Transcript for:
Understanding Brain Structure and Function

hi the topic of this video is the brain the brain has in some ways taken over psychology certainly behavior is still important and all the psychological theories from the late 19th and first half of the 20th century there's loads of them around and we're going to talk about a lot of those in this course but a lot of those a lot of the early theories uh right up until the 1950s and 60s um really lacked scientific evidence because they were theories about the psych the mind the subjective mental life of of individuals and we can't observe that and certainly can't measure something we can't observe so it was really difficult to have a strong Natural Science basis to theories and psychology the theories many of them are very useful models and and and they work well to explain a lot of things and and um we still use many of them today but when it comes down to the scientific method um the one of the basic premises is science is limited to the Natural World things we can observe with our senses and this has always been an issue in Psychology because the psych thing being investigated is not directly observable um so yeah the brain and that now that we have developed really good brain Imaging techniques we can take really we can we can take really good pictures MRIs magnetic resonance imaging it's a particular kind of Technology we can take really really highly detailed pictures right down to the level of individual neurons but then someone developed a technology to put a bunch of those pictures together which is what a movie is a bunch of very similar pictures that change in just small subtle ways and when we see a bunch of them one after another we don't notice their different pictures we see them as moving we see movement and that's that's all a a movie is it's it's a series of pictures when put together our brain interprets as movement okay we've developed some really good brain Imaging tools most importantly fmri functional magnetic resonance imaging so we have learned a lot about the brain now I've told told you both in in the first video and I've told you in class this unit bioc pychology you will be tested on with a multiple choice test 25 multiple choice questions on the entire unit and what those questions we will uh measure primarily is different parts of the nervous system and most importantly the function of those different parts okay um we talked about the the most basic part of the nervous system a neuron a nervous system smell nervous system cell the smallest living thing there is cells and we have a lot of them we have a lot of different kinds of them and we have a lot of of over 100 billion is um nervous system cells called neurons and we talked about the axon the dendrites the synapse you should know all those things but most importantly you need to know their function okay and you will be tested with a 25 question multiple choice test okay on this unit so let's look at the brain and you've all seen a brain you've seen pictures of a brain you may have even seen a picture of a real brain there's illustrations diagrams you could access thousand thousands of videos about the brain um you you can many of them um some probably short as as 12 or 15 minutes and some as long as hours but there are many many videos um explaining the composition of the brain the different parts and the functions of those parts some of them are animated in cartoon form a lot of others are more similar to what we're doing here we're going to look at at the major parts of the brain and the functions not all of the parts of the brain there's a whole lot more that we don't cover in this class you psych Majors when you take a course in biopsychology which you're required to take um you will get into more detail when it comes to the brain now what we're going to do is we're going to start at the bottom and work our way up because if you start at the bottom this area right here that's colored and then move your way up to the middle and move your way up to the outer covering the cortex what you're doing is moving through evolutionary history this part down here is is very similar to reptiles okay lizards they have all these parts to their brain okay lizards don't have a developed lyic system therefore they can't feel they can't learn if you cut off a lizard's tail it will react but we have no evidence that it will experience pain in fact it will grow the tail back which is amazing cut off a a human or a mammal's arm it won't grow back but we have a Reptilian Brain and it shouldn't surprise you that this lower brain is responsible for basic life support Consciousness movement all the things reptiles have to have and are able to do okay so this lower part of the brain we're going to talk about first at the bottom right above the spinal cord okay the brain stem is is is this part where the spinal cord enters into the brain this lower part of the brain sometimes called The Reptilian Brain we're going to start with that then we're going to move up to the middle part of the brain the lyic system um which is the Maman brain mammals have a lyic system they have a hippocampus an Omega a Thalamus a hypothalamus okay uh and then finally we're going to talk about this outer layer the cortex and this is shared by mammals but closer to us the cortex is more like humans in primates especially chimpanzees some gorillas um but it's this part right here in the front the frontal lobe in fact way in the front the prefrontal lobe this is the most human part of the brain no other animal including chimpanzees whose DNA is about 98% identical but what does that 2% that's purely human represent a big chunk of it this area here and it's different than other living things even other chimpanzees because