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大腦神經學：意識篇 – 開欄文
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我求知的主要興趣從倫理學轉向認知科學後，偶而會涉及到一些討論「意識」的科普書籍。讀了恰爾莫斯教授的《具有意識的心靈：追求基本理論》一書後，在我(自以為)了解該書意旨範圍內，我對他「經驗本質」概念和「意識研究上的困難議題」說法兩者，都持存疑態度。自然也就使得我在過去20多年中，進一步讀了不少關於「意識」的書籍以及研究報告。我收集了相當多這方面的論文；本部落格在過去曾經轉載了一些。我也試圖系統性寫下自己的觀點；但因為功力不足，寫寫停停一直無法成章。

在倫理學之外，這是我最希望能把過去讀書心得整理出來的一個領域。先轉載我認為有爭議的兩篇文章來起個頭。

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夢的功能 -- Clarissa Brincat
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我不是醫學院或生命科學領域出身；我的意見自不過是門外漢的道聽塗說。根據我的經驗以及讀過的相關書籍、論文、和報導，我認為：「夢」屬於意識活動種種形式中的一個；因此，我把下文歸於此欄。

What’s the purpose of dreaming?

Dream experts have plenty of possible answers.

Clarissa Brincat, 06/16/25

Your brain never rests. Image: PM Images/Getty Images5 請至原網頁觀看示意圖

We all dream — but why? As with many mysteries of the mind, science doesn’t have one neat answer.

“You’ll get as many answers to the question ‘What is the purpose of dreaming?’ as there are dream psychologists,” says Deirdre Barrett, dream researcher at Harvard University and author of The Committee of Sleep.

According to Austrian neurologist and founder of psychoanalysis Sigmund Freud, dreams offered vital clues to unresolved conflicts buried deep within our psyche. But Freud’s theory, introduced in his 1899 book The Interpretation of Dreams, sparked plenty of controversy. Critics argued that his dream interpretations were overly focused on sex, highly subjective, and impossible to verify—two analysts might offer entirely different readings of the same dream, with no objective way to know who was right.

In the decades since Freud, other scientists have offered alternative explanations for why we dream. One of the most prominent is the threat simulation theory, proposed by Finnish neuroscientist and psychologist Antti Revonsuo in 2000. According to this view, dreaming is an ancient biological defense mechanism. By simulating dangerous situations, our brains rehearse the skills needed to recognize and avoid threats—a kind of virtual reality training ground for survival. A 2005 study lent support to this theory by examining the dreams of Kurdish children exposed to war and trauma. Compared to non-traumatized Finnish children, these children reported more frequent dreams filled with severe threats, suggesting that their minds were practicing how to cope with danger.

But even the threat simulation theory is debated. A 2008 study comparing residents of high-crime areas in South Africa to those in low-crime parts of Wales found that South African participants, despite facing more real-world threats, actually reported fewer threatening dreams than their Welsh counterparts. This result challenges the idea that the brain uses dreams to simulate danger when exposed to trauma.

Another theory suggests that dreams are simply a side effect of memory consolidation—the brain’s way of replaying and reinforcing new memories while we sleep. As the brain’s hippocampus and neocortex work together to file away fresh information, they may also blend it with older memories, creating the often strange mashups we experience as dreams.

Dreams may also help us process and manage emotions, especially negative ones, according to the emotion regulation theory of dreaming. Research focusing on recently divorced individuals experiencing depression found that participants who dreamed about their ex-spouses were more likely to show significant improvement in their mood one year later, particularly if their dreams were vivid and emotionally rich. Another study found that people who dreamed about stressful events they had experienced before sleep woke up feeling more positively about the events the next day, suggesting that dreams can help transform emotional distress into resilience.

Recent brain imaging studies support this idea. People who frequently experience fear-related dreams show reduced activation in fear centers of the brain during waking life, hinting that these dreams may serve as a kind of overnight therapy session, helping us better regulate our emotions when awake.

Ultimately, Barrett suggests that we may be asking the wrong question. “We’d rarely ask the analogous question: ‘What is the purpose of thinking?’” she says. Just as waking thought serves many functions—from planning to problem-solving to daydreaming—dreams likely do too. “The value of dreaming lies in its difference. It’s a distinct mode of thought—one that supplements and enriches our waking cognition.”

In fact, some researchers believe dreams offer a unique mental space for solving problems that stump us during the day. In this altered brain state, regions responsible for imagery become more active, allowing the mind to solve problems requiring visualisation. History is full of famous examples: Mary Shelley reportedly dreamed the central scenes of Frankenstein; German chemist August Kekulé envisioned the ring structure of benzene in a dream; and Russian chemist Dmitri Mendeleev dreamed his final form of the periodic table of the elements.

In the end, dreams may serve many purposes—or none at all—but they remind us that even in sleep, the brain never truly rests.

This story is part of Popular Science’s Ask Us Anything series, where we answer your most outlandish, mind-burning questions, from the ordinary to the off-the-wall. Have something you’ve always wanted to know? Ask us.

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意識面面觀 -- Erwan Dubois
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The enduring mystery of consciousness

Erwan Dubois, 06/02/25

What is consciousness? When does it begin? How can it be measured? Does AI have it? An update on an intimate, universal yet mysterious phenomenon that the neurosciences are only just starting to decipher.

Consciousness: a simple definition, but a complex measurement

From a subjective standpoint, consciousness seems to be a straightforward concept: it is the state we are in when we are awake. And yet, its scientific nature remains difficult to quantify. The main problem lies in its measurability: how do we determine whether a being, human or not, is conscious?

“If you tell me that you’re conscious, I believe you,” explains Catherine Tallon-Baudry, a CNRS research professor at the LNC2 cognitive and computational neuroscience laboratory in Paris. “But if I’m dealing with an organism that’s unable to say it’s conscious, or an artificial intelligence system that claims to be, I can’t be so sure.”

Consciousness is a subjective state. It cannot be observed directly, unlike measurable biological parameters like blood sugar levels or cardiac activity.

A bonobo looking at its own reflection in a mirror. Primates pass the test of self-recognition – including gorillas, which were previously thought to lack this capacity.
Renaud Fulconis / Biosphoto 請至原網頁觀看照片

What beings are conscious? And how do we know?

Are humans the only conscious beings? The question is subject to debate in the scientific community. There is no doubt about the intelligence of many species, but intelligence and consciousness are not the same thing.

Certain primates, dolphins and some birds show signs of self-awareness 1, in the sense that they seem to recognise themselves in a mirror. But the interpretation of this test remains problematic. Many animals fail it even though they engage in behaviours that suggest a form of consciousness 2.

The neurosciences offer another approach: the study of brain activity associated with consciousness 3. For example, laboratory tests can explore “vision at the threshold of consciousness”: an individual is shown brief flashes of images to determine at what point they become consciously perceptible. By analysing how the brain processes information, researchers can establish cerebral markers of awareness. These markers can then be measured in comatose patients who no longer communicate with the outside world, to detect the presence of any residual sentience 4.

The Vincent Lambert case 5 offers a good example of the difficulties in determining whether a person is conscious when they are unable to communicate. But what about animals? Experimental protocols, often reward-based, raise questions: do the subjects’ responses indicate true consciousness or mechanical learning?

Is the brain the only arbiter?

Does consciousness reside solely in the brain? “The entire organism is conscious, not just 1.2 kilos of brain matter,” Tallon-Baudry notes. She supports the idea that consciousness is the result of a complex interaction between the brain and the body – an aspect often overlooked by conventional theories. In the course of multiple studies 6, the neuroscientist has demonstrated that the connections between the heart and the brain make it possible to predict both self-awareness and awareness of the outside world.

Combining neuroscience and experimental psychology, the work of CNRS research professor Nathan Faivre at the LPNC 7 bolsters this theory. His studies 8 have shown that bodily disruptions, such as alterations in corporeal perception, significantly influence our self-awareness and capacity to process sensory information. Faivre’s findings indicate that physical changes can affect our interaction with the environment and alter our entire conscious experience.

A universal theory of consciousness: mission impossible?

Science continues to progress, but with caution. As Tallon-Baudry puts it, “We have hypotheses, but it’s too soon to talk about a theory.” Consciousness is still a young field of study, and the phenomenon itself is exceedingly complex.

A baby plays with coloured plastic balls in front of a mirror. The acquisition of self-awareness is a key stage in child development, but it remains difficult to determine precisely when it occurs.
JCDH / shutterstock.com 請至原網頁觀看照片

Rather than seeking a global explanation, current research focuses on identifying the various components of consciousness and the related biological mechanisms. The path forward will involve breaking the mystery down into a number of more accessible elements.

The philosophical and religious interpretations of consciousness are considered beyond the scope of science. Tallon-Baudry, who identifies herself as a materialist, maintains that research should be limited to what can be studied and measured.

Can artificial intelligence achieve consciousness?

Still, certain questions remain: could an artificial intelligence (AI) system one day reach the point of being conscious? If we define consciousness solely by the ability to process information and exercise reason, some AI systems could already be considered conscious. But if consciousness necessarily implies an organic, subjective and emotional aspect, these machines still have a long way to go.

Jean-Rémy Hochmann, a CNRS research professor at the ISC-MJ 9, explores the developmental origins of unique human abilities such as language and logic by studying cognition in infants: “If you ask a mother if her eight-month-old baby is conscious, she will certainly say yes!” he comments. “Indeed, her baby moves around, smiles, laughs, interacts with others and is even starting to babble. But what about a five-month-old child? Three months? A newborn after only a few minutes or hours of life? In those cases, their behaviour is much less controlled, but our research – as well as the work by Ghislaine Dehaene-Lambertz 10 and Sid Kouider 11 – suggests that the basic cognitive and neuronal structures that enable consciousness are in place very early on, perhaps from birth. Still, we have shown that these structures function more slowly in infants, as much as six or seven times slower at five months than for an adult.”

In the film "Captain America: Civil War" (2016), the character of Vision, played by Paul Bettany, is a digital assistant that has become an autonomous, conscious entity.
Marvel Entertainment / Marvel Studios / Studio Babelsberg / Collection ChristopheL請至原網頁觀看照片

With artificial intelligence becoming more and more powerful and refining its capacity for reasoning, today’s world is nearly reminiscent of the evolution of JARVIS from Marvel comics, Tony Stark’s digital assistant that becomes Vision, an autonomous entity endowed with its own consciousness. It transforms from a simple utility into a being capable of thinking and feeling. Is it pure science fiction? Perhaps. But this metamorphosis raises a very real question: could artificial intelligence one day become conscious?

Consciousness remains one of the deepest mysteries of modern science. Researchers are now trying to unravel its workings by exploring it from various perspectives: sensory perception, self-representation, emotional states, etc. It’s a real puzzle, each piece of which brings us a bit closer to answering that age-old question: what makes us conscious?

