We talked about actually the signals around receptor field in the retina, right? And they house this information, actually process it in the brain. There's a very important topic. And from this study, then you can really try to understand how the brain works, right? Now, these two gentlemen, Hubel and Wiesel, and that they did a beautiful work, including the [FOREIGN] and also a quite important the electrophysiology of the receptive field started. And that they got the 1981 Noble Prize in Physiology and Medicine. Let's look at their approach for this study. The approach, actually, they want to study the visual cortex function, okay? And visual cortex, how can you study it, right? So typically they use a cat. [FOREIGN] And you open, of course the cat is fixed here. [FOREIGN] okay? And then, you insert a electrode into the visual cortex. Visual [FOREIGN], just so you can input the default, right? Layout for C, for example. And then, you have a TV monitor. To show the light stimulation to the cat. The cat [FOREIGN] quite disappointed at the beginning. They try to use the light because in the In the retina, the study actually just uses a light, a spot stimulation. You can get a response from the neuron. But when it went to trial, they used the light stimulation. One light here. One light there. Even here across the whole screen. And those neurons, there should be numerous response, okay? Laser is fun actually, very special. Those cells actually, can only respond when you have a light bar. Just so you [FOREIGN]. Then you can see it. [FOREIGN] The cell [FOREIGN]. And if you [FOREIGN]. For example, this one. You change the direction and the cell doesn't care [FOREIGN]. [FOREIGN] special, okay? So these are from the same cell recording, then you cannot [FOREIGN] only this direction the response system the strongest one. And then [FOREIGN] and [FOREIGN], okay? How will you think about this observation, if you get the recording, get these kind of results? [FOREIGN] This is what we observed. No. They then actually think very hard about this observation, okay? So because in the cell, as we said, the receptive field is a center [FOREIGN] you know, send us around. [FOREIGN] In either case. [FOREIGN] Cortex, so dramatic different. Of course, maybe a lot of computation [FOREIGN] [FOREIGN] If take a look at the, we took a look at the photo receptor. [FOREIGN] So, in the bipolar cell, the computation mainly happens by the horizontal cell, right, making circles around. [FOREIGN] the cell is near the same is around. But to this stage then became a directions important and also you need a light bar. [FOREIGN] Of course, then if you want to study system mechanisms [FOREIGN], what will you do? It's actually, let's first actually record from the LGN, right? Because we know cell is like a bar, and this cell is like, you need a. But then in the middle there was LGN cell, right? So let's record from the LGN. And actually, when people did the recording from the LGN, those neurons, the receptive field is exact the same as the cell. Sent us around, okay? So then the question comes down to how the LGN, the input to this visual cortex, just one synapse. Then you make a transformation, right? Can you imagine a way, especially to achieve which is centers around to this this light bar, and also direction sensitive receptor field.
