ASMR Learn While You Sleep (How to Think About Consciousness Part 2)

[00:00:01]Hey.

[00:00:03]Welcome to part two of reading How to Think About Consciousness, introduced by Christoph Koch.

[00:00:14]Hopefully, I'm saying that right.

[00:00:19]Last time, I gave a bunch of intro.

[00:00:22]We're just going to jump right into it.

[00:00:24]I am recording this right after the last one. So, hopefully, I don't get too tired.

[00:00:31]This section is >> [clears throat] >> a perspective from Michael Graziano.

[00:00:40]Title: Consciousness Can Be Best Understood Using Engineering.

[00:00:48]One explanation for the existence of subjective experience, known as the attention schema theory, is that it emerges from the way our brains monitor and regulate attention and action, all of which is essential for our survival.

[00:01:14]Says profile with this picture.

[00:01:18]Michael Graziano is a professor of neuroscience and psychology at Princeton University and author of several books, including Rethinking Consciousness, A Scientific Theory of Subjective Experience.

[00:01:40]Here we go.

[00:01:43]What if consciousness isn't so mystical after all?

[00:01:49]What if we have just been asking the wrong question all along?

[00:01:55]Drawing on my background in neuroscience of movement control, what you could call the robotics of the brain, I suggest that consciousness can best can be best understood from an engineering perspective.

[00:02:13]Far from being some sort of magical property, it is just a tool, albeit a tool of extraordinary power.

[00:02:25]Engineering and the science of robotics in particular tells us that every good control device needs a model, a quick sketch of the thing it is controlling.

[00:02:37]We already know from cognitive neuroscience that the brain constructs many internal models, bundles of information that represent items in the real world.

[00:02:50]These models are simplified descriptions, useful but not entirely accurate.

[00:02:57]For example, the brain has a model of the body called the body schema to help control movement of the limbs.

[00:03:10]By the same engineering logic, the brain needs to model many aspects of itself to be able to monitor and control itself.

[00:03:19]It needs a kind of phantom brain.

[00:03:23]One part of this self-model may be particularly important for consciousness.

[00:03:29]Here's why.

[00:03:33]Too much information flows through the brain at any moment for it to all be processed in equal depth.

[00:03:42]To handle that problem, the system evolved a way to focus its resources and shift that focus strategically from object to object.

[00:03:52]From a nearby object to a distant sound or to an internal event such as an emotion or memory.

[00:04:01]Attention is the main way the brain seizes on information and processes it deeply.

[00:04:08]To control its roving attention, the brain needs a model, which I call the attention schema.

[00:04:18]Our attention schema theory explains why people think there is a hard problem of consciousness at all.

[00:04:26]Efficiency requires the quickest and dirtiest model pop possible.

[00:04:32]So, the attention schema leaves aside all the little details of signals and neurons and synapses.

[00:04:41]Instead, the brain describes a simplified version of itself, then reports this as a ghostly non-physical essence, a magical ability to mentally possess items.

[00:04:58]Introspection or cognition accessing internal information can never return any other answer.

[00:05:07]It is like a machine stuck in a logic loop.

[00:05:13]The attention schema is like a self-reflecting mirror.

[00:05:18]It is the brain's representation of how the brain represents things and is a specific example of higher-order thought.

[00:05:27]In this account, consciousness isn't so much an illusion as a self-caricature.

[00:05:35]A major advantage of this idea is that it gives a simple reason, straight from current control engineering, for why the trait of consciousness would evolve in the first place.

[00:05:48]Without the ability to monitor and regulate your attention, you would be unable to control your actions in the world.

[00:05:55]That makes the attention schema essential for survival.

[00:06:00]Consciousness in this view isn't just smoke and mirrors, but a crucial piece of the engine.

[00:06:07]It probably co-evolved with the ability to focus attention, just as the arm schema co-evolved with the arm.

[00:06:18]If the attention schema approach is correct, the first attempts at visual consciousness could be built with existing technology.

[00:06:27]But it will take a lot longer to give machines a human-like stream of consciousness.

[00:06:32]It will take time to build a conscious machine capable of seeing, hearing, tasting, touching, thinking abstract thoughts, and feeling emotions with a single integrated focus of attention to coordinate within and between all these domains, and be able to talk about that full range of content. But I believe it will happen.

[00:07:00]Discover more about conscious machines in chapter six.

[00:07:04]Not that I'm advocating for conscious robots. The point is that consciousness itself can be understood.

[00:07:12]It isn't an an ethereal essence or an inexplicable mystery.

