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Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts

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Until the late 1980s it was believed that consciousness could not be investigated by objective experimentation, but today the quest for its biological basis is at the forefront of cognitive research. This book, by a leading researcher in the neuroscience of language and number processing, shows how modern tools such as functional magnetic resonance imaging can pinpoint the physiological markers that reveal long-distance communication networks within the brain, providing data to answer long-standing questions about consciousness.

336 pages, Hardcover

First published January 30, 2014

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Stanislas Dehaene

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Displaying 1 - 30 of 242 reviews
Profile Image for David Rubenstein.
864 reviews2,770 followers
October 17, 2014
This book is a truly fascinating exploration of the biological foundation of consciousness. Stanislas Dehaene is an active researcher in the field. He makes a compelling argument that consciousness can be explained in terms of his "global neuronal workspace theory". In this theory, consciousness means that information that comes into a particular area of the brain through one of the senses becomes available to the rest of the brain. The information becomes "... globally available to all our high-level decision systems." In other words, consciousness is brain-wide information sharing. Dehaene describes a huge body of research that he and others have done, that substantiate his theory.

Perhaps you have heard of a story where a movie theater used subliminal messages to encourage customers to buy Coca Cola. According to the story, individual film frames with the message were interspersed with a movie. They could not be consciously seen, because they flashed by too fast, but they encouraged a significant increase of sales of Coca Cola at the concession stand. Well, this is an urban legend--the story was a hoax.

But this does not mean subliminal messages do no work. Dehaene describes many intriguing experiments that prove that subliminal information--both visual and auditory--can be used to prime people to respond more positively to subsequent tasks. He describes how fMRI (functional Magnetic Resonance Imaging) has been used to correlate this subliminal priming with activity in the brain. The subliminal messages activate neurons in the brain, but not until the messages are increased in duration past some threshold, do they instigate global neuron activity throughout the brain, and the subject becomes conscious of the message.

Here is a fascinating little tidbit: There is a single individual neuron in the brain that is activated if and only if you see a facial image or the written name of some celebrity. A different individual neuron is activated for each different celebrity. I had no idea that neurons could be quite that specific!

Dehaene's "global neuronal workspace theory" has been put to practical use in medicine. Perhaps you have heard of people who have suffered brain injuries, and are almost completely paralyzed. They can only communicate very slowly, for example, by blinking an eyelid. But there are others who are truly completely paralyzed, and they have no means of communicating with the outside world. Doctors have diagnosed these patients as being in a permanent "vegetative state". Dehaene describes how fMRI's and EEG's have been used on some patients to establish that the patients are really conscious, and provide a crude type of two-way communication. And, a technique called Transcranial Mental Stimulation has been used to awaken some "vegetative" patients, and bring them to a fully conscious state. Sometimes, these patients can be awakened to live normal lives.

Toward the end of the book, some intriguing experiments are described that explore self-consciousness--in animals like dolphins! The results of these experiments could be interpreted to mean that some animals are actually self-conscious; they think about the fact that they are thinking. But, since animals do not talk, it is also possible to give other interpretations to the experiments. Obviously, this area is controversial.

Toward the beginning of the book, I was taken aback by the dry writing style. It is not a difficult book to read, but the writing style is close to the scientific style, and does not seem quite right for a "popularized" book for the layman. Getting through some of the prose is slow-going. But then I realized--the book is describing some amazing things. It conveys a good understanding of the biological foundations of consciousness. There have been many recent books written about consciousness--but this one goes far beyond philosophy--this book explains the "how" and the "why".
Profile Image for David Katzman.
Author 3 books534 followers
February 9, 2018
Manages to be fascinating, boring and disturbing all at once. Consciousness is a fascinating metaphysical concept. Linguistic even. Dehaene is reporting on a significant volume of psychological research related to testing and evaluation of consciousness from a scientific perspective. The details and repetitive reporting of these tests in CATB:DHTBCOT is dull, dull, dull. It’s essentially a very long science report. The excessive detail is likely needed to prove his various points, but I was constantly drifting off.

The majority of this book is about conscious awareness and how brain states physically register various images, sounds and thoughts (neuronal activation). He spends a great deal of time reporting on the transitional moment between when something moves from being unconscious to conscious. He discusses what most of us think as the core meaning of “consciousness” and the Self only indirectly as a result of these tests. How can a physical, mechanical object (the brain) give rise to flexible abstract decision-making? How can it think about thinking? How can it revise its goals, for example? So-called AI, computer AI, can “problem solve” to achieve a result. But I think what proves it can’t ever become conscious to my mind is how can it decide the result isn’t worth achieving? Something in the human mind is more flexible and can “edit itself” if you will, in a way that a computer program cannot ever do. Dehaene is a believer that computers can achieve consciousness since all brain states are triggered neurons, which can be turned into programmed software bundles on a massive computer. I think he fails to prove it. He tosses off “flexibility” as something that will simply be developed in the future. And I think that elides the very core issue of consciousness. How can the brain ponder, re-evaluate and revise its own “coded” memories and ideas, which software cannot?

I’m more in line with his description of the “Self.” His description of it is reasonable to me. Consider our image of another person. It might be someone we know well (a child or a relationship partner) or someone we only know at a distance (a celebrity or an acquaintance). In our brain is an amalgamation of memories, thoughts and images of that person. They connect and intertwine and simmer in our brains while we think of other things. When we think of the person, see them, or interact with them directly, those areas of the brain are activated and various assumptions and beliefs are activated or triggered consciously and subconsciously. This seems pretty logical. Now, the Self is just a matter of degree. We have that exact same representation of our Self in our brain that is simply more detailed than we do for others. When we think about our Self, those things come forward and are activated. Many of these thoughts and images may be completely inaccurate. We may have many false interpretations of our own behaviors and thoughts. But we have a Self representation in the brain and that is what the Self is. The unconscious drives many of our choices, but that isn’t what we think of as our Self unless we recognize it and add it to our view of who we are.

Dehaene discusses a so-called “Neuronal Workspace” extensively. This is his term for an environment in the brain where conscious evaluation/decision-making occurs. The brain is able to pull in various thoughts and memories into this working brain environment to weigh the factors before making a decision. One interesting point he makes is that the brain seems to assign a “certainty factor” (born out in the testing) to various memories, thoughts or images. And this certainty factor allows the brain to make decisions by weighing how sure it is about various options. He claims to reject the idea that humans are essential automata or “zombies” that use if/then loops to make decisions. But based on the results he shares, he fails to demonstrate that. Where this “flexibility” and free-will comes into play, he can’t point to it.

Various elements of this book that were disturbing include the author’s seeming anti-abortion stance (not made explicit but implied) and the animal experimentation mentioned throughout. Every time he talked about a study that had forced electrodes or chemicals into animals to test results, I shuddered and felt sickened by even reading this book. It made me think of Mengele.
Profile Image for Chrissie.
2,811 reviews1,427 followers
January 15, 2018
Having completed half, I will no longer continue.

This is confusing and extremely unclear.

The author’s nomenclature is presented too rapidly and in terms too diffuse.

Conclusions are drawn but the proof documented here in the book failed to convince me.

The audiobook is read by David Drummond. It is read too quickly.

Evidently, popular science books are not for me. This and the others I have read have all failed me.
Profile Image for Chris.
407 reviews185 followers
February 19, 2016
Now here is how to write "popular" science for the intelligent reader, one who is not necessarily expert in the particular subject, but who nevertheless has his own technical or scientific background. Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts is most definitely not a dumbed-down creative non-fiction gloss by a staff journalist, like so many recent "popular" science works of questionable worth and accuracy. This is written by a leading researcher in the field. You instantly will trust Dehaene's expertise, yet you will not feel talked down to. And you will be challenged, which is always desirable.

His style is appropriately dry and scientific. When I want literature I read Nabokov—curiously, so does Dehaene who mentions him as one of his favorites. Dehaene follows the usual structure of scientific papers: present the results, present the evidence for the results, then present the results again—a time-tested way to facilitate understanding and also to allow general refutation as necessary. He also shows justifiable pride toward his accomplishments, particularly where his results have led to improved clinical diagnostics and treatment of neurological disorders.

I have only one minor complaint, although it did peculiarly distract my reading: Dehaene's editor should have corrected the overbearing use of the word "massive." This now meaningless, unscientific hyperbolic word was used dozens of times in the last few chapters, becoming an unpleasant noise. I know that my unconscious counted these instances—an ability Dehaene describes in the book in some detail—but the sum total never accessed my consciousness to report on.
Profile Image for Emre Turkmen.
89 reviews22 followers
November 6, 2022
Bilinci yaratan mekanizmalar ancak bu kadar iyi anlatılabilir:)
Profile Image for Mani .
61 reviews20 followers
April 4, 2014
The most comprehensive review of consciousness research from the clinical applications in coma and minimal consciousness conditions to attentional blindness, masking, subliminal priming.

