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Towards a fundamental theory of consciousness

The origin and nature of conscious experiences - sometimes called the Latin word qualia - was a mystery to us from very early antiquity until recently. Many philosophers of consciousness, including modern ones, consider the existence of consciousness to be so unacceptable a contradiction to the fact that, in their opinion, there is a world of matter and emptiness that they declare it an illusion. In other words, they either deny the existence of qualia in principle, or declare that it is impossible to study them meaningfully with the help of science.

If this judgment were true - this article would be very short. And under the cut nothing would have happened. But there is something there ...

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If consciousness cannot be understood with the help of the tools of science, it would only be necessary to explain why you, I and almost everyone else are so sure that we have feelings in general. However, a bad tooth caused my flux. A sophisticated argument to convince me that my pain is illusive will not spare me one iota of these torments. I don’t have sympathy for such a dead-end interpretation of the connection between soul and body, so I’ll probably continue.
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Consciousness is all that you feel (based on information from the sensory organs of the senses), and then you experience (at the expense of perception and judgment).

Melody stuck in my head, the taste of chocolate dessert, boring toothache, love for a child, abstract thinking and the understanding that one day all sensations end.

Scientists are gradually approaching the solution of the mystery that has long troubled philosophers. And the culmination of these scientific studies is expected - a structured working theory of consciousness. The most striking example of the application of this theory is a full-fledged AI (this does not exclude the possibility of the emergence of AI without a theory of consciousness, but based on already existing empirical approaches in the development of AI)

Most scientists take consciousness for granted and seek to understand its connection with the objective world that science describes. A quarter of a century ago, Francis Creek and the rest of the cognitive neuroscientists decided to put aside philosophical debates about consciousness (which have been worrying scientific men at least since Aristotle) ​​and instead set about searching for his physical traces.

What exactly in the extremely excitable part of the medulla generates consciousness? Having learned this, scientists may hope to approach a solution to a more fundamental problem.
In particular, neuroscientists are looking for neural correlates of consciousness (NCC) - the smallest neural mechanisms that, taken together, are sufficient for any particular conscious experience in sensations.

What should happen in the brain for you to have a toothache, for example? Should some nerve cells vibrate with some sort of magical frequency? Do I need to activate some special "neurons of consciousness"? What areas of the brain could such cells be located in?

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Neural Correlates of Consciousness


In the definition of the NCC, the “minimum” clause is important. After all, the brain as a whole can be considered NCC - it gives rise to sensations day after day. And yet the location can be designated even more precisely. Take the spinal cord - a 46-centimeter flexible tube of nerve tissue inside the spine that contains about a billion nerve cells. If the spinal cord is completely damaged as a result of the injury up to the neck, the victim paralyzes the legs, arms and torso, he will not be able to control the intestines and bladder and will be deprived of bodily sensations. Nevertheless, such paralytics continue to experience life in all its diversity: they see, hear, smell, experience emotions and remember as well as before the tragic event radically changed their lives.

Or take the cerebellum - the "small brain" in the back of the brain. This brain system, one of the oldest in an evolutionary sense, is involved in the control of motor skills, body position and gait, and is also responsible for the deft performance of complex sequences of movements.
Playing the piano, typing on the keyboard, figure skating or rock climbing - the cerebellum is involved in all these activities. It is equipped with the most famous neurons called Purkinje cells, which have antennae, fluttering like a coral sea fan, and harbor complex electrical dynamics. And the cerebellum contains the largest number of neurons , about 69 billion (mostly it is the cerebellar labrocytes in the form of stars) - several times more than all other parts of the brain combined (remember - this is an important point).

What happens to consciousness if a person partially loses the cerebellum as a result of a stroke or under a surgeon's knife?

Yes, almost nothing critical for consciousness!


Patients with such damage complain of a few problems, such as playing the piano less fluently or typing on the keyboard less deftly, but never to completely lose any aspect of their consciousness.

The most detailed study on the effect of cerebellar damage on cognitive function has been extensively studied in the context of post-stroke cerebellar affective syndrome . But even in these cases, in addition to coordination and spatial problems (above), only non-critical violations of the executive aspects of management are found, characterized by perseverations , absent-mindedness and a slight decrease in learning ability.

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The extensive cerebellar apparatus is not related to subjective experiences. Why? An important clue is contained in its neural network - it is extremely uniform and parallel.


The cerebellum is almost completely a chain of direct distribution: one row of neurons feeds the next one, which, in turn, affects the third. There are no feedback loops that would resonate back and forth within electrical activity. Moreover, the cerebellum is functionally divided into hundreds, if not more, of independent computational modules. Each of them works in parallel, with separate and non-overlapping input-output, which control movements or various motor or cognitive systems. They almost do not interact with each other, whereas in the case of consciousness it is another indispensable characteristic.

