 Hey everybody, Dr. O here. So this video is a little bit different. We've been talking about the different parts of the cerebrum, different parts of the brain and their functions, and these are just some guidelines you have to keep in mind. I didn't know where to cram them into other videos so I just wanted to put them all together in a separate place. So I'm just going to cover three important guidelines when you're thinking about the function of the cerebrum. So number one, each cerebral hemisphere receives sensory information and sends motor commands to the opposite side of the body. So here we see the right side of the cerebral hemisphere is issuing motor commands to the left side of the body, right? So you've seen that like if someone has a stroke and it affects their left arm, well the stroke is in the right side of the brain. So just remember that everything criss-crosses, so the right side of the brain controls the left side of the body, the left side of the brain controls the right side of the body. Alright, that's number one. Number two, it's not precise, right? Everyone's brain is not exactly the same so the correspondence between a specific part of the brain and what it does is just not precise. So here we see an example of, on the left we see a motor homunculus which is a functional map of the primary motor cortex and a sensory homunculus which is a map of the sensory cortex. And you could say that if you pointed to a specific part of the brain you would say, well this controls the lips there or this receives sensation from the thumb. But we just, it's not the case with everyone, there's not a map where I can't point to a part of the brain and say that in all human beings this is what's occurring there. So it isn't precise like that. I always like to say this is one of the reasons they keep you awake during brain surgery. They don't know what a certain part of the brain is doing so let's say they're cutting out a tumor or something, they need to make sure that it's not affecting a part of your body and they might be surprised by what happens. So that's, so it's not precise at all. We know where the typical brain does typical things but none of us are actually typical textbook human beings. So the functional regions of the brain too, like they don't have clear cut boundaries. We talk like they do but they don't. So where does the sensory cortex and the pride of the lobe stop and the visual cortex of the occipital lobe begin? We don't know exactly where in everyone. So it's messier than a textbook and make it look. And the last thing is something called hemispheric lateralization. The fact that the two hemispheres look exactly the same but their functions are completely different. So each cerebral hemisphere is usually responsible for certain functions that don't occur at the other side of the brain. That's what the hemispheric lateralization means. So this is where a lot of that left brain, right brain conversation happens. So in most people, the dominant hemisphere would be the left brain and that's probably why we're right handed, right? We just talked about how the left side of the brain controls the right side of the body. So if you're right handed, it's probably because you're left brain dominant and that means that you're more comfortable using your right hand. But I can't be sure of that. And I'm not sure about this left brain, right brain stuff too, taking quizzes on the internet and I think we're all a combination of everything. But generally speaking, the left brain, so the left side of the brain, would be where we do a lot of more of our analytical stuff. So reading, writing, math, decision making, language skills, like thinking in words, right? Very concrete stuff. Whereas the right side of the brain, the right cerebral hemisphere is usually going to be a lot of sensations, right? So touch, taste, recognizing faces, recognizing voices, art, imagination, creativity, that's kind of what I think of with the right side of the brain. So obviously we need both sides. Whereas the left side of the brain is where speech comes from. But the right side of the brain is where we recognize voices and the meaning behind sounds, that kind of stuff. So hemispheric lateralization is a big deal. But I don't actually know how much the left brain, right brain stuff is true. Okay, so this is kind of a little bit of a catch-all. So a few more things I need you to know about the cerebrum. I hope this helps. Have a wonderful day, be blessed.