Everything is covered in this book. The author came up with the global neuronal workspace model of consciousness. The meticulous clarification of the multiple conflated meanings of consciousness at the start of the book lays the groundwork for a deep dive into the workings of the subconscious mind followed by the tour of conscious processing of information.
Highly recommended read.
Profile Image for Charlene.
875 reviews694 followers
March 13, 2016
Filled with a lot of wonderful neuroscience. Worthwhile studies. I was with him until he began making illogical arguments at the end. He obviously hates Peter Singer. In this he is not alone. No matter how disdainful researchers find Singer, they are often able to argue against him using research and logic. Dehaene was obviously overcome by emotion and his logic centers failed to light up. A little too much vmPFC activation and not enough dlPFC involvement in his decision-making.

Dehaene argues that Singer is dead wrong. He argues that of course babies and handicapped (his terminology) individuals are conscious and should never be killed. It is clear to me that Dehaene does not really understand Peter Singer's arguments. He misrepresented them. Singer is not in favor of killing babies. Singer is arguing that many animals have consciousness, just as babies and children do. If this is the case, why are we at liberty to kill them? Dehaene took a moral stance (against something Singer wasn't even arguing) and tried to take Singer down with science, and it was a pretty big fail. Dehaene cited studies that showed that even tiny babies had some consciousness, albeit a much less complex version of adult consciousness. If he is to make this argument, then he is stuck addressing consciousness of animals, since the argument he gave about babies and "handicapped" individuals has been made about animals. Indeed he does. He concludes that animals too have consciousness, but since their consciousness is less complex than adult humans, they cannot share special status with humans. Umm What? Did he just forget what he argued only a page or so back? That was a bad note to end with.

If you are more Kantian than Mill in your ideology, then you might not mind Dehaene's argument against Singer, even if it lacks logic and misses Singer's point. Kant and Mill have opposing views in the famous dead baby problem. The soldiers are approaching. The baby is crying. If the soldiers hear the baby, they will kill the baby and kill every last person hiding near the baby. Mill would suggest that since the baby is going to die anyway, you must kill it yourself to save everyone else (in fact, not killing the baby could be tantamount to murdering everyone else). According to Mill's utilitarian approach, letting everyone die serves no good, because in the end, it didn't save the baby. It merely caused more harm, not less. But Kant says there is no logic that can justify the harm of even one person. The baby's life is precious and it is immoral to kill it, even if that means everyone else will die. Kant doesn't care about any logical argument that would suggest that not doing so is essentially murdering everyone else. He makes blanket statements about morality. For Kant, taking any action against the baby is simply wrong. When having to memorize the dead baby problem as an undergrad (so as to not mix up Mill and Kant), I would say, "I just Kant kill the baby!"

Thus, my ears were ringing with Kantian ethics as I read Dehaene. I kept imagining him saying, "You Kant kill the babies but you Kan kill the animals!"

Even with my annoyance, I really did appreciate his solid research on consciousness in individuals in a prolonged state of being unable to communicate. He looked at people in comas, partially unresponsive, etc and provided some truly incredible studies that demonstrate that the mind is often far more active that it appears. Again though, he focused on Singer. Dehaene voiced his anger at Singer, who suggested that people in a vegetative state should be able to die. Somehow Dehaene translated this to mean that Singer did not want to investigate the minds of those in a vegetative state. Singer never said that. Singer is a huge proponent of gathering as much evidence as possible. Singer is saying that now, with the knowledge we have, keeping someone in a vegetative state isn't always kind or moral. In fact for Singer, it is often more kind and moral to kill someone in that state. I feel pretty certain that if we develop tech to cure a vegetative state, Singer would be all for it. Dehaene is basically arguing against a fantom. If he had taken the Singer arguments out of his book, it would have been a great book.
Profile Image for Morgan Blackledge.
806 reviews2,630 followers
September 17, 2017
One readers (QI) review expressed fear and skepticism regarding whether we should or even can understand consciousness via the scientific method.

In her opinion we "need to leave room beyond the conscious machinery model of being human".

My response to her was as follows:

Weather or not we need to leave room beyond "conscious machinery" model of being human, that territory is shrinking daily. I'm still not exactly sure how the systematic investigation of consciousness could possibly be harmfull. I understand that people have very strong intuitions against such inquiries. But I don't understand the exact mechanism by which harm occurs via this line of investigation. Can you elaborate? Perhaps cite an instance when the scientific understanding of consciousness that we currently have has, in any way been harmfull. I can't understand how it is anything less than enriching.

Tibetan Scriptures refer to the distance from the earth to the moon as an unknowable mystical number. Now we pretty much know that the moon's orbit around Earth is elliptical. At perigee — its closest approach — the moon comes as close as 225,623 miles (363,104 kilometers). At apogee — the farthest away it gets — the moon is 252,088 miles (405,696 km) from Earth. To reiterate, that used to be considered unknowable. In order to not know this fact today, one must be willingly ignorant. I see more harm in remaining willingly ignorant then in knowing. Furthermore I feel that it is every bit as possible to have a rich spiritual life in the presence of this knowledge. Even if you're a Tibetan mystic (the Dalai Lama is a major contributor to the scientific investigation into consciousness).

Your sentiments echo the skepticism expressed at the bleeding edge of any scientific field, think physics circa 1900. There were doubts that we would ever understand phenomena that we consider commonsense today. I can think of destructive applications of the findings of advanced physics (e.g. the A-Bomb), but for the life of me, I can't identify the harm of knowing the principals of atomic theory. Pleas help me understand your fears?

As for what we can know and can't possibly know about consciousness via the scientific method. Get ready for a tsunami of good data in the coming decade. Be prepared for conservative estimates of what is knowable in this domain to be shattered. I'd rather be working on the side of making meaning out of all of this, than trying to limit or resist it. That's a little like trying to sweep back the ocean with a broom. The tsunami is coming. Better learn how swim.

All that aside:

This is a truly rich and profound book. To say Stanislas Dehaene is brilliant is an understatement that is it's self an understatement (not even sure that made real sense but you get what I mean, he's real smart). He powns (that's a common gamer portmanteau of the words power and own, connoting masterful execution) the paralyzingly difficult subject subject of consciousness and the brain (as should be obvious by the rather straightforward title Consciousness And The Brain).  Dehaene somehow manages to keep it mercifly accessible (perhaps we can thank his English editors for this) while remaining true to his fancy theory lovin, fancy talkin French intellectual roots (I think that last statement would have been racist in like 1890, perhaps it still is? I sure hope not).

Dehaene began his career as a mathematician. But switched up to neuroscience in the early 1990's. He's best known for his work on numerical cognition, detailed in his oft-cited 1997 book The Number Sense (which has been on my "to read" list for years but to date I have still not read it, as I am ultimately reluctant to read any neuroscience lit from pre 2010 for what ever reason).

Apparently after getting bored with that, Dehaene turned his attention to work on the neural correlates of consciousness, leading to numerous scientific articles leading to this book detailing the current state of the art in the cognitive neuroscience consciousness (perhaps The Cognitive Neuroscience of Consciousness was one of the alternative "on the nose" titles being bandied about at the publisher).

Dehaene is a math dude, and understands how important mathematical models are to real scientific advancement and understanding. He and his colleagues have developed computational models of consciousness and neuronal function (which I can safely say, I will never directly understand, but can at least appreciate from across the vast intellectual divide that separates he and myself).

Additionally, Dehaene has used brain imaging to study language processing and the neural basis of reading. In the book (the one I'm supposed to be reviewing) he discusses the inherent differences between the human capacity for understanding gramer and numeracy. Apparently people are just sort of hard wired to do grammar, and not so much to do math (kind of the "no duh", but what ever).

Most of the stuff I read, I at least get the sense that, cognitively speaking, I belong to the same species as the author. Not so with Dehaene (and a few others such as Pinker and Sapolsky). perhaps I'm overly impressed but I just get the strong sense that Dehaene is thinking in a categorically different way then almost everybody else.

Forinstance: the book destroys the so-called hard problem of consciousness without even so much as mentioning it by name. That might be my favorite thing about this book. It puts Hippy philosopher what's his fuck David Chalmers on the shelf with the rest of the unfortunate dusty ol footnotes and unproductive detours of science (see phlogiston end and ather). In fact, I think it pretty much destroys dualism altogether (please let it be so). Again Dehaene makes it look easy, but even smart guys like Dennete couldn't really do that.

OOOPS!!!!
Not really :(   Actually, in the last few pages of the book Dehaene pays lip service to Chalmers and the "Hard Problome" of consciousness. For a brief shining moment I thought we were going to be free of all of that. No go. I guess we just aren't there yet. Dehaene even uses the Q word (qualiea), oh dear lord, the fog of war doth descend. And then, to make matters worse, right at the 11th hour, Penrose and Hammerove appear, and then the other Q ward (quantum) appears like a poop stain on the page. Man alive! I actually thought we were going to do a book on consciousness without referring to these guys. I guess that's like saying I thought we were going to do an 80s heavy metal video without a smoke machine. Or like saying I thought we were going to do an episode of the new Battlestar Galactica that doesn't involve James  Edward Almos having a histrionic meltdown.

My bad. I should have known better. On that note, I'll end this rant with a quote from George W. Bush:

"There's an old saying in Tennessee — I know it's in Texas, probably in Tennessee — that says, fool me once, shame on — shame on you. Fool me — you can't get fooled again." —Nashville, Tenn., Sept. 17, 2002

WHAT EVER!