Footnotes：

1. “Animal consciousness”, EFSA supporting publication, 2017. https://doi.org/10.2903/sp.efsa.2017.EN-1196(link is external)
2. “The Scientific Study of Consciousness Cannot and Should Not Be Morally Neutral”, Perspectives on Psychological Science, 18(3), 535-543. https://doi.org/10.1177/17456916221110222(link is external)
3. “Neural correlates of consciousness: progress and problems”, Nature Review Neuroscience 17, 307–321 (2016). https://doi.org/10.1038/nrn.2016.22(link is external)
4. “Neural responses to heartbeats detect residual signs of consciousness during resting state in comatose patients”, Journal of Neuroscience, 2021, 41(24) 5251:5262. https://doi.org/10.1523/JNEUROSCI.1740-20.2021(link is external)
5. The Vincent Lambert case in France provides an illustration of the ethical and medical issues related to consciousness. A patient in a state of minimal consciousness sparked a national debate on the end of life, highlighting the difficulty of defining the boundary between consciousness and the lack of consciousness, as well as the implications of this distinction for medical and legal decisions.
6. “Interoceptive rhythms in the brain”, Nature Neuroscience 26, 2023, 1670-1684; “Visceral signals shape brain dynamics and cognition”, Trends in Cognitive Sciences, 23 (6), 2019, 488-509. https://doi.org/10.1016/j.tics.2019.03.007(link is external)
7. Laboratoire de Psychologie et Neurocognition (CNRS / Université Grenoble Alpes / Université Savoie Mont Blanc).
8. “Visual consciousness and bodily self-consciousness”, Current Opinion in Neurology 28(1):p 23-28, 2015. https://doi.org/10.1097/wco.0000000000000160(link is external)
9. Institut des Sciences Cognitives Marc-Jeannerod (CNRS / Université Claude Bernard Lyon 1).
10.. CNRS research professor at the language neuroimaging and brain development laboratory (UNICOG – CNRS / CEA / INSERM / Université Paris-Saclay).
11. CNRS research professor at the LSCP cognitive sciences and psycholinguistics laboratory (CNRS / EHESS / ENS-PSL).

For further reading:

Downloading the human mind
AI needs to align with human values
How to speak to extraterrestrials?
The vestibular system, a little-known sixth sense (video – in French)

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物理學觀點看「意識」及其科學研究 -- Ethan Siegel
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下文中的子標題是我加上的。希構博士這篇文章在提供大量相關資訊外，第1節的「唯物論者的基本前提」和第6節的「意識研究方法論」，對意識研究的論述基礎和研究方法兩者分別提出完整的觀點。所附參考圖和超連接也都很有價值；在此鄭重推薦。

Does physics truly have anything to say about consciousness?

Many, from neuroscientists to philosophers to anesthesiologists, have claimed to understand consciousness. Do physicists? Does anyone?

Ethan Siegel, 05/14/25

The brain is a network of neurons, connected by synapses, embedded in a substrate of four different types of glial cells. There is both white and gray matter in the brain, and a three-layer protective casing surrounding it, all fed by blood vessels. How this organ produces consciousness remains highly mysterious.
Dr_Microbe / Adobe Stock 請至原網頁觀看神經細胞照片

Key Takeaways

* One of the great scientific unknowns here in the 21st century is the physical mechanism behind the observed phenomenon of consciousness.
* What makes human beings like you and me conscious? Is it something mystical? Is it simply electricity? Is quantum physics at the root of it all?
* There are a great many scientists and philosophers, from a great variety of backgrounds, who opine on their approach to the puzzle of consciousness. What does physics have to say?

0. 前言

Every once in a while, scientists will bite off more than they can chew. Just as we normally use that phrase to mean “taking on a task that’s beyond your means to accomplish with the resources you currently have,” that same limitation applies to a wide variety of scientific problems. Whereas the fundamental laws, particles, and interactions of the Universe are exquisitely well known (up to a point), the vast array of complex, composite structures that emerge from those basic building blocks of reality often attain properties that arise in a non-obvious way from their constituent parts.

Featured Videos：Michio Kaku: Quantum computing is the next revolution 請至原網頁觀看視頻

Sometimes, by simulating many-body systems and imposing the proper boundary conditions, we can indeed derive large, macroscopically observable properties from those fundamental rules; the color of a sodium lamp is one such example, the success of a coaxial cable in transmitting radio-frequency signals is another.

At other times, however, the rules are a lot more complex, and we can only state that something happens (or must happen), lacking a full understanding of how it happens. Perhaps no puzzle that falls into this category is more mysterious than the nature of consciousness: something that humans definitively possess, and yet can only describe subjectively.

What does it truly mean to be conscious? Where does consciousness come from? Are humans the only conscious species, or do other animals, non-animal forms of life, or even non-living things possess some form of consciousness? While many have opined and put forth hypotheses on the matter, it remains a mystery. Here’s what physics — the most fundamental of all the sciences — has to say about consciousness.

This rough sketch shows an interconnected network of neurons, similar to the ones present in the human brain. Note that the substrate for this network, including glial cells and the blood vessels that feed them, are present, but not shown here.
Credit: Sunny Labh/Cantor’s Paradise 請至原網頁觀看神經細胞網路圖

1. 唯物論者的基本前提

At the very core of the matter are two basic ideas:

* the idea that we live in a material reality, and that everything that exists in our material reality can be described in terms of, well, the constituent parts of reality that exist in space and time,
* and the idea that any phenomenon — including consciousness — can be rigorously defined and put to experimental, observational, and/or measurable tests.

To a physicist’s way of thinking, these are non-negotiable starting points for attempting to gain a physical understanding of any phenomenon in the Universe.

However, when it comes to consciousness, many who opine on the matter find themselves unconstrained by these concerns. For example, there are those who posit that instead of the “material reality” assumption — an assumption that has held true over and over again whenever we’ve been able to put reality itself to the critical test — that either the mind, a mind-like aspect, or some ill-defined form of consciousness is what’s truly a fundamental and omnipresent feature of reality. This idea, known as panpsychism, is a very old notion in the circles of philosophy, but comes along with the dual problem of being untestable and unfalsifiable. As all of our tests of reality rely on testing objects that are measurable within reality itself, panpsychism is forever locked away from the realm of scientific testability, and hence, holds no interest to physicists who adhere to an evidence-based worldview.

This chart of particles and interactions details how the particles of the Standard Model interact according to the three fundamental forces that quantum field theory describes. When gravity is added into the mix, we obtain the observable Universe that we see, with the laws, parameters, and constants that we know of governing it. However, many of the parameters that nature obeys cannot be predicted by theory, they must be measured to be known, and those are “constants” that our Universe requires, to the best of our knowledge.

Credit: Contemporary Physics Education Project/CPEP, DOE/NSF/LBNL 請至原網頁觀看物理世界解說圖

A materialist view of reality, importantly, doesn’t simply state that “reality is nothing more than the sum of its parts.” Instead, it’s important to remember that, from a physical standpoint, even:

* a very simple set of fundamental ingredients,
* adhering to a simple set of just a few rules,
* can very swiftly wind up creating large numbers of extremely complex outcomes,
* many of which display emergent properties that are not “obviously” encoded, in a trivial way, by the underlying rules and ingredients.

For example, if you take all of the quarks in the Standard Model of particle physics and just leave them in a confined space, they will swiftly bind together into a huge array of composite structures (baryons) that will then swiftly decay away into other, less massive particles. After only about a microsecond, the only quark-containing particles remaining will be protons and neutrons.

Similarly, if you take only protons and neutrons and attempt to combine them together into any imaginable configuration, you will find that there are hundreds of stable (or quasi-stable, i.e., stable over cosmically long time intervals) configurations: the elements and isotopes of the periodic table. It is from these combinations that all of chemistry and biology fundamentally arises, all from just a few fundamental rules and types of raw ingredients.

The elements of the periodic table, and where they originate, are detailed in this image above. Alongside, at right, is a color-coded representation of where the elements composing the human body arise from. Despite being made only of protons, neutrons, and electrons, there are more than 90 naturally occurring elements (and over 200 total isotopes) in the periodic table, each with their own unique physical and chemical properties.

Credit: NASA/CXC/SAO/K. Divona 請至原網頁觀看週期表元素圖

2. 人體的物質基礎

For human beings, the material reality of our composition has been well-studied for centuries. We know that, atomically, we are made of approximately ~10²⁸ atoms. The most abundant atomic species are oxygen, carbon, and hydrogen by mass, with a substantial amount of nitrogen, calcium, and phosphorus, followed by smaller amounts of potassium, sulfur, sodium, chlorine, and magnesium. Other elements, present in smaller quantities, also play a major biological roles, for example: iron, fluorine, zinc, copper, lithium, and even vanadium, which is the least abundant element in the body (with just 110 nanograms worth in a typical human) that has a known biological function.

Those atoms are configured together into a variety of molecules, which are distributed across trillions of cells within the body, which are further organized into organs — large collections of cells that possess specific structures that perform certain essential biological functions — and those organs sum up to make a complete human being. Within the body, of specific relevance to consciousness, is the body’s nervous system, including the human brain. For most of us, there’s an assumption that seems so obvious that “of course consciousness arises in the brain” that it’s rarely challenged. It would mean, if true, that if we want to study human consciousness, we have no choice but to study the human brain.

The human mind is one of the great mysteries of modern science, as we cannot sufficiently explain how the brain in general, or consciousness in particular, works. However, it’s a reasonable “null hypothesis” to presume that electricity, i.e., the flow of electrons, is the primary driver behind our perceptions that we are conscious. Although quantum effects may play a role, it’s an unnecessary complication to presume that consciousness is anything other than the flow of electricity.

Credit: agsandrew/Adobe Stock 請至原網頁觀看示意圖

3. 大腦結構與功能

You then might wonder just how the brain produces consciousness, and what mechanisms are at play. To begin, we can talk about the structure of the brain with some confidence. The human brain, primarily, is composed of two classes of cells:

* neurons, which transmit electrical and chemical signals,
* and glial cells, which are defined by the fact that they do not produce electrical impulses, and are instead thought to form a substrate that supports neurons.

Nearly all discussions of consciousness focus on the neurons and ignore the glial cells. This makes sense on the surface, as one can easily argue that the only difference between a living human (which possesses consciousness) and a deceased human (which no longer does) is the presence of those electrical neural impulses. Take them away, and consciousness ceases to be.

But glial cells may yet play a vital, if only poorly understood, role in the presence of consciousness. Glial cells are known to come in four different types: ependymal cells, astrocytes, microglial cells, and oligodendrocytes. Each type of glial cell performs a series of functions: producing cerebrospinal fluid and aiding in neuroregeneration for the ependyma, biochemically controlling the cells of the blood-brain barrier and providing nutrients to neurons for the astroglia, performing immune functions and maintaining and sustaining normal brain functions for the microglia, and supporting and insulating the axons of neurons for the oligodendroglia.

Microglia (colored green), the smallest of the four main classes of glial cells, play several essential roles in maintaining brain health and function. They are thought to provide support to neurons, but their role in the phenomenon of consciousness has yet to be quantified.

