Science topic

Neural Correlates of Consciousness - Science topic

Explore the latest questions and answers in Neural Correlates of Consciousness, and find Neural Correlates of Consciousness experts.
Questions related to Neural Correlates of Consciousness
  • asked a question related to Neural Correlates of Consciousness
Question
6 answers
I do recognise that there’s a well-known problem (hard though it is) of establishing how consciousness emerges or can be accounted for in physical processes. But I can’t at all agree that there’s a naturalistic, absolute hard problem of consciousness, because it’s an incoherent concept.
Nobody (at least nobody with a clue) supposes that neurophysiology can explain a qualitative difference in the way you and I experience the content of my music mix playing quietly in the background, or see the light reflect off a rainbow, or any of the other ways in which our qualitative experience discriminates from that of other live organisms. To suppose that just because you don’t know the mechanisms of the experience in your own head you will deny them the existence of them in somebody else’s is bizarre and reductionist.
Construct an imaginary metaphor of a magical, wizardry, thing-maker consciousness and you haven’t explained the qualitative data there either. It’s still the question of how consciousness comes into the work whether any magical things happen or whether there’s anybody there at all. To suppose a separate, inexplicable, mysterious, magic ingredient does neither any explanatory good, solve the hard problem, nor explain the evidence. All such arguments for a separate consciousness occurrent substance do, again, be it a magic nonsense or magic substance involved, reduce the hard problem of explaining thisness-of-consciousness (to pick a crazy approach) to the very same hard problem of explaining how consciousness arises in the first place.
If you identify the hard problem entirely with the mechanism through which the feeling-of-redness arises, or "the feeling of the future in an invariant past", or anything else you allude to, then you plainly have just traded in one way of asking a very simple question of the wrong approach. The question is, how do the millions of biological chunks and sub-systems interact with one another and integrate information over time and space? The sense of sight, sound, touch and soil all raise a “hard problem” of projection-understanding and categories-beyond-the-reliable-input-enumeration because by a vast over-engineering of the metaphor arms race (as even you must agree) the response-device signals of a single kind of appropriate examination will allow all in-the-know people to interpret an external reality quite differently. But the “hard problem” isn’t WHY is it that we can punch those signals at all, or make sense of the signals that come out the other end. That’s just the default condition of our very real neurological symposium. Whereas the “humanness” of that experience is also an entirely benignly apparent phenomenon, just as water’s polar nature is an entirely benignly apparentity.
For me the cardinal point is to reckon with how we perceive our own subjective value via multi-sensory data input both direct and indirect in both our two and three dimensional waking experience. And because at the very least you have to be wrong or qualified immensely if you think it’s not merely the interaction between general anatomy, organisation, information processing and output of your brain and all subjective processes such that personal conclusions then magically appear as relevant claims about reality.
P.S. I don't think evolution throws up any magical consciousness, either on its petri-dish experiments, or those novelty subjectiveness media that it comes up with sometimes. So I'd like to challenge that viewpoint, particularly in terms of our understanding of the nuances.
Relevant answer
Answer
Navjot Singh I define consciousness as the subjective experience that we each have arising from the operation of the brain.
In the paper titled the conscious brain, I have identified the importance of understanding how we control our focus of attention.
The brain is a particular combination of biology chemistry and physics and it is a lack of understanding of fundamental physics that has held us back.
Neuroscience has revealed the brain activity in the form of the network of neurons but we have to understand the effect of the electromagnetic wave activity generated by the brain on the operation of the brain as a whole.
Richard
  • asked a question related to Neural Correlates of Consciousness
Question
180 answers
Will it be possible to build an artificial consciousness similar to human consciousness in digitized structures of artificial intelligence if in specific structures of artificial intelligence will digitally reproduce the artificial structures of neurons and the entire central nervous system of humans?
If artificial intelligence that mapped human neurons was built, then it would be a very advanced artificial intelligence. If artificial intelligence was built in such a way that all human neurons would be reconstructed in digital technology, it would mean the possibility of building cybernetic structures capable of collecting and processing data in a much larger database capacity than at present. However, if it would only be the reproduction of simple neural structures and their reproduction to the number of neurons contained in the human organism, then only or mainly quantitative and not necessarily qualitative factors that characterize the collection and processing of data in the human brain would be achieved. Without achieving all of the qualitative variables typical of the human nervous system in a cybernetic counterpart, it might be doubtful to create in this cybernetic structure an artificial nervous system of cybernetic consciousness which is the equivalent of human consciousness.
