when you look at this object i'm guessing your brain is thinking apple right the human brain is so quick to process information it's almost as if the moment we look at something we immediately know what it is but is that how it works because when you slow down the process it's more like a sequence first your brain becomes consciously aware that something's in its visual field you then break down the features like its color the shape and its size and then we mesh that information to something in our memory to label it appropriately so on the surface what seems like an instantaneous event is actually more like a chain of events the visual system is truly truly amazing all right guys welcome to psych explain in this video we're going to talk about the occipital lobe the brain's visual processing center now the occipital lobe is one of the four major lobes of the cerebral cortex we can identify that lobe on this structure here the problem though is that it's really hard to identify because there aren't really defined borders or boundaries like we see with the other lobes for example if i wanted to know where the frontal lobe is or the parietal lobe is i can use this little division this is called the central sulcus sulcus meaning the groove within the brain that divides both hemispheres so this lets me know for example that the frontal lobe is in front of the sulcus and the parietal lobe will be in back of the sulcus okay or i look at this structure okay this is the lateral sulcus right the one that runs right by the ear and this lets me know where our temporal lobe is right you're kind of getting that idea that a lot of the lobes have these big divisions and grooves that really help define the boundaries of specific lobes we don't really see that with the occipital lobe we might have a little sulcus up here one little notch on here a sulcus that goes through there but essentially what we're doing is kind of using our imagination knowing that the occipital lobe runs in the back of the head right so what do we know as i just stated the occipital lobe is in the back of our brain and because we have two hemispheres we have one in our left hemisphere and one in the back of our right hemisphere you can also think about it that is right above our cerebellum that lets us know that it's in the back of the head as well now what else should we talk about the primary region within the occipital lobe and this will be a big focus of today is a region called the visual cortex okay the visual cortex in fact let's label that down here visual cortex so you can't talk about one without the other right you talk about the occipital lobe you've got to talk about the visual cortex and this region helps us process visual information right so everything you see right now me the board is being processed by this region so as we talk about the occipital lobe today in this video we're also going to be identifying and talking about the visual cortex all right so where should we start how does information actually reach the brain and then what do we do with it well we're going to kind of divide this into two different functions and then sub-areas let's start with the first one so the first function is that the occipital lobe and of course visual cortex helps detecting visual stimuli okay detecting visual stimuli so how can we visualize this well imagine that we're looking at an apple right the light waves are bouncing off this will eventually reach we know this region the retina which is in the back of the eye and this is where the light wave is going to convert to electrical signals via transduction and that electrolysis is going to travel up through the optic nerve to the thalamus we talk about that in a different video specifically the lateral geniculate nucleus and from there there's going to be a direct pathway to our occipital lobe okay and where specifically the back of the occipital lobe which is our visual cortex okay so this is kind of the pathway of vision now we can divide this detective visual stimuli into two things in other words once the signal hits the visual cortex what happens let's think about this the first thing is what we're going to label as conscious awareness i want you to think about this when everything hits our cortex we become consciously aware of it now you don't know you're actually looking at an apple just yet all you know is that there's something in our visual field well how do we know that the moment something enters your visual field all the neurons within the cortex start to fire right so you don't know what you're looking at but you know something's there another way to think about it is after you consciously are aware of it is you start to process the visual stimuli so start to process the visual stimuli okay so what does that mean well you don't see an apple but you do see a few things the neurons with individual cortex are going to help make you aware of a few things for example you will be able to make out the size of the object these neurons are going to help make out the shape or form of the object it might help make out if there's any motion right is the object moving and of course the color right so at this stage all we know is that something is in front of us in our visual field and that we have some sort of form or or or identification of this image size shape color and motion and i thought i would share this we're not going to talk about this extensively but there's a lot of good research that deals with kind of this initial stage of processing and this research was done by huble people and weasel okay and weasel and their research which they won the nobel prize for was on these specialized neurons within the visual cortex right they kind of helped us map out what the visual cortex does so for example they put you know these electrodes within this cat's brain they were able to isolate these individual neurons and find that every neuron has a specialty right so in other words they discover this idea of you know specialized neurons just give you a little kind of taste of what their study was about they'd have a you know a cat look at let's say i don't know like a line like this okay and that line would spark all these action potentials so these lines represent action potentials like all this firing of neurons but then if you turn the line just a little bit this way you might have just some firing of action potentials right a few and then if you turn it completely horizontal you have nothing right in other words as the cat is looking at these angles specific neurons only fire when the specific angle or shape or or something's moving or not moving so these are called specialized neurons simple and complex neurons so this is some research to think about that deals with this okay so after we detect the visual stimuli what's next well we have to recognize the object right we are recognizing recognizing the visual stimuli visual stimuli so we know it's there right we've started a process the form size of shape now we can identify what it actually is and what we're doing is we're starting to match that visual stimuli to something already in our mind so even though you're not saying this out loud what you really do is you're saying to yourself have i seen this before right that's essentially if your brain could talk what it's saying now how does it do that what it does and this is more of a hypothesis is that there are some pathways in the brain that lead to other regions that help you figure it out let's think about this so here's kind of one of the big hypotheses is that after information reaches the back of the cortex where this would be the primary visual cortex this is going to send information out of the cortex to other regions and here are the two pathways one of the pathways leads to our temporal lobe okay this is considered the ventral stream you could also call this people call this the what pathway and the reason they call it that is because this is the area of the brain that lets you identify the object right this is all about identification you know what is this that i'm looking at identification you know what am i looking at location right you may think why this region well this is our medial temporal lobe that's where memories long-term memories are processed and possibly stored so that is why this is the what pathway we also have the dorsal pathway that leads to our parietal lobe okay so it kind of leads up here okay and instead of the what pathway you know this is often called the the where pathway okay why is it called the where pathway because it instead of identifying objects we're identifying let's say the location of objects right where they are in space right so more spatial things right so these pathways are essentially let us know what it is i'm looking at i'm connecting it to past memories i'm knowing how far away it is for me this is kind of the the second part of it okay so this is essentially a nice visual for how we take an information we're aware of it and then we recognize and identify it now here's a question for you what if there's damage to the brain right what if there's some sort of lesion right in the area of the brain because of a stroke or traumatic brain injury what could possibly happen let's kind of go right here the the primary issue right is we can see the the see the object but we don't really recognize the object and what this is called if there's damage is visual agnosia okay or visual agnosia okay essentially what happens is is that you can see an object from a sensory level right you see the the light waves on your eye the the light has converted to electricity you can process the information but your brain can't identify it okay this is visual agnosia okay and a subcategory of that which is even more interesting is called prosopagnosia prosop so what is this well first let's kind of you know visualize what visual agnosia is which is do you have perception right think of this like in a circle and then you have a circle around and right there's no perception right you have sensation but no perception prosopagnosia is what we call i'll use a different marker for this facial blindness and what this means similar to our visual ignora is that you can identify features of faces maybe you can take an information but you don't know who people are it's kind of a bizarre thing to think about but you might look at five strangers and you don't know who they are you can process features but you're not really recognizing who they are you might be talking to a loved one you even very rarely might not be able to recognize yourself in the mirror and that is a amazing uh uh thing that could happen with damage to the brain and it's important to know this isn't damage to the eye parts of the corneal lens retina this only occurs with damage to the occipital lobe all right guys thanks for watching i really hope you learned something don't forget to hit that subscribe button comment below and hit the like button i'll see you next time