2
" Their [personal digital assistants] siren voices are living proof of our times - that our mind is software, running on the computer that is our brain. Consciousness is just a couple of clever hack away. We are only meat machines, no better, and increasingly, worse, than computers. According to the more triumphalist voices in the tech industry, we should revel in our soon-to-come obsolescence; we should be grateful that Homo Sapiens will have served as a bridge between biology and the inevitable next step in evolution, superintelligence. Smart money in Silicon Valley thinks so, op-ed pieces proclaim it to be so, and sleek sci-fi flicks reinforce this poor man's Nietzschean ideology.
Mind-as-software is the dominant mythos of liquid modernity, of our hyper-individualized, glove-trotting, technology-worshipping culture. It is the one remaining mythos of an age that believes itself immune to mythology. An age whose elite is witnessing with incomprehension and indifference the dying struggle of the once all-powerful mythos that sustained the West for two millennia - Christianity. "
― Christof Koch , The Feeling of Life Itself: Why Consciousness Is Widespread But Can't Be Computed
3
" Purkinje cells are among the most elaborate of all neurons; the cerebellum maps the body and outside space onto its tens of billions of neurons. Yet none of this seems sufficient to generate consciousness. Why not?
Important hints can be found within its highly stereotyped, crystalline-like circuitry. First, the cerebellum is almost exclusively a feedforward circuit. That is, one set of neurons feeds the next one that , in turn, influences a third one. There are few recurrent synapses that amplify small responses or lead to tonic firing that outlasts the initial trigger. While there are no excitatory loops in the cerebellum, there is plenty of negative feedback to quench any sustained neuronal response. As a consequence, the cerebellum has no reverberatory, self-sustaining activity of the type seen in cortex. Second, the cerebellum is functionally divided into hundreds or more independent modules. Each one operates in parallel, with distinct, nonoverlapping inputs and outputs.
What matters for consciousness is not so much the individual neurons but the way they are wired together. A parallel and feedforward architecture is insufficient for consciousness. "
― Christof Koch , The Feeling of Life Itself: Why Consciousness Is Widespread But Can't Be Computed
4
" This brings me to an objection to integrated information theory by the quantum physicist Scott Aaronson. His argument has given rise to an instructive online debate that accentuates the counterintuitive nature of some IIT's predictions.
Aaronson estimates phi.max for networks called expander graphs, characterized by being both sparsely yet widely connected. Their integrated information will grow indefinitely as the number of elements in these reticulated lattices increases. This is true even of a regular grid of XOR logic gates. IIT predicts that such a structure will have high phi.max. This implies that two-dimensional arrays of logic gates, easy enough to build using silicon circuit technology, have intrinsic causal powers and will feel like something. This is baffling and defies commonsense intuition. Aaronson therefor concludes that any theory with such a bizarre conclusion must be wrong.
Tononi counters with a three-pronged argument that doubles down and strengthens the theory's claim. Consider a blank featureless wall. From the extrinsic perspective, it is easily described as empty. Yet the intrinsic point of view of an observer perceiving the wall seethes with an immense number of relations. It has many, many locations and neighbourhood regions surrounding these. These are positioned relative to other points and regions - to the left or right, above or below. Some regions are nearby, while others are far away. There are triangular interactions, and so on. All such relations are immediately present: they do not have to be inferred. Collectively, they constitute an opulent experience, whether it is seen space, heard space, or felt space. All share s similar phenomenology. The extrinsic poverty of empty space hides vast intrinsic wealth. This abundance must be supported by a physical mechanism that determines this phenomenology through its intrinsic causal powers.
Enter the grid, such a network of million integrate-or-fire or logic units arrayed on a 1,000 by 1,000 lattice, somewhat comparable to the output of an eye. Each grid elements specifies which of its neighbours were likely ON in the immediate past and which ones will be ON in the immediate future. Collectively, that's one million first-order distinctions. But this is just the beginning, as any two nearby elements sharing inputs and outputs can specify a second-order distinction if their joint cause-effect repertoire cannot be reduced to that of the individual elements. In essence, such a second-order distinction links the probability of past and future states of the element's neighbours. By contrast, no second-order distinction is specified by elements without shared inputs and outputs, since their joint cause-effect repertoire is reducible to that of the individual elements. Potentially, there are a million times a million second-order distinctions. Similarly, subsets of three elements, as long as they share input and output, will specify third-order distinctions linking more of their neighbours together. And on and on.
