All About the Brain (Part 3)

In Part 1 I discussed the physical structures of the brain, as well as a couple of the functions that it performs. In Part 2, I traced through the evolutionary development of the brain, from simple to complex. Now, in this final article, I’d like to talk about those things that we think of as making us “truly human.”

The Conscious Creature

ConsciousnessOne of those traits that seem to make us uniquely human (or at least unique in the degree to which we have it) is consciousness. Humans are conscious creatures. But what is consciousness, exactly? It seems to get defined in various ways, but normally it seems to come down to a sense of “awareness” of the outside world or of the “self”, or an idea of executive control over actions. I’ll get to the second interpretation in a moment, but how do we explain the sense of awareness of the world around us? Well, this is clearly a difficult question to answer, as it is difficult even to define what “awareness” means. If I may offer a simple definition, though, it seems as though awareness is an ability to draw attention to something else. It also includes a sense of being “separate” or “self-contained”. Just like a goldfish might not be aware of the water around it, or we might not be (generally) aware of the air we breathe, it is only when a distinction is drawn between an object and the “non-object” around it that we can be said to be “aware” of the object. This also ties in very closely with “self-awareness”—when we draw attention to the distinction between our own selves and the world around us. It is likely possible to provide a more finely-tuned notion of awareness, but I would argue that these two components are crucial.

But where does this awareness come from, then? Well, when breaking it down into attention and distinction, the problem becomes more manageable. Humans (as well as most animals) are able to draw attention to things around them. When I turn my head to look at something, that is a physical sign that I have redirected my attention to that object. When I stare off into space at nothing in particular, however, it is clear that even if my eyes are focused in a general direction, my attention is not on whatever occupies my visual field. In this way, we can state that attention is a direction of cognitive resources toward a specific task. The task can be the recognition or manipulation of an external object, but it can also be an internal task: remembering past objects, calculating abstract math equations, noticing one’s own feelings, etc.

Working MemoryMuch of the research done on attention treats it as a “resource”. In other words, we have a certain attentional capacity, and so we only have a limited amount of it to devote to certain tasks. Some research combines this with a concept called working memory, which deals with all the active, conscious processing of one’s environment. There are several brain areas that have been identified as connected to attention and working memory, but two of them are parts of the frontal and parietal lobes.1 The frontal cortex (which includes the prefrontal cortex that I mentioned in Part 1) is most likely responsible for the task of “executive control”—the ability to tell other brain regions what tasks they should be devoting resources toward. That humans have a large prefrontal cortex means that we are better able to control our attention toward a task (though we certainly aren’t always good at it).

So what of the second component of awareness, the distinction between objects? Well, some of this comes from very basic and necessary perceptual processes that help us to navigate the world. Our brain uses many techniques to distinguish between shapes, sizes, distances, and more. Books have been written on this subject, so I don’t have the space to discuss all of these techniques at the moment. However, suffice to say that the more readily we can identify objects, the more easily we can determine whether they are dangerous, whether they are useful to us, or whether we can manipulate them in some way to make them useful to us. These processes have clear survival benefits, and we are almost certainly not the only organisms who have them. However, we have a unique advantage over these other creatures. We are the only animal with language, and this allows us a way to formalize the distinction of objects. By labelling objects with certain names, we develop an impressive repertoire of categories and prototypes of object characteristics which can be used to more readily identify future objects. These are also taught to children, who spend several years learning and mastering the specifics of these categories.2

Self-aware YamTo summarize, then, humans demonstrate awareness because they are able to draw attention to certain objects, which are perceived to be distinct and separate from the background. This is done using special processes which serve to focus resources towards certain tasks, and well-honed object recognition skills which are built up through experience and memory. The special case of “self-awareness” that I mentioned earlier, then, is simply the ability for our executive control to turn our attentional resources on ourselves, whether that is our physical bodies or our own mental processes. When I think about the fact that I’m thinking, or when I think about how good my own memory is, I’m engaging in self-awareness. But this relies on the same processes involved in awareness of any other sort.