Do you agree with me on the above matter?
In the context of the above issues, I am asking you the following question:
Will it be possible to build an artificial consciousness similar to human consciousness in digitized structures of artificial intelligence if in specific structures of artificial intelligence will digitally reproduce the artificial structures of neurons and the entire central nervous system of humans?
Please reply
I invite you to the discussion
Thank you very much
Best wishes
Relevant answer
Answer
Dear Gerard van Reekum,
Yes of course. As of today, it is not possible to be sure of the implementation of a specific scenario of future developments, including the development of artificial intelligence technologies. However, in our discussion, we try to consider the most likely scenarios for future developments.
Thank you, Regards,
Dariusz Prokopowicz
  • asked a question related to Neural Correlates of Consciousness
Question
57 answers
The knowledge claim about the possibility of Artificial Super-Intelligence in the future raised several questions for us. is it a metaphysical possibility or a philosophical jargon? Can artificial intelligence surpass human intelligence- can A.I machines (which are functionally and behaviourally identical to human agent ) builds independently without the intervention of human intelligence (the A.I machines not only can work but also think like human beings)? Can there be a singularity in the field of artificial intelligence in the future? The fastest development in the field of A.I. within two decades makes us think about future prospects of A.I and the possible threats to humanity in the future. There are several ethical issues are concerned which has to be addressed. If rationality is the criterion for the autonomy of the agency of an organism, as stated by Immanuel Kant, then can Artificial Intelligent machines qualify the criteria of rationality for the status of Autonomy which is applied to the human organism.
Relevant answer
Answer
Interesting thought, and still with an unexpected result.
Super-intellect is created by man through mathematical algorithms. Naturally, when the database becomes more than our consciousness, it looks amazing. Even at times it is pretty trusting that the yak is frightening at times. But that is not how it all depends on us creators, how much we trust the presented results of artificial intelligence. Of course, not all tasks can be solved with artificial intelligence because people are different from each other and it can always be that a solution cannot be solved.
Only if a new algorithm is created without human intervention, and then a super intellect can then be surprised.
  • asked a question related to Neural Correlates of Consciousness
Question
11 answers
-Neural correlate of consciousness (abbreviated: ncc) is a system of neurons in the brain by which consciousness would be possible (i.e. according to neuroscientists and researchers of consciousness studies).
-However, near death studies and psi-researchers (for the last decade up to now) have arrived to a rather correct conclusion that consciousness is able to exsist without any ncc.
-The scientific conclusion of the near death studies and the psi-research is then: ncc is not the necessary condition for the exsistence of consciousness.
-There are then two contradictory research findings.
-What is your scientific research finding(s)? Thanks a lot! Marc.
Relevant answer
Answer
Neural networks are the structural basis for a variety of brain activities. The destruction of neural networks is accompanied by a violation of brain activity, one of which is the cognition of oneself, the world around them, and the Creator. For the natural activity of neural networks, many conditions are necessary both within the brain and throughout the body. The brain consists not only of neurons, but also of the intercellular matrix, glial cells, blood vessels, cerebrospinal fluid. Consequently, the activity of the brain will be determined by the coordinated functioning of all these components. Violation of the activity of any of these components is accompanied by the development of a pathological process that leads to disruption of the activity of neural networks and consciousness. Pathological events outside the brain, for example, at the heart level, are accompanied by a violation of the blood supply to the brain (hypoxia, ischemia, stroke) and disruption of the activity of neural networks. One consequence of these processes is loss of consciousness. Please study carefully the two manuscript in Attachment.
  • asked a question related to Neural Correlates of Consciousness
Question
20 answers
I need a feedback on review o myu paper on EMF effects in nonthermal doses on living creatures which is based on storage capacity of DNA. Can reincarnation be explained by physical mechanisms and can DNa MEMORIZE THE KNOWLEDGE OF OUR ANCESTORS ?
