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Am I conscious of my prefrontal cortex or is my prefrontal cortex me?

by Johninch
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Johninch
#1
Dec28-13, 05:06 AM
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The prefrontal cortex “differentiates among conflicting thoughts, determines good and bad, better and best, same and different, future consequences of current activities, working toward a defined goal, prediction of outcomes, expectation based on actions, and social control …. not only are skills of comparison and understanding of eventual outcomes harbored in the prefrontal cortex but the prefrontal cortex controls the mental option to delay immediate gratification.

The prefrontal cortex is highly interconnected with much of the brain, including extensive connections with …. brain regions involved with attention, cognition, action, …. emotion. The prefrontal cortex also receives inputs from the brainstem arousal systems …. thus, there is coordination between our state of arousal and our mental state.” (wiki)
I would like to know what my 'consciousness' does which my prefrontal cortex does not.

Which circumstances show me that I have a 'consciousness' function?

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atyy
#2
Dec28-13, 08:46 AM
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You need to give an operational definition of "consciousness", or at least say what the operational consequences of having or not having "consciousness" are, if the term "consciousness" is to be meaningful.

Here is a review of prefrontal function by O'Reilly http://www.ncbi.nlm.nih.gov/pubmed/20573407 (free link at the top right of the page).

Take a look also at Miller and Cohen's https://www.earlkmiller.org/wp-conte...ohen-20011.pdf , which I think takes a slightly different point of view from the O'Reilly review.

I have just found out that Earl Miller has a blog https://www.earlkmiller.org/blog/ , which could be interesting.
Pythagorean
#3
Dec28-13, 09:10 AM
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I think what differentiates consciousness from other cognitive processes is the subjective experience (i.e. the hard problem). A well-programmed robot can do a lot of things that consciousness can do: it could even be made to "adapt" and "learn" and score high on intelligence tests. One may even call some robots autonomous.

But few would dare to conjecture that robots (or any non-living systems) are having a subjective experience. So I think that's mostly what people are asking about. While it's largely a philosophical question, there are neuroscientists pursuing a scientific result. Christoph Koch is a popular one, but I don't know that he's proposed anything.

One person that has proposed a scientific explanation is Giulio Tononi: Integrated Information Theory.


Francisco Varela talks about phase synchronization (which may be synthesized with Tononi's ideas).

http://www.nature.com/nrn/journal/v2...0401_229a.html

Friston's Free-energy principle seems to carry some of the ideas of information entropy that Tonini brings up. I don't know how relevant their treatments are to each other, but the basic point is that information entropy is often associated with consciousness:

http://www.nature.com/nrn/journal/v1...l/nrn2787.html

Some other literature that support Tonini's idea:
http://www.ncbi.nlm.nih.gov/pubmed/16195466
http://www.ncbi.nlm.nih.gov/pubmed/23946194

As far as specificity for the prefrontal cortex, the general view implied by this perspective is that consciousness is not down to any one cortex; that it's globally distributed. One never knows to what extent neural activity is "just" computation vs. computation associated with consciousness, or how inter-connected the two are.

Johninch
#4
Dec28-13, 11:22 AM
P: 96
Am I conscious of my prefrontal cortex or is my prefrontal cortex me?

Quote Quote by atyy View Post
You need to give an operational definition of "consciousness", or at least say what the operational consequences of having or not having "consciousness" are, if the term "consciousness" is to be meaningful.
Yes, that is exactly my problem. I have read that consciousness does not do anything. So I am looking for examples to show that it really does do something, as evidence that it exists and is not illusory.

Thank you for the links. The piece about volume-based neural communication was illuminating. I haven’t read all the articles thoroughly yet, but I wonder if the descriptions about fading of consciousness during sleep would tend to support my understanding that consciousness is integral to the various brain functions and not separate from them. Do you know if there are experiments to determine whether there is consciousness when the prefrontal cortex is sleeping but the other brain regions are active? Or the other way round (if this is possible).

