The human brain can be compared to a modern flight simulator in several respects. Like a flight simulator, a consciousness continuously updates an internal model of external reality by using a continuous stream of inputs applied by the sensory organs and employing past experience as a filter. It integrates sensory-input channels into a global model of reality, and it does so in real time. However, there is a difference. The global model of reality constructed by the brain is updated at such great speed and with such reliability that we generally do not experience it as a model. For us, phenomenal reality is not a simulation constructed by our brains; in a direct and experientially untrancendable matter, it is the world we live in. Its virtuality is hidden, where the flight simulator is easily recognized as a flight simulator–it images always seem superficial. 107
Finally, the brain also differs from a flight simulator in that there is no user, no pilot who controls it. The brain is like a total flight simulator, a self modeling airplane that, rather than being flown by a pilot, generates a complex internal image of itself with and its own internal flight simulator. The image is transparent and thus cannot be recognized as an image by the system. Operating under the condition of a naïve-realistic self-misunderstanding, the system interprets the control element in this image is a nonphysical object: the “pilot” is born into a virtual reality with no opportunity to discover this fact. The pilot is the ego. The total flight simulator generates an Ego Tunnel but is completely lost in. 108
Metzinger argues that human consciousness is the result of our brains modeling reality at such high resolution that we are incapable of recognizing it as a mere simulation of reality. We model the outside world, and it seems real; we don’t recognize that it’s a limited simulation of what’s actually out there. Without noticing, we accept the simulation as reality itself.
We also model our internal reaction to this simulated “outside” world to such a high degree that it also seems real. We model our outer world, and we model ourselves as agents within it.
Conscious states could be exactly those states that “meta-represent” themselves while representing something else. This classical idea has logical problems, but the insight itself can perhaps be preserved in an empirically plausible framework. 30-1
Some of the details of the Ego Tunnel model of consciousness were difficult to comprehend, but I was satisfied with just getting the main outline. I didn’t want to spend hours re-reading and re-reading passages that were tricky, but I may do so in the future upon a complete re-read of the book. Some of the interviews scattered throughout the book seem to be slightly off-message and I had trouble integrating them with the main thread of the book.
After summarizing his theory, Metzinger moves to topics I find highly interesting; free will, religion and spirituality, the Buddhist doctrine of not-self, and the uniquely human fear of death. Take a look at the quotes below for a sampling.
Ideas per Page:1 4/10 (medium)
Related Books: Waking Up by Sam Harris; Why Buddhism is True by Robert Wright; On Having No Head by Douglas Harding; Straw Dogs by John Gray; The Silence of Animals by John Gray
Recommend to Others: If you are interested in models of consciousness.
Reread Personally: Maybe, but after other authors on the topic
Modern neuroscience has demonstrated that the content of our conscious experience is not only an internal construct but also an extremely selective way of representing information. This is why it is a tunnel: what we see in here, or what we feel and smell and taste, is only a small fraction of what actually exists out there our conscious model of reality is a low dimensional projection of the inconceivably richer physical reality surrounding and sustaining us. Our sensory organs are limited: they evolve for reasons of survival, not for depicting the enormous wealth and richness of reality in all its unfathomable depth. Therefore, the ongoing process of conscious experience is not so much an image of reality is a tunnel through reality. 6
The ego, as noted, is simply the content of your PSM [phenomenal self-model] at this moment (your bodily sensations, your emotional state, your perceptions, memories, acts of will, thoughts). But it can become the ego only because you are constitutionally unable to realize that all this is just the content of a simulation in your brain. It is not reality itself but an image of reality – and a very special one indeed. The ego is a transparent mental image: you – the physical person as a whole – look right through it. You do not see it. But you see with it. The ego is a tool for controlling and planning your behavior and for understanding the behavior of others. 8
The same general idea holds for more complex states: their phenomenal content is precisely that aspect of a state (say, of happiness plus relaxation) that not only emerges naturally in everyday situations but can also because by a psychoactive substance – or, at least in principle, triggered by an evil neuroscientist experimenting on a living brain in a vat. The problem of consciousness is all about subjective experience, about the structure of our inner life, and not about knowledge of the outer world. 11
Consciousness is a very special phenomenon, because it is part of the world and contains it at the same time. All our data indicate that consciousness is part of the physical universe and is an evolving biological phenomenon. Conscious experience, however, is much more than physics plus biology – more than a fantastically complex, dancing pattern of neural firing in your brain. What sets human consciousness apart from other biologically evolved phenomena is that it makes a reality appear within itself. It creates inwardness; the life process has become aware of itself. 15