Relevant answer
Answer
No.  There's no evidence for what you're discussing.  More than 350,000 people are born every day, and if such things as you're discussing existed, there'd surely be evidence that some of those newborn infants had some kind of conscious knowledge without needing to learn it -- e.g., a child born in China who could speak Japanese, without being exposed to it.  You seem to be positing a kind of Lamarckian inheritance of acquired characteristics, or in this case, acquired knowledge.  Do you really think that the more you study physics, the better your children and grandchildren will be at physics, simply because they inherit your DNA?  There's no evidence for that.  Certainly, we inherit a range of reflexes, instinct, capacities, and even emotions.  This can be explained based on natural selection, and to some extent, accounted for by molecular genetics.  We humans inherit the ability to learn language -- however we don't inherit conscious knowledge of any particular existing (or ancient) languages.  In a way, certain kinds of knowledge may be passed down from previous generations -- for example, fear of heights or reactions to certain kinds of predators -- this can be explained through natural selection.  But there's no evidence of inheritance of the kinds of things you're talking about (e.g., knowledge of science).  To say that "the total number of souls is constant," and try to justify that statement with reference to conservation laws in physics, makes no sense.  Those laws say that (for example) energy is conserved BUT can be transformed.  So whatever energy may be associated with conscious activity could be transformed (for example) into thermal energy.  You seem to be starting with a conclusion that you want to justify (reincarnation) and then to be searching around for anything that might support such a conclusion.  That's not how science is supposed to work.  If anything, you should be looking to see if there is any evidence to falsify your conclusion, and the theories associated with your conclusion.  You are free to have whatever faith you want about life after death.  But pretending that science supports that faith is a completely different matter, and really not acceptable.  
  • asked a question related to Neural Correlates of Consciousness
Question
4 answers
are there three-qubit quantum circuits with uncertainty?
Relevant answer
Answer
I think yes. You may be interested in (1) Metcalf, Benjamin J., et al. "Quantum teleportation on a photonic chip." Nature Photonics 8.10 (2014): 770-774. (2) arxiv.org/pdf/1410.3941.
  • asked a question related to Neural Correlates of Consciousness
Question
19 answers
For all the formidable progress made in numerous fields by cognitive neurosciences, we are still in the dark about very many aspects of attention. One thing that is now beyond doubt is the multiplicity of processes that underlie it, for attention is involved in numerous other fundamental cognitive processes — perception, motor action, memory — and any attempt to isolate it in order to study its constant features is bound to prove sterile. For over a century and a half attention was a crucial topic in neurophysiology and psychology. In the early days of scientific psychology it was viewed as an autonomous function that could be isolated from the rest of psychic activity. However, this idea soon came to be seen as inadequate. At the beginning of the 20th century researchers became convinced that attention underpinned a general energetic condition involving the whole of the personality. Within a few years the emergence of the Gestalt and Behaviourism paradigms caused these studies to be overshadowed, and it was not until the second half of last century that they regained their importance.
For a long time the debate was influenced by the hypothesis that attention constitutes a level of consciousness varying widely in extension and clarity and only functioning in relation to its variations: from sleep to wakefulness, from somnolent to crepuscular, from confusion to hyper-lucidity, from oneiric to oneiroid states, and so on. Subsequently other approaches of considerable theoretical importance linked attention to emotion, affectivity and psychic energy or social determinants. Yet what do we really know about attention, the sphere of our life which orients mental activity towards objects, actions and objectives, maintaining itself at a certain level of tension for variable periods of time? How and to what extent is attention related to consciousness? Why does only a minimal part of the information from the external world reach the brain even though the physical inputs strike our senses with the same intensity? And why is it that, although they enter our field of consciousness, most of these inputs do not surface in our awareness? It is well known that in the selection of stimuli, attention is strongly influenced by individual expectations. They ‘decide’ which objects and events appear in our awareness, and which are destined never to appear. The law of interest regulates a large part of the selection of the objects and topics on which our attention is focused. 
Relevant answer
Answer
all human activities need attention. If the attention system has little energy they are structured pathological reactions. for example, the depressive disorder has, in many cases, a deficiency of attentional processes such as: sustained attention, attentional flexibility, etc.
  • asked a question related to Neural Correlates of Consciousness
Question
4 answers
Relevant answer
Answer
 Can you give me the English translation of it?
