How the Brain Does Consciousness: Biological Research Perspectives

Beelzebuddy said:
It's call "pattern recognition." It's sort of a thing the brain does. Do we really gotta get into something this simple?
Click to expand...

That's right, it's pattern recognition, it's the sort of thing the brain does. Biological research doesn't expect to find the sorts of things the brain does not do.

ETA: The significant finding here is that a representation anticipates the shift of attention. The textbook scenario has been sensory input needing to be matched with memory, but these findings indicate a more elegant solution, imagine the upcoming state and note divergences. It's relevant because imagination and prediction have so often been assumed to always involve conscious awareness in some way.

Beelzebuddy said:
Yeah, no, nothing in this thread has supported your assertions. You're pointing out different bits of neural function and going "look, here, consciousness" without connecting them in any recognizable fashion.
Click to expand...

Well, "Look, here, consciousness" isn't how I'd describe the goal of brain research.

In any case, when it comes to neural correlates of consciousness, the connection between the neural states/behaviors and the conscious states/experiences isn't known. The correlations are certainly there, they're documentable, and they're useful, but there is no framework within which to explain the correlations, to say why a given neural state does correlate with a particular conscious experience, and not some other one, or none.
 
Last edited:
Piggy said:
In any case, when it comes to neural correlates of consciousness, the connection between the neural states/behaviors and the conscious states/experiences isn't known.
Click to expand...

It would be helpful to know if synapses functions change.
 
Piggy said:
Interesting little bit from "Human", in a discussion of human moral thinking:

This is pertinent to research that I have done on people who have had the connection (the corpus callosum) between the two hemispheres of their brains severed for medical reasons. What this does is to isolate the right hemisphere from the speech center, which usually is in the left hemisphere, so not only can't the right hemisphere communicate with the left himsphere, it can't talk to anyone else either. With special equipment, you can tell the right hemisphere to do something by giving a visual command to one eye, such as "pick up a banana." The right hemisphere controls the motor movement on the left side of the body, so the left hand will pick up the banana. Then if you ask the person, "Why did you pick up the banana?" the left brain's speech center answers, but it doesn't know why the left hand picked up the banana, because the right hemisphere can't tell it that it read a command to do so. The left himesphere gets the visual input that there is indeed a banana in the left hand. Does it say, "Gosh, I don't know"? Hardly! It will say, "I like bananas," or "I was hungry," or "I didn't want it to fall on the floor." I call this the interpreter module. The intuitive judgment comes out automatically, and when asked to explain, out pops the interpreter to make a rational explanation, keeping everything neat and tidy.
Click to expand...
Click to expand...

I'll probably get told this isn't appropriate for this thread, but anyway.
Presumably in the example above, if the person was left handed (or if you gave them a keyboard) you could use a second visual command to ask the right hemisphere why it picked up the banana, which would then write down 'Because you told me to'.

Does this mean there are now two consciousnesses in the same brain?
 
Piggy said:
Interesting little bit from "Human", in a discussion of human moral thinking:
Click to expand...

"With special equipment, you can tell the right hemisphere to do something by giving a visual command to one eye, such as 'pick up a banana.'"
That part is wrong. If you presented the stimulus to one eye it would end up represented in both the left and right occipital lobes. What is actually done is to flash the stimulus in the left visual field of both eyes, ensuing that it would only end up in the right occipital lobe.
http://www.macalester.edu/psychology/whathap/ubnrp/split_brain/Standard Experiment.html
 
Last edited:
Piggy said:
As far as brain research, tho, I'd say the first 3 are solid, since we've no indication that blindness or deafness mess up any of the necessary real-estate -- that's besides the obvious behavioral evidence -- and there's no reason a loss of tactile sensation should, either.
Click to expand...

Right.

So if you have a person, who has no concept of visual stimuli at all, being conscious just like you and me, what does that say about the relationship between visual stimuli and consciousness?
 
