How the Brain Does Consciousness: Biological Research Perspectives

[rocketdodger]

You're right, RD, I don't understand. I can't even recognize my own views in your description of them. I just have no response to that.

Wait ... you are telling me that you don't remember making posts about what the evolutionary advantage of human consciousness is?

 

[Piggy]

Piggy, can you post a link for the 2006 Owen et al research? thanks.

No links, but I've got the cite.

Owen, A.M., Coleman, M.R., Boly, M., Davis, M.H., Laureys, S. & Pickard, J.D. (2006). Detecting awareness in the vegetative state, Science, 313(5792), 1402.

 

[Piggy]

Then correct him. Explain. Elucidate. Freakin' talk. Don't just dismiss everyone and go off on wild-ass tangents. This is a discussion forum, not a collection of soapboxes. If he's misunderstanding your position, learn him the hell why.

That's not something I care to do here if it gets us on a derail, which it would. "Wild-ass tangents" are exactly what I'm trying to avoid.

 

[Piggy]

Can you explain what you actually believe about consciousness in a single post. That way the rest of us might be able to discuss it sensibly with you.

Exactly what I believe doesn't matter, and that's one of the conversations I don't want to have, because the topic of the thread is brain research on consciousness. (Which I'd like to get back to.)

Granted, I've got my interpretations of various studies, but I don't care what anyone posts about any given study, the methods, the findings, the applications, whatever, criticism and alternative conclusions as well, of course.

But the reason I wrote the OP was so we could avoid discussion of whether or not people are conscious (we are), or if people move through various conscious states over an average day (we do), or whether the brain generates consciousness (it does), or -- if you want to know how an organ does what it does -- whether it's a good idea to observe the organ doing what it's doing (it is).

Not to mention discussions of p-zombies, brains in vats, hypothetical conscious machines, and the differences between reality and simulations.

And the purpose of this thread isn't to decide what consciousness is. That's why the stipulative definition is so broad, to allow a lot of brain research in.

The purpose is to discuss research and studies on the animal brain that shed any light on the phenomenon of conscious experience.

Which I'd like to get back to soon.

 

[Piggy]

Wait ... you are telling me that you don't remember making posts about what the evolutionary advantage of human consciousness is?

All I'm asking you is which brain activity you think consciousness is the same as.

I don't really see that you and I disagree on that point, unless your answer is "all of it".

 

[Piggy]

Just a random spotting....

Call It a Reversible Coma, Not Sleep

Dr. Emery Neal Brown, 54, is a professor of anesthesiology at Harvard Medical School, a professor of computational neuroscience at M.I.T. and a practicing physician, seeing patients at Massachusetts General Hospital. Between all that, he heads a laboratory seeking to unravel one of medicine’s big questions: how anesthesia works.

Not entirely about consciousness, but there's this:

Q. What has your research shown so far?

A. Under general anesthesia, the brain is not entirely shut down. Certain parts are turned off; others are quite active — not only “active,” but there is a level of activity that is quite regular.

Our observation is that it is this regular activity prevents the brain from transmitting information and contributes to a state of unconsciousness. It’s analogous to stopping communication down a phone line when transmission is blocked. You could block transmission another way: by sending a loud signal down the line so that that signal was the only thing you hear. So in some parts what we see is that activity is turned off, leading to unconsciousness. In other parts, we see activity that is more active than normal. This also leads to unconsciousness. In sum: the drugs alter the way the brain transmits information.

Interesting to compare with the other anesthesia study, as well as the seizure study.

 

[Piggy]

Another random spotting, and one which involves both brain research and computer modeling.

It doesn't address consciousness directly, but I include it because the issue of decision-making is so prominent in biological research on consciousness, as is the relationship between automatic and volitional decisions, and because it's important to know what the brain does before, after, and outside of conscious awareness.

Do 'Traffic Lights' in the Brain Direct Our Actions? Delayed Inhibition Between Neurons Identified as Possible Basis for Decision Making

Often the problem of decision-making entails the selection of one set of brain processes over multiple others seeking access to same resources. Several mechanisms have been suggested how the brain might solve this problem. However, up to now, it is a mystery what exactly happens during a rapid choice between two options....

As the structure and activity of the brain are just too complex to answer this question through a simple biological experiment, the scientists constructed a network of neurons in the computer. An important aspect of the model in this context is the property of nerve cells to influence the activity of other nerve cells, either in an excitatory or inhibitory manner. In the constructed network, two groups of neurons acted as the senders of two different signals. Further downstream in the network, another group of neurons, the "gate" neurons, were to control which of the signals would be transmitted onward.

As the cells within the network were connected both with exciting and inhibiting neurons, the signals reached the gate as excitatory and, after a short delay, inhibitory activity. In their simulations, the scientists found that the key for the gate neurons' "decision" in favour of one signal over the other was the time delay of the inhibitory signal relative to the excitatory signal. If the delay was set to be very small, the activity of the cells in the gate was quenched too quickly for the signal to be propagated.