  • asked a question related to Neural Correlates of Consciousness
Question
245 answers
For over a century, the sciences of mind have tried to throw light on the most obscure secrets of the brain. But the more maps are drawn, the more mechanisms that are discovered, the harder it becomes to arrive at an understanding. It becomes increasingly clearer that cerebral organization is much more complex and dynamic than was suspected until a few decades ago. Many researchers believe that what will help our understanding of social life will be the powerful development of technology or, more precisely, the face-off between man and computer (of incredible power) which will generate organisms capable of going beyond the simulation of cerebral functions; they will learn from their own inner states, interpret the data of reality, set their own objectives, and converse with humans; above all, they will make decisions on the basis of their own ‘value systems’. In a not-too-distant future, it is thought, these organisms will be able to acquire greater and greater autonomy, self-conservation, their own creativity, value hierarchies and, perhaps, even have an ethic based on ‘freedom’.
If we are to go far beyond the confines of what today is defined human, to the point of including entities which are the product of hybridization of biological organisms and articifical ones (humanoids, cyborgs and so on), we believe we should consider how we might get there. This is an extremely relevant question which relates to the set of those functions which make man the highest expression of evolution: above all, it concerns consciousness, that huge and complex variety of neurobiological, phenomenological and psychological events that, ever since the first stages of development, have prepared the ground for the emergence of the Self, which enables us to become aware, to lay down values and hierarchies of values, rules and decisions about everything ranging from freedom to necessity.
Relevant answer
Answer
I believe that the question of time, mentioned in our discussion, is absolutely important. I would try to discuss it with you. In the course of evolution, biological life on our planet has activated two strategies for adapting to the passage of time. First of all it inscribed elements in the genetic code which could facilitate an adequate flexibility in the face of environmental changes (light, temperature, precipitations); in the second place it endowed the animal nervous system with structures which can guarantee the sensorial and motor activities triggered over time. Compared to the higher order of animals, consciousness has also enabled humans to develop the capacity for an inner representation of time which has had great benefits in terms of adaptation and reproduction. In fact, the consciousness of time took longer to form than the consciousness of space. Now, if it is true that the experience of time is different from the experience of space, it is nonetheless of the same essence. The sense of time and, more in general, temporal experience is a quality of consciousness and should be investigated as such. There is general consensus among neuroscientists today that our perception of time originates in the different pace at which we perceive changes over a specific interval, relying on minimum correlation thresholds between neural processes and cognitive events supported by wide-ranging integration with diffused synchrony. More accurate knowledge of these correlations could clarify both the nature of the local events and the process of global synchrony which lies at the heart of an experience.
There is still no agreement about the nature of the processes underlying the phenomena of succession and duration. For over 150 years it was believed that the extent of the interval between certain events was the real key to the cognition of time, and enquirers failed to grasp the difference between the succession of neuronal events and the order of this succession. The succession of acts of consciousness is not the consciousness of their succession. We need other models to explain why our states of consciousness are accompanied by the consciousness of their succession. 
  • asked a question related to Neural Correlates of Consciousness
Question
4 answers
Orch-OR theory for consciousness asserts that the microtubules are the neural structures that support the quantum effects. Let's assume that it is true. Therefore, if they have to play a role in the brain, they need to effect the signal transmission in the brain. Is there any indication for such an effect?
Relevant answer
Answer
Dear Abolfazi,
Indeed microtubules are important in function of ion channels and neurotransmission. I think most importantly the microtubules are involved in transport of proteins (including ion channels), neurotransmitters/modulators, organelles (including mitochondria) from soma to the periphery. This microtubular role is very critical for axonal transport of neurotransmitters to the pre-synaptic terminal, without it the terminal will not have enough neurotransmitter and energy required for synaptic transmission. Anything that disturbs or reduces microtubular function results in significant neuronal dysfunction.
best wishes,
Refik
  • asked a question related to Neural Correlates of Consciousness
Question
103 answers
Instead of gradually replacing biological neurons with silicon neurons as in Chalmers' Fading Qualia, I attempt to gradually replace dividable functions of biological neurons with silicon emulation.
The question is, at which manipulation stage does our brain lose consciousness (qualia)?
1)   Replacement of axonal spike propagation with an external artificial mechanism that uses radio transmission (e.g. WiFi): Causality between presynaptic neuronal firings and postsynaptic PSPs is preserved, but now neurons are physically isolated.
