That Neuroscience Guy - Q&A: Consciousness Special

Episode Date: June 6, 2021

Have you ever wondered what consciousness actually is? What separates conscious beings from artificial intelligence? As it turns out, not much. In a special Q&A episode, I discuss the neuroscience of consciousness. 

Hi, my name is Olof Kregolsen, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm That Neuroscience Guy. Welcome to the podcast. Today, I'm going to be taking your questions. Remember, you can email your questions to thatneuroscienceguy at gmail.com, or you can post them on my Twitter feed, at thatneurosciguy. I polled a bunch of students, friends, family, and even strangers, and the most common question that came up was, what is consciousness? So today I'm only going to answer one question. Today is the neuroscience of consciousness. One question. Today is the neuroscience of consciousness.

Consciousness typically refers to your awareness of yourself and the world around you. People take it to mean your unique pattern of thoughts, memories, feelings, and sensations. And awareness is thought to be subjective and unique to you. But what does it really mean, and how can we explain consciousness? Well, let's start with perception. A key aspect of the definition of consciousness is that you perceive the world around you. For instance, we talked in a previous episode about vision. Visual information flows into the brain and the dorsal visual stream creates the world around you. It helps position where things are and your location relative to them. Concurrently, at the same time, the ventral visual stream is identifying objects.

So your visual system is creating this visual world around you and it has learned to identify things. At the same time, your proprioceptive system is giving your brain information about the state of your body, whether you're standing up or sitting down, whether you're cold or you're hot. And working with the visual brain, it's putting you into the world. It's positioning you in space. Adding to this, you have taste, smell, and hearing, providing other sensory input that puts you in the world and lets you know what's going on. And you have learned what all of this stuff means. You combine that with the motor system of the brain that we'll talk more about. You combine that with the motor system that we'll talk more about in future episodes, but the motor system essentially allows us to move around and interact with the world.

Now, let's think of a couple of examples. Apalysia is a sea slug, and it's quite famous because Dr. Eric Kandel did a lot of his Nobel Prize winning research on human memory using Apalysia as a model. And Apalysia has a very simple behavior. If its gill, which is put out for feeding, is touched, the gill withdraws. It's called the gill withdrawal reflex. And after a period of time, Apalysia puts the gill back out for feeding again. And if you keep touching the gill, it actually learns to not withdraw the gill. It learns to ignore the stimulus. So is this consciousness at a simple level? Apalysia does have an awareness

of the world around it, at least in terms of a very specific stimulus, and it has a response for it. If you move up to other animals, you might consider foraging behavior, animals that scurry around looking for food. Well, they're aware of the world around them. For instance, a mouse might know where to go to find something good to eat in your house. And if it doesn't find something there, it can make some very simple decisions to try a new location. A mouse's behavior can be thought of as a form of consciousness. A mouse is aware of the world around it, and it can make some simple choices. In all of these examples, we're actually talking about learning. Apelizia and a mouse and other organisms can learn.

Apelizia at a very simple level learns that if the gill is constantly stimulated, it shouldn't withdraw it. And a mouse can learn where not to go in your house, for instance, if it perceives danger. And it can also learn where food is, of course, and it can learn a good place to make a nest. So not only

are these animals simply reacting to the world around them through sensory perception and motor output, but they're also adapting in their learning. This takes us right into decision making. You might think that you've got a lot of free will and tie that to consciousness. But let's think about what really happens. When you decide what to have for dinner, you're going through a fairly straightforward value assessment where you're trying to decide which of many options is the most favorable. Now, you might think, well, I'm just going to try something new, but that is a form of exploration, which is a natural behavior to do. And when someone, for instance,

pressures you to eat something, you might resist it, which is an emotional response, or you might really want it because of peer pressure. But at the end of the day, that's just your emotional system biasing values. So we can think of decision-making as having a lot of free will, but is it really? Is it really a conscious process? Well, it is in some sense, because you are probably consciously evaluating the choices in front of you, but really your brain is just going through a value assessment and weighing the pros and cons, and eventually you make a choice.