Credit: Gerry Shaw/Wikimedia Commons, CC BY-NC-SA 請至原網頁觀看神經膠質細胞圖

In addition, the brain contains blood vessels, salts, a differentiated composition (gray matter and white matter), and is covered in three different types of meninges, or protective coverings: dura mater, arachnoid, and pia mater.

4. 意識ABC和量子意識論

Most often, when people discuss consciousness, they assume that:

* it arises from the brain,
* it is driven by neuronal activity and that all other cells serve only as “support,”
* it appears, definitively, in humans (but not necessarily in any other living creature),
* and that it’s associated with our most advanced, highest-level abstract thoughts.

It is in this framework that examinations of consciousness often take place. We typically conduct MRI studies while humans are in various states — sober or intoxicated, calm or stimulated, awake or asleep, in REM sleep versus in non-REM sleep, in a state where long-term memories are formed versus one in which they are not, etc. — measuring the various types of brain activity that are and aren’t present, in our attempt to study how the firing of neurons in the brain corresponds to a variety of conditions experienced by a human subject.

But these are experiments that, although they are an important part of research into the workings of the human brain, assume that consciousness is simply driven by classical, electrical activity in the human brain. That’s a possibility, but far from the only one.

A fruit fly brain as viewed through a confocal microscope. The workings of the brain of any animal are not fully understood, but it’s eminently plausible that electrical activity in the brain and throughout the body is responsible for what we know as “consciousness,” and furthermore, that human beings are not so unique among animals or even other living creatures in possessing it.

Credit: Garaulet et al., Developmental Cell, 2020 請至原網頁觀看顯微鏡下果蠅大腦圖

There are a variety of functions that take place inside living organisms, including in brains, that rely not only on signals (electric and chemical) that invoke classical physics alone, but that either suggest or even require some sort of quantum interaction. Some animals can orient themselves with Earth’s magnetic field by taking advantage of inherently quantum processes like magnetoreception. A mathematical equivalence has been shown between the classical physics of brain responses and the probabilistic wave equations of quantum mechanics. Quantum mechanics plays an essential role in photosynthesis, and large networks of tryptophan, found in sub-elements of neurons (as well as elsewhere), exhibit the phenomenon of quantum superradiance.

One hypothesis about consciousness is that it doesn’t arise from electro-chemical impulses and neural connections, but rather that quantum entanglement between microscopic cellular structures known as microtubules is the underlying culprit. Because neurons contain these microtubules, the idea goes, and these microtubules control a number of functions — controlling the movement, growth, and shape of the cells — perhaps they are the site of quantum processing that’s fundamental to consciousness. An experiment performed on microtubules showed that laser-induced excitations propagated within them to great distances in awake patients, but not within patients under anesthesia. However, almost nobody defines “consciousness” as the opposite of “being unconscious” (except, perhaps, for anesthesiologists), and so this hypothesis remains on the fringes.

Natural neurons are connected to one another across various synapses, and as synaptic connections are strengthened, neurons become more likely to fire together: something that occurs when the brain learns. An artificial neural network models these neurons as nodes that are encoded with a specific value, and the connectedness of the nodes can strengthen or weaken dependent on whether they take on identical or different values from one another.

Credit: Johan Jarnestad/Royal Swedish Academy of Sciences 請至原網頁觀看自然與人工神經細胞比較圖

5. 意識相關課題

But one must wonder: how can we even define what “consciousness” is? Many give it a definition akin to U.S. Supreme Court Justice Potter Stewart’s threshold test for pornographic content: I know it when I see it. This, however, is an arbitrary definition in many ways, and there is no widely agreed-upon definition for what consciousness actually is.

* Are all humans conscious? Does this include newborn babies? Sleeping humans? Humans still developing in the womb?
* Are animals other than humans conscious? Many brain-containing animals, from dogs to cats to horses to birds, exhibit strong individualistic preferences and behavioral oddities — what many would call personalities — and observations such as these have been validated through scientific studies. Is a brain a sufficient and necessary ingredient for consciousness to be achieved?
* Do living organisms without brains exhibit consciousness? Simple subjective awareness, or the ability for an organism as a whole to act as a unified structure that engages in acts of self-protection and self-preservation, particularly in response to various stimuli in their environments, may be enough, as many have suggested.

It’s a very challenging problem: one of a universally agreed-upon definition for what consciousness even is. Before we can move on to questions such as, “Is consciousness quantum in nature?” we should at least be able to answer the yet-unanswered question of “What even is consciousness?“

A fascinating class of organisms known as siphonophores is itself a collection of small animals working together to form a larger colonial organism. These lifeforms straddle the boundary between a multicellular organism and a colonial organism. Because it responds to stimuli in its environment all as one unified unit, it could arguably be construed to be conscious as a whole, beyond the mere behavior of its constituent parts.

Credit: Kevin Raskoff, Cal State Monterey; Crisco 1492/Wikimedia Commons 請至原網頁觀看管水母圖

It might seem like these are scientific questions, as there are certainly scientific ideas and hypotheses out there about consciousness, and a number of scientific experiments that have been performed and documented that touch upon many of these (and other surrounding) issues.

But consciousness, without an agreed-upon, robust definition for what it is, can hardly be said to have advanced to a point where we can study it scientifically. Much like chemistry 400 years ago, physics 1000 years ago, or astronomy 5000 years ago, consciousness research today is an example of the very beginnings of science: science in its infancy, or science that has not yet moved beyond the realm of speculation or philosophy.

In fact, the most compelling definition of consciousness that I’ve ever heard didn’t come from a scientist of any variety, but rather from the recently-deceased philosopher Daniel Dennett, who simply posed that consciousness was the ability to understand, “I am me,” or to otherwise possess an internal conception of what we call “one’s self.” Humans have clearly crossed this threshold and are conscious; dogs have as well, as if you have two dogs and call one of their names, the dog whose name you called will respond differently from the dog whose name you didn’t call. Rather than being a property that’s special to humans and to human brains, consciousness may simply be a physical manifestation of an emergent property associated with any form of life itself.

This drawing shows a variety of human, monkey, and ape skulls from a variety of extant species. The older apes have smaller cranial capacities and smaller brains than humans, but all such examples of the specimens shown here are assumed to have achieved what we would call “consciousness.” Many less-evolved creatures, and perhaps even all living things, may justifiably be considered conscious at some level.

Credit: schinz de Visser, 1845/public domain 請至原網頁觀看多種動物顱骨圖

6. 意識研究方法論

The big takeaway from all of this is that if you hear a claim that purports to explain consciousness, there are a few critical things you should be asking yourself.

* What is the definition of consciousness that they’re using, and how can it be tested for, at least qualitatively?
* In terms of explanatory power, any theory of consciousness should be able to make testable predictions that, if they are shown not to be borne out by experiment, measurement, and observation, will falsify that theory. What, therefore, are this theory’s testable predictions?
* And, perhaps most importantly, can this explanation detail how what we perceive of as consciousness arises from purely physical entities, without invoking some sort of mystic quality that exists outside of our physical reality?

If the claim does not clearly answer any of these three types of questions, then what you have encountered is not an explanation of consciousness; it is merely a not-fully-baked germ of an idea. To be sure, there are a lot of non-physicalist theories of consciousness out there, but none of them are “theories” in a scientific sense; only in an informal, idea-esque sense. If we want an understanding of how something we can observe within our physical reality behaves, there must be a physical underpinning of it: whether that’s fundamental, emergent, or a combination of the two. There are a great many things that remained unexplained at the present time, and consciousness is one of them. However, that doesn’t give me cause for any despair; it simply reminds me of what my differential equations professor told my class back in college:

“Most of the differential equations that exist cannot be solved. And most of the differential equations that can be solved cannot be solved by you.”

Consciousness is a very difficult puzzle: one that is difficult to even define, much less to solve. But it is just as much a part of our physical reality as anything else we interact with, and any approach that asserts otherwise has a fatal flaw from the outset: it’s already abandoned science.

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大腦空空 -- Ed Cara
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Brains Scans Reveal What Really Happens When Your Mind Goes Blank

Scientists argue that blanking out is its own state of consciousness, distinct from having your mind wander off.

Ed Cara, 04/24/25

Mind blanking might be a universal experience, but some people are more prone to it, a new review suggests. © Cans Creative via Shutterstock 請至原網頁觀看示意圖

If you’ve ever had your mind blank out while in the middle of something, you’re far from alone. In research published this week, scientists are making the case that mind blanking is a genuine brain phenomenon.

Researchers from Belgium, France, and Australia conducted the study, a review of the existing data on mind blanking. They argue that blanking out should be seen and studied as its own state of consciousness, similar to but separate from things like having your mind wander.

The authors are all experts in consciousness research, and they were inspired to collaborate following a related annual conference about three years ago. According to Athena Demertzi, director of the Physiology of Cognition lab at the University of Liège, the topic of mind-blanking isn’t exactly new to some scientists, particularly those studying meditation. But interest in it has also been steadily gathering steam among researchers studying cognition and sleep in recent years.

“Cognitive scientists have begun to recognize that individuals may also experience moments of blankness during wakefulness in their everyday life,” she told Gizmodo in an email. “Meanwhile, in the field of sleep and dreaming research, special categories of dreams, such as so-called ‘white dreams,’ where individuals recall having dreamt but cannot retrieve any content, have drawn increasing attention.”

Demertzi and her colleagues reviewed data from around 80 research papers relevant to mind blanking, which included studies of theirs where they measured people’s brain activity during reported moments of the volunteers having nothing on their mind. And they came to a simple conclusion.

“Mind blanking is real, it’s not just a matter of forgetting or a failure to report. At times during the day, our stream of thoughts can simply stop, leaving us with the experience of thinking about nothing,” she said. “In our review, we show that mind blanking is not merely a subjective impression or an illusion. It corresponds to a distinct brain state, one that differs from those associated with the experience of specific mental content.”

According to the researchers, mind blanking is linked to its own unique patterns of brain activity. In studies where people were asked to explicitly clear their mind of any thoughts, for instance, brain scans revealed reduced activity in certain regions like the supplementary motor cortex and hippocampus. Data from electroencephalograms (EEG) also indicate that parts of the brain might enter a sleep-like state when we blank out.

The team’s findings, published Thursday in the journal Trends in Cognitive Sciences, also suggest that people experience mind blanking between 5% and 20% of the time on average. And certain people seem more prone to blanking out than others, such as those with attention-deficit/hyperactivity disorder (ADHD). That said, more research is needed to confirm these findings and to help answer plenty more open questions about the nature of mind blanking.

“For instance, we don’t yet know how long mind blanking episodes typically last, or whether there are different types. Could some instances be voluntary? Might mind blanking occur during high-performance states, such as flow?” Demertzi noted. “A deeper understanding of its neural mechanisms is also needed. Is mind blanking the result of a failure to generate mental content, or is it a failure of access (where content exists but doesn’t reach conscious awareness)?”