2)   Further replacement of postsynaptic PSP integration with an external artificial mechanism: Causality between presynaptic neuronal firings and postsynaptic somatic membrane potential is preserved, but now without sophisticated dendritic-somatic computation.
3)   Further replacement of transformation from postsynaptic somatic membrane potential to postsynaptic firing (Hodgkin-Huxley Eq. mechanisms) with an external artificial mechanism that integrates presynaptic firings and activates postsynaptic neurons by current injection accordingly: Causality between presynaptic neuronal firings and postsynaptic neuronal firings is preserved, but now without an intact internal variable, the membrane potential.
4)   Mere replay of spatio-temporal neuronal firing patterns by external current injection: Zero causal interactions among neurons.
Relevant answer
Answer
Dear Nordin,
In a sense all your experiments have been done. The neurons whose firing correlates most closely with 'basic qualia' are those in primary sense receptors. If you poison these with simple things like a very bright light (to bleach retinal receptors temporarily) or chilli pepper (to block taste buds) or background noise (to block high frequency hair cell responses in the cochlea) you lose the qualia. You can replace the qualia with bionic implants at least for cochlea and now a bit for retina. Things are a bit more complex because colours do depend on integration in visual cortex, but we have a pretty good idea which neurons correlate best to which qualia.
But that has got us nowhere. Because it seems very clear that you do not actually experience anything if only these cells fire and not some cells further forward in the cortex. You get 'cortical blindness' and such things. Yet you need the early cortical cells even for imagining the qualia. The problem is that in a functioning brain the firing of specific neurons is irrevocably correlated with certain pathways of message sending and it seems likely that qualia arise once those messages have been sent and arrived somewhere where they can be experienced. Where are the 'qualia' in an expresso coffee machine? For sure they are in the sachet you put in the top - either dark arabica or columbia mild aromatic. But you get no taste until you put a cup under the bottom and wait for the machine to work. 
Qualia are not where a certain cell is firing. That I think we can be sure of, because the firing of a cell soma means nothing to anything until some neurotransmitter has arrived further along. Only God could know the cells are firing otherwise and it is 'me' seeing the red, not God. The tricky part is knowing what 'me' is. What is 'me' in your model?
  • asked a question related to Neural Correlates of Consciousness
Question
186 answers
What are the existing tests for machine consciousness that directly tests qualia generated in a device? I find many proposals, but they only seem to test functional aspects of consciousness related neural processing (e.g. binding, attentional mechanisms, broadcasting of information), but not consciousness itself.
I have a proposal of my own and would like to know how it compares with other existing ideas.
The basic idea is to connect the device to our brain and test if qualia is generated in our "device visual field". The actual key to my proposal is how we connect the device and how we set the criteria for passing the test, since modern neurosynthesis (e.g. artificial retina)  readily leads to sensory experience.
My short answer is to connect the device to one of our cortical hemispheres by mimicking inter-hemispheric connectivity and let the device take over the whole visual hemifield. We may test various theories of consciousness by implementing candidate neural mechanisms onto it and test whether subjective experience is evoked in the device's visual hemifield.
If we experience qualia in the "device visual hemifield" with the full artificial hemisphere, but not when the device is replaced with a look-up table that preserves all brain-device interaction, we have to say that something special, say consciousness, has emerged in the full device. We may conclude that the experienced qualia is due to some visual processing that was omitted in the look-up table. This is because, in regard to the biological hemisphere, the neural states would remain identical between the two experimental conditions.
The above argument stems from my view that, in case of biological to biological interhemispheric interaction, two potentially independent streams of consciousness seated in the two cortical hemispheres are "interlinked" via "thin inter-hemispheric connectivity", without necessarily exchanging all  Shannon information sufficient to construct our bilateral visual percept.
Interhemispheric connectivity is "thin" in the sense that low-mid level visual areas are only connected at the vertical meridian. We need to go up to TE, TEO to have full hemifield connectivity. Then again, at TE, TEO, the visual representation is abstract, and most probably not rich enough to support our conscious vision as in Jackendoff's "Intermediate Level Theory of Consciousness".