Piggy said:
That's right, it's pattern recognition, it's the sort of thing the brain does. Biological research doesn't expect to find the sorts of things the brain does not do.
Click to expand...
Only part of it is pattern recognition, and only in certain scenarios. If you are told to listen for sound X amongst chatter, and not sound Y, and you haven't ever heard those sounds until the start of the experiment, I am pretty sure the type of recognition would not be the same as heaing your name after you have learned it. In the "your name" case it is easily explainable with known neural network models, in the novel sound case it involves a much more complex mechanism which is not easily explainable. Basically, how do you get a neural network to be able to memorize things without changing node edge weights in the same way each time (since the way synapses change between short term and long term memory are different ) ? This is the question of "working" memory and how it works http://en.wikipedia.org/wiki/Working_memory

But beyond pattern recognition, there is the whole "that was my name! " part that needs explaining -- and isn't that the part we are interested in? So simply saying "pattern recognition" doesn't help. You could abstract the "recognition" part away completely, what we are interested in is what comes after the recognition.[/QUOTE]

Piggy said:
but there is no framework within which to explain the correlations, to say why a given neural state does correlate with a particular conscious experience, and not some other one, or none.
Click to expand...

Nonsense, we already have much of the framework. You yourself just said "pattern recognition," implying that the reason your name stands out amongst chatter, when you aren't actively listening for it, is because your auditory network pattern matches that sequence of sounds to something important and sends information up the pipeline about it. Same goes for visual stimuli, and tactile stimuli, etc. We know how all those subsystems work, pretty well at least, to the point where we could probably re-build them if we had the technology. Same goes for long term memory.

On top of that, we aren't clueless when it comes to the framework that puts it all together. At the very least it isn't hard to imagine various network configurations and simply drop them from the contender list because they would never end up producing observed behavior. In particular, knowing how conscious experience is closely tied to focus pretty much narrows it down to a very small number of possibilities.
 
Last edited:
TmoonII said:
Other than cell death?
All I can find is hypothesis.
Click to expand...

Well, consider the evidence in favor of that "hypothesis," as you say.

First, I am almost certain there is plenty of research showing that altering synaptic plasticity drastically changes the function of the brain.

Second, we know from neural network models that the only way to alter the computation taking place between "runs" is by 1) creating new edges or 2) modifying edge weights. I am pretty sure a network can function in a minimal way without those mechanisms, but as soon as you "shut it off" all is lost. So, since we sleep, you can bet we need either 1) or 2) in order to wake up the same person the next day. And we know neurons don't grow new dendrites or axons that fast, so pretty much the only logical option is for synapses to be plastic.

Third, we know from research that the way the human brain develops is to start with a bunch of synapses and as it learns only keep the ones that are being used, which again requires the synapses to be plastic -- how else would a neuron know whether a synapse has been used or not ?
 
Jeff Corey said:
"With special equipment, you can tell the right hemisphere to do something by giving a visual command to one eye, such as 'pick up a banana.'"
That part is wrong. If you presented the stimulus to one eye it would end up represented in both the left and right occipital lobes. What is actually done is to flash the stimulus in the left visual field of both eyes, ensuing that it would only end up in the right occipital lobe.
http://www.macalester.edu/psychology/whathap/ubnrp/split_brain/Standard Experiment.html
Click to expand...

You might want to write the author. I believe these were his experiments.
 
rocketdodger said:
Right.

So if you have a person, who has no concept of visual stimuli at all, being conscious just like you and me, what does that say about the relationship between visual stimuli and consciousness?
Click to expand...

I dunno, RD. Sounds like a philosophical question to me.

Are we still posting and discussing research on the brain, or are we doing something else now?

ETA: In terms of biology, I'd say it indicates that the brain behavior required for conscious awareness does not depend on incorporating impulses from the visual system.
 
Last edited:
Guybrush Threepwood said:
I'll probably get told this isn't appropriate for this thread, but anyway.
Presumably in the example above, if the person was left handed (or if you gave them a keyboard) you could use a second visual command to ask the right hemisphere why it picked up the banana, which would then write down 'Because you told me to'.