.
Johninch
#5
Dec28-13, 11:34 AM
P: 96
Quote Quote by Pythagorean View Post
I think what differentiates consciousness from other cognitive processes is the subjective experience (i.e. the hard problem).
An example of subjective experience is the sensation of color. I look at the sky and my cones detect blue wavelengths, which are reported to the visual cortex. Instead of a “blue” sensation, I might theoretically see “450nm”, but the “color” sensation is much more informative. The visual data includes a huge variety and combination of hues and intensities. It’s really very clever. How else could I process such an amount of information received from the eyes? We don’t “see” color, we just recognize, label and pass the processed data to working memory. The form of the data in memory has to closely represent the intricacies of the visual data, otherwise, when we retrieve it, there would be matching problems. If the eye could only see one wavelength of blue, or if we only processed one wavelength, we might just as well “see” a number, it’s the same deal – the number is not the reality either. Its personal, but if we assume that most people are doing the same thing with a similar outcome, what do we mean by subjective?

I am even more puzzled by the example of the binding problem, where it’s not understood how we distinguish a blue square and a yellow circle. I can’t explain how it’s done either, which I put down to my ignorance. But considering what else the brain can do, I don’t see why this binding exercise should be so especially difficult. Is it not just a question of pathways to keep the blue and the square together as an object? Why is this especially difficult?

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Pythagorean
#6
Dec28-13, 11:57 AM
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what do we mean by subjective?
Just that a single person is experiencing it for themselves and can't share their own experience directly with others (though we have machinery to represent and transfer it: language and symbolism).

The binding problem is part of the hard problem, but the binding problem is more of a technical one, isn't? Like other aspects of cognition, we can recognize how a robot might integrate several inputs into a single output or decision, it's just a matter of "following the wires"... but adding the subjective experience in is what makes it interesting.

I think Varela's paper touches on it. At least, it fits under the auspice of:

http://en.wikipedia.org/wiki/Binding...ization_theory

But there's also circuitry (anatomical) considerations :

http://psych.colorado.edu/~oreilly/p...roreillyip.pdf
Evo
#7
Dec28-13, 12:08 PM
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Quote Quote by Johninch View Post
Yes, that is exactly my problem. I have read that consciousness does not do anything. So I am looking for examples to show that it really does do something, as evidence that it exists and is not illusory.
"Consciousness" (since we don't want to wander into philosophy) is the state of being aware, it is the result of brain activity.

We will use this definition

: the condition of being conscious : the normal state of being awake and able to understand what is happening around you
http://www.merriam-webster.com/dictionary/consciousness
atyy
#8
Dec28-13, 12:34 PM
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There is a discussion of some approaches to defining "consciousness" in this introductory article.

http://www.frontiersin.org/Human_Neu...012.00263/full
Introduction to research topic - binocular rivalry: a gateway to studying consciousness.
Maier A, Panagiotaropoulos TI, Tsuchiya N, Keliris GA.

Another article you may find interesting is (unfortunately not free)

http://www.ncbi.nlm.nih.gov/pubmed/22681695
Neuronal discharges and gamma oscillations explicitly reflect visual consciousness in the lateral prefrontal cortex.
Panagiotaropoulos TI, Deco G, Kapoor V, Logothetis NK.
Neuron. 2012 Jun 21;74(6):1139.
Neuronal discharges in the primate temporal lobe, but not in the striate and extrastriate cortex, reliably reflect stimulus awareness. However, it is not clear whether visual consciousness should be uniquely localized in the temporal association cortex. Here we used binocular flash suppression to investigate whether visual awareness is also explicitly reflected in feature-selective neural activity of the macaque lateral prefrontal cortex (LPFC), a cortical area reciprocally connected to the temporal lobe. We show that neuronal discharges in the majority of single units and recording sites in the LPFC follow the phenomenal perception of a preferred stimulus. Furthermore, visual awareness is reliably reflected in the power modulation of high-frequency (>50 Hz) local field potentials in sites where spiking activity is found to be perceptually modulated. Our results suggest that the activity of neuronal populations in at least two association cortical areas represents the content of conscious visual perception.