of the number of connections between their that can communicate with each other this is where we think this is where you control yourself when you get angry okay so we'll begin with the lower part move to the middle and then go to the upper and from here a lot of it is just you learning it because it's right in front of you okay at the very bottom of the brain just above the the the brain stem is there's there's two things the medulla and the ponds if those are damaged you die in immediately heartbeat and breathing are regulated in the lower part of the brain so if your ponds your medulla are damaged you will die okay it's that simple so here's two things you need to associate medulla and ponds uh basic life support okay um and especially the lower brain the bottom part of the brain often times called the the lower brain that's your Reptilian Brain basic life support the second thing is What's called the reticular formation or the reticular activating system this is not in one place these blue lines are like a net like a webbing and this net or webbing spreads throughout the brain okay this reticular formation is involved in arousal and attention when you wake up it becomes very active the neurons that make up the reticular formation uh become very active excitatory and activate parts of your brain arousal attention if all of a sudden there were a loud noise your reticular formation would become very active to activate your brain so that you could uh determine where the noise is coming from and perceive identify the noise interpret it um and and determine how to reacts to it so reticular formation arousal attention focus um awake um it's pretty simple okay there's your second Association reticular formation and any of a number of words arousal attention alertness um and when you're highly motivated to walk into a concert or for a ball game to start uh that heightened state of arousal and motivation that's not going to happen with now without your reticular formation being very very active the next part is this area in the back this area here it's a it it it looks like a separate area sometimes called the little brain this area is extremely important now up here we're going to talk about the motor cortex which sends signals to your body to muscles so that you can move whether it comes to pointing your finger scratching an itch running walking raising your arm um any movement any movement the signals are send from up here we're going to talk about the motor cortex but many signals are sent in order for you to walk or run or dance or dive off a a board flip three times and and um enter into the water hopefully without making a splash what coordinates all those movements puts them together into one overall gross movement like running that's the cerebellum cerebellum is phenomenally important it regulates and coordinates body movement your posture your balance okay all movement all muscles working together are regulated by the cerebellum so with the cerebellum there's two associations you have to make body movements coordinating regulating body movements putting them all together into one gross movement um and the other thing is it regulates procedural memory you have two different kinds of memory things you know and things things you can do and sometimes people are really good at doing something have difficulty explaining exactly how they do it because they've mastered it as a skill um but in terms of knowledge of exactly how they do it they may not be able to explain it very well because skills are stored in procedural memory and the cerebellum is the gatekeeper for skill memory because skills involve ordinating movements the hippocampus is the gatekeeper for um what we know the things we know um knowledge um episodic memory memories if I ask you what you know or ask questions about what happened in the past you would activate your hippocampus and give me answers okay if I asked you to show me how to serve a a tennis ball um that's a skill and in order for you to show me the right way to serve a tennis ball um or to throw a split fingered fast ball um in order for you to show me how to serve how to throw a particular pitch you would have to activate your cerebellum because the skill not in words in movements the skill um is in what's called procedural memory and the gate deeper and the actual memory is in the muscles but to to pull them all together and remember how to pull all those movements together that involves procedural memory um and and the cerebellum if your C cerebellum is damaged you could still move but you'd have trouble moving fluidly you you would move more robotically because the cerebellum puts it all together so one of the things we' have difficulty if you if you look at robots move they're pretty hky jerky u a a robot walking like a human you won't see one do that and that's because the cerebellum um is is a really really um important part of all that and it's been hard to create a machine in a robot that coordinates all the movements into fluid gross movements like walking or run running or dancing that's where we get the adjective robotic from okay so that's your lower brain there's a number of of of reticular formation cerebellum medullan Pond and you need to somehow remember the function of each of these that's the important thing is to remember the functions okay oh also the cerebellum is is regulates the mechanics of speech in order for you to make a vowel there's not much to it that's why monkeys can go heyy okay vowels are um um sounds that we make with our vocal cords where they're unobstructed they just come out say any consonant and there's a bunch of them and to say t you have to use your tongue to say k you have to use your upper mouth there's a number of muscles okay associated with