The authors ultimately hope their work can inspire others in the field to start paying more attention to blanking out. Meanwhile, I just want scientists to one day unravel where exactly in the brain all my intrusive thoughts about my cat come from.

相關網頁：

Brains Cognition

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昏迷病患的意識狀態 ---- Aria Bendix
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先進儀器能夠更精準的測出：昏迷病患是否仍然有「隱蔽知覺」。

Brain scans of some unresponsive hospital patients show detectable activity

Scans suggest many people with severe brain injuries are more aware than originally thought.

Aria Bendix, 08/18/24

When a patient with a brain injury is unresponsive, doctors turn to certain basic tests to see if they could still have some awareness: calling their name, clapping near their ear or inserting a cotton swab in their nose.

Those who don’t wake up are often believed to have lost consciousness.

But a new study suggests that a quarter of brain-injured patients who don’t physically respond to commands are doing so mentally. The results were published this week in the New England Journal of Medicine.

The study looked at 353 patients who, from the outside, seemed to have lost consciousness due to a brain injury. The sources of these injuries varied from accidents to heart attacks and strokes. Of those patients, 241 were diagnosed as being in a coma, a vegetative state or having only minimal consciousness.

The researchers gave the patients verbal commands, like telling them to imagine themselves swimming or to open and close their hands. For 60 of the 241 patients, there was evidence that they could still perform those tasks in their head. The study refers to this as “cognitive motor dissociation.” Some doctors prefer the term “covert awareness.”

The mental tasks were demanding enough that even some of the other patients who had recovered enough to physically respond to verbal queues couldn’t perform them, said Dr. Nicholas Schiff, an author of the study and a neurologist at Weill Cornell Medicine.

The findings suggest that covert awareness is more common than originally thought: Small studies previously estimated that around 10%-20% of unresponsive patients had it. The new study is larger than its predecessors.

“It’s both an incredible finding, but also kind of scary,” said Caroline Schnakers, assistant director of the Casa Colina Research Institute, who studies the same phenomenon but was not involved in the new research.

The idea that so many patients “could be able to at least respond to their environment, but are not given the right tools for doing so — that’s very alarming for clinicians,” she said.

Schiff said 1 in 4 patients is likely a conservative estimate.

“We know we missed people,” he said. “We also know that patients who have severe brain injury have what are called fluctuations in arousal. They have good and bad times of the day.”

His team measured patients’ mental activity through brain wave tests and functional MRIs. Unlike a standard MRI, which produces 3D images of the brain, a functional MRI measures activity in the brain based on blood flow. When conscious people are told to follow a command, certain areas of the brain become more active, and blood flow to these areas will increase.

Not all hospitals have this technology, however, meaning doctors could miss out on diagnosing patients. Many hospitals use CAT scans or standard MRIs — along with physical exams — to determine if a patient’s mind is still active. If those tests don’t show signs of consciousness, doctors may falsely assume there’s no hope for improvement.

“They’re going to be treated as if they’re fully unresponsive,” Schiff said. “No one’s going to guess that they’re there.”

Dr. David Greer, chair of the neurology department at Boston University School of Medicine, pointed to one limitation of the study: The patients didn’t all have the same injuries or level of brain dysfunction.

“It’s a fairly heterogeneous group, and I think that has to be a caveat,” said Greer, who wasn’t involved in the research.

Schiff, however, said brain dysfunction tends to be relatively similar across injuries.

Among the patients in his study, young people and those with traumatic brain injuries — the kind linked to external events like falls or car crashes — were more likely to have covert awareness.

“Traumatic brain injury patients are notorious for looking really bad for weeks to even months, and then having a remarkable delayed recovery at six months or 12 months,” Greer said. “Those are the ones that I’m always super cautious about to make sure I’m not making any snap judgments.”

But he noted that even if a patient is conscious, it’s not a guarantee that they’ll return to their normal lives one day.

“The worst message that people can take from this as a family is to say, ‘Oh, they’re in there and they’re going to make a full recovery,’” Greer said. “I think that would be very misleading for families to have that kind of false hope, because many if not most of these patients will still have a severe disability.”

But the findings do offer hope for connecting patients to certain treatments in the future. For now, the options are limited: A Parkinson’s drug, amantadine, has shown some promise in helping people recover consciousness. Some doctors also prescribe Ambien, stimulants or antidepressants.

Brain implants or neuromodulation (using electrical currents to alter brain activity) could represent the next wave of treatments, Schnakers said. She emphasized the need to provide families with options for their loved ones.

“The family will ask, ‘What can we do?’ It’s actually something that we have not thought about very seriously,” she said, adding: “This is not acceptable anymore.”

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《意識理論小百科》簡介 ----- Àlex Gómez-Marín
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Seeing the consciousness forest for the trees

Towards a map of consciousness

Àlex Gómez-Marín, 07/25/24

編者前言：

The American public intellectual and creator of the television series Closer to Truth, Robert Lawrence Kuhn has written perhaps the most comprehensive article on the landscape of theories of consciousness in recent memory. In this review of the consciousness landscape, Àlex Gómez-Marín celebrates Robert Kuhn’s rejection of the monopoly of materialism and uncovers the radical implications of these new accounts of consciousness for meaning, artificial intelligence, and human immortality.

The scientific study of consciousness was not sanctioned by the mainstream until the nineties. Let us not forget that science stands on the shoulders of giants but also on the three-legged stool of data, theory, and socio-political wants. Thirty years later, the field has grown into a vibrant milieu of approaches blessed and burdened by covert assumptions, contradictory results, and conflicting implications. If the study of behaviour and cognition has become the Urban East, consciousness studies are the current Wild West of science and philosophy.

The American public intellectual, international corporate strategist, and PhD in neurophysiology, Robert Lawrence Kuhn is one of the few pioneers attempting to provide some comprehensive order to such a vexed matter. In a recent article entitled “A landscape of consciousness: Toward a taxonomy of explanations and implications”, the creator and host of the public television series Closer to Truth has begun to rescue such an ultimate frontier of human knowledge from the sterile provincial quarrels, egocentric delusions of grandeur, and myopic glares that plague the field of consciousness research.

The origins of our perplexity in making sense of experience itself can be traced back to Galileo Galilei, who programmatically excluded subjective experience from the purview of science. One can interpret this sagacious move as a means to understand nature in two phases: let us first start with what lends itself to measurement and mathematisation (the “primary phenomena of motion and touch”, in Galileo’s words) and leave for later what resists it. “I think that tastes, odors, colors, and so on (…) reside only in consciousness”, he wrote in The Assayer in 1623.

Such a strategy proved tremendously successful, giving rise to physics, then chemistry, next biology, and finally psychology. The progression of scientific disciplines reaped great (but progressively diminishing) returns. Studying matter is, no doubt, hard. But there is something about life and mind that particularly defies the so-called scientific method. Four hundred years later, we can’t ignore the elephant in the room anymore: experience is what makes science possible and yet a proper science of consciousness seems unattainable. The Galilean knot remains untied. Today we call it “the hard problem”.

It is ironic and fascinating to note that the hard problem of consciousness has amplified the “toothbrush problem” of theorists. Consciousness researchers treat their explanations much like toothbrushes: everyone has their own, but nobody wants to use someone else’s. Moreover, until quite recently, most researchers could only get their toothpaste in the supermarket monopoly of materialism, a philosophical doctrine often presented as a scientific fact. But things are changing. To hold on to the analogy, an orthodontics of consciousness is coming about. New comprehensive views are allowing to expand our jaws, correct misplaced teeth, and prevent misaligned bite patterns.

Kuhn’s review is a paradigmatic instance of such an individual and collective reckoning. His is not a normal piece of work. It is a beauty and a beast—a unique creature in content and style. It could have been a book, but he decided to publish his magnum opus in the journal Progress in Biophysics and Molecular Biology as open-access 142-page double-column article. The piece is 175 thousand words long, including nearly a thousand references. In it, Kuhn articulates a taxonomy of about 225 theories of consciousness.

Gathering under the same roof most of the greatest contemporary thinkers of one of the greatest questions one can ever try to answer, Kuhn’s landscape enacts the quasi-extinct art of true scholarship. Very few scholars can see beyond their theoretical bellies, nor would devote the time and effort necessary to put such a myriad of views together with his exquisite intellectual humility and rigour. The living proponents (too often deadly opponents) will still agree to disagree but, at least, they can now see the forest for the trees.

The landscape comprises 10 major categories and it is organised in a gradient of “isms”, from die-hard materialist positions to mind-only propositions. Materialism gets a great deal of space and attention with nearly a hundred authors nested in 10 subcategories, such as neurobiological, computational and informational, homeostatic and affective, embodied and enactive, representational, etc. The landscape also makes some dualisms respectable. The (false) two-alternative forced choice between (promissory) materialism and (ridiculed) dualism is over. Materialism is not the only game in town anymore. Quantum approaches to consciousness do have their deserved place too. We then encounter a great range of fascinating kinds of panpsychism, monism, and idealism. Integrated Information Theory has its own category, remaining the only scientific approach that is philosophically unclassifiable in the landscape.

Remarkably, Kuhn devotes an entire section to “anomalous and altered states”, describing decades-long serious scientific investigations on taboo topics such as extra-sensory perception and survival of consciousness after bodily death. I call them “the edges of consciousness” because they are true frontiers of knowledge and also marginalised (stigmatised and/or ignored) by dogmatic skeptics. The final category gathers “challenge theories” which point to the intractability of the mind-body problem. The piece ends underscoring the implications of all such explanations of consciousness for ultimate meaning, artificial intelligence, and human immortality.

Apart from the imperative presence of the godfathers of the field such as Christof Koch and David Chalmers (and along with other legendary philosophers and neuro-celebrities), it is delightful to find a series of not-so-popular but crucial authors such as David Bentley Hart, Michel Bitbol, David Bohm, Jacobo Grinberg, Dean Radin, Rupert Sheldrake, Rudolf Steiner, and Ian Stevenson. When was the last time you read a piece cordially inviting philosophy, neuroscience, quantum physics, psychical research, theology, and religion to the same table?

Yes, the map is not the territory (nor the terrain). Yes, all models are ultimately wrong (but some are more useful than others). Yes, too often we conflate models with captivating metaphors or cartoonish mechanisms enacting covert metaphysics. And yes, most theories of consciousness aren’t mathematically formulated nor empirically testable. Shall we then rush to prune the landscape? Not yet.

Let us enjoy a real taste of epistemic and metaphysical pluralism after years of philosophical monotheism and neuroscientific chauvinism. Of course brains play a key role in consciousness. But the real question, as William James saw more than a century ago, is whether their function is productive or permissive. Much like the picture of Earth that astronaut William Anders took from the Moon during the Apollo 8 mission, Kuhn’s landscape simultaneously offers an orienting and disorienting experience. We need a larger Overton window from which to contemplate what we know, what we don’t, and what we think we do but actually ignore.