I believe the above are related to the approach supported by Koch that Pythagorean mentioned above.

Another approach (which I found by googling "efference copy and consciousness") is described by Haggard and Clark:
http://web.gc.cuny.edu/cogsci/privat...d-Clark-CC.pdf

Patrick Haggard's 2002 Nature Neuroscience review is available from his web site http://www.icn.ucl.ac.uk/Staff-Lists...&Title=Prof%29
Pythagorean
#9
Dec28-13, 02:44 PM
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I'll just post the abstract of the clinical paper I cited above relating to Tononi's work. It is consistent with Evo's definition. Tonini and Koch speak more in general about consciousness being empirical ("Neural Correlates of Consciousness"). But either way, the clinically significant aspect generally pertains to the wakefulness and awareness:

One challenging aspect of the clinical assessment of brain-injured, unresponsive patients is the lack of an objective measure of consciousness that is independent of the subject's ability to interact with the external environment. Theoretical considerations suggest that consciousness depends on the brain's ability to support complex activity patterns that are, at once, distributed among interacting cortical areas (integrated) and differentiated in space and time (information-rich). We introduce and test a theory-driven index of the level of consciousness called the perturbational complexity index (PCI). PCI is calculated by (i) perturbing the cortex with transcranial magnetic stimulation (TMS) to engage distributed interactions in the brain (integration) and (ii) compressing the spatiotemporal pattern of these electrocortical responses to measure their algorithmic complexity (information). We test PCI on a large data set of TMS-evoked potentials recorded in healthy subjects during wakefulness, dreaming, nonrapid eye movement sleep, and different levels of sedation induced by anesthetic agents (midazolam, xenon, and propofol), as well as in patients who had emerged from coma (vegetative state, minimally conscious state, and locked-in syndrome). PCI reliably discriminated the level of consciousness in single individuals during wakefulness, sleep, and anesthesia, as well as in patients who had emerged from coma and recovered a minimal level of consciousness. PCI can potentially be used for objective determination of the level of consciousness at the bedside
http://www.ncbi.nlm.nih.gov/pubmed/23946194

Though I don't think that clinical wakefulness is what the OP had in mind. I believe the OP is literally looking for neural correlates with respect to the PFC.
Pythagorean
#10
Dec28-13, 07:19 PM
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Also, differences in qualia can easily be explained by neuroscience too:

This was just published in Nature Neuroscience:
Does a unique olfactory genome imply a unique olfactory world?
http://www.nature.com/neuro/journal/...l/nn.3608.html
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atyy
#11
Dec29-13, 12:01 AM
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Johninch, are you trying to ask what it would take for neurobiology to answer a question such as "Does a cockroach feel pain?"?
Johninch
#12
Dec29-13, 04:42 AM
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Quote Quote by atyy View Post
Johninch, are you trying to ask what it would take for neurobiology to answer a question such as "Does a cockroach feel pain?"?
No, I am only trying to see the connection between the function of the PFC and internal awareness or “consciousness”.

Let me put the question another way:
External awareness means that the brain uses the senses of the body to get information about the outside world, which is delivered in some form to the PFC.
How does neurobiology see internal awareness working? I gather that this area is the subject of continuing research, but is there a temporary hypothesis?

Let me sharpen the question with an example:
I sit pondering over the pros and cons of a decision. The only thing happening is neural activity in my PFC. Is that what we mean by consciousness? – neural activity in the PFC? I am struggling to understand what awareness does.