An important lesson that can be learned from the analysis of the spinal cord and cerebellum is that the genius of consciousness is not born so easily in any place where nervous tissue is excited. Something else is needed. This additional factor lies in the gray matter, which is the notorious cortex of the brain - its external surface. All available evidence indicates that neocortical tissues are involved in generating sensations.

You can narrow the area of ​​the hearth of consciousness even more. Take, for example, experiments in which the right and left eyes are exposed to various stimuli. Imagine that the Lada Priory photo is visible only to your left eye, and the Tesla S picture is only visible to the right. We can assume that you will see some kind of new car from the layouts of Lada and Tesla on each other. In fact, within a few seconds you will see the Lada, after which it will disappear and Tesla will appear - and then she will disappear, and Lada will appear again. Two pictures will be in the endless dance to replace each other - scientists call it a binocular competition, or rivalry of retinas. Ambiguous information enters the brain from the outside, and it cannot be defined: Lada or Tesla?

If at the same time you are lying inside a tomograph that registers brain activity, scientists state activity in a wide range of cortical zones, collectively referred to as the “posterior hot zone”. These are the parietal, occipital, and temporal areas of the back part of the cerebral cortex, and they play the most important role in tracking what we see.

Interestingly, the primary visual cortex, which receives and transmits information from the eyes, does not reflect what a person sees. A similar division of labor is also observed in the case of hearing and touch: the primary auditory and primary somatosensory cortex do not directly contribute to the content of the auditory and somatosensory experiences. Conscious perception (including images of Lada and Tesla) give rise to subsequent processing stages - in the back hot zone.

It turns out that visual images, sounds and other vital sensations originate within the posterior cortex. As far as neuroscientists can judge, almost all conscious experiences originate there.

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Mind counter


For operations, for example, patients are anesthetized so that they do not move, maintain stable blood pressure, experience no pain, and subsequently have no traumatic memories. Unfortunately, this is not always possible to achieve: every year, hundreds of patients under the influence of anesthesia are more or less conscious.

Another category of patients with severe brain damage as a result of trauma, infections, or severe poisoning may last for years without being able to talk or respond to treatment. Proving that they feel life is an extremely difficult task.


Imagine a cosmonaut lost in the universe who listens to the attempts of the mission control center to contact him. The failed radio does not broadcast his voice, which is why the world regards him as missing. Something like this can describe the hopeless situation of patients whose damaged brain deprived them of contact with the world, a kind of extreme form of solitary confinement.

In the early 2000s, Giulio Tononi of the University of Wisconsin-Madison and Marcello Massimini first used the zap and zip method to determine whether a person is conscious or not.

Scientists applied a coil with wires in the sheath to the head and sent an electric shock (zap) - a strong charge of magnetic energy that caused a short-term electrical current. This energized and inhibited partner cells of the neurons in related regions of the chain, and the wave resonated in the cerebral cortex until the activity subsided.

A network of electroencephalogram sensors attached to the head recorded electrical signals. As the signals gradually spread, their tracks, each of which corresponded to a certain point under the surface of the skull, were transformed into a film.

The entries did not demonstrate some typical algorithm - but they were not completely random.


Interestingly, the more predictable the flashing and fading rhythms were, the higher the proportion of the likelihood that the brain was unconscious. Scientists measured this assumption by compressing the video data using an algorithm that archives computer files in a ZIP format. Compression provided an assessment of the complexity of the brain response. The conscious volunteers demonstrated a “measure of perturbation complexity” from 0.31 to 0.70, with the index falling below 0.31 if they were in a state of deep sleep or under anesthesia.

The team then tested zap and zip on 81 patients who were minimally conscious or insane (in a coma). In the first group, which demonstrated some signs of non-reflective behavior, the method correctly showed that 36 out of 38 are conscious. Of the 43 patients in the "vegetable" state, with whom relatives at the head of the hospital bed never managed to establish communication, 34 were classified as unconscious, and nine more were not. Their brains reacted in the same way as those who were conscious, which meant that they were also conscious, but they were not able to communicate with their relatives.

Current research aims to standardize and improve the methodology for neurological patients, as well as to extend it to patients in psychiatric and pediatric departments. Over time, scientists will identify a specific set of neural mechanisms that generate experiences.


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By and large, we need a convincing scientific theory of consciousness that will answer the question of the conditions under which a particular physical system — be it a complex chain of neurons or silicon transistors — experiences sensations. And why is the quality of the experience different? Why does the clear blue sky feel differently than the grinding of a poorly tuned violin? Do these differences in sensations have any particular function? If so, which one? The theory will allow you to predict which systems will be able to sense something. In the absence of a theory with verifiable predictions, any conclusion about the consciousness of machines is based solely on our inner sense, which, as the history of science has shown, should be relied upon with caution.

