Transcription
I would like you for a moment to pay attention to everything that is around you. And think about this. How accurately does your brain represent the reality that is in front of you? All the objects, the sounds, the people and the smells. And how different do you think your reality is to that of everyone else?
While I was growing up, I always thought that I have an incomplete sense of reality. I always thought that I don't experience the world as it actually is. And whatever I experience is different than what everybody else is experiencing. You see, when I was about 12 months old, I had an accident. I fell off the stairs of my house while I had an earbud in my left ear. During the fall, the earbud damaged my eardrum, which consequently left me with a hearing impairment in my left ear. A hearing impairment that I still carry with me today.
At the beginning, this impairment caused a few problems and perhaps a couple of funny moments. If you have ever met me, you probably noticed that I have difficulty carrying a conversation if you sit on my left. Or if you have been my student, you probably noticed that when someone talks to me in class, I have difficulty locating where that person is sitting. This is because we need to combine information from both ears to locate the source of a sound. Or if you have ever slept with me, you probably noticed that when I sleep on my on my good ear, I miss all the pillow talk.
However, over the years, I came to love this impairment. And I came to love it because it made me think about it. It made me really curious about a number of things. How accurately does my brain represent the world compared to someone without a hearing impairment? And how different is the representation of the world that each one of us has? In a sense, do we all have the same perspective on things? Or does each one of us has their own?
All this curiosity about how we perceive the world drew me to psychology and eventually to the neurosciences, to the study of the human brain. Now, when you study the human brain, you realize that we know almost nothing about it. But if there is one thing that we do know, is that the human brain does not mirror reality for us. It has rather evolved to construct reality for us. What it does is that it takes information from the sensory organs, the eyes, the nose, the ears, and it constructs a reality that is largely based on two things.
The first thing that influences how the brain constructs reality is the context. The context within which we receive some information from the sensory organs. Take this image for example. How many of you think that these two oval shapes in the middle have the same brightness? When we look at them, we see them as being slightly different. The one to your right looks slightly darker. However, these are two identical pieces of information. They have the same shape, same size, same color, same brightness. But this reality that is in front of us is only revealed to us when we remove the background. When we remove the context that is causing the illusion. Within the context, our brain is constructing a reality that is slightly different from the actual reality. And even if we know that they're exactly the same, we can't help but see them as being different. We cannot override what our brain is constructing. And this is just one example of how the context influences our perception. Very powerful stuff.
Now, I would like you to take another example. Look at this sentence written in the Turkish language. Some letters of the words have been removed. Do you think you can find which letter is missing from each word? If you don't speak any Turkish, the answer is no. You can only guess. But look now at the English translation of this sentence. Again, with some letters removed. Can you read the sentence now? Of course, you can. Your perception is not always reality. Question is, why can you fill in the gaps in the English but not the Turkish sentence? Well, this is due to the second thing that influences how the brain constructs reality, which is our previous experience with the world. The things we know, the things we learned, the things we remember. If you take the word "your" for example, there's no a priori reason for why we should put an O between the Y and the U there. But we do that, and we do it because based on our previous experience with the world, based on our knowledge of the English language an O there is the most probable outcome. Our brain performs statistical operations and fills in any gaps it has with whatever it thinks the most probable outcome is. And this is the power of the previous experience and how it shapes our reality.
Now, so the human brain takes information from the sensory organs and it constructs a reality that is influenced by our previous experience, and it is some sometimes very easily tricked by the context. But apart from that, the human brain has another problem. It has very limited capacity for representing the world. The feeling that we get when we experience the world is that we experience it in all of its detail. We feel that we don't miss a thing. However, that feeling is an illusion. And to to illustrate that, I'm going to ask you to play a little game. On the screen, I'm going to show you six different playing cards that you already saw, and I'm going to give you just 5 seconds to select one, focus on it, and try to remember it. Okay? Here are the cards. You need to select one, focus on it, and try to remember it. Okay? Have you done it? Now, I'm going to pick them up, and when I put them back on the screen, I'm I'm going to remove one of the six cards. And I'm willing to bet that the card I removed is the one that you selected. Here are the remaining five cards. Can you find your card in there? No, it's gone.
Now, why do most of you fall for this trick? Well, it has everything to do with the brilliance of your brain and its limitations. Your brain, with approximately 85 billion neurons and trillion connections between those neurons, can process huge amounts of information in milliseconds. And it can do all that on just 20 watts of power. Think about that. This is just 1/3 of the power that the average TV screen uses today. And as you can probably guess, it is not enough power to process all the information that is around us. So, the brain is confronted with much more information that it can possibly process. It has an information overload problem. And the question is, how does it solve this problem? Well, it has evolved mechanisms to only select the information that is most important. One such mechanism is attention.
Now, think of attention like a form of mental currency that your brain has to choose very carefully how to spend. It's exactly like normal currency, like the euro, for example, with perhaps the only difference that although the government can haircut your deposits in euro, nobody can haircut your attention deposits, right? But like normal currency, although some of you may have more than others, nobody has an unlimited amount. You only have some of it. And again, like normal currency, you have to pay to get something you want, you have to pay attention to really see something. But our brain has enough power to pay attention at one thing at a time. And that one thing is what we become aware of. Everything else is filtered out and it never enters awareness. So, while I had you focusing on the card that you selected, you probably missed the fact that all of the cards were changed, not just the one that you selected. And this type of misdirection is an elegant form of attention control, and it's exactly what magicians have been using for centuries to trick people. Such simple phenomena are so powerful that they're being used by scientists today all over the world to study how the brain is organized and how it functions.
But for everybody else, the fact that our brain can represent a very small fraction of the reality that is in front of us, and even when it does that, it sometimes constructs a reality that is not very accurate, it can teach us a few lessons. I'm going to mention just two that I I think are among the most important ones. The first is that it explains why we need science and technology. On one hand, we rely on technology to overcome the limitations of our bodies. Our visual system, for example, can only distinguish a very small fraction of the electromagnetic spectrum. And our auditory system, a small fraction of the sound waves. So, we rely on devices such as the microscope, the telescope, or even the telephone we all use every day to overcome the limitations of our bodies. But the question now is, if we can rely on our own senses, on our own perception, to understand and make sense of the world, what do we do if we want to gain a precise understanding of what the universe is made of and the laws of nature? Well, the answer is that we rely on science. Systematic observation and careful controlled experimentation, in other words, the scientific method, has proven to be the only way we have for forming testable explanations, for making predictions about the world, for acquiring and building knowledge. So, the next time you look around you, I would like you to remember that your perception is so limited, it can be tricked so easily that you have no real difference from a person with a hearing impairment. We are all practically blind and deaf. And I would like you to appreciate all the progress we have made in understanding the universe despite being practically blind and deaf. And of course, that all this progress relied primarily on the scientific method.
Now, there is, I think, another, perhaps more important, lesson from all this. And it is about human communication. If there is one thing that defines us humans, it's that we are social animals. We like to interact with each other. We like to communicate. But each one of us has their own unique experiences with the world, their own unique memories. If we fail to take this into account, we'll most certainly fail to communicate effectively. So, the next time you try to communicate with another person, I would like you to remember that each one of us has their own unique perspective on things. Taking this into account can significantly influence your communication ability. It can make the difference between getting the job and not getting it. It can determine your influence and effectiveness as a group member and your emergence as a group leader. It can affect your influence as a friend and as a lover. In a sense, it can determine how efficiently you live your personal and professional life. So, the obvious question is, and I'm going to leave you with this, which of the two is the true impairment? A hearing loss, or the failure to take into account the fact that each one of us has their own unique perspective? Thank you.