[00:07:18]The attention schema theory puts it in context and gives it a concrete role in adaptation and survival.

[00:07:28]Instead of an ill-defined epiphenomenon, a fog extruded by the brain and floating between the ears, consciousness becomes a crucial component of the cognitive machine.

[00:07:52]That was all of Michael's perspective.

[00:08:01]Next section is consciousness a quantum phenomenon.

[00:08:10]The idea that consciousness has its origins in the notoriously notoriously weird phenomena of quantum physics has existed in the fringes for decades.

[00:08:22]It is finally being put to the test and early results are intriguing.

[00:08:35]The most famous of the various fringe hypotheses associating consciousness with quantum phenomena is known as orchestrated objective reduction or orc OR.

[00:08:50]Orchestrated objective reduction.

[00:08:54]It says that consciousness arises when gravitational instabilities in the fundamental structure of space-time collapse quantum wave functions in tiny structures called microtubules that are found inside neurons and in fact in all complex cells.

[00:09:19]To make sense of that, we must start with quantum theory and its textbook formulation. This says that a particle exists in a cloud of probabilities where it can appear both here and there say simultaneously until it is snapped into a definite classical state upon observation.

[00:09:44]This is what physicists refer to as the collapse of the quantum wave function.

[00:09:50]A mathematical entity that describes all possible states of a particle before it is observed.

[00:09:58]But we don't know what, if anything, induces collapse and there are all manner of interpretations of what is going on.

[00:10:13]In the late 1980s, building on earlier earlier ideas, the physicist Roger Penrose proposed that objective wave function collapse is a result of the inherent incompatible in incompatibility of quantum theory and general relativity, which describes gravity as the result of mass warping space-time.

[00:10:41]Unlike quantum fields and the particles they manifest, gravitational fields don't exist in an uncertain state, at least as far as we can tell.

[00:10:54]Penrose's idea was that any observation of a quantum particle forces an interaction with the classical gravitational field associated with the apparatus, creating a conflict that drives the quantum particle to collapse into a definite a definite state.

[00:11:13]It was a big leap, but Penrose went further, postulating that each time a quantum quantum wave function collapses in this way in the brain, it gives rise to a moment of conscious experience.

[00:11:30]This is where Stuart Hameroff, an anesthesiologist at the University of Arizona, entered the picture.

[00:11:38]He had been studying proteins called tubulin and the hollow cylindrical microtubules structures they form, trying to figure out their role in cell division.

[00:11:51]Crucially, they seem to be affected by anesthetics, which cause loss of consciousness.

[00:11:58]This led Hameroff to posit that microtubules inside neurons could be exploiting quantum effects, somehow translating gravitationally induced wave function into consciousness, as Penrose had suggested.

[00:12:16]Penrose and Hameroff published their Orch OR paper in 1996 to much incredulity.

[00:12:27]On the one hand, here was an audacious attempt to bridge the quantum and classical worlds while explaining the origin of our moment-to-moment experience.

[00:12:41]On the other, critics complained that they had committed the fallacy of minimizing mysteries.

[00:12:49]Just because consciousness and quantum mechanics are both mysterious doesn't mean that those mysteries must have a common source.

[00:13:00]And although Penrose, Hameroff, and their collaborators developed the concept in more detail over the following decades, without solid experiments to back up their ideas, Orch OR remained beyond the pale of mainstream consciousness research.

[00:13:20]In the last few years, however, several groups have begun to demonstrate that it is possible to test one cornerstone of Orch OR.

[00:13:30]The idea that quantum effects could exist in the brain.

[00:13:36]In 2023, Ararat Kalra and Gregory Scholes, physical chemists both then at Princeton University, looked at how energy absorbed in the form of light propagates through microtubules.

[00:13:55]They tagged these structures along their length with a fluorescent dye in order to observe this.

[00:14:02]To their surprise, energy diffused about five times further than expected according to classical calculations, suggesting a quantum phenomenon was at play in the microtubules.

[00:14:16]Remarkably, when they do doused the microtubules with two general aesthetics, etomidate and isoflurane, the diffusion length fell slightly but significantly from seven to six nanometers.

[00:14:37]These anesthetics do interact with micro microtubules, which is interesting, says Scholes, since it would link the quantum effects to consciousness.

[00:14:47]The trouble is this experiment was done on isolated microtubule compounds in test tubes, a far cry from the complexities of actual neurons inside the brain.