The apricot-pink of the setting sun is not a property of the evening sky; it is a property of the internal model of the evening sky, a model created by your brain. The evening sky is colorless. The world is not inhabited by colored objects at all. It is just as your physics teacher in high school told you: out there, in front of your eyes, there is just an ocean of electromagnetic radiation, a wide and ranging mixture of different wavelengths. Most of them are invisible to you and can never become part of your conscious model of reality. What is really happening is that the visual system in your brain is drilling a tunnel through this inconceivably rich physical environment and in the process is painting the tunnel walls in various shades of color. Phenomenal color. Appearance. For your conscious eyes only. 20
Our conscious experience of the world is systematically externalized because the brain constantly creates the experience that I am present in the world outside my brain. 23
Just like the water droplets that form a real cloud, some elements leave the aggregate at any given moment, while others join. Consciousness is a large-scale, unified phenomenon emerging from a myriad of physical micro-events. As long as a sufficiently high degree of internal correlation and causal coupling allows this island of dancing micro-events in your brain to emerge, you live in a single reality. A single, unified world appears to you. 30
If this idea is true, the brain state creating your conscious perception of the book in your hand right now must have two logical parts: one portraying the book and one continuously representing the state itself. One part point of the world, and one part itself. Conscious states could be exactly those states that “meta-represent” themselves while representing something else. This classical idea has logical problems, but the insight itself can perhaps be preserved in an empirically plausible framework. 30-1
Just as swiftly and effortlessly, the book-model is bound with other models, such as the models of your hands and of the desk, and seamlessly integrated into your overall conscious space of experience. Because it has been optimized over millions of years, this mechanism is so fast and so reliable that you never noticed its existence. It makes your brain invisible to itself. You are only in contact with its content; you never see the representation as such; therefore, you have the illusion of being directly in contact with the world. And that is how you become a naïve realist, a person who thinks she is in touch with an observer-independent reality. 42-3
We are unable to attend to the construction process that generates the model of the book in our brains. As a matter of fact, attention often seems to do exactly the opposite: by stabilizing the sensory object, we make it even more real. 44
In between 430 and 650 nm, human beings can discriminate more than 150 different wavelengths, for different subjective shades, of color. But if asked to re-identify single colors with a high degree of accuracy, they can do so for fewer than 15. The same is true for other sensory experiences.… Technically, this means we do not possess introspective identity criteria for many of the simplest states of consciousness. Our perceptual memory is extremely limited. You can see and experience the difference between green number 24 and green number 25 if you see both at the same time, but you are unable consciously to represent the sameness of green number 25 overtime. 49, 50
note that when you learn a difficult task for the first time, such as tying your shoes or riding a bicycle, your practicing is always conscious.… whenever the system is confronted with a novel or challenging stimulus, its global workspaces activated and represented in consciousness. This is also the point when you become aware of the process. 56
Those things in the evolution of consciousness that are old, ultrafast, and extremely reliable – such as the qualities of sensory experience – are transparent; abstract conscious thought is not. From an evolutionary perspective this is very new, quite unreliable (as we all know), and so slow that we can actually observe it going on in our brains. In conscious reasoning, we witness the formation of thoughts; some processing stages are available for introspective attention. Therefore, we know that our thoughts are not given but made. 61-2
What do we gain by saying that the neuronal correlate of consciousness is a particular metastable state of a very complex, highly dynamic, nonstationary distributed system – a state characterized by sequences of ever-changing patterns of precisely synchronized oscillations? Further research will lead to more detailed descriptions of such states – but these will likely be abstract, mathematical descriptions of state vectors. Eventually, advanced analytics methods may reveal the semantic content, the actual meaning of such state vectors, and it may be possible to minute manipulate the states and thereby alter the contents of consciousness, thus providing causal evidence for the relation between neuronal activity and the contents of phenomenal awareness. However, this is probably about as close as we can come, in our attempts to identify the neuronal correlates of consciousness. 69-70 [quoting Wolf Singer]
Monkeys can even learn to control a brain-machine interface that lets them grasp objects with a robot arm controlled by certain parts of their brain. 80
In its origins, the “soul” may have been not a metaphysical notion but simply a phenomenological one: the content of the phenomenal ego activated by the human brain during out of body experiences. 85-6
The history of philosophy has shown that technological metaphors had considerable limitations; nevertheless, virtual reality is a useful one. Nature’s virtual reality is conscious experience – a real-time world-model that can be viewed as a permanently running online simulation, allowing organisms to act and interact. 104
