Hello, Vsauce. Michael is here. Where are your fingers? Jokes aside. This is a fairly simple question. You should be able to answer it. But how do you know? How does anyone know anything?

You could say, well, I know where my fingers are. I look directly at them. Or, I can touch them, I feel them, they are here, and it's good. Your feelings are a great way to find out everything. In fact, we have more than the usual five senses that we are talking about. For example, your kinesthetic meaning, proprioception. This is what the police evaluate during the sobriety test in the field. This allows you to tell where your fingers and hands, as well as the head and legs in your body are all in relation to each other without having to look or touch other things. We have more than five feelings, we have at least twice as many, and then some. But they are not perfect.

There are optical illusions, sound illusions, illusions of temperature, even tactile illusions. Can you turn the tongue upside down? If so, excellent. Try it. Slide your finger along the outer edge of the tip of your upturned tongue. Your tongue can feel your finger, but in the wrong place. Our brains never needed to develop an understanding of the touch of language. So, when you touch the right side of your tongue, when it's turned over to your left side, you feel the feeling on the opposite side, where your tongue usually is, but not when it's turned upside down. It's pretty bizarre, cool and a bit humiliating, because it shows the limits of the accuracy of our feelings, the only tools we need to get that here.

The philosophy of knowledge, the study of knowledge, is called epistemology. Plato famously said that what we know is what is true, what we believe and that we have an excuse for faith. these justifications can be irrational or they can be rational, they can be based on evidence, but not too sure, because proven is not synonymous with truth. Fortunately, there are things that we can know without demanding proof, without even having to leave the house, things that we can know as true only for a reason. This is what we know a priori. An example is the statement "all bachelors are not married". I do not need to study every bachelor on the ground to know that this is true. All bachelors are not married, because that's how we define the word "bachelor". Of course, you need to know what the words bachelor and unmarried mean. Oh yeah? Good. Excellent. Great. But how do you know?

This time I mean functionally, how do you know? Where is knowledge biologically in the brain? What are memories made of? We are far from being able to fully answer this question, but studies have shown that memories do not exist in the brain in separate places. Instead, what we call memory probably consists of many different complex relationships throughout the brain between a variety of brain cells, neurons. The basic cellular mechanism, which is believed to underlie the formation of memories, is long-term potentiation or LTP. When one neuron several times stimulates another neuron, this signal can be increased using LTP, linking them stronger, and this connection can last a long, even a lifetime. A collection of different brain cells, neurons that are burned together in a certain order many times and repeatedly, can reach long-term potentiation, becoming more sensitive to each other and more ready for shooting in the same way in the future in the future. They are a physical thing in your brain , it's easier to shoot, because you are reinforcing this shooting pattern. You remembered. This branching forest of shooting friends looks messy, but look closer. It can be a memory of your first kiss. A live souvenir of the event. If I went into your brain and cut these cells, can I make you forget your first kiss, or can I make you forget where your fingers are? Only if I cut out a lot of your brain. Because memories are not simply stored in one connection, they are stored throughout the brain. The events that lead to your first kiss are stored in one network, how she felt as she smelled in different networks, everything came together, creating what you call the memory of your first kiss.

How many memories can you fit into?