your oral cavity with movements of your mouth and in order to make any vowel we have I'm sorry in order to make any consonant we've got to use our lips our tongue our teeth um f make the sound for things you have to put your teeth on your your tongue you can't do it and what that does is it Alters the air flow as it comes out first by way as it passes your vocal cords which affects the air flow coming from your lungs you can't talk without breathing out okay but then your oral cavity These Fine movements only humans can do that okay this is why primates um are are not able to master language they can do some sign language and teaching chimpanzees raised in captivity in human homes sign language they're able to do things um that a 2-year-old can do which is pretty amazing for an animal but that's a long way from designing rocket ships to fly to the moon and back so and and and a big part of what we can are able to do in terms of language is wrapped up in these consonants okay and that has to do with the cerebellum controlling the movements of the muscles in our oral cavity to make the all the consonant sounds there's not that many vowel sounds okay so that's another part of the sarabellum it's really really it's associated with speech production now the middle the the middle oftentimes called the lyic system um is this area that you see here and you can see the thalamus you can see the hippocampus you can see the amydala just this little it looks like an almond in fact I think the word Amiga is is based upon the word for almond in some language okay we don't talk about the basil ganglia but inside that is the nucleus cumbent which I've already talked about you didn't have to you w responsible for remembering it but in the basil gangling is the the nucleus accumbent which uh releases dopamine so that you feel pleasure reward reinforcement Etc but we're going to talk about the the thalamus the hippocampus the amigdala and the hypothalamus and you'll need to make a distinction between the phalus and the hypothalamus let's start with that the phalus that right there this is the relay station from all your senses so when information comes in from your eyes your ears your tongue rather than the wires from your eyes going all the way into the visual processing area and the wires from your ears going all the way to your auditory processing center all the wires from our um all of our senses except smell and we'll talk about that in just a moment all of the wiring bringing in information from all of our senses except smell go to the phalus and the thalamus identifies which sense and then the thalamus sends it the visual back here to the occipital lobe and and your visual sens processing so comes from your eyes to here and from your um from the thalmus back to the accept lob same with your hearing it's sends it to the auditory lobe okay um so the thalmus and this is the thing you absolutely must remember it's the relay station from the senses to sensory processing areas incoming information comes from the senses to the phalus and to the phalus to the appropriate sensory processing area okay when you go to sleep at night to cut down on the stimulation it doesn't turn your senses off it turns them all down and of course by closing your eyes you turn down your visual but it turns down hearing it turns down smell you still can hear and smell but the volume is turned way down and this plays a major role um in going to sleep and waking up the moment you wake up your Thalamus turns way up and all of your senses are fully functioning with the volume turned up okay there's a number of things you just learned about the phalus the hypothalamus is terribly terribly important if it's damaged you die it directs all basic biological needs so the hypothalamus sends out signals for most of your automatic called autonomic systems you don't have to decide and tell yourself to digest food you you don't have to decide and tell yourself you're hungry or thirsty okay when you um um see some kind of image that stimulates you sexually you don't have to decide to get sexually stimulated you don't have to take conscious control of of causing those parts of your body to become aroused okay all the autonomic nervous system functions are directed by the H hypothalamus okay it it directs um breathing heartbeat appetite thirst sexual drive hypothalamus directs basic biological needs that's the association have to remember these next to you already know the amydala regulates emotions uh and with with damaged igula you if it's if it's nonfunctional you cannot experience feel experience be consciously aware of fear anxiety anger they go away if it's damaged you have functional problems with emotions okay not a good thing to get damaged hippocampus learning in memory hippocampus learning in memory hippocampus learning in memory without a functioning hippocampus you cannot remember anything that happens to you if it's damaged the old memories are still there and can influence your behavior and your reactions you're unconscious but you can't remember anything from the past hippocampus is the place all new memories come in and old memories come out to Consciousness so we can remember them so the hippocampus is very active when we're asleep at night because when we're asleep especially in rem we do a lot of memory consolidation in storage physically storage things we'll talk about that more in the unit um on memory and in the unit on uh Consciousness where we talk about sleep that's part of this testing unit in fact it's the next unit okay I'm going to stop this video um because I'm concerned about them being too long and I'm going to call this video the brain part one and then I will pick up with the c Cal cortex the outside in the next video okay signing off