I have a suggestion, but I am not trying to push any homemade theories, I am only trying to help in getting answers which I can understand. Could it be like this:

When time is short, the PFC works autonomously and takes decisions before awareness has had time to form. I see this when I am playing doubles in tennis. I am at the net and a ball comes at me like a bullet. I return it for a winner, but I am only aware of this when the ball is sailing out of the court. I don’t know how I did it, neither at the time nor afterwards. But when the ball comes at me slower, I am aware of all my actions in returning it. This example tells me that consciousness is the sensation of PFC activity, when physically possible. When events proceed too fast, conscious awareness is not possible.

What do you think?

.
atyy
#13
Dec29-13, 09:56 AM
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Quote Quote by Johninch View Post
No, I am only trying to see the connection between the function of the PFC and internal awareness or “consciousness”.

Let me put the question another way:
External awareness means that the brain uses the senses of the body to get information about the outside world, which is delivered in some form to the PFC.
How does neurobiology see internal awareness working? I gather that this area is the subject of continuing research, but is there a temporary hypothesis?

Let me sharpen the question with an example:
I sit pondering over the pros and cons of a decision. The only thing happening is neural activity in my PFC. Is that what we mean by consciousness? – neural activity in the PFC? I am struggling to understand what awareness does.

I have a suggestion, but I am not trying to push any homemade theories, I am only trying to help in getting answers which I can understand. Could it be like this:

When time is short, the PFC works autonomously and takes decisions before awareness has had time to form. I see this when I am playing doubles in tennis. I am at the net and a ball comes at me like a bullet. I return it for a winner, but I am only aware of this when the ball is sailing out of the court. I don’t know how I did it, neither at the time nor afterwards. But when the ball comes at me slower, I am aware of all my actions in returning it. This example tells me that consciousness is the sensation of PFC activity, when physically possible. When events proceed too fast, conscious awareness is not possible.

What do you think?

.
I'm not sure I understand you. Can you read this abstract and tell me if this is what you are talking about? Let me know if you don't understand the terms, and I can try to explain, but I need to understand what your question is. Bolding and colours below are mine.

http://www.pnas.org/content/103/49/18763.full
Relative blindsight in normal observers and the neural correlate of visual consciousness
Hakwan C. Lau and Richard E. Passingham

"By using a paradigm based on metacontrast masking, we created experimental conditions in which the subjective report of consciousness differs but the objectively measured ability to discriminate visual targets does not. This approach allowed us to study the neural correlate of consciousness while having performance levels carefully matched in healthy human subjects. A comparison of the neural activity associated with these conditions as measured by functional MRI showed that conscious perception is associated with spatially specific activity in the mid-dorsolateral prefrontal cortex (area 46). Further analysis confirms that this activation is not only free from any performance confound, but is also not driven by differences in the timing of the physical stimuli. Our results suggest that the prefrontal cortex is important for the essentially subjective aspects of conscious perception."
Johninch
#14
Dec29-13, 11:38 AM
P: 96
Quote Quote by atyy View Post
"By using a paradigm based on metacontrast masking, we created experimental conditions in which the subjective report of consciousness differs but the objectively measured ability to discriminate visual targets does not. This approach allowed us to study the neural correlate of consciousness while having performance levels carefully matched in healthy human subjects. A comparison of the neural activity associated with these conditions as measured by functional MRI showed that conscious perception is associated with spatially specific activity in the mid-dorsolateral prefrontal cortex (area 46). Further analysis confirms that this activation is not only free from any performance confound, but is also not driven by differences in the timing of the physical stimuli. Our results suggest that the prefrontal cortex is important for the essentially subjective aspects of conscious perception."
Most of the material in the paper is too much for my level, but the above extract is understandable. Yes, it is an example of what I am asking about.

Therefore I would go on to ask whether I can reasonably extrapolate the results to non-visual brain activities. If yes, then I would think that the study provides a strong indication that conscious perception takes place in the PFC - that possibly the DLPFC is where ‘consciousness happens’.

Could that be correct?

