What did you think about when you saw the name of this article? Did you click on it because you already know the answer and wanted to see if we got it right? Or maybe because you never actually wondered about this yourself and it made you curious? Or do you think about this often and haven’t come up with an answer on your own?
Maybe you took a step back and then, based on the subject matter, thought about why you thought anything at all. How is it that your brain is allowing you to understand what we’re saying to you right now and then form opinions about it? What is it in your brain that makes you think or understand anything?
Despite the fact that neuroscience is a 20th-century discipline and psychology dates back to the 1870s, we still know very little about certain parts of the brain and how they function. That doesn’t mean we know nothing, though, which is a good thing. We’re constantly learning, constantly progressing, and one day we may fully understand all the subtle intricacies of the human mind. But for now, do we know how thoughts and consciousness are formed? Let’s have a look.
The Basic Science
Let’s start with some fundamentals. How does your brain do anything? Neurons. Neurons are the basic building blocks that make your brain do everything from ensuring you keep breathing to creating new mathematical formulas if that’s something you do. Neurons make it all happen.
Neurons are nerve cells and they group together in neural tracts and send signals to one another. They receive sensory input from outside of the brain, which could be anything from signals in your stomach about food you’re digesting to smells in the air, music you’re hearing, a movie you’re watching or a cold breeze you feel on your neck.
The neurons send electrical signals between each other and also throughout your nervous system, controlling your entire body in response to the sensory input they receive. Some of it is totally out of your control, like the way your intestines contract as food is digested or the way your heart beats. Some of it is all up to you, like deciding if you want to go for a walk or just veg on the sofa. But how your neurons work controls it all.
To manage everything your brain needs to control, you have between 80 and 100 billion neurons. These are connected by synapses of which you have 500 trillion. Electrical impulses are formed in the neuron thanks to positive ions flowing across the cell membrane. Any given neuron is permeable to both sodium ions and potassium ions, but the flow of potassium out is larger than the leak of sodium in, which allows for a negative inner charge until the neuron actually fires and the sodium channels open. Then these ions are exchanged thanks to action potential. Sodium rushes in and the neuron is depolarized. Potassium channels open and the potassium rushes out. A little spark is formed and your neuron can send a signal to the next in line. Now imagine it happening millions of times along the axons that connect your neurons.
When your neurons send impulses, they create neurotransmitters. These cause other neurons to fire. As the neurotransmitters spread, hundreds and then thousands of neurons will fire, and this is essentially how a thought is formed.
So, in simple terms, stimulus from outside the brain sends a nerve signal to the brain. That causes the neuron to fire. The neuron produces neurotransmitters that make a chain reaction across many neurons, thought forms as a result. This happens in a fraction of a second, up to about half a second.
Of course, your brain has many sections that govern many different functions, but we’re not getting into deep neuroscience here, just how the thing works in the first place. With that in mind, let’s look a little closer at what it does now that we know how it does it.
What Your Brain Does
One thing to remember about those firing neurons in your brain will form patterns for you. If you do things repeatedly, the same way, your brain will create a neural pathway that actually strengthens as you continue to do and react the same way. That can, in part, explain why people get into routines and habits. Your brain is quite literally wired to do things a certain way if you allow it to happen. That’s also why learning to do something a new way once you’ve adapted to a different way can be difficult. Your brain has established it should be done one way and you’re trying to write a new pattern for it.
Learning things makes the connections between neurons, and these neural pathways, stronger. You have reinforced the thought, an idea, a behavior, whatever it is. It is now something you know. The more you do it, the stronger it gets, the better you are at it. That is why repetition and practice are often essential to learning.
Your brain weighs about three pounds and is made of both gray matter and white matter. The gray matter is on the outside and it allows you to process and interpret the information that you receive from all the external stimuli and sensory data in the world. The white matter is inside, and that sends information to different parts of your brain and throughout your nervous system so you can do things and react to what you’re experiencing.
How does your brain decide what to do, and when, and where? That’s an anatomy question.
Brainatomy!
There are multiple parts to your brain, but three main parts comprise the whole thing. The front of your brain is called the cerebrum. That’s where you find the cerebral cortex. This is a full 80% of your brain, so most of what you’re doing happens here. The cerebrum is where you interpret external stimuli like things you see and hear. It’s also where you do your learning, your reasoning, speaking, and where emotions are controlled.
Next up is the cerebellum. This little guy is in the back of your brain, just above the brainstem. Do you have any motor skills whatsoever? Can you stand upright without falling down? Thank your cerebellum for that. It handles balance, coordination, and your fine motor skills.