At the end of the day, beyond the sweet dopamine hit of seeing one’s name in the hall of fame, Kuhn’s forest may reveal to each and every fervent tree advocate that they are all missing the point but, additionally, that they all have a point. As Leibniz wrote in a letter to Nicolas Remond in 1714, “I have found that most of the sects are right in a good part of what they propose, but not so much in what they deny”. Isn’t it both commendable and ludicrous to realise that hundreds of extremely clever people think they solved the problem of consciousness and are convinced that everyone else is wrong?

Kuhn’s faithful description of each position without the urge to adjudicate deserves nothing but praise and gratitude. This uncommon ability is an urgent antidote to the academic vice of hearing only one’s own voice while shouting at each other. In fact, if there is something more interesting than consciousness itself is the sociology of its researchers. Let us leave the consciousness hunger games behind and realise that there is plenty of food for thought for everyone. Rather than divide and conquer, let us unite and wonder.

Àlex Gómez-Marín：

Theoretical physicist and neuroscientist, professor at the Instituto de Neurociencias of Alicante in Spain, and director of the Pari Center in Italy.

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Consciousness came before life
Gödel and the nature of the mind
Consciousness does not require a self

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意識的性質和如何享受有意識的樂趣--LINDSEY LAUGHLIN
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我不是大腦神經學家；但不客氣的說，就 “psychoactive substances” 這部份的論述而言(下文倒數第二段)，讓我懷疑寇合博士已經走火入魔。他可說是李蕊博士2.0。

我頗難苟同下文所呈現寇合博士對「意識」的觀點；但我一時沒有精力整理出我的淺見；或許掛掉以前能找時間談談。

對「意識」議題有興趣的朋友，可參見以下相關報導/評論：《意識可靠幻覺論》、《現實與對現實的認知》、和本欄2024/05/09等多篇貼文。

The nature of consciousness, and how to enjoy it while you can

In his new book, Christof Koch views consciousness as a theorist and an aficionado.

LINDSEY LAUGHLIN, 05/18/24

Unraveling how consciousness arises out of particular configurations of organic matter is a quest that has absorbed scientists and philosophers for ages. Now, with AI systems behaving in strikingly conscious-looking ways, it is more important than ever to get a handle on who and what is capable of experiencing life on a conscious level. As Christof Koch writes in Then I Am Myself the World, "That you are intimately acquainted with the way life feels is a brute fact about the world that cries out for an explanation." His explanation—bounded by the limits of current research and framed through Koch’s preferred theory of consciousness—is what he eloquently attempts to deliver.

Koch, a physicist, neuroscientist, and former president of the Allen Institute for Brain Science, has spent his career hunting for the seat of consciousness, scouring the brain for physical footprints of subjective experience. It turns out that the posterior hot zone, a region in the back of the neocortex, is intricately connected to self-awareness and experiences of sound, sight, and touch. Dense networks of neocortical neurons in this area connect in a looped configuration; output signals feedback into input neurons, allowing the posterior hot zone to influence its own behavior. And herein, Koch claims, lies the key to consciousness.

In the hot zone

According to integrated information theory (IIT)—which Koch strongly favors over a multitude of contending theories of consciousness—the Rosetta Stone of subjective experience is the ability of a system to influence itself: to use its past state to affect its present state and its present state to influence its future state.

Billions of neurons exist in the cerebellum, but they are wired “with nonoverlapping inputs and outputs ... in a feed-forward manner,” writes Koch. He argues that a structure designed in this way, with limited influence over its own future, is not likely to produce consciousness. Similarly, the prefrontal cortex might allow us to perform complex calculations and exhibit advanced reasoning skills, but such traits do not equate to a capacity to experience life. It is the “reverberatory, self-sustaining excitatory loops prevalent in the neocortex,” Koch tells us, that set the stage for subjective experience to arise.

This declaration matches the experimental evidence Koch presents in Chapter 6: Injuries to the cerebellum do not eliminate a person’s awareness of themselves in relation to the outside world. Consciousness remains, even in a person who can no longer move their body with ease. Yet injuries to the posterior hot zone within the neocortex significantly change a person’s perception of auditory, visual, and tactile information, altering what they subjectively experience and how they describe these experiences to themselves and others.

Does this mean that artificial computer systems, wired appropriately, can be conscious? Not necessarily, Koch says. This might one day be possible with the advent of new technology, but we are not there yet. He writes. “The high connectivity [in a human brain] is very different from that found in the central processing unit of any digital computer, where one transistor typically connects to a handful of other transistors.” For the foreseeable future, AI systems will remain unconscious despite appearances to the contrary.

Koch’s eloquent overview of IIT and the melodic ease of his neuroscientific explanations are undeniably compelling, even for die-hard physicalists who flinch at terms like “self-influence.” His impeccably written descriptions are peppered with references to philosophers, writers, musicians, and psychologists—Albert Camus, Viktor Frankl, Richard Wagner, and Lewis Carroll all make appearances, adding richness and relatability to the narrative. For example, as an introduction to phenomenology—the way an experience feels or appears—he aptly quotes Eminem: "I can’t tell you what it really is, I can only tell you what it feels like."

Going beyond consciousness’ limits

The takeaway from the first half of Then I Am Myself the World is that IIT might offer the best-fit explanation for consciousness—a view, it’s worth mentioning, that is highly contested by many other neuroscientists. But the greater message, addressed later on, is that we, as human beings, have the capacity to expand and transform our own conscious experiences. Why settle for a life lived in semi-darkness when we can pull back the curtains and experience an explosion of light?

Koch discusses transformative states of consciousness in the second half of his book, including near-death, psychedelic, and mystical experiences. He also discusses the expansive benefits of sustained exercise—drawing upon his personal experiences as a bicyclist and rock climber—through which a person can enter “the zone.”

“Some consider these states a higher form of consciousness. Perhaps. I call them transformative ... transformative experiences achieve transcendence, conveying a sense of equanimity, a feeling that everything is as it should be.” He places special emphasis on ‘the flow,’ which he defines as “a mental state in which you are totally engaged with the world while only dimly aware of yourself.” Being in the flow, also known as direct awareness, is the experience of being completely present.

Notably, the posterior hot zones of Buddhist monks, who spend years training themselves to quiet mental noise through meditation, are silenced during states of pure presence. EEG measurements confirm this; a dearth of electrical activity in the brain, especially in the neocortex, translates into the experience of calm, immediate awareness. It seems likely, Koch says, that psychoactive substances and near-death experiences have a similar effect on the posterior hot zone, triggering experiences of “boundless space ... without body, without self, and without time.”

Yet, the average individual has few opportunities to experience such neocortical quieting. “As a denizen of the twenty-first century, you only rarely experience the spontaneity of this stream,” he writes. Yet, it is this silent space that he suggests makes one feel most connected and engaged with the direct experience of life.

Koch suggests that exercise, meditation, and the occasional guided psychedelic might be beneficial to many people. Substances such as psilocybin can enhance one’s feeling of well-being and facilitate pure presence. It is rare to have a close brush with death, and mystical transformations typically come unbidden; in contrast, psychoactive substances—though not entirely predictable—are more consistently available and can be managed safely. Koch’s book implies that there’s immense psychological benefit of entering "the flow" through chemistry that might outweigh the small risks involved.

Overall, Then I Am Myself the World is a smoothly written must-read for anyone interested in a detailed introduction to the relationship between the brain, consciousness, and transformative experiences. However, it also bears witness to Koch’s personal journey from a neuroscientist studying the tangible elements of brain states to a man swept up by a quest to expand and transform his own life experiences. As a reader, one can’t help but identify with Koch’s drive to live life to its fullest—ultimately, this is a human quest. Then I Am Myself the World is, at its heart, a cogent reminder to cherish our own conscious experiences while we have the power to do so.

Lindsey Laughlin is a science writer and freelance journalist who lives in Portland, Oregon, with her husband and four children. She earned her BS from UC Davis with majors in physics, neuroscience, and philosophy.

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意識先於生命-S. Hameroff等
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依照作者群的邏輯，或許「意識先於宇宙」，以及「意識是大爆炸的根本原因」這兩個命題，應該也有三分可信度。我所說的「邏輯」，各位可以比較原文標題和其中兩句話後看出我的意思：

1) 原文標題：”Consciousness came before life”；在文法上，過去式表示動作「已完成」。
2) “We don’t yet know what consciousness is,…, so the possibility that conscious feelings existed before life cannot be excluded.”；換句話說，只要承認「無知」，一切都有可能。
3) “Of course, we cannot test for signs of consciousness, which is private and unobservable.”；如果「一個人還不知道『意識』是什麼」，那她/他憑「什麼」認為它具有這個(private)或那個(unobservable)性質。

下文其它部份的論述過於高深，我就不給別人打我臉的機會了。

Consciousness came before life

The fundamental cause of evolution

05/08/24

Stuart Hameroff |Professor of Astrobiology, Psychology and Anesthesiology, and Director of the Center for Consciousness Studies at The University of Arizona, Tucson, Arizona.
Anirban Bandyopadhyay | Principal Research Scientist at the National Institute for Materials Science (NIMS) in Tsukuba, Japan.
Dante Lauretta | Regents Professor of Planetary Science and Cosmochemistry, and Director of the Arizona Astrobiology Center, The University of Arizona, Tucson, Arizona. He led NASA’s OSIRIS REx mission to Asteroid Bennu.

Most scientists believe that consciousness came after life, as a product of evolution. But observations of extraterrestrial organic material, along with Roger Penrose and Stuart Hameroff’s quantum theory of consciousness, provide reason to believe that consciousness came before life. In fact, argue Hameroff and his collaborators, consciousness may have been what made evolution and life possible in the first place.

Most scientists and philosophers believe that life came before consciousness. Life appeared on Earth about 3.8 billion years ago; consciousness and feelings, it’s said, evolved later due to complex biological information processing, perhaps only recently in brains with language and tool-making abilities. In fact, though, there’s good reason to think that consciousness preceded life, and was central to making life and evolution possible.

What is life? It is often described as its functions: metabolism, adaptation, reproduction, etc. But non-biological systems can have similar functions, for example, oceanic hydrothermal vents can metabolize, transform energy and synthesize chemicals, weather and climate systems adapt to changes in solar radiation, volcanic activity, and other natural factors, and a seed crystal in a solution can lead to the formation of more crystals with the same lattice structure, essentially reproducing itself. In the 19^th century “vitalists” proposed life was a living field, force, or élan vital, but vitalism was eclipsed by molecular biology and genetics.

Erwin Schrödinger suggested that a form of “quantum vitalism” accounted for life’s unitary oneness, and Herbert Fröhlich later proposed that quantum coherent vibrational modes, similar to those in a laser, could play a central role in various biological processes (“Fröhlich coherence”). The idea is that in a crystal-like structure, laser-like coherent vibrations could be driven by small random changes in temperature or energy.

This was proven by Anirban Bandyopadhyay’s group for biological microtubules – self-assembling cylindrical lattice polymers of the protein tubulin. Microtubules dynamically organize the interiors of all animal and plant cells, as part of the cell’s structural cytoskeleton, and appear also to serve as its nervous system and memory bank.