The first realistic step would be to test the idea with two biological hemispheres, where we may assume that both are "conscious". As in the last part of the linked video above, we may rewire inter-hemispheric connectivity on split brain animals to totally monitor and manipulate inter-hemispheric neural interaction. Investigating conditions which regains bilateral percept (e.g. capability of conducting bilateral matching tasks) would let us test existing ideas on conscious neural mechanisms.
Relevant answer
Answer
Masataka,
''Machine consciousness can exist without emotion. What do you think?''
I do not think so. Emotions are about being concerned and not indifferent of what we do or about what is happening.  This is related to the basic motivationa and desires of action. No emotion, no action, no desire to live basically.  Desire to survive, or not being hurt are totally necessary.  Most of consciousness is about these emotions . It is why marketing is targetting emotions and not reason to steer the will of peoples. 
An agent is conscious while doing somthing if and only if there is a WHAT IS LIKE TO DO THIS THING for the agent.  So only the agent itself can experience it.  No automated non conscious test can provide an objective diagnostic if an agent is experiencing a what is like to do the action.  Externally, the only thing that can be tested by a non-conscious agent is what is being done;  Any qualia associated with what is being done can be externally observed.  We humans have a theory of mind, i.e. a built-in capacity to attribute a What is like to do something to an other human.  Not only do we observe the external facial expression of another human but attribute and experience what the other person feel.  We simply put ourself in the shoe of the other person doing this expression and knows what that person feel because we assume that the other person is more or less like ourself and attribute to the person our own emotions when we do such experession.  An automata or a test cannot have a theory of mind because it has no possibility of attributing emotions.  BUt the human theory of mind is far from being 100% correct.  As a child I remember crying when watching Bambi.  Bambi is simply a sequence of drawins and all the feelings that I attributed to bambi where only in me and not in Bambi. 
  • asked a question related to Neural Correlates of Consciousness
Question
7 answers
(And how difficult would it have been for the researchers to resist the urge to zap their poor subject in and out of consciousness at will?)
Relevant answer
Answer
Re: Gregg. If you are referring specifically to the topic of this thread then see the link in my first comment. You may also want to look at a commentary on said article linked below. 
If you are referring more to consciousness in general then that is a bit more challenging as far as what literature to recommend. I attached the Crick & Koch paper below if that is helpful.
  • asked a question related to Neural Correlates of Consciousness
Question
9 answers
I am looking for studies that investigate the neural mechanisms of inner speech. PubMed searches only seem to produce studies on hallucinations in schizophrenia. I wonder if there are studies on everyday inner speech, i.e. thought. 
  • asked a question related to Neural Correlates of Consciousness
Question
354 answers
I have a thought experiment (video link: "Paradox of Subjective Bilateral Vision"16:00-28:00) that results in very strange situations if "high-level visual areas themselves are not sufficient for conscious vision, (or low/mid-level visual areas are necessary)", namely, that the neural mechanism of conscious vision, its verbal report and solving of perceptual visual tasks (e.g. bilateral symmetry detection) violates physics that we know of today. I would like to know if there is any experimental/theoretical evidence on this issue. Thanks in advance!
Thanks to the two contributors, the above question has developed into a discussion on how subjective vision gain simultaneous holistic access to spatially distributed neural codes. There have been claims that 'holistic access' should be considered as a serious constraint on the neural mechanism of subjective experience. In case of vision, the seamless and the unified nature of our bilateral percept can be thought as an indicator of our consciousness mechanism having holistic access to wide-spread neural representation.
Unlike many popular theories of consciousness, some scientists believe that holistic access should be solved by actual physical processes in the realm of established science. In other words, there should be some single 'entity' that has causal physical access with consequences, to all subjectively experienced information. Although, there are surprising small number of models on consciousness that actually implement such a mechanism.
I explain my "Chaotic Spatiotemporal Fluctuation" hypothesis in the linked video (40:00 - 50:00), where holistic access is implemented by deterministic chaos components in neural fluctuation. Here, I define holistic access as 'every local change in the distributed neural code evoking global system-level changes in neural fluctuation', which relies on the so-called 'butterfly effect' of deterministic chaos. For the sake of clarification, the link between 'holistic access' and 'subjective experience' goes beyond physics that we know of today.
I would very much appreciate comments on the first question too.    