Does this mean there are now two consciousnesses in the same brain?
Click to expand...

That's a damn good question.

I don't know that it's rightly phrased, tho.

I hate it that our language is so thingy, consisting of nouns (consciousness) and adjectives (conscious), when it should be verby because it's really a behavior.

But anyway, there's a good bit of split-brain research out there. For instance, they've done studies in which they've shown that one side can know what object one hand is holding behind a screen, from the feel of it, but the other half has no clue what it is.

Asking "Are there two consciousnesses?" isn't as useful as asking "What is the brain doing now?"

On the other hand, because we're talking about conscious experience, it really is necessary to ask what such an experience might be like, especially for the silent half, if it has any experience at all. But I don't know of any research to refer to for that question.

For the other half, it doesn't seem to be appreciably different from anybody else's, except possibly when deliberate attempts are made to trick it.
 
Piggy said:
You might want to write the author. I believe these were his experiments.
Click to expand...
I don't think so.
The original experiments were done by Sperry. This guy knows less than my average intro psych student. Why should I have to pay any attention to his BS?
 
Piggy said:
I dunno, RD. Sounds like a philosophical question to me.
Click to expand...
Anything beyond direct reference to peer reviewed research is "philosophical" to you. That's your problem. If you want to ever actually "understand" things you have to make some abstractions and connections in your own head, and be willing to call it "inference" instead of "philosophy."

I honestly think that if someone told you they were gonna drive a car 200 miles, and cited a study showing the car once drove 300 miles, you would respond with "but where is the study showing it can drive 200 miles? 300 is not 200."

Piggy said:
Are we still posting and discussing research on the brain, or are we doing something else now?
Click to expand...

Since when has it been a discussion? Looks to me like you citing studies, people making inferences based on those (and other) studies, and you responding with the sentiment that since those inferences are not backed up directly by other studies then they are merely "assumption" or "supposition" or "purely conjuecture" and aren't worth much in turn.

Is that the "discussion" you are after? Doesn't seem like the "discussion" anyone else is after, perhaps that is why the thread is so slow.

Piggy said:
ETA: In terms of biology, I'd say it indicates that the brain behavior required for conscious awareness does not depend on incorporating impulses from the visual system.
Click to expand...

Ah, see, now we are having a discussion.

Also, now you have a conundrum, because the above conclusion doesn't play well with your desire to limit the discussion to "actual research" and not delve into the "assumptions and suppositions" one can make using such research as evidence. A direct conclusion from the above might be:

1) The brain behavior required for consciousness doesn't depend on visual input (it might still use the visual system somehow), which means any references you make to studies that use visual input need to be framed in that context -- something you have not done because you are so hesitant to draw any hard conclusions. Why does consciously monitoring for a stimulus allow us to perceive it so much better? Well, if such behavior doesn't directly depend on the kind of stimulus in question, there are a number of inferences one can make about how the mechanics behind it might be organized. And there is no reason to doubt the validity of such inferences -- neuroscientists aren't necessarily smarter than you or I, piggy, they just chose a different line of work.

For instance, your refusal to answer the simple question of what your own conclusions are regarding the nature of human consciousness is bewildering to me. Are you afraid to be wrong? Thats the point of a forum, making posts and learning from your mistakes.

2) The brain behavior required for consciousness does depend on visual input, in a person who can see, and the brain behavior required for consciousness doesn't depend on visual input in a person who is blind. In which case, the only way to make sense of a "generic" human consciousness is to abstract away from the direct topography of seeing and blind people and look at the kind of information processing pathways their brains have in common -- somethign you seem categorically unwilling to do, because it involves computer science and modeling and all sorts of ideas that can't be gotten with a scalpel/microscope/ MRI machine alone.

3) The brain behavior required for consciousness depends on visual input in both blind and seeing people, meaning blind people are not conscious. Obviously this isn't a serious contender.
 
You must log in or register to reply here.

Back
Top Bottom