[MUSIC] Hi, nice to meet you again. I'm Duck-Joo Lee. How are you? We've had a very meaningful time in the last class, haven't we? We examine the modern philosopher's views on the world. They tried to figure out the life with their intelligent brain. We already had a chance to understand their fierce study on the cognition by practicing our own self-reflection. Also, it wasn't too difficult to know the fundamental conundrum of philosophy since it was a written explanation of what we have experienced. Sometimes logic is hard to follow, and it is easier to understand that the tough problems of life through practice. It is the same reason why we emphasize the importance of practicing experiments in the engineering education these days. Today let us think about the role of a brain in the aspects of self reflection. What is the self when we ever think about ourselves? What are those things which we surely experienced, we clearly recognized, and we are sure about. Why don't we listen to neuroscientist's views and experiences on that issue. Are those research work on the human brain will clear up philosopher's problem and psychologist's experiments? It is getting much more interesting. The optical image of external thing, fallen on the retina, is transmitted to brain. Then we perceive the external thing. If we see a tree, we perceive the tree in our own ways. Information delivery across the brain networks is transmitted chemically and electrically through brain cells called neurons. These cells are connected together forming pathways that electricity can flow through. The phenomenon of communication between different neurons are called synapse, and chemicals are released and are stored in neurons in the process of storing information. We can see the resemblance between the brain and a computer by looking at the similarity between a transistor and a neuron. Computer chips are made of billions of transistors. Both computer chips and the brain work in similar ways; neurons and transistors connect to each other in massive quantities forming multilayered electrical networks that perform certain functions. The brain is composed of many networks between neurons. The structures of these networks can be modulated by the environment over time. The brain function can be reprogrammed through the modulated network structures, allowing humans to have the ability to learn and grow autonomously. These programs also have the possibility of going awry causing stress, addictions, and false perceptions, etc. The human brain contains 100 billion neurons and each neurons has about 10 to 15 synaptic connections. This number often compared to the number of galaxies in the universe. Experience is just the phenomenon happening. merely within one layer of the brain. Those experiences will be stored inside the brain. Those piled memories are what we call the subconsciousness. The subconscious processes are actually what determine how we experience and perceive the world. Here is a simple model of a network of neurons in the brain. Through learning and the development, neural pathways form within neural networks. Pathways across the networks run the function of the brain. At the beginning of the neural network formation, there are many electrical pathways in the network. When certain thinking process and behavior are repeated over a long time, corresponding pathways are reinforced and the activity of the brain is likely to acclimate to strong canyon like neural pathway. Neural plasticity is the ability for neurons to form a new pathways in the brain network. So once we habituate ourselves in certain fixed pathways, it means the neural plasticity loosed its flexibility and getting stable. In other words, as we form our own structure of thought we tend to have our own interpretations of the things and to see the world accordingly. So each individual likely has different perception in things and that's why the philosopher said that we can never see the true nature of things. Each person has different patterns of the canyon like path ways. By recalling memories that are related to previous one's life, the neural networks related to those perceptions and behaviors become active. The previous figures in this class are provided by Grayson and the professor, Jaime in UC San Diego. They are heavily involved in the research in figuring out the mechanism of the self-reflection. You all probably have recognized that's why we cannot see the true nature of things as the philosophers would say. It is because of the different patterns of a neural pathway in the process of perception and cognition. Even without any expert knowledge, now you understand that what we see are an illusion and that they are not in the real world. Our past is in control of our present and that is how our thoughts and the beliefs are built. Of course what we perceive as ourselves are all illusion. A particular shape of our neuron that was called a default model network is a heavily implicated in the coherent perception of an embodied shape. Bruce Hood, experimental psychologist and brain expert in cognition talked that neural system in our brain composed of 100 billions of cell generate various patterns in response to individual's environmental conditions along their childhood. Those past living experience determine individual mental stability behaviors, cognition, attitude and characters, and when facing the external stimuli, individuals distinct neural structure elicite an expected responses which are different from the others. In his book 'The self illusion', he argues that so called Self is composed of piled up senses perception, and thoughts, which are based on the 'bundle theory' of David Hume. Therefore there is no controllable self, that means, no free will. Our consciousness is always in the past. In the Society of Mind, the Marvin Minsky wrote. "We normally assume that consciousness is knowing what happens in our minds right at the present time. I will argue that consciousness does not concern the present, but the past. ;It has to do with how we think about the records of our recent thoughts." The common opinions between the philosophers and the brain scientists are that we cannot see the reality. We cannot cognize the reality. And we perceive things differently. Those are what we have experienced in the second lecture also. We get stressed because of the different picture stored in our brain. which is not real. Now, how do you want to do? How do you want to do about your information in your brain? Today, we continue piling up data to our brain. You will find out what is it in our brain through self reflection. Before learning the methodology how to escape from this stress, we need to know more how the mind is formatted, why we have illusion, that we see the reality. and what is the reality? in the rest of the third week lectures, you can anticipate next, series of lectures. Thank you.