It's still a GREAT fuckin book.
Profile Image for Práxedes Rivera.
450 reviews14 followers
November 12, 2021
What a great read! Dehaene glides effortlessly into an abysmally difficult topic...he uses no big words or lofty concepts but an easy to understand exploration of this hotly debated area. Since the dawn of time humans have pondered 'what is consciousness?' The author and his team use modern science to propel this conversation forward.

It is important to remember that in order to make this subject matter measurable (and worthy of scientific examination) it must be simplified. So it is not a definitive tome on consciousness, just those portions that modern science can attempt to verify. But it is still a very rewarding book. Highly recommended.
Profile Image for Todd Martin.
Author 4 books80 followers
October 20, 2014
The question “Can the human mind understand itself?” may sound like another nebulous and unanswerable Zen koan along the lines of “What is the sound of one hand clapping?” but it turns out that scientists have learned a remarkable amount about the brain’s function in general and consciousness in particular. Though there is still much to be discovered, here’s what we do know for sure: consciousness is produced by the brain. Indeed, it could hardly be otherwise without invoking supernatural explanations.

Each of us, in fact, has direct, first-hand experience with the brain-as-mind phenomenon. This is because changes in brain states produce changes in consciousness that we can directly observe in ourselves. Thus our perceptions and behaviors as infants differed from those we experienced as toddlers, teenagers and adults … our awareness changed as our brains developed. It’s also why our consciousness during sleeping and waking states differs significantly and why our consciousness can be profoundly altered when certain chemicals are imbibed, or if the brain is damaged in some way such as through physical trauma, stroke or disease.

Before continuing any further, it’s worth mentioning that the term ‘consciousness’ can be defined in several different ways. For our purposes it can be taken to mean ‘awareness’. Thus, you are conscious of the words on the screen in front of you because they have entered your awareness. This can be contrasted with the many functions that our brains perform unconsciously – such as: regulation of body functions, processing of inputs from the senses, interpretation of symbols, consolidation of memories, and filtering of unimportant stimuli (for example, you were probably not aware of the sensation of your shirt against your skin until you read this sentence and thought about it for a moment). In fact, your brain performs so many functions unconsciously that consciousness can be thought of as a very thin veneer on the surface of our largely unconscious minds.

It turns out that experimental evidence supports the conclusion that the mind is a product of the brain as well. Thus scientists are able to manipulate our consciousness experimentally to affect what we see, hear and perceive, and with the advent of brain scanning techniques, the physical mechanisms that come into play can be directly observed. Here’s one clever example of a manipulation of your auditory perception called the McGurk Effect: https://www.youtube.com/watch?v=G-lN8...
The illusion works because the brain is hard wired to process auditory and visual information simultaneously. By tricking your brain, your conscious perception is fooled as well.

Another example comes from brain stimulation experiments with patients suffering from epilepsy who have had electrodes implanted in their brains. Stimulation of certain neurons produce conscious sensation such as the smell of toast, or a vision of a face or the sensation that one is separated from their body. Perhaps someday the science will have progressed to the point that we’ll be able to excite specific neurons to produce full blown auditory and visual hallucinations that are indistinguishable from reality.

In Consciousness and the Brain Stanislas Dehaene (a professor at the Collège de France) provides an overview of the current state of our scientific understanding regarding consciousness and the brain. The bulk of the book consists of summaries of psychological and neurological experiments, their outcomes and a description of what this tells us about brain function. Dehaene also touches on the evolutionary advantages of consciousness and his own studies using the analogy of consciousness as a “global neuronal workspace” that functions much like the ‘working memory’ in a computer.

There’s some good information to be found in the book, but I have to admit that I found much of the text to be pretty dull stuff. Dehaene basically steps through an extended laundry list of experiments (focusing in particular on his own research) in inordinately excessive detail … particularly for a book intended for a lay audience. Despite the interesting topic, I found myself bored with the text for extended periods of time. It was a bit like being trapped in a room with a guy that drones on endlessly about his job.
Profile Image for Lis Carey.
2,213 reviews136 followers
December 18, 2017
It seems we are, finally, starting to solve the mystery of what consciousness is, and how the brain creates it.

Moreover, this is not just a fascinating scientific breakthrough, but one with important clinical implications. These are breakthroughs that are starting to make it possible to identify which patients in a "persistent vegetative state" or "minimally conscious state," have conscious activity going on in their brains, despite their inability to communicate.

More than that, it's becoming the basis experimental treatments that are, sometimes, able to bring some of these patients back to full conscious awareness and ability to communicate and control their lives.

In addition to these practical medical applications, Dehaene also discusses research on the existence and limitations of consciousness in non-human animals, and the prospects for conscious machines and true artificial intelligence. He's more optimistic than many others about the possibility of true consciousness and free will in computers, but he makes a logical case for it, regardless of whether I'm fully convinced. (I'm not, but the people qualified to make that case have done so in books that won't be summarized in a few lines in a review of this book.)

Dehaene gives us a lively, engrossing discussion of the history and current developments in the field of consciousness research, and Drummond does, in my opinion, an excellent job of reading it.

Recommended.

I bought this audiobook.
Profile Image for Mike.
49 reviews21 followers
September 12, 2018
Although this book does contain some fascinating science (much of which is overly technical), I was extremely disappointed overall. Even though the entire book is ostensibly concerned with consciousness, Dehaene spends absolutely no time defining what he means by the notoriously loaded term. Adding insult to injury, he then proceeds to haphazardly use "consciousness" in many different ways throughout the book. This is supremely frustrating, to say the least. Maybe I should've known better, given the fact that the Author seems to conflate consciousness and thoughts in the title itself.

Additionally, he almost completely ignores major philosophical and methodological issues posed by thinkers such as philosopher David Chalmers. When he does briefly touch upon them in the final chapter (why wait until the final chapter?!) he dismisses them casually in a few paragraphs.

If you're gonna write a book about the science of consciousness, give it the treatment it deserves. This book belongs alongside other consciousness works that are stunningly confused—such as Dennet's "Consciousness Explained"—books which impressively manage to drag you along for hundreds of pages without ever precisely defining what they're talking about.

Do your consciousness a favor and skip this one.
Profile Image for Bart Jr..
Author 16 books32 followers
February 26, 2014

It is wonderful to find a book that has taken consciousness from a philosophical subject, approachable mostly by way of metaphor, to the scientific, experimental level.
Mr. Dehaene begins, as is often necessary in science, by defining the term consciousness in a clear and unambiguous manner that delineates it from other related and often conflated terms such as awareness and attention.
But the majority of this book concerns data taken from nuts-and-bolts experiments in the lab, many using brain-imaging equipment, that give information about actual brain processes that occur during consciousness and how they differ from those of unconscious processing. And sometimes startling insights about the evolution of consciousness and the reasons it may have developed.
Four "signatures" of consciousness were identified from this experimental data, and using these signatures, a theory of consciousness was developed and also a practical method for determining the actual state of animals, babies, or patients who have suffered brain trauma or paralysis and are not able to communicate directly with people.
This is cutting-edge, ground-floor science, and I am thankful to live in an era where I can access this knowledge. It is in the nature of science that new experiments and findings on the nature of consciousness will doubtless now occur rapidly, but this is the finest book on consciousness I have read thus far.

Profile Image for BetseaK.
78 reviews
December 1, 2014
This is a splendid work, wonderfully well-organised and written with exceptional clarity and depth. A joy to read! Highly, highly recommended!

Profile Image for Oleksandr Golovatyi.
493 reviews42 followers
July 12, 2020
Readlax: Скорочтение! Как читать быстро и осмысленно (промо)

Лучшие цитаты и заметки из книги:

"современная наука выделяет минимум три концепции: бодрствование - состояние? в котором пребывает неспящий человек и которое изменяется? когда мы засыпаем или просыпаемся; внимание - концентрация наших психических ресурсов на той или иной информации; и доступ в сознательный опыт - то, что происходит, когда мы осознаем полученную информацию и можем передать ее другим"

"я считаю, что под сознанием вообще принято понимать доступ в сознательный опыт - когда мы не спим, то можем осознавать практически все, на что решим обратить свое внимание."

"наш мозг способен обрабатывать информацию неосознанно"

"Мы с моими сотрудниками разработали теорию так называемого единого нейронного рабочего пространства. Мы полагаем, что сознание - это трансляция единого информационного потока в коре головного мозга: основой этого процесса является нейронная сеть, смысл существования которой сводится к активной передаче актуальной информации в пределах мозга."

"внимание действует отдельно от доступа в сознательный опыт"

"Особенно интересным и увлекательным свойством осознания себя является одна странная петля. Когда я думаю о себе, "я" участвует в этом дважды, и как тот, кто воспринимает, и как то, что оказывается воспринято. Как такое возможно? Ученые когнитивисты зовут это рекурсивное чувство осознавания метапознанием: способностью думать о собственном разуме."