Now, some would say that consciousness is tied to higher level constructs. There's a lot of interesting research that looks at some fairly complex behaviors. For instance, one of my favorite researchers is Dr. Joshua Green, who's done some fascinating work at moral behavior and ethical decision making. And you might have heard of some of his work. decision-making. And you might have heard of some of his work. He's investigated, for instance, why people might be biased to do one thing versus the other and why they act morally as opposed to rationally in certain situations. Because I like his work so much, I'm going to devote a whole episode to Dr. Joshua Green's work. But at the end of the day, he's shown us that moral and ethical behavior is really just, it's brought about by a complex firing pattern between neurons and parts of the brain that are associated with your emotional system and other parts of the brain

that are your rational decision-making systems. And these ethical decisions are really just a product of all this neural firing. Perhaps another interesting one is the work by Dr. Secchi, who's really looked at the neural basis of love. In fact, Dr. Secchi's work has been able to differentiate between you see a picture of someone that you love romantically versus someone that you love platonically. Dr. Secchi's work has also even found a part of the brain that's supposed to be more active when you look at a potential lifelong partner. So even a complex construct

like love can be tied into a complex pattern of neural firing. And that's where I'm really going with this. What we perceive to be consciousness is really just a complex pattern of neural firing, at least in the mind of a neuroscientist, no pun intended. Consider Google's DeepMind computer. Google's DeepMind computer learned to play Go and chess. And those are pretty complex behaviors. Is that consciousness? Being able to analyze a chessboard and make a decision? It sure sounds like it. And think of the AI that you carry on your phone. It can recognize faces and other objects, and it can even suggest to you where you should go shopping,

based on your location or any number of other factors. Is that a form of consciousness? number of other factors. Is that a form of consciousness? I think so. So how does it arrive? You have to remember the vast number of neurons and neural connections in your brain. Your brain might seem kind of small, but it holds over 100 billion neurons. That's more than the number of stars in the Milky Way galaxy. And more so than that, there's 10 to the 15th connections. That's an incredible amount of neural connections. That's in the quadrillion billions. So how do we get to consciousness from there? Well, it's really a result of all of those neurons and all of those interconnections. If you only had one neuron that had input and one neuron that had output, think back to Apalysia the slug,

then if that neuron fires, your input neuron, the output neuron fires, and you're pretty much limited that simple response. But as the number of neurons increases, the complexity increases. Think of your television. Think of the number of pixels on the screen. I'm sure you considered that when you bought it. As you increase the number of pixels on your TV screen, you increase the complexity of the information you can show.

Think about that for a second. Imagine if I tried to sell you a 20 by 10 pixel TV. All of the visual information would have to be represented by 200 squares. The resolution wouldn't be that good. For some of us, we can actually think back to what we call 8-bit graphics in the 80s video game era. The reason the graphics weren't that great is the resolution wasn't that good, and the computer's ability to draw quickly as well. But with better computer video resolution, or TV resolution, we can draw more complex pictures. Well, the same is true in your brain.

The more neurons you have and the more neural connections, the more complex the information you can represent. That's the way your brain can differentiate between so many things, but it's also the way your brain can respond to so many things. By having so many neurons and neural connections, your brain can learn extremely complex patterns, such as romantic love or ethical decision-making. So what is consciousness? At a simple level, it's just your awareness of yourself and the world around you. And the neural basis of consciousness derives simply from having 100 billion neurons and considerably more interconnections. It's that complex matrix that gives a rise to all of our thoughts, memories, feelings, and considerably more interconnections. It's that complex matrix that gives a rise to all of our thoughts, memories, feelings, and sensations.

My name is Olof Kregolsen, and I'm That Neuroscience Guy. If you've got questions, please email me, thatneuroscienceguy at gmail.com, or post them on my Twitter feed, at That Neuroscience Guy. Feel free to check out my website as well, www.olivkrigolson.com. Thanks for listening, and I'll see you on the next episode.