Self-Control and Free Will

I mentioned earlier that in addition to awareness, consciousness is also often seen as having a sense of control over one’s own actions. I have already covered the basics of this sense of control. The prefrontal cortex is responsible for direction resources and setting goals, which in a broad way controls our actions. But this brings up a tricky question: If my actions are the result of neurons in my brain, do I really have “free will”? Can I really “choose” to do anything, or is it all handled in a deterministic, cause-and-effect fashion in my brain?

Free will is a concept that needs to be made more precise. As a concept that has been discussed by philosophers for centuries, the term has been used in a variety of different ways. However, there are three main views that are expressed on the matter. The first is that of determinism. This states that human action is totally determined by previous states of the world (which would include brain states). The second is indeterminism or libertarianism (in a philosophical sense, of course, not a political sense). This view states that we are causal agents that are capable of independently starting chains of events. The third view is compatibilism, which argues that free will and determinism can co-exist. In other words, free will and agency are not destroyed if our actions are predetermined by states of the world.

Dilbert on Free WillIn order to resolve this debate, I think we also must come to terms with ideas about the “self”. The major question is, “Do ‘I’ exist?” In other words, am I merely a bundle of flesh and bones that acts in a causally determined way, or is there some sense in which I am an active agent? This is, of course, a tricky question to answer. On the one hand, it certainly appears that our brains simply take in information about the outside world and then react to it. On the other hand, it definitely feels like we are causal agents. We feel like we are in control—like being in the driver’s seat of a human vehicle. So how could one resolve these two?

I think that one key point to remember is this: We are our brains. When we are thinking, it is actually our brain thinking. When I raise my hand, it is actually my brain telling my hand to raise. When you remember your most recent birthday, it is your brain remembering the memory and processing it. In other words, even though we feel like some independent entity, we are our brains, and our brains are us. It is a strange thing to comprehend, but once one comes to terms with it, I think the debate is resolvable to at least some degree.3

Brain MachineSo do we have free will? Well, let’s apply this concept. If I am my brain, then when my brain acts, it is I who is acting. And even though my brain is a result of previous states of the world, fashioned by my genetics and my upbringing and the food I just ate, it is still my brain that is sending electrical impulses to initiate action. Even if my “choice” is predetermined, I am still part of the process of decision-making. To draw an analogy, imagine a machine that receives a number from 1 to 10, and then outputs either the letter A or B. If the number is 10, it will output a B. Otherwise, it will output an A. In other words, we have a situation where the machine’s response is completely predictable based on the inner workings of the machine and the input from the environment. Can this machine be said to “choose” A or B? I still think so. Why? Because it is still a crucial step in the process. If we had a number from 1 to 10, but no machine, then we would have no response at all. Or if the machine were set up differently, we would get different results. (We might get a C or a D or even an electric shock!) In other words, while the machine is not making a free choice that is independent of all causes and effects in the world, it is still making a choice. And that choice is crucial to future states of the world. Now imagine a machine that is complex enough to handle many different forms of input all at the same time, integrate them, and produce goal-directed responses. It is still a product of the world around it, but it has real effects on the world as well.

In short, my own opinion is that libertarian free will does not exist. We do not make choices in a vacuum, apart from any considerations of our environment or our own brain. I’m not even sure what such a thing would look like, to be honest. If we are influenced but not constrained by our brain, this implies that there is some element which is entirely free from influence. But what would that do, exactly? It seems to me like it would simply be a random factor. If it is truly influenced by nothing at all, it seems like it must be absolutely random. So I tend to reject libertarian free will. At the same time, however, I think that there is at least something that can still be said about the will even in a purely deterministic universe. When we remember that we are our brains, then the self is not simply an illusion—it is a processing mechanism that makes real choices. The feeling we have of being somehow “separate” is simply a product of how the brain feels when the brain is doing work.

No Man Is an Island

After this discussion about consciousness, awareness, attention, control, and free will, there is at least one question that remains (but probably many more). Are humans the only ones with these attributes?