"Когда объект наблюдения идеально неподвижен, наша зрительная система это учитывает и решает заполнить место дефицита информации образом близлежащей текстуры (например, механизм "заполнения" "слепых пятен")"

"многие люди думают, что, читая слово, они воспринимают его мгновенно "как единое целое", опираясь на его визуальный образ; на самом деле в их мозгу происходит сложная цепочка буквенного анализа, о котором они совершенно не подозревают"

"явление называется "сублиминальный прайминг повтора""

"Строчная "а" совсем не похожа на заглавную "А". Принимать две эти фигуры за одну и ту же букву мы можем только под влиянием культуры. Эксперименты между тем показывают удивительное - у людей, прекрасно владеющих навыком чтения, это знание становится абсолютно неосознанным и встраивается в систему ранней обработки зрительных образов: сублиминальный прайминг равно выражен как при повторе визуальной формы слова ("радио" и "радио"), так и при использовании разных образов ("радио" и "РАДИО")"

"веретенообразная извилина воспринимает абстрактное значение слова независимо от того, заглавными буквами оно записано или строчными"

"вентральный канал, устанавливающий связь между изображением и словом, может работать и в бессознательном режиме"

"Нейроны зрительной системы постоянно в работе, и в конце концов они привыкают к особым сочетаниям фрагментов, характерным для того или иного знакомого им объекта. Заучив эти сочетания, они продолжают реагировать на них даже под анестезией - следовательно, подобное объединение происходит без участия сознания. Оттуда же, из бессознательно накопленной статистики, идет, вероятно, и наша способность распознавать написанные слова: средний читатель, достигнув взрослого возраста, успел прочесть не один миллион слов, и в зрительных отделах коры его мозга вполне могут содержаться нейроны, натренированные распознавать часто встречающиеся сочетания букв - "он", "не", "ция". Точно так же и у опытного шахматиста некоторые нейроны могли приспособиться к распознаванию положения фигур на шахматной доске. Подобное автоматическое объединение, производимое специальными цепочками нейронов в мозгу, весьма отличается от объединения, к примеру, новых слов в предложение."

"когда человек находится под анестезией, способность его мозга объединять слова в предложения резко падает"

"зрительная система у нас умная, она может бессознательно собрать буквы в слово"

"Вам достаточно взглянуть на слово, и оно тут же займет свое место в общей структуре дискурса. Мы не следим за тем, как знак превращается в смысл"

"удалось даже доказать, что слова, на которые мы не обращаем внимания, могут повлиять на мнение говорящего о беседе, которой он занят"

"В ходе экспериментов Марсел продемонстрировал еще одно удивительное явление: мозг, по-видимому, стремится бессознательно обработать все возможные значения слова, даже неоднозначные или неподходящие."

"наше подсознание способно хранить и параллельно восстанавливать все возможные семантические ассоциации для данного слова, даже если слово это имеет несколько значений и в контекст вписывается только одно из них. Бессознательно мозг предлагает варианты, сознательно - делает выбор."

"мозг способен бессознательно обрабатывать синтаксические связи и значения слов в правильно построеном словосочетании"

"бессознательно воспринятые слова влияют на мозг слабее, чем воспринимаемые сознательно"

"в некоторых случаях более эффективное решение задачи может быть получено не за счет цененаправленных сознательных усилий, а за счет работы на самом краю бессознательного"

"мы можем бессознательно производить простейшие математические действия, в том числе вычислять среднее и сравнивать числа между собой"

"сну явственно сопутствует высокая бессознательная активность мозга, способствующая консолидации памяти и возникновению озарений"

"К работе за пределами сознания приспособлены даже высокоуровневые области коры, которые работают с воспринимаемыми извне познаниями из области культуры, например с чтением или математическими расчетами"

"Передача и распространение информации - крайне важная функция сознания (Уильям Джеймс. Принципы психологии, 1980)"

"наше бессознательное зрение предлагет различные варианты, а сознание выбирает самый подходящий из них"

"В целом парадигма условного рефлекса предполагает, что эволюция отвела сознанию особую роль - научаться с течением времени, а не просто жить в настоящем"

"В мозгу человека преобладают паралельные, самоизменяющиеся структуры, мозга работает с вероятностными распределениями, а не с дискретными символами, и устройство его радикально отличается от архитектуры современных компьютеров. Нейробиологи давно уже отказались от сравнения мозга с компьютером."

"изображения, демонстрировавшиеся менее 50 миллисекунд, рассмотреть было очень трудно, а изображения, находившиеся на экране 100 миллисекунд или дольше, становились видимыми"

"наше сознание не может активизироваться по двум направлениям одновременно и потому мы в каждый момент времени получаем не больше одного "ломтика" осознанности. Когда префронтальная и теменная доли совместно обрабатывают первый стимул, они не могу разом взять и заняться вторым. Сам факт концентрации на первом стимуле зачастую не позволяет нам воспринять второй... чтобы второй стимул мог достигнуть сознания, ему приходиться ждать, пока оно закончит с первым"

"важная вещь: мы осознаем неожиданные события с большим отставанием от реальности"

"человеческий мозг собирает факты так медленно, что информация, которую мы относим к осознанному "настоящему", на самом деле успевает устареть минимум на треть секунды. Длительность этого периода может быть даже больше половины секунды - если поступающие данные так незначительны, что могут преодолеть порог сознательного восприятия лишь после долгой аккумуляции"

"восприятие любого другого физического явления, состоит из двух этапов: сначала бессознательная оценка, затем сознательное возбуждение"

"доступ в сознательный опыт связан с фазовым переходом в динамике нейронных сетей"

"можно сделать вывод о том, что автографом сознательного восприятия является не просто наличие гамма-ритма, а его усиление на позднем этапе"

"когда мы говорим, что осознаем те или иные данные, то на практике имеем в виду ровно следующее: информацыия достигла особого хранилища, в котором стала доступна всему остальному мозгу"

"осознав какую-то информацию, мы можем удерживать ее в мозгу долгое время после исчезновения соответствующего стимула из окружающего мира"

"я полагаю, что гибкое распространение информации является отличительным свойством сознательного состояния"

"теория глобального нейронного рабочего пространства позволяет объяснить массу наблюдений относительно сознания и связанных с ним механизмов мозга. Она объясняет, почему мы осознаем лишь малую толику информации, хранящейся у нас в голове."

"двухмесячный ребенок уже показывает высокие результаты тестов на наличие сознания, однако наши тесты показывают, что детское сознание имеет одно важное отличие от взрослого: мозг младенца работает значительно медленнее, чем мозг взрослого человека."

"Миелиновые оболочки - жировые мембраны, окутывающие аксон, - созревают на протяжении всего детства и даже подросткового периода. В первую очередь они создают электричесткую изоляцию, обеспечивая таким образом повышенную скорость и точность распостранения нейронных импульсов в отдаленные точки. Мозговая сеть сознания у ребенка уже собрана, но еще не заизолирована, поэтому интеграция идет гораздо медленнее"

"метапознание ... способность думать о том, что мы думаем"

"Метапознание - это способность знать границы собственных знаний, определять меру веры или уверенности в собственных мыслях"

"я вслед за Наомом Хомски полагаю, что язык развивался не как система коммуникации, а как средство репрезентации и главным его достоинством является то, что он позволяет обдумывать новые идеи, а не просто делиться ими с окружающими. Наш мозг постоянно и непрерывно назначает символы для всех ментальных репрезентаций, а потом составляет из этих символов совершенно новые комбинации"

"из десяти наиболее часто употребляемых глаголов английского языка шесть относятся к знаниям, чувствам или целям (find, tell, ask, seem, feel, try)"

"Рекурсивная функция человеческого языка вполне может оказаться двигателем сложных составных мыслей, которые недоступны представителям других видов"
Profile Image for Noreen.
109 reviews26 followers
March 16, 2015
As someone with what I feel is a particularly noisy brain, I really enjoyed this book about recent discoveries in neuroscience. (I do a great deal of reading because it helps focus my "mind" -- whatever that is.)

The findings of Dehaene and his team appear to be groundbreaking. Why aren't they in the headlines, at least the human interest story about methods being developed for determining the level of consciousness in comatose people?

The book is very well organized. It's real science, written in a way that is easy for a non-scientist to comprehend. Critical thinking and the scientific method are employed throughout. The author sticks with the facts. He uses little conjecture and lets us know when he does. He gives caveats and plays the devil's advocate. He explains efforts to screen bias and errors out of experimental procedures. He backs up his conclusions with lots of data. The endnotes and bibliography are extensive. I've read some general interest books on science lately that are mostly speculation and groundless conclusions, so this was refreshingly rational.

What is not new is that there is vastly more activity going on in our unconscious mind than comes to our conscious attention (or what he calls "conscious access" to distinguish it from unconscious attention) and that we can think about only one piece of information at a time. He disagrees with scientists who think consciousness is a backseat driver, a useless "spandrel" of evolution. He believes it is biologically adaptive. He uses subjective reports of experience to make objective determinations of what consciousness is, what it does, and what it is good for. We can't read minds and our instruments for measuring brain activity are still rudimentary, so we must rely on subjective reports; Dehaene has configured studies to make those reports as reliable as possible. His team's theory is called the "global neuronal workspace." "We propose that consciousness is global information broadcasting within the cortex: it arises from a neuronal network whose raison d'être is the massive sharing of pertinent information throughout the brain."