Speaking of your brainstem, that’s the last part. There are several sections in your brain stem, and the whole part is chiefly concerned with the more automatic functions of your body. Things like chewing and blinking are controlled in your brain stem, as well as breathing, sleeping, and your heart rate.
But wait, you might say. What about your frontal lobe? Or your occipital lobe? Those are in there too, and they are part of the cerebrum. Your brain has two hemispheres and four main lobes. The frontal lobe, which is obviously located at the front, controls things like personality, speaking, decision-making, and, for whatever reason, your ability to smell.
In the middle, you’ll find the parietal lobes that aid in spatial understanding, your sense of touch and pain, object identification, and understanding speech.
At the back of the brain, you’ll find your occipital lobes and those help you with seeing things and understanding visual stimuli. Understanding movement, color, and shape all happens in the occipital lobes.
Last but not least is your temporal lobes. These help with short-term memory, smell again, facial recognition, and emotional awareness.
There are also a number of other structures in your brain, including the amygdala, the hippocampus, the pituitary gland, the hypothalamus, the prefrontal cortex, and so on. As you can see, it’s a real mixed bag when it comes to what part of your brain does what. There doesn’t seem to be a lot of organizational structure going on there, so the whole thing needs to work together to have a fully functional mind.
So maybe now we have a basic idea of how thoughts are formed in a brain, but what about consciousness? That’s not a reaction to external stimuli. Where does the you that exist in your brain come from?
Consciousness
We’ve got good news and bad news when it comes to explaining consciousness. The good news is, if you’re experiencing any of what we’re saying right now, you are conscious. The bad news is that’s about all science can tell you about your consciousness.
Something in the way that all your neurons and synapses connect throughout your entire brain creates your conscious experience. But what does that even mean? We can say fairly certainly that consciousness is a product of your brain. If you undergo anesthesia, your consciousness actually disappears for a short time. You’re not asleep, you’re not dreaming, and there’s no sense of yourself anymore because anesthesia shuts off nearly all the electrical activity in your brain.
If you want a specific answer about how the inner workings of your brain allow consciousness to form, then you’re going to have to wait for a while. We don’t have an answer to that yet.
We can describe some of the dimensions of consciousness, what needs to happen for consciousness to be a thing. That includes the ability to have thoughts and feelings and be aware of them, some degree of wakefulness, and some degree of sensory organization that allows us to group concepts and perceptions together in an understandable way.
All of those things are more philosophical than biological, however. There’s a little crossover, but the ability to have thoughts and feelings isn’t really a scientific concept that can be explained in the same way as sodium and potassium ions moving in and out of neurons in your brain. Some have argued that your consciousness can’t actually be a biological process and that biology only represents the consciousness in the way a frown may represent sadness. It shows the emotion, but it is not the felt emotion, just like patterns in your brain may show consciousness but are not consciousness itself.
MRIs and EEGs show that there is more activity in your thalamus and its connections through your brain when you are awake than asleep. We know something is happening in there, but not what or how. Sorry if that’s disappointing.
What We Don’t Know
The fact is even neuroscientists can’t explain to you with a lot of detail how a brain works because there are so many things they don’t know. Those trillions of synapses we mentioned earlier? Each one is home to 100,000 molecular switches. Each of those is full of protein molecules that transmit information between themselves.
Given that studying thought and consciousness requires investigating a living brain and not damaging it while studying it, you can see how it would be almost impossible to fully map a conscious mind when you’re dealing with such ungainly numbers and such sensitive material.
We have a general understanding of how you can learn something, but not how your brain processes the information. In order to fully understand the human brain, we probably have to map it. So far, only a handful of organisms have had their brains fully mapped. It took four years to make a basic map of a mouse brain and a human brain has 1,100 times as many neurons. A team of scientists around the world have been collaborating on the project for years now and many millions of dollars have been spent, but we’re only a fraction of the way through the job.
One of the big problems with understanding how a brain works and even mapping it is that your brain and my brain are not the same brain. Neural pathways are formed differently, and information is processed differently. There are people out there who have severe brain damage, have even lost portions of their brain, whose brains are able to adapt and alter function. So even a map of the brain can’t explain everything about how a human mind works because it’s very subjective.
Neuroscientists have written extensively about many things we don’t know. For instance, the number of neurons is a ballpark number. We don’t know exactly how many a brain has, and it’s probably safe to assume that your brain and my brain have different numbers of neurons because neurogenesis exists and that can create neurons, while others can be destroyed.
We don’t know why drinking alcohol makes you feel relaxed. We don’t even know exactly how Tylenol works in your brain. We’re not sure why the left side of your brain is linked to the right side of your body, and vice versa. We don’t even know why we dream.
While we are learning more and more about the biology of the brain, the fact is there’s just a lot about what it can do and why that we can only guess at.