Anirban’s team sent low-power electromagnetic signals of varying frequency into microtubules and measured their conductance. They found distinctive self-similar resonance conductance patterns where each conductance response is grouped into sets of three, and then these groups are themselves grouped into larger sets of three. These “triplets-of-triplets” repeat in microtubules every three orders of magnitude, in kilohertz, megahertz, gigahertz and terahertz.

The “triplets-of-triplets” are phase shifted to make a unique structure called a “time crystal” (first described for biology by Arthur Winfree in the 1960s). In ordinary crystals, like salt or quartz, atoms are arranged in a repeating spatial pattern. But in a time crystal patterns also repeat in time, in a regular, repeating cycle returning to the same positions over and over. This movement happens without using energy – it's a stable, perpetual motion at the atomic level.

Microtubules are biologic time crystals that enable living systems to operate coherently over many orders of spatiotemporal scale. Microtubule vibrations emanate within each tubulin from aromatic organic molecules (rings that are made up of carbon atoms arranged in a closed loop with clouds of delocalized ‘pi resonance’ electrons). Simpler versions of these coherent oscillations, their resonance across frequencies, and time crystal behavior in early molecular systems may be considered putative “signs of life.”

What is consciousness? Many scientists view it as an emergent property of complex biological computation among simple brain neurons. But if so, how do we account for eons of purposeful behavior by earlier, simpler creatures, long before brains or genes? Animal behavior is driven by “reward,” which is made up of pleasurable feelings. Could feelings have been motivation for life right from its start?

We don’t yet know what consciousness is, nor what role it plays in the universe, so the possibility that conscious feelings existed before life cannot be excluded. Of course, we cannot test for signs of consciousness, which is private and unobservable. But anesthesia is selective, blocking consciousness while affecting very little else. We can therefore test molecular systems for what goes away under anesthesia. Furthermore, we have a plausible scientific story about what consciousness might be, which implies that conscious feelings did exist before life. Let’s look at that story now.

Penrose’s quantum consciousness

According to the physicist and Nobel laureate Sir Roger Penrose, quantum mechanics contains the key to consciousness. Quantum particles can exist in multiple wave-like possibilities simultaneously (“quantum superposition”), described by a wavefunction. In a nutshell, Penrose argues that consciousness is made of collapses of quantum superpositions into definite states.

Imagine a spinning coin that can land either heads or tails. In the quantum world it could land and exist simultaneously as both heads and tails in two locations, when no one was looking. However, when a conscious human observes the superposition, the coin is seen to have landed on either heads or tails in one position – the wavefunction has collapsed into one of the two possibilities.

For Penrose, such collapses, or “quantum state reductions,” occur spontaneously and ubiquitously in the random microenvironment due to an objective threshold, (objective reduction, OR). Moreover, OR events in the random microenvironment are predicted to be, or cause, “proto-conscious” moments, available to then be orchestrated and optimized in biological systems.

Penrose’s proposal is a novel answer to the “Measurement Problem” – the problem of explaining why we can never measure quantum superpositions because the very act of doing so seems to collapse them into definite states. The quantum pioneers John von Neumann and Eugene Wigner earlier suggested that the act of conscious observation causes quantum collapse, so that “consciousness collapses the wavefunction.” But although this interpretation still has some supporters (including Henry Stapp and David Chalmers), it cannot explain consciousness itself, and nor can it explain how quantum superposition is possible.

Penrose reverses von Neumann and Wigner’s interpretation. For Penrose, it’s not that consciousness causes the collapse of the wavefunction, but that the collapse of the wavefunction causes (or, perhaps, is) consciousness. This suggests the beginnings of an explanation of consciousness, but it raises the question: what collapses the wavefunction, if not consciousness?

To answer this question, Penrose first tries to explain the nature of superposition. How can a single particle exist in multiple states simultaneously? Here Penrose applies Einstein’s theory of general relativity (in which matter and gravity are equivalent to curvature in spacetime geometry) to tiny quantum particles with tiny spacetime curvatures. Superposition of a single particle in two locations could then be seen as two opposing curvatures in spacetime – a blister or separation in the fabric of reality at the most fundamental Planck scale, 10^-33 cm.

Now Penrose can explain what collapses the wavefunction. He suggests that spacetime separations are unstable and undergo spontaneous objective reduction (OR) due to a threshold related to fundamental spacetime geometry at times t= ħ/E_G. This is a form of the uncertainty principle, where ħ is the Planck-Dirac constant and E_G represents the gravitational self-energy of spacetime separation. This is the energy required to separate an object (or its equivalent spacetime curvature) from itself. When the threshold is reached, separation/superposition terminate, and an OR event occurs which selects a single local reality, collapsing the short-lived beginnings of multiple, separated universes into one.

This alone is significant, but Penrose goes further, reaching for an explanation of consciousness. He supports his claim that consciousness is caused by or made up of waveform collapses by appealing to Gödel’s Incompleteness Theorem. This states that within a sufficiently complex formal system, there are always true statements that cannot be proven within that system – they are “non-computable.” We call these statements the Gödel sentences of the system; an “external determinant,” or a more powerful system, is required to prove a system’s Gödel sentences.

Penrose argues that conscious minds are not like these complex formal systems, since they don’t have any Gödel sentences. Put differently, consciousness involves a non-computable process – a process which cannot be classically computed. In contrast, familiar, classical reality is algorithmic and “computable.” Penrose therefore concludes that the non-computable process and its attendant conscious “feelings” or “qualia” must come from outside classical physics, namely from quantum physics with its own set of laws.

Although the quantum processes are non-computable and non-algorithmic, their selections are not random, according to Penrose. Rather, they are influenced by “Platonic values” intrinsic to spacetime geometry. Penrose proposed that each OR event marked a moment of phenomenal awareness – a fundamental unit of conscious experience. His picture thus provides the beginnings of explanations of quantum superposition, wavefunction collapse, and consciousness itself.

Penrose’s OR events would have been happening at the level of spacetime geometry in the microenvironment since the early universe – long before life arose. The qualia would presumably be random, disconnected, and lacking context. Penrose thus calls them “proto-conscious.” However, occasionally proto-conscious OR events would be pleasurable, and occur in molecules which could stabilize, resonate, desire and rearrange for more pleasure, prompting the origin and evolution of life.

Life and proto-consciousness in the primordial soup

How might proto-conscious OR events give rise to life? Life on earth is envisioned to have begun in a “primordial soup” – an oily froth of liquid and nutrients with occasional energy inputs. Simulations of this primordial soup in the 1950s found “amphipathic” molecules, which have sweet-smelling, oil-like (“aromatic”) rings on one end, and water-soluble structures on the other.

The aromatic rings are the basis for organic chemistry – the chemistry of life – due largely to clouds of delocalized “pi resonance” electrons, which envelop hydrocarbon rings and have quantum interactions with neighboring rings in quantum-friendly regions where photons can be absorbed, re-emitted (fluorescence), couple to mechanical vibrations (optical phonons), electricity (excitons), and enhanced light emission (super-radiance). Regions of aromatic rings inside certain brain proteins, friendly to quantum effects, are where anesthetics act to selectively block consciousness. Aromatic rings are also central to many psychoactive compounds including dopamine, serotonin, LSD and DMT .

In the ancient primordial soup, amphipathic molecules are thought to have formed soap molecule-like “micelles,” which envelope the insoluble, oil-like aromatic rings. These micelles were theorized by Alexander Oparin to have become biological “proto-cells,” developed behaviors for survival, and then become cells and organisms. But why would this have happened, long before genes and brains? What would motivate simple creatures’ purposeful behavior to survive?

Consider the following scenario, which contains a possible answer. In the primordial soup, quantum-coupled, entangled aromatic rings in superposition within micelles could have reached threshold for Penrose OR at times t=ħ/E_G, resulting in sequences of random, disconnected proto-conscious moments. Some of these would exhibit positive reinforcement, a primitive form of pleasure. Thus, this mechanism could have served as a feedback fitness function for aromatic rings on amphipathic molecules to arrange within micelles for OR events which increase pleasure and avoid displeasure. Thus, the origin of life may have been prompted and driven by conscious feelings right from the start. Evolution may have worked to optimize, organize, and prioritize more advanced conscious experience involving memory, belief, forecasting, intention and iteration, driven by primitive, and then more advanced forms of pleasure-seeking. Life became the vehicle for consciousness.

How could we possibly find out whether something like this story is correct? The key might lie in the asteroids, ancient relics from the very dawn of the solar system.

Searching for extraterrestrial “signs of life” and “roots of consciousness”

The first section of this article suggested that we might consider collective coherent oscillations and other features as putative “signs of life.” Recent Japanese and US missions to near-Earth asteroids Ryugu and Bennu have returned with organic-rich materials, including some spherical structures reminiscent of micelles, called organic nanoglobules. These come in various forms, some of which involve aromatic molecules arranged in complex patterns with a range of textures and compositions.

We are studying the samples from the recent NASA mission to near-Earth asteroid Bennu led by Dante Lauretta and intend to study PAHs and especially nanoglobules for putative “signs of life.” These would be in the form of:

1) coherent oscillations among aromatic rings
2) cross-frequency phase coupling and resonance, like music
3) quantum optical fluorescence with phonon vibrations
4) time crystal behavior, e.g. repeating “triplets-of-triplets” at different scales
5) entanglement between separated aromatic rings
6) psychopharmacological effects of extraterrestrial poly-aromatic hydrocarbons, e.g. in cerebral organoids
7) self-replication and/or self-assembly
8) interaction with genetic material (RNA).

We will pay special attention to nanoglobules with complex patterns of aromatic materials, which could conceivably be akin to the micelles that Oparin thought were the starting point for life. Initially at least we will study intact nanoglobules “noninvasively” with quantum tunnelling and cloaking.

In preparation to analyze samples from Bennu we have revisited a well-studied polyaromatic molecule retrieved from the Murchison meteorite which fell in Australia in 1969. It is known as “Murchison Insoluble Organic Material Molecule” (M-IOM-M) and has numerous clusters of polyaromatic rings in a branching network, usually shown in two dimensions. Meteorite samples carry possible earthly contaminants, but this type of molecule has not been seen on earth, and similar molecules are apparent in the Bennu samples.

In three-dimensional energy minimization simulation, M-IOM-M folds into a two-nanometer, cigar-shaped dimer. Simulation of numerous such dimers showed they self-assemble into linear filaments, and numerous filaments align in parallel in a slight offset lattice, which curves into a cylinder, resembling a microtubule. Molecular dynamics simulation of M-IOM-M show time crystal behavior, with “triplets of triplets” petahertz oscillations, and binding to RNA. Thus four putative signs of life (numbers 1, 4, 7 and 8 above) were observed in simulation of M-IOM-M.These analyses will be carried out with actual experiments on PAHs and nanoglobules from Bennu. If the simulation results are confirmed, standard evolution “life-came-first” theories will be challenged.