In the end, he takes the approach that we have the capability of one day decoding and modeling how the brain works. He takes the materialistic view further than some by predicting that human subjective experience, or self-consciousness, will be decoded as well. He claims it is not so much a hard problem as a complex one -- and that we will eventually unravel it. He says the idea of qualia will one day be as antiquated an idea as vitalism. Though the idea of vitalism has been supplanted by the recipe for life that is DNA, we still haven't really got it figured out, as illustrated by this interesting video entitled "What is Life? Is death real?" by Kurtzgesagt: https://m.youtube.com/#/watch?v=QOCaa.... So I would repeat the words of Ben Goldacre from the title of his book: "I think you'll find it's a bit more complicated than that."

He goes on to argue that we are a machine with free will, and that that is not a contradiction in terms. Well, if consciousness is real, and though it is subjectively experienced it can be objectively measured, then so is free will, and maybe morality, and so on. A slippery slope. My two cents on free will is that it's a non-issue: an illusion created by our consciousness, which has us convinced that we are in the driver's seat. If anything's driving our meat machines, it's our genes. Our consciousness also has us convinced that since we're in charge of ourselves, something needs to be in charge of the world. And that since we have a self, something with a self had to have invented us. That could explain a lot about religion. In contrast, we are learning from molecular biology that we, that life itself, is actually self-organizing -- that life creates itself, that it "emerges" once sufficient complexity is reached. That is such a bizarre concept to us. Of course, I could go further and say consciousness itself is an illusion of consciousness, but then I'd be in disagreement with everything in this book, no matter how well presented. My argument is a poor one, anyway, because if life emerged from complexity, then consciousness could also. And life is real … isn't it? So I guess I'll keep reading about these hard questions. It's an endlessly fascinating subject. We are enchanted with ourselves. And why shouldn't we be?
Profile Image for Carol.
191 reviews3 followers
July 7, 2014
A first-rate work by eminent cognitive neuropsychologist Stanislas DeHaene, outlining his "global workspace" theory of consciousness. According to DeHaene, there are four hallmarks of a conscious thought: sudden widespread ignition of circuits in the parietal and prefrontal lobes; a late slow wave called the P3 wave across the top of the head detectable by EEG; a late burst of high-frequency "gamma" waves; and synchronization of two-way exchanges across widely separated parts of the brain. Although DeHaene rejects dualism and does not think consciousness has magical or supernatural qualities, he concedes that there is much that we do not know about consciousness and rejects the oft-made comparison of the brain to modern-day computers as sloppy and superficial.

DeHaene admits subjective experience as raw material for research, but argues that subjective experience should be backed up by empirical studies facilitated by modern-day research tools such as EEG and functional MRI that can image electrical charges in progress. He rejects theories based on subjective experience untested by empirical studies; of Freud, he states, " It would not be a huge exaggeration to say .... the ideas that are solid are not [Freud's] own, while those that are his own are not solid"

Although DeHaene is justly proud of his French heritage, he writes in a graceful, nuanced English prose, accessible to the nonspecialist, that would be the envy of most native English speakers.

Profile Image for Gaurav Gautam.
15 reviews
September 18, 2018
Gets boring in some parts because of the writing style, but the content makes up for it.
Profile Image for Nelson Zagalo.
Author 14 books456 followers
May 19, 2015
[Para ler com links, imagens e formatação completa, ler em
http://virtual-illusion.blogspot.pt/2...]

Stanislas Dehaene oferece-nos um excelente trabalho de divulgação da investigação científica que se tem realizado nas últimas décadas à volta do conceito de 'consciência'. A abordagem escolhida por Dehaene é a de simplificar o domínio, libertando dos tabus a que área foi votada pelos próprios investigadores. O domínio dos estudos da consciência foi sempre bastante frágil, à semelhança do estudo das emoções, por ser considerado não apenas complexo, mas impossível de vergar ao método experimental. Desta forma este livro de Dehaene funciona quase como uma lufada de ar fresco na desmistificação e facilitação de acesso àquilo que designamos de consciência.

Dividiria o livro em três grandes partes, a introdução ao conceito e sua sustenção evolucionária, que ocupam os primeiros capítulos, simples e cheios de metáforas que se percebem muito bem, e que nos garantem uma noção bastante concreta do que é a consciência. A segunda parte, um pouco mais densa, nomeadamente por se procurar sustentar as ideias com muitos estudos realizados no campo e que acabam dedicando demasiado tempo a tecnicismos do cérebro, perdendo por vezes a nossa atenção. E depois o capítulo final no qual se aponta ao futuro da área, com dados e especulações extremamente instigantes. Deste modo quero deixar apenas algumas notas sobre a definição do conceito, e depois dedicar algumas linhas à projecção para estudos futuros.

Comecemos pela definição de consciência que Dehaene apresenta :

“consciousness is brain-wide information sharing. The human brain has developed efficient long-distance networks, particularly in the prefrontal cortex, to select relevant information and disseminate it throughout the brain. Consciousness is an evolved device that allows us to attend to a piece of information and keep it active within this broadcasting system. Once the information is conscious, it can be flexibly routed to other areas according to our current goals. Thus we can name it, evaluate it, memorize it, or use it to plan the future.” (abertura do Capítulo 5)

Isto levaria-nos a questionar de que serve então a consciência, porque não funcionamos apenas por meio de processos não-conscientes? E é nesse sentido que se torna interessante analisar o processo em termos evolucionários, que Dehaene define assim:

“consciousness supports a number of specific operations that cannot unfold unconsciously. Subliminal information is evanescent, but conscious information is stable — we can hang on to it for as long as we wish. Consciousness also compresses the incoming information, reducing an immense stream of sense data to a small set of carefully selected bite-size symbols. The sampled information can then be routed to another processing stage, allowing us to perform carefully controlled chains of operations, much like a serial computer. This broadcasting function of consciousness is essential. In humans, it is greatly enhanced by language, which lets us distribute our conscious thoughts across the social network.”

Isto é um processo que me interessa particularmente, porque o conceito de hipertexto é fundamentalmente baseado no mesmo. Se Vannevar Bush procurava emular a nossa capacidade de pensamento associativo, ou seja de processamento de múltipla informação, em paralelo, que ocorre no não-consciente, fundamental em termos de agilidade cognitiva, pelo meio ficou esquecido o problema do consciente, ou seja, o modo como filtramos a informação do exterior, como consolidamos a informação e a transportamos para o não-consciente, via processos em série. Este problema agravar-se-ia depois ainda mais com o surgimento do hipermedia/multimedia, em que os documentos passavam não apenas a apresentar diversidade não-linear de informação, mas modelada por meios distintos.

Por isso aceder a um documento multimedia, em que o conteúdo que se pretende transmitir, é espartilhado em vários objectos distintos de media a tempos não-lineares, torna a compreensão mais difícil do que aceder a um documento linear e num único meio. A ideia de que os objectos distintos se reforçam mutuamente acaba por não funcionar já que os múltiplos meios obrigam de imediato a um consumo maior de consciência. Usando linguagem informática, poderemos descrever o processo da seguinte forma: quanto mais meios distintos utilizar numa mensagem, mais software tenho de fazer o receptor carregar para o consciente, para conseguir descodificar cada meio, sobrando menos capacidade para descodificar a essência do que se quer comunicar. Ou seja, não lemos um texto, uma foto, um vídeo ou sons da mesma forma, precisamos de usar recursos apreendidos em experiências anteriores, para descodificar cada um desses sinais. Nesse sentido - um texto, ou um vídeo, ou um áudio - permitem ao receptor concentrar-se quase exclusivamente na mensagem, assumindo o meio quase como transparente.

Daí que o enfoque comunicativo do multimédia não possa ser a multimedialidade mas antes a interatividade, como tenho defendido ("Media Criativos e Interactivos" (2010), Jornalismo 'Interactive Storytelling'? (2015)). Porque aquilo que diferencia os novos media dos tradicionais é apenas, e só, a interatividade, já que a união de diferentes media vem desde os anos 1930 sendo feita pelo cinema. E quando falo de interatividade, não falo de um processo aberto, ou rizomático, de acesso a múltiplas fontes de informação, mas antes de um processo cíclico de interacção - conversacional - entre o artefacto e o receptor. Daí que pensar, desenhar e construir um artefacto a partir do seu potencial de interatividade, seja totalmente distinto de o fazer a partir do potencial de junção de diferentes media.


No último capítulo são várias as questões e desafios apresentados para os quais ainda não temos respostas, e que se revelam de enorme importância, das quais escolho aqui discutir duas:

1: "Can we figure out whether a monkey, or a dog, or a dolphin is conscious of its surroundings?"

