the brain is what causes consciousness[4] to stop and start, and which determines what anybody's experience actually is. I don't know of any serious objection to that idea.
Click to expand...
4 - Magical binding agent

No one should object because it's a tautology. Yeah, your memory determines what you remember. The activity of the brain determines what the brain is doing. If you take out the magical thinking which you insist you're not using, you're left with redundant non-statements.

In this way, we can start investigating the biological differences among various brain tasks that are associated with different aspects of consciousness. For example[3,1], tasting an apple, imagining tasting an apple, and imagining someone else tasting an apple. (Each of these is done in a way that uses some of the same brain parts as the others, but distinct ones as well.
Click to expand...
3,1 - perception versus recall of stimulus

We also look at what happens when the brain perceives, responds, remembers, and learns with and without the involvement of consciousness[2,1] -- e.g. recognition of facial cues for emotions by certain blind people, or immediate and delayed response to extremely brief visual input.
Click to expand...
2,5 - Attention, self-consciousness, specifically regarding stimuli falling below activation thresholds or using indirect communication pathways.

And the problem with attempting to define consciousness in terms of functions like attention, memory, perception, learning, imagination, and so forth is that all of these can be involved in what the brain is doing when consciousness[4] is not involved or when it is. So they fall short of providing a coherent explanation of the phenomenon of conscious awareness.[5]
Click to expand...
4 - Magic
5 - self-awareness

From an evolutionary point of view, there is no reason to assume that consciousness[?] is different from everything else the brain does. We should expect it to be the result of selection, and to be enabled by physical structures evolved to that purpose.

And so far, we've gotten no surprises on that point.

The picture that's emerging is of a faculty that coordinates a wide variety of impulses in order to generate a continually shifting sense of self-in-the-world,[5] which always lags a split-second behind the events we feel we are aware of.
Click to expand...
? - Could be any of them, here, but I'm guessing magic
5 - Self-awareness

But no, that's the hypothesis you're proposing. There ain't no such faculty, ain't no such structure, ain't no picture emerging. The brain works just fine as a set of highly recurrent but distributed mechanisms, with no little homunculus calling the shots anywhere. That's just your [5] talking to you, little bastard ain't half as important as it thinks.

Piggy said:
I think it's safe to assume that your fellow motorists are [awake and alert], even if some of them are impaired by drugs or lack of sleep or what have you. [Passing out] while driving quickly results in a wreck if you don't wake up very soon.

For a biologist, the interesting questions are, what are people [attending to] and [ignoring] (among everything bombarding our senses) at various times during the commute, and how is the brain "deciding" what's included and what's excluded, and to what degree is consciousness involved in the physical performance of the commute?
Click to expand...
Fixed most of it, except for the last one which uses the magical meaning. I know it can't be "just, y'know, whatever the brain is doing" because that makes your statement a tautology. Of course brain activity is involved in brain activity.

TmoonII said:
I believe in cellular memories. Thus with this belief, consciousness continues to exist regardless of the acknowledgement of said person. It might be possible to wipe every cellular memory chemically, but under the natural process of decay, even those under the influence of neurotoxicity still retain consciousness at a cellular level.
Click to expand...
I take back what I said earlier, piggy. This is illucid, you're just a little incorrect. You, we can fix.
 
TmoonII said:
To be influenced is to be collectively conscious.

I believe in cellular memories. Thus with this belief, consciousness continues to exist regardless of the acknowledgement of said person. It might be possible to wipe every cellular memory chemically, but under the natural process of decay, even those under the influence of neurotoxicity still retain consciousness at a cellular level. Mad cow might be more of a maintenance challenge to cellular integrity, but all cells remain cells. And the storage of memories within the brain might not be accessible from lobe to lobe for communication, but [I believe] consciousness is possible without verbal acknowledgement.
Click to expand...

I'm sorry, this thread isn't about belief and it's not about cells. It's about scientific research on the brain. You might want to start a new thread on that subject, tho.
 
rocketdodger said:
Because like it or not the only way to make sense of consciousness is by understanding biological neural networks, and like it or not the only way to make any sense of biological neural networks is with models and simulations.
Click to expand...

That's fine, and there are plenty of places to discuss models and simulations, but this thread is about research being done directly on the animal brain, so if you'd like to contribute, please start posting on that topic.

The existence of this thread does not in any way imply that models and simulations are not useful tools.

rocketdodger said:
You named the thread "how the brain DOES consciousness." It seems like you aren't as interested in the "does" as you claim.

For instance -- what does any of the research you have cited thus far lead you to conclude about the "does," piggy?
Click to expand...

If you have a question about a particular study that's been cited, and the conclusions drawn from that study, then you're perfectly free to join in.

But I'm not going to go back over the posted studies in an attempt to answer that question. Sorry.

Anyway, as predicted, this particular discussion is proving to be a waste of time, so I'm not going to continue expending effort on it.
 
Beelzebuddy said:
Fixed most of it
Click to expand...

I don't see any discussion of the research there, nor do I see a coherent argument, or any evidence of any understanding of the research, so there's really nothing else I can say about that on this thread.

I'll get back to posting on brain research later this evening.
 
Piggy, please stop telling everyone who disagrees with you to leave the thread. It's kind of annoying.
 
You must log in or register to reply here.

Back
Top Bottom