Relevant answer
Answer
Arnold,
'For example, in retinoid space, the color of a red car would properly overlap the shape of the car at one location, while the color of a house nearby would properly over lap its shape at a different location. This is commonly referred to as perceptual/phenomenal binding.'
So does this happen also cross-modally?
In other words, would an example super-linear cross modal retinoid neuron would be something like the below?
super-linear: A (brass,x1,y1,z1) + A(trumpet tone,x1,y1,z1) < A( brass,x1,y1,z1) AND trumpet tone,x1,y1,z1))
  • asked a question related to Neural Correlates of Consciousness
Question
40 answers
The visual system is perhaps the best understood visual system of mammalian brain. However, one question has always bothered me...
How can our perception of the visual world (e.g. flowers in a pot, a deck railing that is horizontal, trees in the distance) all appear to be solid and stationary while our gaze (and presumably our entire representation of the visual world in area 17 of visual cortex) is fluctuating wildly in response to eye and head movements? Wouldn't this require re-mapping of the visual world on the neocortex with every saccade and head movement?
Furthermore, how can we clearly discern movement of single objects within our visual environment (a flying bird in our peripheral vision) when the whole visual world is gyrating with every saccade and rotation of our head? Is this a simple problem that I somehow just didn't hear the answer to?
Relevant answer
Answer
Response to the original question:
When you decide to move your eyes, the same signal which activates your eye muscles is also sent ( by recurrent collaterals) to the brain to prepare it (by the same amount and direction of the movement) to anticipate the displaced image.
If instead of consciously moving your eyes , you instead move the eye by gently tapping the side with a finger, the brain cannot anticipate or correct for this displacement . The world will appear to jerk.
Conversely, if you send a signal to your brain that your eye is going to move, but the muscle is, in reality, paralyzed so that your eye remains in the same place, an experience of movement will also occur, since the image did not appear in the updated location as expected.
Objects which move on their own, tend to appear in different places with respect to a stable background - like a person walking in front of the building- . the background doesn't move, but the person keeps appearing in different places with respect to the building , so we infer that the person moved but that the building is stable. .
Actual movement is not necessary to experience the sensation of movement. Check stroboscopic effect (motion in film), phi phenomenon (apparent motion when light jumps from one light bulb to another or the autokinetic effect (when the precise position of an airplane against the sky appears closer or further- because it cannot be evaluated against a background. )
  • asked a question related to Neural Correlates of Consciousness
Question
4 answers
For some time now there has been controversy between the people who think that the cerebral cortex is important to consciousness and those that think it is sited in the brain stem. In this question I note that the arrangement of connection between the precuneus and the PAG would offer a compromise allowing PAG based influence to directly affect cortex influence. In which case both schools of thought are vindicated.
Relevant answer
Answer
Consciousness must be based in cognition. The site http://www.cognitivestyles.com has a review of relevant direct quotes from about 300 recent papers (‘1a Lateral Frontopolar’ to ‘1f. Aspects of Depression’ on the drop-down list) which together suggest that cognition is based solely in the lateral frontopolar, medial frontopolar, anterior cingulate extending into dorsolateral prefrontal working memory, superior parietal and inferior frontal gyrus. Nothing more. You can look through the quotes and see what you think.
There is also an extended pictorial model of consciousness extracted from psychology and philosophy (eg Heidegger’s ‘Being and Time’ with both its spatiality and temporality in diagrams). Evidence from history identifies the nodes in the model with the cognitive modules in the cortex.
The model predicts that consciousness (in contrast to cognition which can be unihemispheric) always involves communication across the hemispheres, between the nodes. This communication is probably occurring somewhere down lower. This must extend far beyond something merely between the precuneus and the PAG - I too would like to know where this location is.
Both schools thus appear to be correct.
  • asked a question related to Neural Correlates of Consciousness
Question
8 answers
When ones is handling a sequence of equations, what about his semantic perpective? How he is really "aware" about those symbols (and so on)?
Relevant answer
Answer
In my opinion, the boundary between "mere symbol shuffling" and "actually understanding" is not as crisp as some people (e.g. Searle) seem to think. It is a matter of degree, it is a spectrum. Like when a computer program is proving a theorem: I would argue that the program as a whole does to some extent "understand" what it is doing; it is doing reasoning at a semantic level (to some extent). But of course this program is executed on hardware that is only capable of mere symbol shuffling. The same is in my opinion probably true for humans (e.g. human mathematicians): a human brain is probably at the lowest level only doing something like "mere symbol shuffling" (the atoms and molecules in your brain do nothing more than obey the laws of physics), but still, as a whole, actual intelligence and understanding is emerging from these low-level processes.