Neste ponto Dehaene discute os vários estágios do conhecimento científico porque passámos em termos do que separa o homem dos animais, sendo que no mais recente estágio se assumia que o que determinava esta diferença estava na capacidade do homem poder reflectir sobre si mesmo, algo que nos estudos mais recentes se tem demonstrado, com grande evidência, que vários animais são também capazes de fazer, ou seja, os animais possuem consciência. Deste modo Dehaene procura elaborar uma ideia que demonstre a linha que nos separa dos animais, e fá-lo usando uma abordagem cognitiva assente nos processos de linguagem, com a qual concordo inteiramente:

“although we share most if not all of our core brain systems with other animal species, the human brain may be unique in its ability to combine them using a sophisticated “language of thought.” René Descartes was certainly right about one thing: only Homo sapiens “use[s] words or other signs by composing them, as we do to declare our thoughts to others.” This capacity to compose our thoughts may be the crucial ingredient that boosts our inner thoughts. Human uniqueness resides in the peculiar way we explicitly formulate our ideas using nested or recursive structures of symbols (..) in agreement with Noam Chomsky, language evolved as a representational device rather than a communication system—the main advantage that it confers is the capacity to think new ideas, over and above the ability to share them with others. Our brain seems to have a special knack for assigning symbols to any mental representation and for entering these symbols into entire novel combinations (..) The recursive function of human language may serve as a vehicle for complex nested thoughts that remain inaccessible to other species. Without the syntax of language, it is unclear that we could even entertain nested conscious thoughts such as He thinks that I do not know that he lies. Such thoughts seem to be vastly beyond the competence of our primate cousins.”

2: "Could we ever duplicate them in a computer, thus giving rise to artificial consciousness?”

Para o o final Dehaene deixa um assunto, semelhante ao do ponto anterior, mas numa direcção diferente. Se no caso dos animais, estamos focados em tentar perceber o que nos coloca em planos diferentes, no caso da Inteligência Artificial, estamos interessados em perceber se será verdadeiramente possível criar um processo matemático que simule a consciência. Um tópico que me tem preocupado nos últimos anos, por causa da minha investigação na área de emoções, e que discuti aqui já a propósito de um livro de Oliver Sacks e de uma talk de António Damásio.

“I have no problem imagining an artificial device capable of willfully deciding on its course of action. Even if our brain architecture were fully deterministic, as a computer simulation might be, it would still be legitimate to say that it exercises a form of free will. Whenever a neuronal architecture exhibits autonomy and deliberation, we are right in calling it “a free mind” — and once we reverse-engineer it, we will learn to mimic it in artificial machines (..) Our neuronal states ceaselessly fluctuate in a partially autonomous manner, creating an inner world of personal thoughts. Even when confronted with identical sensory inputs, they react differently depending on our mood, goals, and memories. Our conscious neuronal codes also vary from brain to brain. Although we all share the same overall inventory of neurons coding for color, shape, or movement, their detailed organization results from a long developmental process that sculpts each of our brains differently, ceaselessly selecting and eliminating synapses to create our unique personalities. The neuronal code that results from this crossing of genetic rules, past experiences, and chance encounters is unique to each moment and to each person. Its immense number of states creates a rich world of inner representations, linked to the environment but not imposed by it. Subjective feelings of pain, beauty, lust, or regret correspond to stable neuronal attractors in this dynamic landscape. They are inherently subjective, because the dynamics of the brain embed its present inputs into a tapestry of past memories and future goals, thus adding a layer of personal experience to raw sensory inputs. What emerges is a “remembered present,” a personalized cipher of the here and now, thickened with lingering memories and anticipated forecasts, and constantly projecting a first-person perspective on its environment: a conscious inner world.”
Profile Image for Stetson.
520 reviews311 followers
October 21, 2023
There is no shortage of books on consciousness. It is catnip to both dilettantes and experts alike. Given that consciousness research has carried an intellectual stigma, especially among those in hard sciences, it has been a field populated by dilettantes and wild-eyed philosophers.

Stanislas Dehaene is no dilettante though, he is a bonafide expert in cognitive neuroscience, which is the fancy, respectable label we've finagled for the study of the higher-order stuff our brains do; stuff that we can't completely explain with our traditional scientific approaches. Questions like: How does our brain generate a conscious thought? Why does so much of our knowledge remain unconscious? How can we test consciousness in animals, babies, and those with severe brain injuries?

Dehaene provides a brief tour of important findings from cognitive neuroscience while drawing in relevant cross-disciplinary insights. Unfortunately, some of the cited research is now known to be a bit spurious (e.g. the priming studies), but nevertheless, the general picture of what we know about the brain and consciousness is well represented.

Generally, this work largely reads as a defense of the global workspace theory (GWT) of consciousness, especially if one is familiar with most the research highlighted. The author, Stanislas Dehaene, is one of the leading proponents of GWT. It is a framework for thinking about how the brain generates conscious thoughts and experiences, analogizing subjective experience to that of the theater. According to GWT, the brain contains many specialized processes or modules that operate in parallel, much of which is unconscious. Attention acts as a spotlight, bringing some of this unconscious activity into conscious awareness on the "global workspace." The global workspace is a functional hub of broadcast and integration that allows information to be disseminated across modules. GWT facilitates an understanding of top-down control of attention, working memory, planning, and problem-solving through this information sharing. As such, it can be classified as a functionalist theory of consciousness.

GWT is intuitive and a pretty compelling explanation of consciousness. It works well descriptively but is plagued by vagueness and isn't always consistent with brain physiology. It does not appear to answer the hard problem of consciousness, which is how and why any mental process can be conscious at all, providing just a functional account of the cognitive role of consciousness, but not its nature or essence. However, I am not sure how important solving the hard problem is; if GWT gains enough predictive power both for the behavioral of neuronal circuits and that of the behavior of individuals, then it is capturing something about how consciousness works (assuming consciousness is actually relevant to our behavior, which is a safe assumption though Chalmber's zombie argument would allege otherwise).

Obviously, GWT isn't there yet, otherwise I wouldn't be saying this, but I can envision a path where GWT achieves greater validity. But this again least us back to its lack of specificity in its own functional terms. It needs more mechanism and a way to specify the nature of the content, the code if you will, of complex neurological mechanisms. Dehaene discusses a number of interesting relational points in GWT-inspired experiments but none of this ends up constituting direct evidence of how a global workspace is constructed in the brain.

Dehaene acknowledges the contributions and challenges of other models, such as integrated information theory, recurrent processing theory, and higher-order thought theory. But these theories are subject to few comparisons or in-depth discussions. Consciousness and the Brain is a great introduction of cognitive neuroscience and GWT.

695 reviews73 followers
April 25, 2015
*This book was extremely exciting for me because my model of consciousness has been, for quite some time now, Yggdrasil, and the theory set forth in this book, including the map he draws… confirms everything I have thought. If you made his map beautiful--it's Yggdrasil.

-Haven't had this much fun reading a book since Ayn Rand's Intro to Objectivist Epistemology!
-This book was not actually what I was looking for--it is not so much about what we DO with conscious thoughts once we have them, it is more an entire book about the fine line between consciousness thoughts and unconsciousness ones.
-But that's fine because this book is awesome. Having a clear understanding of the conscious and unconscious workings of our brain is super fun.
-Again I am blown away by how much humans have been able to correctly infer about the workings of their brains without any fancy machinery (Ayn Rand especially). Fancy machinery and billions of studies prove that humans are brilliant and actually have had their brains pretty well figured out for a long time.

Notes:

-Consciousness is currently defined as "the global information broadcasting in our brain" or "brain-wide information sharing"

-The author says science has reached no conclusions yet about free will nor the concept of self

-We can only focus on ONE thing at a time, for real, never text and drive. Moreover, we should not really be playing with the radio and driving or eating and driving either. Your brain LITERALLY cannot attend to more than one thing at a time. It can go back and forth so that you feel like you are multitasking, but you're not. You are not watching the road while you are doing the other thing. And witnesses that were doing something else at the time should not be trusted. TURN THE TV OFF unless you are actively watching it and get it out of bars and public spaces!

-Way too many studies, as usual, on Western brains. There were some studies in here that I am fairly sure would not trick the brains of hunter-gatherers. Frustrating that almost all of our knowledge of the brain comes from damaged brains (especially people with epilepsy). Conclusions about the human brain should only be made after those epileptic brains are compared to normal brains in children, hunter-gatheres, hunter-gatherer children, and monkeys.

-Something shown for 40 milliseconds will not be consciously perceived, something shown for 60 milliseconds will.

-Our unconscious mind is brilliant and very functional--it is basically a statistician, it can generate very sophisticated hunches, and works a lot faster than our conscious broadcast

-Virtually all the brain's regions can participate in both conscious and unconscious thought

-Incubation phase of ideas just as crucial as we all know it is

-Some decisions (like decorating) are better done without too much conscious focus i.e. our subconscious will make a better choice.

-Dreams are about the last 24 hours.

-Our army of unconscious neurons approximates the true probability distribution of the states of the world, while our consciousness reduces it to all-or-none samples.

-Experiments show that subliminal stimuli undergo a rapid exponential decay in the brain. With effort we may keep subliminal information alive for a slightly longer period. Only consciousness allow us to entertain lasting thoughts. (This is the sense of super ego, "no, stay here, stay focused on this")

-Though consciousness overflows language--we perceive vastly more than we can describe--anything we focus on consciously will be tied to language, the goal to perceive without words is a fruitless one, anything you are trying to express that you don't have words for is being pulled from the subconscious, after it is made conscious you will have words for it.

-Page 113 author summarize social science theory that contradicts what he stated in the first chapter--science has not reached any conclusions about the self but this French philosopher and fiction writer has! But the information is presented as if the author agrees that we have no self, just a made up story we tell ourselves to feel good. And we can't predict our own behavior any better than some else's? Seriously?