[00:15:02]Physicist Max Tegmark has argued that even if quantum effects do exist somewhere in biology, the brain is too wet, warm, and noisy for them to persist long enough across a sufficient number of neurons to sustain the kind of quantum processing that could plausibly explain our consciousness.

[00:15:29]Yet, there are tantalizing hints that they do persist.

[00:15:35]In 2018, a team led by Na Li at Huazhong University of Science and Technology in Wuhan, Wuhan, China, anesthetized 80 mice using four different isotopes of xenon gas.

[00:15:56]The isotopes that contained an odd number of neutrons in their nucleus, giving them a quantum property called spin, were found to be about 20% weaker in their anesthetic effects, which Li and colleagues took as support for the idea that consciousness relies on quantum phenomena.

[00:16:20]Many remain unconvinced, but some have been sufficiently intrigued to examine the result further.

[00:16:30]Kenneth Kosik at the University of California, Santa Barbara, for example, has been exploring the anesthetic strength of different xenon isotopes in brain organoids.

[00:16:43]These mini brains, comprising several million cells and a ball about the size same size as a lentil, are grown in a lab by mimicking what happens during the natural growth of embryos.

[00:16:59]Whether or not organoids have inner experience, their electrical activity gives consciousness researchers something tangible to measure.

[00:17:08]And it is already clear that these bundles of neurons respond to anesthetics.

[00:17:14]In 2022, Kosik and his colleagues found that diazepam, which has a sedating effect by enhancing the effect of a neurotransmitter called GABA, made the organoids electrical bursts more regular.

[00:17:32]Others found that the electrical activity of brain organoids implanted in mice was dampened by isoflurane anesthetic.

[00:17:42]If the action of anesthetic in brain organoids proves to be partly quantum in nature, it would make Penrose and Hameroff's proposal more plausible.

[00:17:53]It would show that quantum effects do operate in the brain for starters, and suggest that those effects have some relation to consciousness.

[00:18:04]But even then, these experiments still fall short of convincing evidence in favor of Orch OR.

[00:18:12]It is a long way, after all, from demonstrating the weakening of anesthetic potency to revealing the presence of a full-blown microtubule quantum computer that assembles all our sensory input and memories into a rich stream of consciousness.

[00:18:42]Here is another perspective. This one is Anil Seth.

[00:18:50]We perceive the world and ourselves through and because of our living bodies.

[00:18:59]Can the theory of predictive processing, which holds that the brain is constantly making and correcting guesses about the world around us, explain the key properties of consciousness?

[00:19:12]Profile.

[00:19:13]Anil Seth is Professor of cognitive cognitive and computational neuroscience at the University of Sussex, UK, and author of Being You, A New Science of Consciousness.

[00:19:31]I believe that science is capable of explaining consciousness, but only if we stop treating it as a single big mystery or what requiring a humdinger solution.

[00:19:44]Instead, we must break it down into its various related properties and address each in turn.

[00:19:51]What I call the real problem of consciousness then is how to explain and predict and control [clears throat] the various properties of consciousness in terms of physical processes in the brain and body.

[00:20:08]Let's focus on conscious content, that is, what you are conscious of, and conscious self, which is the experience of being you.

[00:20:21]My strategy for explaining the properties of consciousness is based on an increasingly popular theory in cognitive neuroscience called predictive processing.

[00:20:31]The bedrock idea is simple.

[00:20:33]Imagine that you are your brain locked inside the bony vault of your skull trying to figure out what's out there in the world.

[00:20:42]A world that from the perspective of the brain also includes the body.

[00:20:50]All you have to go on are noisy and ambiguous sensory signals, which are only indirectly related to what's out there, and which certainly don't come with labels attached.

[00:21:02]I'm from a cup of coffee. I'm from a tree.

[00:21:07]Perception in this view has to be a process of inference of neural neurally implemented probabilistic guesswork.

[00:21:19]When I see a red coffee cup on the table in front of me, this is because red coffee cup is the brain's best guess of the hidden and ultimately unknowable causes of the corresponding sensory signals.

[00:21:38]How are these perceptual best guesses arrived at?

[00:21:43]According to predictive processing, the brain is constantly calibrating its perceptual predictions using data from the senses.

[00:21:53]By continually updating its predictions to minimize sensory prediction errors, the brain will settle and resettle on an evolving best guess of its sensory causes.

[00:22:05]And this is what we consciously perceive.

[00:22:10]Perception in this view isn't a passive registration of an external reality.

