 Welcome everybody. My name is Chauvre, I'm a professor in Tobuque University, and I teach cognitive psychology. And I want to share you some insights in what we, what you get when you give our first lectures in psychology. So what is cognitive psychology? Cognitive psychology is a core discipline in psychology. It means wherever you go, you will teach, it will be taught. And it's really about the basic components of our mind. We think about memory, about attention, learning, perception, and so forth. These are all basic elements of our mind that determine how we can behave intelligently in the world. Now, I want to show you some insights in what we have when we teach on, in this case, perception. Now, you probably all know when you were a kid that, well, we basically have five senses, at least that's the rumor. What are those senses? Well, you know them. You see, you have the eyes for seeing, the ears for hearing, nose for smelling, and so forth. So that's the basic thing that people know. What people often don't know is that actually we have much more senses than those five. Some people may say, you know, I have a sixth sense, but really we have more than six also. So, for instance, for instance, think about balance, feeling vibration, we have senses for temperature, pain, and also canesthesia. That's about how you move your arms in the tension on the muscles and so forth. These all are part of our perceptual system. And they are, and if we count, well, we may have about 12 to 15 sense different senses. Okay, that's lesson one from psychology. Lesson two from psychology is comes from neuroscience. We all know that each of those senses, they have a dedicated brain area to which they project. So we have visual information for the visual cortex, the auditory cortex is for auditory perception, and so forth. Now, these cortical areas in the brain are indispensable for seeing, hearing, and so forth. Imagine somebody has a brain tumor in visual cortex, they may suffer from cortical blindness. So those people, their eyes are fine, but yet they don't see well. And the same for hearing, dumbness, and so forth. So, so far, so good. However, there is more than that. First of all, I should say, we know an awful lot about how this information in these primary cortical areas is processed. But there is a bit more, it is more complex than that. Rather, the some perception is much more than the sum of the activities in these cortical areas. Now, what do I mean with that? Take, for instance, a simple example, which the Dutch are very happy with, and that is with French fries. Now, simple question. When do French fries actually taste well? Well, taste, you may say, that has to do with tongue and mouth. And so, yes, indeed, they should be a bit salty, and they should be fatty, and they should also preferably a bit taste like potatoes. But there's more than that. They should also smell like potatoes. So smell, yes, it's important as well. It kicks in also. Are we there? No, they should also look like French fries. So you don't want them to be blue or green, but rather they should be golden brown. Are we there yet? No, they should also be crispy. Now, and crispy is a really difficult one, because it has to do with muscle tension. And at the right tension, it should crack, and the cracking is about hearing. It's really important that they crack on exactly the right time. Okay, so we already have motor cortex, auditory cortex, visual cortex, somatosensory cortex, taste cortex. Are we there yet? No, they should also be hot, of course, and that's temperature. It's, again, different senses. And is that fine? I'm sorry. We also need pain. And pain because they should be sizzling hot and sizzling hot. How is that coded in the brain? It's pain. So again, different senses kicking just for this single French fry. Are we there yet? No, the Dutch. It's really about the mayonnaise. French fries are only an excuse to have mayonnaise and mayonnaise again. Well, that should be creamy, white, cold, and so forth. So we get a really complex innovation here of different senses to get good fry. So a single person like the taste of fry depends on many, many senses. Okay, this cooperation between the senses, you may think you may add up, but it's actually always the case. So here I have another example taken from visual stability. Now, imagine you look at the right side of this video and what you see there is a bee who is sitting still. Now, you also see this little circle there. What is that? That's what the eyes are actually looking at. So we can look with eye trackers where the subject is looking. And here we have a free recording of a subject just looking at this image. Now what's on the left side of this image? Well, this is what actually the information that is sent to the visual brain from the eyes. So on the left side, what you see there is a small circle where the subject is looking. And that's the information sent to the brain. And the brain now has to figure out from this information on the left what's actually in the image on the right. And so what you see there, eyes are never still. They always, in fact, if your eyes would be stable completely still, you would be blinded to seconds because the receptors adapt very quickly. So this very jiggling moving is very important to see. Otherwise, you would be blind. But imagine what the visual cortex has to do to figure out what's this wibbling image to make a stable image. The basic option of this is the visual cortex needs to know where the eyes are looking. So it needs to, and it gets this information from motor areas. So motor areas, they don't just talk to the eyes, but also to the visual cortex to tell where they're looking at. Otherwise, we can come up with this table image. So that's another example of where senses cooperate. Here, another example from how we stabilize our head. We have a chicken here, and actually you