-Unconscious perception is narrowly recored. When brought into conscious focus it is broadcast to all systems--hence the importance of bringing unsettling emotions into conscious awareness to figure them out!

-Scientists know exactly what parts of the brain to stimulate to make people feel like they are floating above their bodies and see a white light

-Four signatures of consciousness: intense neuronal activation that leads to a sudden ignition of parietal and prefrontal circuits, P3 wave, high frequency oscillations, many regions exchange bidirectional and synchronized messages over long distances forming global brain web

-"No experiment will ever show how the hundred billion neurons in the human brain fire at the moment of conscious perception." REALLY? The history of science has taught you nothing?

-"By measuring the speed of activation with MRI, we confirmed that a a baby's language network is working--but at a speed much slower than in an adult…. The mere fact that an attentive two-month-old, during language processing, activates the same cortical network as an adult is unfortunately inconclusive… however our experiment also showed that babies possess a rudimentary form of verbal working memory. When we repeated the same sentence after a fourteen-second interval, our two-month-olds gave evidence of remembering…already at two months, their brain bore one of the hallmarks of consciousness, the capacity to hold information in working memory.

-Most parents will not be surprised to learn that their two-month-old baby already scores high on tests of consciousness--but four times slower than an adult.

-"The Swedish pediatrician Hugo Lagercrantz and the French neurobiologist Jean-Pierre Changeux have proposed a very interesting hypothesis: birth would coincide with the first access to consciousness. In the womb, they argue, the fetus is essentially sedated, bathed in a drug stream that includes 'the neurosteroid anesthetics pregnanolone and the sleep-inducing prostaglandin D2 provided by the placenta.' Birth coincides with a massive surge of stress hormones and stimulating neurotransmitters such as catecholamines; in the following hours, the newborn baby is usually awake and energized, his eyes wide open. Is he having his first conscious experience? If these pharmacological inferences turn out to be valid, delivery is an even more significant event than we thought: the genuine birth of a conscious mind.

Profile Image for Simon Lavoie.
139 reviews18 followers
October 16, 2020
Après avoir été raillée, déclarée inutile ou illusoire, la conscience s'est hissée au coeur d'un important mouvement de recherche neuroscientifique. L'identification des tâches uniquement possibles via un traitement conscient et celle des aires cérébrales spécifiquement impliquées dans celui-ci connaissent des avancées significatives. Le code de la conscience présente l'hypothèse de l'espace neuronal global en laquelle consiste l'essentiel des contributions de Stanislas Dehaene et de son équipe à ces problèmes et à un certain nombre d'autres – non des moindres : spécificité cérébrale humaine, conscience et métacognition animales, simulation artificielle de la conscience, dépassement des corrélations par une causation délibérée d'états conscients, identification et remédiation des états pathologiques (des états végétatifs à la schizophrénie), formulation d'une théorie cognitive et évolutionnaire synthétique faisant sens des propriétés émergentes dans la conscience à l'aide de celles des réseaux de neurones.

L'hypothèse de l'espace neuronal global conjugue les trois facteurs qui auraient joué un rôle moteur dans l'avènement de la science de la conscience : utilisation de tests faisant varier à volonté les conditions dans lesquelles les stimulations sensorielles accèdent ou non au traitement conscient, raffinement de la définition de la conscience par soustraction à celle-ci des opérations possibles via un traitement inconscient, et confiance envers l'introspection comprise comme sources de données, comme rapport par les participants de ce qu'ils ont vu ou entendu.

Une portion importante de l'hypothèse de Dehaene repose sur l'identification des marqueurs cérébraux récurrents de l'accès conscient du traitement des stimulations sensorielles : enregistrement d'une onde P3 (onde positive survenant un tiers de seconde après l'enregistrement inconscient d'un stimulus), enregistrement d'ondes gamma et d'un embrasement d'activités des aires corticales (préfrontales, pariétales, temporales, cingulaires). Une autre portion centrale consiste à identifier les opérations uniquement possibles via un accès conscient du traitement des stimulations (que celles-ci soit d'origine sensorielle ou interne au système cérébral). Ces opérations spécifiques comprennent le partage flexible de l'information à autrui et à une variété de processeurs mentaux (langage, mémoire à long terme, évaluation et planification), la stabilisation des représentations ou du contenu mental par réduction du doute et de l'ambivalence, le traitement ou transformation des représentations mentales par séquences d'opérations mentales, la mise en mémoire de travail des résultats des séquences de traitement intermédiaires.

Il s'agit d'un ouvrage écrit avec clarté, efficacité, soutenu par des illustrations économes en nombre, et qui s'avère stimulant autant par la solidité des données sur lesquels il s'appuie que par les perspectives et les lacunes à combler qu'il identifie.

Le lecteur intéressé notamment à acquérir une vision réaliste des continuité et discontinuité entre l'intelligence consciente et ce que des systèmes artificiels peuvent accomplir dans l'état actuel trouvera de précieuses indications, notamment sur le dépassement de la modularité propres aux systèmes primaires par les axones anormalement longues des aires du cortex associatif à l'œuvre dans le traitement conscient - dans la sélection, l'enrichissement et la réverbération de ce contenu à l'ensemble des processeurs mentaux. Réverbération qui n'aurait pour équivalent, présentement, que le presse-papiers des ordinateurs d'aujourd'hui.

Le dépassement proposé d'un certain nombre de visions, qui apparaissent simplistes a posteriori, de la division du travail conscient et inconscient, et de la diversité de ce que chacun d'eux réalise en terme de calcul et de transformation apporte une satisfaction indéniable et plus générale à la lecture. L'enrichissement de notre vision des variétés de traitement inconscient est présenté comme une des raisons pour la position de premier plan qu'occupe l'hypothèse de l'espace de travail neuronal global dans le paysage neuroscientifique contemporain.

Celui ou celle qu'intéresse la progression, au sein des neurosciences et de la pensée évolutionniste, des postulats de la sociologie et de l'anthropologie sur une origine sociale de la conscience y trouvera également son compte - ce qui fut mon cas. Dehaene rejoint notamment, sans en faire état, Michael Tomasello quant à l'hypothèque suivant laquelle la localisation, dans un même espace ou format représentationnel, de ce que nous savons et de ce que les autres savent représente une nouveauté clef au plan cérébral. Cet espace ou format est dit commun, au plan de la circuiterie cérébrale, du fait que le même réseau neuronal s'activant lorsque nous pensons à nous-même s'active lorsque nous pensons aux autres. Ce réseau s'avère également former le mode de fonctionnement par défaut de la conscience. Lorsque, à l'état de repos, la pensée consciente s'absorbe en elle-même, les aires qui s'activent sont celles de l'évaluation de soi et des autres, de la communication (voire du débat et de la justification). L'équivalent serait enregistré chez les macaques, qui à l'état de repos pensent, par défaut, alternativement à eux-mêmes et aux autres. La comparaison de ce que nous savons et de ce que les autres savent est par surcroît présentée comme formant partie d'une capacité de production de représentations et de connaissances plus stables et plus fermes que celles livrées par le traitement inconscient; comparaisons et évaluations permises en partie par un transfert du contenu mental aux autres, c'est-à-dire à un réseau social dont les membres s'engagent à délibérer et à mettre ce qu'ils savent à l'épreuve (un processus, tant individuel que collectif que Hugo Mercier et Dan Sperber ont rendu célèbre sous le concept de vigilance épistémique). La délibération est ainsi comprise comme une conséquence du transfert communicationnel du contenu mental-conscient qui découle de l'architecture du cerveau conscient.
Profile Image for Pim.
7 reviews
July 28, 2025
Toch wel een van de lastigste boeken die ik gelezen heb qua kennis en algemene woordgebruik. Ik heb ook zeker bepaalde termen en woorden moeten opzoeken. Echter was het wel bokkeninteressant want we weten gewoon nog zo weinig over het brein. Bloed fascinerend
153 reviews60 followers
May 9, 2014
The most clear point you get from "Consciousness and the Brain" are the huge strides made in the study of consciousness over the last 25 years.

After reading Dahaene's other books, focused on how the brain processes quantities/math and reading, I great anticipated this book, which goes to the more general topic of consciousness from a neurological perspective. Specifically what a conscious thought is, and how we can identify it when we see brain activity.

He first spends a chapter discussing the processing in our brain that is subconscious - which turns out to be quite a bit. Our subconscious does much more higher level processing that I would have expected; for example, extracting some features of visual image before the conscious brain even get a chance to see the image. The other important hallmark of our subconscious is the swirling mass of processing that's happening even when our mind is supposedly at rest - masses of stimuli just waiting to get promoted to a conscious thought.

The key to understanding consciousness then, is finding out where our subconscious ends and consciousness begins. This is where the revolution in neuroscience and cognitive science has taken place. Given, for example, an image, we know how to present images that will be perceived consciously, and those that will be detected subconsciously but never rise the level of consciousness. Playing with that line, and seeing what happens in the brain just when it is crossed forms the core of Dahaen's exploration.

Although our subconscious does an amazing level of processing, it is very focused and local to certain parts of the brain, depending on the stimulus. When consciousness happens, we see a flood - he calls it an ignition - of activity that flows throughout the brain, from the low level to the upper levels and back again, and through geographically disparate parts of the brain. It is this global activation that is the hallmark of consciousness.