What about consciousness? Penrose OR is the most specific scientific proposal for consciousness but is difficult to detect. However, some “signs of life” are pre-conditions for OR and could be detected, e.g. coherent oscillations, quantum optical superposition effects and triplets-of-triplets. If we find such signs of life in a sample, we will expose them to anesthetic gas to see if they are inhibited proportional to anesthetic potency in blocking consciousness in animals and humans. If so, these processes may be considered putative “roots of consciousness.”

In this way, we hope to dig deeper into the role and place of both life and consciousness in the universe. Our strategy depends on the idea of Penrose OR. This is controversial, both as a solution to the quantum measurement problem and as the source of consciousness. But Penrose OR is testable, profound, more sensible than alternatives, and comes from one of the truly great minds of these past two centuries. Occam’s razor would surely favor one grand solution to three great mysteries. Why couldn’t Penrose OR be the solution to the quantum measurement problem, consciousness, and the “spark of life”? If it is, then consciousness has to be seen as fundamental – not a consequence of evolution, but a prerequisite for it.

Acknowledgements: We thank Sir Roger Penrose and Eugene Jhong

You can see Stuart Hameroff live, debating in ‘’ alongside biologist Denis Noble and philosopher Antonella Tramacere at the upcoming HowTheLightGetsIn Festival on May 24th-27th.

This article is presented in partnership with Closer To Truth, an esteemed partner for the 2024 HowTheLightGetsIn Hay Festival. Dive deeper into the profound questions of the universe with thousands of video interviews, essays, and full episodes of the long-running TV show at their website: www.closertotruth.com.

References

Chalmers D, McQueen K (2022). Consciousness and collapse of the wavefunction, in Consciousness and Quantum Mechanics, ed. S. Gao (Oxford: Oxford Press).
Craddock TJA et al (2017) Anesthetic alterations of collective terahertz oscillations in tubulin correlate with clinical potency. iSci. Rep. 7:9877. doi: 10.1038/s41598-017-09992-7
Everett H (1957). Relative state formulation of quantum. Mech. Rev. Modern Phys. 29, 454–462. doi: 10.1103/revmodphys.29.454
Fröhlich H (1970) Long range coherence and the actions of enzymes. Nature 228:1093. doi: 10.1038/2281093a0
Hameroff S (2017) The quantum origin of life: how the brain evolved to feel good, in On Human Nature eds M Tibayrenc and FJ Ayala (Elsevier 333–353).
Hameroff S, Penrose R (1996a) Orchestrated reduction of quantum coherence in brain microtubules. Math. Comput. Simul. 40, 453–480. doi: 10.1016/0378-4754(96)80476-9
Hameroff S, Penrose, R. (1996b). Conscious events as orchestrated space–time selections. J. Conscious. Stud. 3, 36–53.
Hameroff S, Penrose R (2014) Consciousness in the universe: a review of the ‘Orch OR’ theory. Phys. Life Rev. 11, 39–78.
Hameroff S, Watt RC (1982) Information processing in microtubules. J. Theor. Biol. 98, 549–561. doi: 10.1016/0022-5193(82)90137-0
Lauretta D et al (2017) OSIRIS-REx: sample return from asteroid (101955) Bennu. Space Science Reviews 212 (2017): 925-984.
Lazcano Antonio (2016) Alexandr I. Oparin and the origin of life: a historical reassessment of the heterotrophic theory. Journal of Molecular Evolution 83: 214-222.
Lauretta D (2024) The Asteroid Hunter, Grand Central Publications
Pathak AK, Hameroff S, Ghosh S, Lauretta D, Bandyopadhyay A (2024) “Signs of Life in Murchison IOM Molecule (M-IOM-M): “Triplets of Triplets” Poster Presentation at Arizona Astrobiology Center Poster Forum, May 3, 2024 https://static.uahirise.org/aabc/pathak-hameroff-may-24.pdf
Penrose R (1989) The Emperor’s New Mind, Oxford: Oxford Univ. Press.
Penrose, R. (2022) New physics for the Orch OR consciousness proposal, in Consciousness and Quantum Mechanics, ed. S. Gao (Oxford: Oxford Press).
Sahu et al ,(2013a) Atomic water channel controlling remarkable properties of a single brain microtubule: correlating single protein to its supramolecular assembly. Biosens. Bioelectron. 47, 141–148. doi: 10.1016/j.bios.2013.02.050
Saxena K et al (2020) Fractal, scale free electromagnetic resonance of a single brain extracted microtubule, a single tubulin protein and a single neuron. Fractal Fractional 4:12. doi: 10.3390/fractalfract4020011
Schrödinger, E. (1944). What is Life? Cambridge, MA: Cambridge University Press.
Singh P et al (2021) Electrophysiology using coaxial atom probe array: live imaging reveals hidden circuits of a hippocampal neural network. J. Neurophysiol. 125, 2107–2116. doi: 10.1152/jn.00478.2020
von Neumann, J (1955) Mathematical foundations of quantum mechanics." (1955).
Wigner EP (1961) Remarks on the mind–body question. In (IJ Good, ed.) The Scientist Speculates.
Winfree AT (2010) The Geometry of Biological Time, Springer
Pathak et al, 2024: https://static.uahirise.org/aabc/pathak-hameroff-may-24.pdf

You can see Stuart Hameroff live, debating in ‘’ alongside biologist Denis Noble and philosopher Antonella Tramacere at the upcoming HowTheLightGetsIn Festival on May 24th-27th in Hay-on-Wye.
This article is presented in association with Closer To Truth, an esteemed partner for the 2024 HowTheLightGetsIn Festival.

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「什麼才算是意識？」對談 – Dan Falk/ Christof Koch
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	胡卜凱等級：8 留言｜加入好友

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	胡卜凱

索引：

causal powers：因果能力(採取行動並導致某種結果的能力)
goo：有粘黏性的東西
gradient：(不同)程度的，坡度，傾斜度
imbued：灌輸，使充滿，使滲透，深深影響
LLM：large language model；大型語言模型
neuromorphic engineering：神經形態計算工程：以人腦結構與功能為範例的電腦計算方式
woo-woo：假的，不科學的，想像出來的，空穴來風的，無憑無據的
英文解釋：
Derogatory/Informal
noun – unconventional beliefs regarded as having little or no scientific basis, especially those relating to spirituality, mysticism, or alternative medicine. "some kind of metaphysical woo-woo"
adjective -- relating to or holding unconventional beliefs regarded as having little or no scientific basis, especially those relating to spirituality, mysticism, or alternative medicine. "quartz crystals that were so popular with the woo-woo crowd"

What Counts as Consciousness

Neuroscientist Christof Koch on human minds, AI, and bacteria.

DAN FALK, 05/06/24

Some years ago, when he was still living in southern California, neuroscientist Christof Koch drank a bottle of Barolo wine while watching The Highlander, and then, at midnight, ran up to the summit of Mount Wilson, the 5,710-foot peak that looms over Los Angeles.

After an hour of “stumbling around with my headlamp and becoming nauseated,” as he later described the incident, he realized the nighttime adventure was probably not a smart idea, and climbed back down, though not before shouting into the darkness the last line of William Ernest Henley’s 1875 poem “Invictus”: “I am the master of my fate / I am the captain of my soul.

Koch, who first rose to prominence for his collaborative work with the late Nobel Laureate Francis Crick, is hardly the only scientist to ponder the nature of the self -- but he is perhaps the most adventurous, both in body and mind. He sees consciousness as the central mystery of our universe, and is willing to explore any reasonable idea in the search for an explanation.

Over the years, Koch has toyed with a wide array of ideas, some of them distinctly speculative -- like the idea that the Internet might become conscious, for example, or that with sufficient technology, multiple brains could be fused together, linking their accompanying minds along the way. (And yet, he does have his limits: He’s deeply skeptical both of the idea that we can “upload” our minds and of the “simulation hypothesis.”)

In his new book, Then I Am Myself The World, Koch, currently the chief scientist at the Allen Institute for Brain Science in Seattle, ventures through the challenging landscape of integrated information theory (IIT), a framework that attempts to compute the amount of consciousness in a system based on the degree to which information is networked. Along the way, he struggles with what may be the most difficult question of all: How do our thoughts -- seemingly ethereal and without mass or any other physical properties -- have real-world consequences? We caught up with him recently over Zoom.

In your new book, you ask how the mind can influence matter. Are we any closer to answering that question today than when Descartes posited it nearly four centuries ago?

Let’s step back. Western philosophy of mind revolves around two poles, the physical and the mental -- think of them like the north and the south pole. There’s materialism, which is now known as physicalism, which says that only physical really exists, and there is no mental; it’s all an illusion, like Daniel Dennett and others have said.

Then there’s idealism, which is now enjoying a mini-renaissance, but by and large has not been popular in the 20th and early 21st century, which says that everything fundamentally is a manifestation of the mental.

Then there is classical dualism, which says, well, there’s clearly physical matter and there’s the mental, and they somehow have to interact. It’s been challenging to understand how the mental interacts with the physical -- that’s known as the causation problem.

And then there are other things like panpsychism, that’s now becoming very popular again, which is a very ancient faith. It says that fundamentally everything is “ensouled” -- that everything, even elementary particles, feel a little bit like something.

All of these different positions have problems. Physicalism remains a dominant philosophy, particularly in Western philosophy departments and big tech. Physicalism says that everything fundamentally is physical, and you can simulate it -- this is called “computational functionalism.” The problem is that, so far, people have been unable to explain consciousness, because it’s so different from the physical.

What does integrated information theory say about consciousness?

IIT says, fundamentally, what exists is consciousness. And consciousness is the only thing that exists for itself. You are conscious. Tonight, you’re going to go into a deep sleep at some point, and then you’re not conscious anymore; then you do not exist for yourself. Your body and your brain still have an existence for others -- I can see your body there -- but you don’t exist for yourself. So only consciousness exists for itself; that’s absolute existence. Everything else is derivative.

It says consciousness ultimately is causal power upon itself -- the ability to make a difference. And now you’re looking for a substrate -- like a brain or computer CPU or anything. Then the theory says, whatever your conscious experience is -- what it feels like to see red, or to smell Limburger cheese, or to have a particular type of toothache -- maps one-to-one onto this structure, this form, this causal relationship. It’s not a process. It’s not a computation. It’s very different from all other theories.

When you use this term “causal powers,” how is it different from an ordinary cause-and-effect chain of events? Like if you’re playing billiards, you hit the cue ball, and the cue ball hits the eight ball …

It’s nothing woo-woo. It’s the ability of a system, let’s say a billiard ball, to make a difference. In other words, if it gets hit by another ball, it moves, and that has an effect in the world.

And IIT says you have a system -- a bunch of wires or neurons -- and it’s the extent to which they have causal power upon themselves. You’re always looking for the maximum causal power that the system can have on itself. That is ultimately what consciousness is. It’s something very concrete. If you give me a mathematical description of a system, I can compute it, it’s not some ethereal thing.

So it can be objectively measured from the outside?