One of the main theories of consciousness is the theory of the global neural workspace (GWT), advanced by psychologist Bernard Baars and neuroscientists Stanislas Dean and Jean-Pierre Change.


To begin with, they argue that when a person is aware of something, many different areas of the brain receive access to this information. Whereas if a person acts unconsciously, information is localized in the specific sensory-motor system (sensory-motor) involved. For example, when you type quickly, you do it on the machine. If you are asked how you do this, you will not be able to answer, because you have limited access to this information, which is localized in the nerve chains that connect the eyes with quick finger movements.

Global accessibility generates only one stream of consciousness, because if a process is accessible to all other processes, then it is accessible to them all - everything is connected with everything. This is how the mechanism of suppression of alternative pictures is carried out.
Such a theory well explains all mental disorders, where failures of individual functional centers connected by patterns of neural activity (or a whole brain area) distort the general flow of the “working space”, thereby distorting the picture in comparison with the “normal” state (healthy person) .

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Towards a fundamental theory


The GWT theory claims that consciousness stems from a special type of information processing: it has been familiar to us since the days of the birth of AI, when special programs had access to a small, publicly accessible data store. Any information recorded on the “bulletin board” became available for a number of auxiliary processes — operational memory, language, planning module, recognition of faces, objects, etc. According to this theory, consciousness occurs when incoming sensory information recorded on the board into many cognitive systems — and they process data for speech reproduction, storage in memory, or performance of actions.

Since the space on such a bulletin board is limited, at any given moment we can only have a small amount of information. The network of neurons that transmit these messages is presumably located in the frontal and parietal lobes.

As soon as these scanty (scattered) data is transmitted to the network and become publicly available, the information becomes conscious. That is, the subject is aware of it. Modern machines have not yet reached a similar level of cognitive complexity, but it is only a matter of time.

GWT Theory claims that the computers of the future will be conscious


The General Information Theory of Consciousness (IIT), developed by Tononi and his colleagues, uses a very different starting point - the experiences themselves. Each experience has its own special key characteristics. It is immanent, exists only for the subject as a “host”; it is structured (a yellow taxi slows down as the brown dog runs across the street); and it is concrete - different from any other conscious experience, like a separate frame in a movie. In addition, it is whole and definite. When you sit on a bench on a warm, clear day and watch the children play, the various elements of the experience — the wind blowing through your hair, the feeling of joy from the laughter of the little ones — cannot be separated from each other without the experience not being what it is.

Tononi postulates that such properties — that is, a certain level of awareness — have any complex and conjugate mechanism, in the structure of which a set of cause-effect relationships is encrypted. It will feel like something coming from within.

But if, like the cerebellum, the mechanism lacks complexity and conjugation, it will not be aware of anything. As the theory goes,

Consciousness is an inherent random ability associated with such complex mechanisms as the human brain.


The theory also deduces from the complexity of the underlying interrelated structure a single non-negative number Φ (pronounced “fy”), which quantitatively expresses this awareness. If F is zero, the system itself is not aware at all. Conversely, the larger the number, the more inherent in the random power the system possesses, and the more conscious it is. The brain, which is characterized by colossal and highly specific connectivity, has a very high O, and this implies a high level of awareness. The theory explains various facts: for example, why the cerebellum is not involved in consciousness or why the zap and zip counter actually works (the numbers given by the counter are F in a rough approximation).
The IIT theory predicts that an advanced simulation of the human brain based on a digital computer cannot be conscious — even if its speech cannot be distinguished from a human one. Just as the simulation of the large-scale gravitational attraction of a black hole does not deform the space-time continuum around a computer using a code, a programmed consciousness will never produce a conscious computer. Giulio Tononi and Marcello Massimini, Nature Magazine 557, S8-S12 (2018)

According to IIT, consciousness cannot be calculated and calculated: it must be built into the structure of the system.


The main task of modern neuroscientists is to use the ever more sophisticated tools at their disposal in studying the endless connections of various neurons that form the brain to further delineate the neural traces of consciousness. Given the confusing CNS device, it will take decades. And finally, to formulate the main theory on the basis of fragments of the existing ones. The theory that interprets the main puzzle of our existence: as an organ that weighs 1.36 kg and is similar in composition to bean curd, embodies the sense of life.

One of the most interesting applications of this new theory, in my opinion, is the possibility of creating an AI with consciousness and, most importantly, sensations. Moreover, the fundamental theory of consciousness will make it possible to develop methods and ways to realize a more rapid evolution of human cognitive abilities. Man - the future.

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Main source

Source: https://habr.com/ru/post/444518/


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