He does an excellent job of discussing what has been discovered, and also where the findings have been early or inconclusive. His copious references will allow anyone who wants to pursue the literature further an onramp to the original papers.

Lastly, he discusses some work done relating to consciousness - how we can detect whether someone in a non-responsive state like a coma is actually consciously able to process or if their brain is too damaged. His brief discussion of consciousness in other animals, and what makes human consciousness and thought unique is intriguing. As a computer scientist, I also found his discussion of the prospect of actual thinking machines - something he sees as eminently possible - food for thought.

If you aren't deeply familiar with literature on neuroscience, then this book provides a great feel for where the state of the art lies today. More importantly, Dahaene pulls it together into a coherent whole, adding his own informed opinions to the discussion. Highly recommended.

On a more personal note, his findings back up a thought that I've been having lately, that philosophy is simply an thinking about thinking without much data to back it up. The consciousness described by Dahene is not only physical, but detectable and most importantly, testable. That is, we have now have the means to start to answer precise questions about how consciousness works through scientific experiment, rather than relying on the theoretical frameworks and viewpoints that philosophers have typically relied upon.
Profile Image for Ci.
960 reviews6 followers
November 27, 2015
This is a clear and intelligent account of scientific exploration in our conscious thoughts. Its merit is evident in its clear writing style, its useful compilation of latest scientific data, and the author's superior first-hand knowledge in this field. But this is a book written by a scientist in a field trembling with border dispute between what can be scientifically understood, and what should be left to the philosophers and theologians. Our author opines that all of human consciousness can be, and will be, understood through science only. In his opinion, which is shared largely by mainstream scientific community, is that there is no unsolvable problem, only if one can define the problem scientifically first. Such naive scientism confidence detracts of the overall book.

Scientists try to pin down a precise definition of "consciousness" to a testable process. The current idea is to define it as "conscious access" -- a process of getting input from external world, process the inputs through a "global neuronal network" throughout our brain, and then report back the results through language and other means. This defined "consciousness" is far narrower than what philosophers and theologians use. The "self-other" identification, the particular "qualia" that individual experience even given the same inputs, and the over-arching problem of what drives the overall "consciousness" process, can hardly be swept aside with the same label of "conscious access".

The scientists have made great strides with the latest technology in observing and analyzing brain's function under various sensory inputs. Yet it is only convincingly accomplished in the small portion of what David Chalmers, a philosopher at University of Arizona called "the easy problems" -- the cognitive process, but not the hard ones such as "qualia". (page 262). The author disagree, 'the hard problem just seems hard because it engages ill-defined intuitions".

Consciousness is one of the ultimate questions for human existence. Scientists are often optimistic over the reach of scientific methods, rarely discuss the "negative capacity" of one's own metier. I share with William James' resistance to the wholesale explanatory power of medico-materialistic tendencies. Being human, our \ life is nourished both by the rational and the irrational; anyone tries to dissect a butterfly knows the fluttering beauty vanished the moment one tries to catch it with the net of pure reason in the name of scientific investigation.

We need to leave room beyond "conscious machinery" model of being human.
Profile Image for Thom.
1,790 reviews70 followers
December 10, 2016
Very thorough book about recent findings differentiating brain signal processing and consciousness. It contains an extensive bibliography and an excellent index, though the information content could be improved slightly through more color images.

The unconscious brain still responds to external stimulus (primarily sounds) at one level, but these responses don't go anywhere. The author uses the interesting metaphor of Sherlock Holmes, gathering several clues before acting on the information. In the unconscious mind, Sherlock is absent, and the clues go unprocessed.

This book describes a process of masking information, similar to optical illusions, so the conscious mind does not see it. Another example is the famous gorilla that walks through the basketball scene - when the brain is focused on one thing, it misses another. This masking is then utilized, with MRI and other modern methods, to study just how information flows in the brain. When conscious, this leads to an information cascade that doesn't appear otherwise.

These techniques can be (and have been) used on patients assumed to be in a vegetative state, what earlier generations would have called brain-dead, and was successful in predicting recovery of some patients. To me, this was the most important part of the book - reaching a patient who could be "locked in" their own unresponsive body.

The author has participated in some preliminary work on modeling this brain function on a computer, and this wasn't explained as well as it could be. I hope that other people working on this with him present papers, articles or books on this topic soon - computing capacity continues to grow and what seemed impossible years ago is much easier today.

In summary, some great ideas are presented, occasional anecdotes get the message across, and the topic is fairly accessible. The language was a bit technical at times, and a few more illustrations would help with those less knowledgeable about the brain. A solid 4½ stars, and highly recommended.
Profile Image for Riccardo.
107 reviews
August 24, 2016
È possibile dare una definizione della coscienza? E non parliamo qui di una definizione filosofica ma addirittura scientifica: dei dati su cui poter lavorare; dei marcatori misurabili della coscienza. Secondo Dehane sì. Tuttavia, nella lettura di questo libro e tenendo presente il suo antecedente "Il pallino della matematica", mi viene da pensare che o la coscienza e anche l'autocoscienza siano un refluso dell'evoluzione oppure che sia uno strumento nato dall'evoluzione il cui scopo sia quello di aiutarci a migliorare le nostre possibilità di sopravvivenza andando al di là delle capacità settoriali temporanee del nostro cervello. In entrambi i casi, l'autocoscienza è destinata a scomparire. Cerco di spiegarmi meglio. Grazie all'autocoscienza, la cui caratteristica più potente sembra essere il linguaggio ossia un mezzo per rappresentare i propri pensieri e ragionarci su, l'uomo è stato in grado di andare al di là delle capacità inconsce e delle risposte automatiche che fanno già gran parte del lavoro; basta pensare al battito cardiaco, alla respirazione, alla capacità di sommare piccole cifre, alla possibilità di imparare dall'esperienza etc. Ecco poi però che lì dove la chimica non è in grado (o non lo è ancora) di arrivare, interviene la coscienza, che secondo Dehane è il frutto di collegamenti a larga scala dei nostri neuroni, che ci permette di andare al di là dei limiti a cui sono preposte le varie parti del nostro cervello.
Ma allora se così è, non vedo quale sarà, dal punto di vista evolutivo, l'utilità della coscienza se il cervello sarà in grado di automatizzare sempre più processi..
Queste sono le conclusioni a cui arrivo seguendo la via indicata da Dehane e inoltrandomi poi da solo nella selva dei pensieri susseguenti.

Tuttavia, come qualcuno mi ha fatto notare, non è detto che Dehane abbia ragione e cioè che la coscienza sia scientificamente misurabile
Profile Image for Safaira .
23 reviews1 follower
January 28, 2023
The first time I heard about this book was when my professor told me that we would use it as study material for our course. I was interested, because I am not used to reading popular science books as study material. However, do not let the 'popular science' aspect fool you, my professor called this the 'best book on consciousness that we have at the moment', and I can see why.

First of all, this book is saturated with research. Both by the author and others. Secondly, the build-up towards what consciousness is, is easy to follow. Deheane first philosophizes about the challenges of studying consciousness, then about why he was able to study it, followed by what consciousness is not needed for (aka what the brain can do unconsciously) and what it is needed for. The chapters after that zoom in on what it actually is (an information-sharing brain wave called P3 which is late and synchronized). The last chapters are about loss of consciousness (where he puts his version of consciousness to the test) and about animal/baby consciousness.
Usually, when I read books like this, the build-up is less chronological and more confusing. Because authors philosophize about different perspectives in consciousness, but Deheane saves that for last.

The third reason as to why I like this book is that there have been a lot of studies that were simple in nature (no complex environmental settings), but yet garnered amazing results. I am always in awe of the resourcefulness of researchers. In addition to that, Deheane was not only good at incorporating studies, but also their shortcomings of course.

And lastly, his theory seems to be true. I get why my professor said it was the best book out there, because Dehaene actually put his theory of consciousness to the test. It was not limited to philosophy. And the results show that the P3 is a very, very important part of what we call consciousness.

This book made me less of a dualist!
This entire review has been hidden because of spoilers.
1,057 reviews4 followers
July 15, 2020
A sweeping review of the current science around the physical workings of the brain and how it manifests itself as consciousness. The book is so comprehensive that it gets a little dull and repetitive in places, as well as a little too deep in the weeds for a general reader. But, that’s not really a valid criticism of the book (it’s my fault as a reader). What it does do is present some amazing and very clever neuroscience as these brilliant researchers attempt to tease out what consciousness is (scientifically, not philosophically), how it works, what its purpose is, and whether and how it applies to those we traditionally believe lack it (those in a vegetative state, infants, non humans). Dehaene has developed the idea of consciousness as a neuronal workspace, gathering input from many different subsystems and making connections and decisions from these, a concept that works well to explain the data. Along the way, we find out how perceptual input becomes conscious (slowly, ultimately reaching a phase-shifting threshold … or not), how neurons process information, how and why the brain uses certainty (and uncertainty) to make decisions and a whole bunch of amazing stuff that will surely form the basis for a deeper understanding of consciousness to develop in the decades to come. I’ll probably forget a lot of the specific factual information in this book, but the concepts really changed my thinking about how consciousness works.

Grade: A-
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