But the simple fact remains: you are never in direct contact with your own body. What you feel in the rubber-hand illusion, what AZ feels, or what Philip feels when his left arm is “plugged in” is exactly the same as what you feel when you attended the sensation of your hand holding this book right now which is the feeling of pressure and resistance when you lean back in your chair. What you experience is not reality but virtual reality, a possibility. Strictly speaking, and on the level of conscious experience alone, you live your life in a virtual body and not in a real one. 114
… Schizophrenics sometimes lose the sense of agency and executive consciousness entirely and feel themselves to be remote-controlled puppets. 121
From a scientific, third-person perspective, our inner experience a strong autonomy may look increasingly like that it has been all along: an appearance only. At the same time, we will learn to admire the elegance and the robustness with which nature built only those things into the reality tunnel that organisms needed to know, rather than burdening them with a flood of information about the workings of their brains. We will come to see the subjective experience of free will as an ingenious narrow computational tool. Not only does it create an internal user-interface that allows the organism to control and adapt its behavior, but it is also a necessary condition for social interaction and cultural evolution. 129
A lucid dream is a global simulation of a world in which we suddenly become aware that it is indeed just a simulation. It is a tunnel whose inhabitant begins to realize that he or she actually operates in a tunnel all the time. 140
[Researchers] have created an artificial starfish that gradually develops an explicit internal self-model. Therefore-like it machine uses actuation-sensation relationships to infer indirectly its own structure and then uses this self-model to generate forward locomotion. When part of its leg is removed, the machine adapts its self-model and generates alternative gaits – it learns to limp. 189
But let’s not evade the deeper question. Is there a case for phenomenological pessimism? The concept may be defined as the thesis that the variety of phenomenal experience generated by the human brain is not a treasure but a burden: averaged over a lifetime, the balance between joy and suffering is weighted toward the latter in almost all of its bearers. From Buddha to Schopenhauer, there is a long philosophical tradition positing, essentially, that life is not worth living. 199
We are driven to seek pleasure and joy, to avoid pain and depression. The hedonic treadmill is the motor that nature invented to keep the organism running. We can recognize the structure in ourselves, but we will never be able to escape it. We are the structure. 199
In fact, according to the naturalistic worldview, there are no ends. Strictly speaking, there are not even means – evolution just happened. 200
We are Ego Machines, but we do not have selves. We cannot leave the Ego Tunnel, because there is nobody who could leave. The Ego and its Tunnel are representational phenomena: they are just one of many possible ways in which conscious beings can model reality. Ultimately, subjective experience is a biological data format, a highly specific mode of presenting information about the world, and the ego is merely a complex physical event – an activation pattern in your central nervous system. 208
The self is not a thing but a process. 208
Metaphorically, the central claim of this book is that as you were reading these last several paragraphs, you – the organism as a whole – were continually mistaking yourself for the content of the self-model currently activated by your brain. 209
Mortality, for us, is not only an objective fact but a subjective fact, an open wound in our phenomenal self-model. We have a deep, inbuilt existential conflict, and we seem to be the first creatures on this planet to experience it consciously. Many of us, in fact, spend our lives trying to avoid experiencing it. Maybe this feature of our self-model is what makes is inherently religious. We are this process of trying to become whole again, to somehow reconcile what we know with what we feel should not be so. 210-1
Whereas spirituality might be defined as seeing what is—as letting go of the search for emotional security—religious faith can be seen as an attempt to cling to that search by redesigning the Ego Tunnel. Religious belief is an attempt to endow your life with deeper meaning and embedded in a positive meta-context – it is the deeply human attempt to finally feel at home. 211
But everything we know points to a conclusion that is simple but hard to come to terms with: evolution simply happened – foreightless, by chance, without goal. There is nobody to despise or rebel against – not even ourselves. And this is not some bizarre form of neural philosophical nihilism but rather a point of intellectual honesty and great spiritual depth. 212
A dozen of those volunteers rated the psilocybin experience as being the single most spiritually significant experience of his or her life, and an additional 38% rated it to be among the top five most spiritually significant experiences. More than two-thirds of the volunteers rated the experience with psilocybin to be either the single most meaningful experience of his or her life or among the top five most meaningful experiences. 226
It’s important to remember that for thousands of years people of all cultures have used psychoactive substances to induce special states of consciousness: not merely religious ecstasy, relaxed cheerfulness, or heightened awareness but also simple, stupid intoxication. 230
Philosophers can help by initiating and structuring the debates and illuminating the logical structure of ethical arguments and the history of the problems to be discussed. 238
1 A measure of the number of new or distinct ideas per page. 10/10 would be conceptually dense, like a textbook. 1/10 would be almost completely fluff.