Conversely, a larger delay caused the gate to open for the signal. Results from neurophysiological experiments have already shown that a change in delay properties is possible in real neurons. These findings therefore support the hypothesis of Kremkow and colleagues that such temporal gating can form the basis for selecting one of several alternative options in our brain.

 

[Piggy]

Link on SD led to this cool study involving brain observations and computer models which takes the issue of decision-making into the arena of conscious experience:

How Our Brains Get Tripped Up When We're Anxious

In the study, they tested the idea that neural inhibition in the brain plays a big role in decision-making by creating a computer model of the brain called a neural network simulation.

"We found that if we increased the amount of inhibition in this simulated brain then our system got much better at making hard choices...."

Through their model they looked at the brain mechanisms involved when we choose words. They then tested the model's predictions on people by asking them to think of the first verb that comes to mind when they are presented with a noun.

"We know that making decisions, in this case choosing our words, taps into this left-front region of the brain, called the left ventrolateral prefrontal cortex," Munakata said. "We wanted to figure out what is happening in that part of the brain that lets us make these choices...."

They then tested the model's predictions that more neural inhibition in the brain makes it easier to make choices by examining the effects of increased and decreased inhibition in people's brains. They increased inhibition by using a drug called midazolam and found that people got much better at making hard choices. It didn't affect other aspects of their thinking, but rather only the area of making choices. They investigated the effects of decreased inhibition by looking at people with anxiety.

"We found that the worse their anxiety was, the worse they were at making decisions, and the activity in their left ventrolateral prefrontal cortex was less typical," Munakata said.

It'd be informative to know what "less typical" meant, exactly.

 

[Piggy]

Looking at some Crick and Koch articles, as well as the Schiff (where the Owen was cited) and some others. More later.

 

[rocketdodger]

All I'm asking you is which brain activity you think consciousness is the same as.

I don't really see that you and I disagree on that point, unless your answer is "all of it".

All I'm asking you is "which part of consciousness?"

That is rather the point.

 

[TmoonII]

All I'm asking you is "which part of consciousness?"

Can you rephrase the question? I am unaware of different parts of consciousness and would like to be aware of them.

 

[Beelzebuddy]

anyone but piggy: Here's some brain research on consciousness
piggy: That's not consciousness, get out of the thread
abp: What's consciousness, then?
piggy: That's not part of the thread, so I'm not telling

lol que?

But the reason I wrote the OP was so we could avoid discussion of whether or not people are conscious (we are), or if people move through various conscious states over an average day (we do), or whether the brain generates consciousness (it does), or -- if you want to know how an organ does what it does -- whether it's a good idea to observe the organ doing what it's doing (it is).

Please cite some actual brain research addressing the italicized items.

 

[rocketdodger]

Can you rephrase the question? I am unaware of different parts of consciousness and would like to be aware of them.

Well think of it this way:

Can someone blind from birth be conscious?
What about someone deaf from birth?
Someone with no sense of touch?
Someone with no long term memory?


What about a combination of those? Can someone with no long term memory and no sensory perception besides hearing be conscious, for example?

 

[Piggy]

Does anybody have any good cites or books on studies of synesthesia?

I'm interested in how/where the binding happens.

 

[Piggy]

All I'm asking you is "which part of consciousness?"

That is rather the point.

The question of which brain activity is correlated with any specific process is a pretty ambitious question to try to answer, but at random let's take the phenomenon of your name "jumping out at you" from background chatter in a roomful of people.

If we consider the process of that particular arrangement of sounds corresponding to a conscious awareness of "someone just said my name", while all the other vocal sounds bombarding the ear do not correspond with any particular conscious experience but rather "there are lots of people talking in this room", then what brain activity is responsible for (or associated with) the two cases and how do they differ and how do they overlap?

Of course, the next question would be "Why is that so?"

That's the best I can understand "part of consciousness" anyway -- if that's not what you meant, just let me know.

 

[Piggy]

Please cite some actual brain research addressing the italicized items.

Take your pick of anything that's been cited. If those issues are genuine problems, it should be easy to point out in the research.

 

[Piggy]

Can someone blind from birth be conscious?

Certainly.

What about someone deaf from birth?

Certainly

Someone with no sense of touch?

Certainly

Someone with no long term memory?

Well, people who've lost LTM are no doubt still conscious. Being born without it would really screw with your development, tho. Still, I see no reason why a person who could survive that would not be conscious.

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.

In fact, that's implicit in Schiff's article about brain injury, where he mentions Owen's study.

Since nobody has ever proposed that folks who lose LTM cease to be conscious, I can't see any reason to claim that they do. I don't know of any cases of absence of LTM from birth.

 

[Beelzebuddy]

what brain activity is responsible for (or associated with) the two cases and how do they differ and how do they overlap?

Of course, the next question would be "Why is that so?"

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

Take your pick of anything that's been cited. If those issues are genuine problems, it should be easy to point out in the research.

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.

 

[TmoonII]

Oh, "state" of consciousness. So there must be many, since consciousness occurs in the unaware.

 

[Piggy]

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.