should hear nice music from Diana Ross upside down. But in the meantime, figure out how it just imagined how it might sound. But here we have a chicken that is moved. And the interesting part of this, you see lots of chickens here. They're all moved, but look how they stabilize their head. So wherever you move, the chicken stabilizes her head. How does she know that? Well, because there is sensory information about where I'm moving. And that's sent towards the head and the motor system, too. And actually an interesting motor company, they use that information to stabilize their car. So this was actually an ad from Mercedes-Benz. So when does this develop this integration between the senses? Well, here's an example of Kuhl and Meltzer that did that a long time ago. They had babies sitting in a rocking chair. And those babies, they could see two videos of a speaker. One speaker said, ah, ah, so they moved her mouse like ah. And the other speaker said, ee, ee, ee. Now, the baby can look at both videos and just wondering what's going on. But at some point they hear ah, ah. And what does the baby do? He immediately looks at the face that's pronouncing ah. And if the baby hears ee, ee, he starts looking at the face that says ee. So we have here the baby knows already how sounds should be articulated. He knows about ah and ee. Now, what's interesting about this phenomenon is that the baby is only four months old. He hasn't spoken yet. And so the baby has no knowledge in principle of what ah and ee sounds does. Yet he knows where to look at how they should be articulated. So long before babies can talk, they already know about how we move our mouth and what sound it should produce. Again, another demonstration that eyes and ears are strongly connected. So all these examples demonstrate that information from different senses gets integrated with each other. But also realize that all senses continuously transmit information to the brain. So while you're watching me, you feel your shoes, you may hear your mother in the background and so forth. So how does the brain then actually know which information belongs together and which not? How do you know that the sounds that you hear are related to the movements that you see here, but not, let's say, to the screen, to the other part of the screen that you're looking at? Now that's a difficult question. We've solved this problem. It's known as scene analysis. What is scene analysis? It's your cameras nowadays are smart. They not just take a picture, but they actually recognize that this is a microphone, that that's a video camera, and that this is your face. How do they do that in the visual system? Because they're also, how do you know what belongs together and what not? And for the visual system, we've discovered various kind of laws. And here I show you one more. This is look at this picture and just try to figure out what it is. Now this may be difficult and you may have to look at it for a while and still don't know what it is. But now watch it. I will ruin your brain because I'll tell you what it is. And from now on, you will always see it immediately because now you see, now you discover, these are letters covered by circles A, B, C, D. But now look at the black parts. The black parts on the left, the letters, and the black parts on the right are identical. Why is it that you see it on the right side, but not on the left side? Now the reason why it is is because there is a law in scene analysis which says that boundaries belong to objects. Now what does it entail? For instance, take this little part here. That part in the left side was difficult. You thought, your visual system thought it belongs to the letters. But once we covered it with circles, there is this rule which is, no, no, no, that critical part there is actually not from the letter. Ignore that because it's from the circle. And so that's noise. And this is, whereas this part, the other part on the left here, that is now critical for the level C. So this rules now tells us what the characteristics of a circle is and which to ignore. It separates signal from noise. That is what scene analysis does. Okay, but how does the brain know for the multisensory domain? So here we also have many senses bring sending information to the brain. And how does the brain know which information belongs together? Yes or no. So here we have an example of clapping hands. Imagine I do this, right? So I have my motor system which says I'm moving my hands. My auditory system says I hear a clap. My visual system sees something and then it suddenly stops. But I also see lands here, a microphone here and so forth. How do we know that this belongs together and the other part should be ignored? Well, what do hearing, seeing and feeling have in common then? Well, for one, and that's for sure, they arrive at approximately the same time in the brain. And so there is differences in neural processing time and in transmission time of vision and vision. But they arrive at about the same time in the brain. And that is for the brain a very good cue to tell this is no coincidence. We should take that together, take it all together. But they may also come from the same location because we can hear where the sound comes from. You know where your hands are and the visual system knows about the location. So maybe it's also location that is a cue which tells you this all comes from the same location, treat them together. Or you may also have learned in due course of development how clapping hands sound. So they sound like flesh on flesh and not something like this. And you may learn by association from memory that they should belong together. Yes or no. All these properties may play a role, but we in our university are looking at many other different aspects of scene analysis in the multi sensory domain. That's what I had to say, my friends hope to see you soon at Tilburg University. Ok.