That’s correct.

But of course there was the letter last year that was signed by 124 scientists claiming that integrated information theory is pseudoscience, partly on the grounds, they said, that it isn’t testable.

Many years ago, I organized a meeting in Seattle, where we came together and planned an “adversarial collaboration.” It was specifically focused on consciousness. The idea was: Let’s take two theories of consciousness -- in this case, integrated information theory versus the other dominant one, global neuronal workspace theory. Let’s get people in a room to discuss -- yes, they might disagree on many things -- but can we agree on an experiment that can simultaneously test predictions from the two theories, and where we agree ahead of time, in writing: If the outcome is A it supports theory A; if it’s B, it supports theory B? It involved 14 different labs.

The experiments were trying to predict where the “neural footprints of consciousness,” crudely speaking, are. Are they in the back of the brain, as integrated information theory asserts, or in the front of the brain, as global neuronal workspace asserts? And the outcome was very clear -- two of the three experiments were clearly against the prefrontal cortex and in favor of the neural footprint of conscious being in the back.

This provoked an intense backlash in the form of this letter, where it was claimed the theory is untestable, which I think is just baloney. And then, of course, there was blowback against the blowback, because people said, wait, IIT may be wrong -- the theory is certainly very different from the dominant ideology -- but it’s certainly a scientific theory; it makes some very precise predictions.

But it has a different metaphysics. And people don’t like this.

Most people today believe that if you can simulate something, that’s all you need to do. If a computer can simulate the human brain, then of course [the simulation is] going to be conscious. And LLMs -- sooner or later [in the functionalist view] they’re going to be conscious -- it’s just a question of, is it conscious today, or do you need some more clever algorithm?

IIT says, no, it’s not about simulating; it’s not about doing -- it’s ultimately about being, and for that, really, you have to look at the hardware in order to say whether it’s conscious or not.

Does IIT involve a commitment to panpsychism?

It’s not panpsychism. Panpsychism says, “this table is conscious” or “this fork is conscious.” Panpsychism says, fundamentally, everything is imbued with both physical properties as well as mental properties. So an atom has both mental and physical properties.

IIT says, no, that’s certainly not true. Only things that have causal power upon themselves [are conscious] -- this table doesn’t have any causal power upon itself; it just doesn’t do anything, it just sits there.

But it shares some intuitions [with panpsychism] -- in particular, that conscience is on a gradient, and that maybe even a comparatively simple system, like a bacterium -- already a bacterium contains a billion proteins, [there’s] immense causal interaction -- it may well be that this little bacterium feels a little bit like something. Nothing like us, or even the consciousness of a dog. And when it dies, let’s say, when you’re given antibiotics and its membrane dissolves, then it doesn’t feel like anything anymore.

A scientific theory has to rest on its predictive power. And if the predictive power says, yes, consciousness is much wider than we think -- it’s not only us and maybe the great apes; maybe it’s throughout the animal kingdom, maybe throughout the tree of life -- well, then, so be it.

Toward the end of the book, you write, “I decide, not my neurons.” I can’t help thinking that that’s two ways of saying the same thing -- on the macro level it’s “me,” but on the micro level, it’s my neurons. Or am I missing something?

Yeah, it’s a subtle difference. What truly exists for itself is your consciousness. When you’re unconscious, as in a deep sleep or on anesthesia, you don’t exist for yourself anymore, and you’re unable to make any decisions. And so what truly exists is consciousness, and that’s where the true action happens.

I actually see you on the screen, there are lights in the image; inside my brain, I can assure you, there are no lights, it’s totally dark. My brain is just in a goo. So it’s not my brain that sees; it’s consciousness that sees. It’s not my brain that makes a decision, it’s my consciousness that makes a decision. They’re not the same.

For as long as we’ve had computers, people have argued about whether the brain is an information processor of some kind. You’ve argued that it isn’t. From that perspective, I’m guessing you don’t think large language models have causal powers.

Correct. In fact, I can pretty confidently make the following statement: There’s no Turing test for consciousness, according to IIT, because it’s not about a function; it’s all about this causal structure. So you actually have to look at the CPU or the chip -- whatever does the computation. You have to look at that level: What’s the causal power?

Now you can of course simulate perfectly well a human brain doing everything a human brain can do -- there’s no problem conceptually, at least. And of course, a computer simulation will one day say, “I’m conscious,” like many large language models do, unless they have guardrails where they explicitly tell you “Oh no, I’m just an LLM -- I’m not conscious,” because they don’t want to scare the public.

But that’s all simulation; that’s not actually being conscious. Just like you can simulate a rainstorm, but it never gets wet inside the computer, funny enough, even though it simulated a rainstorm. You can solve Einstein’s equation of general relativity for a black hole, but you never have to be afraid that you’re going to be sucked into your computer simulation. Why not? If it really computes gravity, then shouldn’t spacetime bend around my computer and suck me, and the computer, in? No, because it’s a simulation. That’s the difference between the real and the simulated. The simulated doesn’t have the same causal powers as the real.

So unless you build a machine in the image of a human brain -- let’s say using neuromorphic engineering, possibly using quantum computers -- then you can’t get human-level consciousness. If you just build them like we build them right now, where one transistor talks to two or three other transistors -- that’s radically different from the connectivity of the human brain -- you’ll never get consciousness. So I can confidently say that although LLMs very soon will be able to do everything we can do, and probably faster and better than we can do, they will never be conscious.

So in this view, it’s not “like anything” to be a large language model, whereas it might be like something to be a mouse or a lizard, for example?

Correct. It is like something to be a mouse. It’s not like anything to be an LLM -- although the LLM is vastly more intelligent, in any technical sense, than the mouse.

Yet somewhat ironically, the LLM can say “Hello there, I’m conscious,” which the mouse cannot do.

That’s why it’s so seductive, because it can speak to us, and express itself very eloquently. But it’s a gigantic vampire -- it sucks up all of human creativity, throws it into its network, and then spits it out again. There’s no one home there. It doesn’t feel like anything to be an LLM.

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眼睛錯覺可能說明「意識」如何形成 -- Emily Cooke
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此研究的重要性在於：它「證明」了，或至少「顯示」了，「意識」的形成需要根據過去的「經驗」，就大腦神經學而言，「經驗」就是「記憶」，也就是「神經細胞」構成的網絡。此所以完全失去「記憶」，也就沒有「意識」可言：這是阿茲海默症可怕之處。

Optical illusion reveals key brain rule that governs consciousness

Emily Cooke, 05/02/24

A study of mice starts to unravel how the brain gets tricked by this kind of optical illusion, and it gives clues about how visual perception works.

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The new study investigated the perception of brightness in mice by looking at how they responded to an optical illusion called the neon-color-spreading illusion, an example of which is illustrated above. (Image credit: Mabit1, CC BY-SA 4.0 DEED, via Wikimedia Commons https://creativecommons.org/licenses/by-sa/4.0/deed.en；請至原網頁查看照片)

Optical illusions play on the brain's biases, tricking it into perceiving images differently than how they really are. And now, in mice, scientists have harnessed an optical illusion to reveal hidden insights into how the brain processes visual information.

The research focused on the neon-color-spreading illusion, which incorporates patterns of thin lines on a solid background. Parts of these lines are a different color — such as lime green, in the example above — and the brain perceives these lines as part of a solid shape with a distinct border — a circle, in this case. The closed shape also appears brighter than the lines surrounding it.

It's well established that this illusion causes the human brain to falsely fill in and perceive a nonexistent outline and brightness — but there's been ongoing debate about what's going on in the brain when it happens. Now, for the first time, scientists have demonstrated that the illusion works on mice, and this allowed them to peer into the rodents' brains to see what's going on.

Specifically, they zoomed in on part of the brain called the visual cortex. When light hits our eyes, electrical signals are sent via nerves to the visual cortex. This region processes that visual data and sends it on to other areas of the brain, allowing us to perceive the world around us.

The visual cortex is made of six layers of neurons that are progressively numbered V1, V2, V3 and so on. Each layer is responsible for processing different features of images that hit the eyes, with V1 neurons handling the first and most basic layer of data, while the other layers belong to the "higher visual areas." These neurons are responsible for more complex visual processing than V1 neurons.

Until now, scientists have debated the extent to which V1 neurons respond to illusory brightness, such as the brightness people perceive when looking at the neon-color-spreading illusion. In a series of lab experiments in mice, researchers have now shown that these neurons play a fundamental role in this process and that their activity is also tempered by feedback from V2 neurons. So there's a volley back and forth between these different layers of the visual cortex.

This knowledge may bolster our understanding of consciousness, the researchers said in a paper published April 23 in the journal Nature Communications.

"The observed relationship between V1 and V2 in processing the illusion implies that consciousness is a top-down process," as opposed to a bottom-up process, co-author Masataka Watanabe, an associate professor in the department of systems innovation at the University of Tokyo, told Live Science in an email.

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This is an alternative version of the neon-color-spreading illusion. In this case, the brain perceives the colored blue lines as belonging to a blue circle, but in reality, the background is still white and the blue lines don't form a closed shape. (Image credit: blebspot, CC BY-SA 3.0 DEED, via Wikimedia Commons https://creativecommons.org/licenses/by-sa/3.0/deed.en)

Top-down processing refers to the way our brains interpret our surroundings by taking prior experiences into account, rather than solely relying on visual stimuli alone. By contrast, pure bottom-up processing would take the different features of an image and snap them together like puzzle pieces, making a coherent picture without input from a person's memory.

Other studies have implied that consciousness is a top-down-process, but this mouse study provides direct evidence for it, Watanabe said. The answer isn't black and white though, as some argue that consciousness likely arises from a mixture of both.

What is the new evidence? In the study, mice were shown a combination of neon-color-spreading illusions and other, similar-looking patterns that did not trigger the illusion. Simultaneously, Watanabe and colleagues measured the activity of neurons in the rodents' brains with implanted electrodes.

The team also measured whether the mice saw the illusions as bright by assessing how much the pupils in their eyes dilated or constricted. This response matched that seen in humans when we perceive changes in light levels.

V1 neurons respond to both illusory and non-illusory images, but they take longer to respond to the former. This supports the theory that V1 neurons need feedback from higher visual areas to process these types of illusions, the team reported.

The researchers then tried experimentally inhibiting the activity of the higher visual area neurons, finding that V1 neurons were less likely to respond to the illusions. This provided further evidence that a higher-level feedback loop is needed to perceive the illusion.

Going forward, the team plans to conduct further studies in which they'll mess with the activity of higher visual area neurons in mice, Watanabe said. They hope that this will shed more light on the neural mechanisms underlying consciousness in mice, and by extension, in humans.

Related:

The brain-bending secret behind hundreds of optical illusions has finally been revealed
Super-detailed map of brain cells that keep us awake could improve our understanding of consciousness
How this trippy illusion will make you see an 'expanding black hole'
This optical illusion tricks you into seeing different colors. How does it work?
A new type of optical illusion tricks the brain into seeing dazzling rays

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

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