Chimp and MirrorWell, it certainly seems as though other animals have awareness and attention. A gazelle could not survive without being able to direct attention toward the oncoming lion. And many animals would not last long were they not able to distinguish objects in the world. (Distinguishing food from non-food seems to be a prime example.) So with those two characteristics, it seems that many animals have “awareness”, though this would manifest in varying degrees, and may not include self-awareness. The mirror test is an reasonable way of examining whether an animal recognizes its own reflection or perceives it as another animal; all the great apes, rhesus macaques, dolphins, orcas, elephants, and magpies have been able to pass the test.4

How about executive control? This gets a little trickier to determine, since some behaviours (even some complex ones) can be the result of reflexive action. Geese, for example, have a fixed action pattern which leads them to roll an egg back to its nest. Simply seeing the egg will trigger the action, and even if the egg is removed, the action will continue as if the egg is still there. It will also be triggered by egg-like objects. So clearly, even if an action seems to be the result of intentional behaviour, it may simply be a reflex. However, there are certainly other animals capable of exerting intentional goal-directed behaviour. Chimpanzees, for example, are able to use twigs as tools to get food, which shows a high level of creativity in goal satisfaction. It seems reasonable that the larger an animal’s prefrontal cortex is, the better able they will be to produce intentional behaviours and control over actions. This would include most mammals at the very least. If this intentional goal-directed behaviour is taken as evidence of compatibilist free will, then it can be said that these animals have some level of free will as well.

So, it seems that other animals can also be said to be conscious (or perhaps “sentient” might be a better word here). If animals are aware of their surroundings and perhaps themselves, and have executive control and free will, I think it can safely be argued that they are conscious creatures. They may not be conscious to the same degree as humans, but it seems that we are not lonely conscious creatures.

Summary

BrainIn this three-part series, we’ve taken a look at some of the structures and functions of the brain. We’ve also looked at how the brain developed throughout its evolutionary history, and some of the learning mechanisms that have been with us since the early days. We’ve explored the phenomena which we take to be most indicative of humanity and found that our actions can be compatible with the causes and effects of brains. Finally, we’ve found that these “human” characteristics are shared to some extent in many creatures around us.

As I’ve said numerous times, this is far from being comprehensive. I’ve barely scratched the surface of what could be said about the brain. But I hope that I have been able to offer some valuable insight into the nature of the brain and how it is remarkable, yet explainable. And although we have not solved all the mysteries that our brains have to offer, the quickly-growing field of neuroscience offers us exciting new opportunities to discover amazing things about the most complex organ on earth: the human brain. I hope you’ve enjoyed this series, and happy thinking!

Notes:

  1. It is difficult to pin down specific brain areas with a phenomenon as complex as attention, because different brain regions handle different components of the process. When you draw your attention to the words on the screen, you must devote attentional resources to the task, you must reorient your head and eyes to bring the words into the field of vision, you must focus your eyes properly to receive the incoming image, you must interpret the image and process the words, you must hold the words in your memory for a short time, and you must comprehend the semantic meaning of the words and phrases. All these are handled by different regions of the brain, so it becomes difficult to strip away each part of the process to find which region handles which part of the task. []
  2. Anyone who has heard young children call every four-legged animal a “doggy!” knows that it takes a while for them to learn what distinguishes a dog from a cat from a horse from a cow. []
  3. Please note that I don’t intend for this to be the final word on the issue. This debate has been going on for thousands of years, and will likely continue on for a thousand more. I am only trying to offer some interesting conclusions based on what we know about the brain. []
  4. Interestingly enough, human infants generally don’t pass the mirror test until about 18 months. []

2 responses to “All About the Brain (Part 3)”

Raja Thangavelu

It is very interesting and easy to understand.
I think this is also applicable to many of the self – aware and learning systems that we. software product developers, develop for enterprises to enable decision making.

Keen to see more of these..

bo moore

Hello and thank-you for a sane and “literal” presentation of brain history and basic functions. I’ve been searching for a simple and organized outline of the basic brain FOREVER! Most academic articles are technical and specific; most popular science articles are tainted with “supernatural” interpretations and conclusions. The squishy world of organic intelligence is foreign territory for a geologist, but I have ventured into human evolution due to a personal interest in the difference between the literal Asperger brain and the dominant (by majority) social brain. I’m looking for real differences in organization and processing, and do not think at this point that Aspergers is mild Autism.

Looking forward to reading more of your blog.

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