I have read that the DLPFC is also a major site of working memory, which is involved in waking thought and selective attention. This would seem to be consistent with the generation of ‘consciousness’.

I found the following paper on Working Memory very interesting, although disappointingly it doesn’t make any reference to consciousness.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784289/

.
Pythagorean
#15
Dec29-13, 12:53 PM
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Crick and Koch posited the frontal lobe as the seat of visual consciousness:
http://www.ncbi.nlm.nih.gov/pubmed/9542889

But recent evidence, citing Koch has challenged the view of a "seat of consciousness" in favor of a distributed view:

However, the fact that neural activity in two cortical areas (LPFC and temporal cortex) reflects phenomenal perception in an all-or-none manner supports the view that consciousness is not localized in a unique cortical area but, rather, is an emergent property of global networks of neuronal populations
http://www.cell.com/neuron/abstract/...273(12)00380-7

They cite:
http://www.ncbi.nlm.nih.gov/pubmed/11823801

A more recent publication:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3664777/

The global/distributed view correlates also with Tononi's research, given the correlations between cortical connectivity and degree of consciousness.
Johninch
#16
Dec31-13, 07:03 AM
P: 96
Quote Quote by Pythagorean View Post
Crick and Koch posited the frontal lobe as the seat of visual consciousness:
http://www.ncbi.nlm.nih.gov/pubmed/9542889
Thanks. I found your first link (above) the most interesting as it was not too technical.

.
bohm2
#17
Jan3-14, 03:36 PM
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Quote Quote by Johninch View Post
I would like to know what my 'consciousness' does which my prefrontal cortex does not.
I don't think anybody has been able to answer your question. Areas of the brain appear to provide the mechanisms of consciousness/thought but that doesn't answer your question, I think. To answer your question we would have to understand how the brain (unlike other organs) is able to spit out mental stuff like consciousness. But we cannot understand the mind's causal basis. Neither direct examination of consciousness nor of the brain can identify the properties that cause or provide the mechanism for consciousness, or as McGinn points out, how "technicolour phenomenology [can] arise from soggy grey matter." That question appears (to me) to be unanswerable from a neuroscience perspective as presently understood. Too bad, because I think it's one of the most (if not the most) interesting question. But studying the neural correlates of consciousness is the only option we are left with.
.Scott
#18
Feb11-14, 08:39 PM
P: 540
Quote Quote by Johninch View Post
Yes, that is exactly my problem. I have read that consciousness does not do anything. So I am looking for examples to show that it really does do something, as evidence that it exists and is not illusory.
Before I attempt to address this question, let me give you my background. I am and have been a professional software engineer since before the term was created - since June 1971 to be exact. I may be the most experienced active programmer on the planet and I am exceptionally good at debugging other peoples systems.

As was mentioned before in this thread, any robot that anyone has ever built or has ever designed to be built has no consciousness. There is a common layman notion that all you need to do to make a computer conscious is to make it sufficiently complex. But you would find it exceptionally hard to find any accomplished computer programmer that will subscribe to that theory. Computer systems have been getting more and more complex and the people who develop them fully realize that there is nothing conscious in them nor anything that would eventually lead to consciousness.

There are some very technical and relevant things that can be said about this consciousness. The hard problem is not that hard - or at least not that immovable. But, unfortunately, the prevailing view in these forums is that anything further is speculation or not credibly published or whatever.

So this is where it gets to be very difficult to continue. But I can ask you questions:

Given that the mechanism at the foundation of human consciousness is apparently so sophisticated that we have yet to incorporate it in a computer, what would it take, based on Darwinian economics, for such a mechanism to persist in any species?

You also asked whether the consciousness was specifically located in the prefrontal cortex. If you look at brain injury results you might get some sense that it is not - but my real answer is more involved and relies on some very expert (but forbidden) speculation.

Doing my very best not to cross any lines.
Yours truly,
Scott Bowden


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