This quickly balloons to staggering numbers of irreducibly higher-order distinctions. The maximally irreducible cause-effect structure associated with such a grid is not so much representing space (for to whom is space presented again, for that is the meaning of re-presentation?) as creating experienced space from an intrinsic perspective. "
― Christof Koch , The Feeling of Life Itself: Why Consciousness Is Widespread But Can't Be Computed
5
" Finally, Tononi argues that the neural correlate of consciousness in the human brain resembles a grid-like structure. One of the most robust findings in neuroscience is how visual, auditory, and touch perceptual spaces map in a topographic manner onto visual, auditory, and somatosensory cortices. Most excitatory pyramidal cells and inhibitory interneurons have local axons strongly connected to their immediate neighbours, with the connections probability decreasing with distance. Topographically organized cortical tissue, whether it develops naturally inside the skull or is engineered out of stem cells and grown in dishes, will have high intrinsic causal power. This tissue will feel like something, even if our intuition revels at the thought that cortical carpets, disconnected from all their inputs and outputs, can experience anything. But this is precisely what happens to each one of us when we close our eyes, go to sleep, and dream. We create a world that feels as real as the awake one, while devoid of sensory input and unable to move.
Cerebral organoids or grid-like substances will not be conscious of love or hate, but of space.; of up, down, close by and far away and other spatial phenomenology distinctions. But unless provided with sophisticated motor outputs, they will be unable to do anything. "
― Christof Koch , The Feeling of Life Itself: Why Consciousness Is Widespread But Can't Be Computed
6
" The cause-effect information is defined as the smaller (minimum) of the cause-information and the effect-information. If either one is zero, the cause-effect information is likewise zero. That is, the mechanism's past must be able to determine its present, which, in turn, must be able to determine its future. The more the past and the future are specified by the present state, the higher the mechanism's cause-effect power.
Note that this usage of 'information' is very different from its customary meaning in engineering and science introduced by Claude Shannon. Shannon information, which is always assessed from the external perspective of an observer, quantifies how accurately signals transmitted over some noisy communication channel, such as a radio link or an optical cable, can be decoded. Data that distinguishes between two possibilities, OFF and ON, carries 1 bit of information. What that information is, though - the result of a critical blood test or the least significant bit in a pixel in the corner of a holiday photo - completely depends on the context. The meaning of Shannon information is in the eye of the beholder, not in the signals themselves. Shannon information is observational and extrinsic.
Information in the sense of integrated information theory reflects a much older Aristotelian usage, derived from the Latin in-formare, 'to give form or shape to.' Integrated information gives rise to the cause-effect structure, a form. Integrated information is causal, intrinsic, and qualitative: it is assessed from the inner perspective of a system, based on how its mechanisms and its present state shape its own past and future. How the system constrains its past and future states determines whether the experience feels like azure blue or the smell of wet dog. "
― Christof Koch , The Feeling of Life Itself: Why Consciousness Is Widespread But Can't Be Computed
8
" It was only as a mature man that I became mortal.
The visceral insight of my end came to me abruptly more than a dozen years ago. I had wasted an entire evening playing an addictive, firstperson shooter video game that belonged to my teenage son—running through eerily empty halls, flooded corridors, nightmarishly twisting tunnels, and empty plazas under a foreign sun, emptying my weapons at hordes of aliens pursuing me relentlessly. I went to bed late and, as always, fell asleep easily. I awoke abruptly a few hours later. Knowledge had turned to certainty
—I was going to die! Not right there and then, but someday.
...
My interpretation of this queer event is that all the killing in the video game triggered
unconscious thoughts about the annihilation of the self. These processes produced sufficient anxiety that my cortico-thalamic complex woke up on its own, without any external trigger. At that point, self-consciousness lit up and was confronted with its mortality. "
― Christof Koch , Consciousness: Confessions of a Romantic Reductionist
13
" Three additional properties hold for any conscious experience. They cannot be doubted. First, any experience is highly informative, distinct because of the way it is. Each experience is informationally rich, containing a great deal of detail, a composition of specific phenomenal distinctions, bound together in specific ways. Every frame of every movie I ever saw or will see in the future is a distinct experience, each one a wealth of phenomenology of colors, shapes, lines, and textures at locations throughout the field of view. And then there are auditory, olfactory, tactile, sexual, and other bodily experiences—each one distinct in its own way. There cannot be a generic experience. Even the experience of vaguely seeing something in a dense fog, without being clear what I am seeing, is a specific experience. "
― Christof Koch , The Feeling of Life Itself: Why Consciousness Is Widespread But Can't Be Computed