  • asked a question related to Neural Correlates of Consciousness
Question
4 answers
The Angular Gyrus Model of Consciousness places the experiential image in the Angular Gyrus, but perhaps this is premature. It is possible that the Angular Gyrus is too early in the integration process, and the point of intersection between the integration process, and the experiential image is later in the integration process, and therefore deeper into the temporal lobe. What is your opinion on this?
Relevant answer
Answer
Too much damage to be a useful model for my research then. Although the differences between him and H.M. are instructive.
  • asked a question related to Neural Correlates of Consciousness
Question
3 answers
Negativity of ERP has been often related to up-state and (the concomitant) awareness (He & Raichle; Bachmann, 1994 book; VAN in Revonsuo et al., Uttal & Cook on sleep vs awake ERPs to auditory signals, etc). At the same time, from my years of long experience in the perception and NCC lab, I can tell that introspecting on what goes on after stimulus presentation and up to the report (this interval lasting from about 1 to about several seconds) does not cause the awareness of the stimulus to disappear abruptly, but continues for some time in a vague, "shadowy" form. Essentially, this is the basis for our reports in experiments. If negativity lasts after the first standard P1, N1, P300 components and coincides in time with this introspection, it could really be a correlate of conscious perceptual contents.
Relevant answer
Answer
Thanks, Johannes, for clarifying this. I overlooked some of the experimental details so perhaps at present my question cannot be answered in substance because it has no real empirical foundation for it in your experiment.
  • asked a question related to Neural Correlates of Consciousness
Question
17 answers
While there is still a lot of debate as to what consciousness is and where it is loacted (cf. dualism vs. monism) some claim that techniques inspired from the eastern world like meditation and sophrology lead to a widening of consciousness.
And indeed changes in brain activation have been observed in people while meditating. However, are these really correlates of a widening consciousness or rather a response to the relaxation induced by these techniques? Would this suggest that consciousness is located in the brain?
Relevant answer
Answer
There is much accumulated evidence (see e.g. recent findings of PEt - positron emission tomogrpahy) that there is a strong correlation between the brain activity and the contents of our consciousness. (Some recent results suggest that even certain dream contents can be identified). Nevertheless nobody knows how to find a one-to-one relation between thoughts, emotions etc. and brain activity patterns. For me the main question is whether one accepts the existence of the "self" who is the subject of all sensations or considers the "self" only as a mental construct, the result of processes. I think that there is no chance for structured and rational discussion on such matters between two persons who disagree at this point. For one group the only reality is the brain and its activites and they larely disregard the subjective sensations of the test subject. Others would cocentrate on the states of conscisuousness. EEG also detects characteritsic differences in trance or in hypnosis (the so-called theta waves). But it dose not really help to understand the porcesses behind them. And thos who look for altered states of conscoiusness are not after brain awes but after the experience itself.
  • asked a question related to Neural Correlates of Consciousness
Question
4 answers
I write about the diagnosis of vegetative state and minimally conscious state.
In some hospitals, the diagnosis is mainly done on a radiological basis while in other places specialists mainly rely on evaluative scales.
I am interested in knowing if any "radiological criterion" exist on the basis that some remaining awareness/consciousness can be ruled out (or not excluded), as this is not clearly a simple matter of functional activation in the cortex.
Can anyone help me?
Relevant answer
Answer
As a practicing Neurologist, I can assure you that there is no accepted clinical role of imaging in the diagnosis of VS and MCS. All correlational findings from either FDG-PET or fMRI are for research purposes only and at this time are not well-enough studied in a sufficiently large sample to be certain of their significance. Hence, no "radiologic criteria" are currently incorporated; the definitions of each are exclusively clinical. The American Academy of Neurology is currently asking for input on a "Practice Parameter" that will discuss these criteria, and is due out in several months. Although some discussion of imaging has been raised, to my knowledge there will be no radiologic components in the primary diagnosis, only as "supportive findings"that cannot be used to either diagnose OR EXCLUDE VS.