[00:22:18]>> [clears throat] >> It is an active construction, a kind of controlled hallucination in which the brain's best guesses are tied to the world and the body through a continuous process of prediction error minimization.

[00:22:35]Predictive processing isn't a theory of consciousness in the sense that solving the hard problem would require.

[00:22:43]Instead, at least at first, it is best thought of as a theory for consciousness science in the real problem sense.

[00:22:53]It provides a method for building explanatory bridges between neural mechanisms and aspects of what conscious experiences are like from the perspective of the person experiencing experiencing them.

[00:23:08]This is what my colleagues and I have been doing in my laboratory at the University of Sussex, UK.

[00:23:13]Some of our experiments are very simple, for example, finding that people are consciously people consciously perceive expected images more quickly and more accurately than unexpected images.

[00:23:36]But the really exciting work is taking us deeper into the phenomenology, the what it is likeness of conscious experience.

[00:23:46]In one example, we are investigating the phenomenology of different varieties of visual hallucination in terms of their dependence on different kinds of perceptual prediction.

[00:23:58]By progressively accounting for the deep structure of perceptual experiences, not only the specific contents they present, like a cat or a coffee cup, but how they unfold over time and space, my belief is that aspects of the hard problem are already beginning to dissolve.

[00:24:18]And this process gathers momentum when we consider the experience of of being a conscious self from the same real problem perspective.

[00:24:30]Contrary to how things might seem, selves aren't essences of you that peer out through the windows of the senses from somewhere inside the skull.

[00:24:42]Instead, the self is a perception, too.

[00:24:47]Experiences of being you are collections of brain-based best guesses.

[00:24:54]And understanding this further erodes the dualistic intuitions on which the hard problem rests.

[00:25:02]Just as consciousness has many aspects, there are also many ways we experience being a self.

[00:25:11]For now, let's drill down the most basic aspect of conscious selfhood, the experience of being a body.

[00:25:21]I think of this as a rudimentary feeling of simply being a living organism.

[00:25:27]Partly expressed through emotions and moods, but at its deepest layers, without any describable content at all.

[00:25:37]It is here that the perception of the body from within, known as interoception, comes to the fore.

[00:25:46]Interoceptive sensations tell the brain about the internal state of the body.

[00:25:53]Blood pressure, say, or how the heart is doing, and therefore, enable the brain to perform its most important task, keeping the body alive.

[00:26:06]Like all sensory signals, interoceptive signals are only indirectly related to their causes, and so interoception must also involve a process of best guessing.

[00:26:19]And just as inference about the causes of visual signals underpins visual experiences, my proposal is that interoceptive inferences underpin other kinds of experiences.

[00:26:31]In this case, bodily experiences like emotions and moods.

[00:26:38]Following the real problem strategy, the differences between emotional experiences and visual experiences can now be understood in terms of the different kinds of perceptual prediction at play.

[00:26:53]Visual experiences of objects are generally concerned with figuring out what's there.

[00:26:59]So, it makes sense for the corresponding perceptual experiences to have the character of things with specific locations and physical extents.

[00:27:10]Emotional experiences, by contrast, are generally concerned with the organism's physiological condition and prospects of staying alive.

[00:27:21]These experiences and experiences of being a body, more generally, don't have shapes and locations in space.

[00:27:30]They instead have valence, which in psychology means things are good or bad now or likely to be good or bad in the future, which is what it is like to feel an emotion.

[00:27:45]The upshot is that the deepest layers of selfhood are intimately tied to our material nature as living creatures.

[00:27:56]The interoceptive predictions that underpin all self-related experiences are there to regulate our internal bodily state to keep us alive.

[00:28:09]And from this, everything else follows.

[00:28:12]Our perceptions and experiences, whether of the self or of the world, are inside-out controlled hallucinations deeply rooted in the flesh and blood machinery that evolved, develops, and operates from moment to moment in light of a fundamental biological drive to stay alive.

[00:28:36]We perceive the world and ourselves with, through, and because of our living bodies.

[00:28:48]I'm going to stop here for today.

[00:28:51]In the quote above the end of that section, our perceptions are inside-out controlled hallucinations deeply rooted in flesh and blood that evolved to help us stay alive.

[00:29:07]The next section we will start with the big consciousness bet.

[00:29:14]27 years ago, a neuroscientist and a philosopher bet a fine a case of fine wine on whether scientists would have cracked the neural basis of consciousness by 2023.

[00:29:27]Spoiler alert, they didn't.

[00:29:33]I hope you enjoyed I hope you found that relaxing. Thanks for watching.