[MUSIC] Let's talk about attention. Let's talk about how attentive we are to the details of what we, let's start by talking about how attentive we are to the details that we see in the world. And as you know, the way that visual information travels is from the retina to the thalamus and the to the primary visual context. And there is a stop in thalamus, because the thalamus is the translator for visual cortex. And so what you would think is, okay, well, that's all that needs to happen, we're gonna stop there, and then the message will go on. But look at what the reality is. The reality is that the retina does project to the thalamus, which does project to the visual cortex. But this same thalamic neuron that gets input from the retina, also gets other inputs. In fact, it gets a huge amount of input back from the part of visual cortex to which it talks. It also gets input from places in the brainstem that release neuro-modulatory neurotransmitters that are important in mood and affect. And in fact, this input from visual cortex is much, much, much bigger than the input from retina. It far outnumbers it, as does the input from brain stem. Now, it does outnumber it in quantity, in quality of connection, or the type of connection. These inputs are different from this input. In the words of George Orwell, some are more equal than others, and the retina is more equal than the others. None the less, this is, the input back from the visual cortex is huge. It's not there for no purpose. What does it do? It tells us what we expect to see. We are seeing, this is the pathway that allows us to see what we expect to see. What's the advantage of that? The advantage of that is it's like a habit. It's as though you have a perceptual habit. You can cut down on the amount of time it takes you to decipher and interpret a visual scene, by using expectations. If you wake up in the morning and you see just the barest trace of a human person, a humanoid form. You're pretty sure it's the person that you sleep in a bed with. You're pretty sure it's not some stranger that you've never met. You don't need a whole lot of information. The expectation is pretty strong enough situation. So Expectation allows us to cut down on processing time and make faster perceptual judgments. Now, there are also disadvantages to having us see what we expect to see. And those disadvantages might be obvious to you. One is that it feeds in to expectations which are essentially status quo. So they feed in to, for instance, stereotypes. If we expect to see something because we've always seen it, or it's always portrayed in our world. Then it's harder, it's gonna take an extra step to say okay, well we're actually not seeing what we expect to see. We're seeing something different. And that's why some of us are detectives and some of us are not. [LAUGH] I'm absolutely terrible at detecting changes in the, in my co-workers. So when they get a haircut, or they change their hairstyle, or they have new clothes, or a new jacket or something, I almost never notice. But Columbo, a very famous TV character, would always notice such a thing. So some of us are more detective-like than others. But this important concept of perceiving what you expect to perceive, is something that all of the senses do, not just vision, but we do this throughout our cerebral cortex. What has happened before has a boost up in what we're perceiving right now and what we're thinking right now. We like those established patterns of thought and perception, they're quicker, they're faster, they take less processing energy. And that's great. But every once in a while they're wrong. So that's the disadvantage. In the next segment we're gonna look at how attention critically controls our very essence of being, and what the world means to us. [MUSIC]
