Dr. Octavio Choi presents Brain Basics: An Introduction to Cognitive Neuroscience

[Music] so we're going to start in a moment with dr. toffee choy Octavio choy I'll say I saved my sort of thank you now for him toffee is also the reason that we're having this program he is she'll read in your bio about him in the briefing book it is one of the the premier up-and-coming psychiatrist and neuroscientist trained both as an MD and a PhD toffee is one of a new wave of doctors who are so change lives who are introducing neuroscience into their clinical practice as well Taavi direct forensic psychiatry here in Oregon works intentionally with the criminal justice system as going to get us kicked off with a really basic question of how does the brain work he has the toughest job of the entire day I told you tens of thousands of people are trying to figure out we're giving him about 40 minutes to get us up to speed but if there's one person who can do it it's Taavi and with that let me hand it off to you microphone excellence working this is actually probably the toughest talk of the garage put together trying to explain the brain in 40 minutes and so let's get to it so I'm an assistant professor at OHSU and I am the director of the forensic evaluation service at the Oregon State Hospital and that capacity I have the privilege of living neural law boots on the ground evaluating criminal defendants with various types of medical and brain conditions and assessing how responsible they might be for the offenses so let's start with the case that something that you might all be an efficient of considering imagine there's a defendant to causing a public disturbance with urinating in public swearing in public and the 25 year old man no criminal history excellent physical health never miss a day at work in his life alert oriented aware intelligent using language in a very well good memory intact memory can learn new things and basically when you're asking about why he did it he just says well I don't fit in care didn't care now imagine if two months prior to this incident a tamping iron 13 inches a 13 pounds 43 inches long inch and a quarter in diameter shot through his skull and penetrated the front of his brain would that kind of affect the way you might think about how guilty this person might be for their acts might that in fact be a strong reason for why this person behave the way they did a lot a lot of you were smiling not in your heads many of you know this is the famous case of Phineas Gage the most famous patient in neuroscience I think half of cognitive neuroscience textbooks start with the story of Phineas Gage so who is Phineas Gage he was a railroad format and back in 1848 suffered a terrible accident and from the Boston Post reported it the four men and a railroad in Cavendish was tamping down you know he was exploding rocks to make way for a railroad track and you have to put you know gunpowder is explosive and you tap it down with the tamping iron which caused a spark in the rock and it exploded an ax tamping iron was driven through his newest kelp you know a hundred years later back in 2004 a Phineas Gage the skull was currently at the Harvard Museum and the doctor has got the his skull imaged in a 3d in a cat scanner created a 3d model of the skull and was able to digitally remaster exactly the path of the of the tapping iron so this is just a showing off that you know we have the skull we're kind of creating a bunch of three slices with cat scan and reconstructing with a computer to make a three-dimensional model that's completely after dinner eat eat ale this is part of the computer revolution with increasing computing power you can take these two-dimensional slices and make 3-dimensional models and there you see the tapping iron and going to is go aouch now the amazing thing what amazing things about Phineas Gage is that he survived and in fact he was treated by a physician named John Martin Harlow who became famous by reporting on the case of Phineas Gage and here's what he had so I'm going to read this because he's such a good writer the equilibrium or balance so to speak between his intellectual faculties and animal propensities seems to have been destroyed he is fitful irreverent indulging at times in the grossest profanity which was not previously as custom manifesting but little difference for his fellows impatient of restraint or advice when it conflicts with his desires at times / tenaciously obstinate all of that yet appreciates and vacillating devising many plans of future operations which are no sooner arranged and they are abandoned in turn for others appearing worth you sound like anyone we know a lot of us who work with you know with the criminal defendants I mean this describes a lot me know some very impulsive kind of personalities but the difference of Phineas Gage is that before his injury although untrained in the schools he possessed a well-balanced mind was looked upon by those who knew him as shrewd smart businessman very energetic and persistent in executing his plans of operation and this regard his mind was radically changed so decidedly that his friends and acquaintances said he was no longer gage now uh you know Phineas Gage is often appointed to as sort of the start of the birth of modern cognitive neuroscience and why is this he was really for the first clear example written the literature of someone who suffered a brain injury I had very specific impairments which pointed to the key principle of the brain but different parts of the brain do different things damage different parts of the brain there will be specific impairments of result so in the key a key phrase is the equilibrium or balance between his intellectual faculties and animal propensity seems to have been destroyed so his intelligence as he was thought of back then was intact his memory wasn't asked he was able to have a conversation with you he knew where he was he could learn new things all that stuff was intact and also his emotions were intact he was able to feel happy and sad and all those things but the balance between those two things were was destroyed and I would argue that's the best way to summarize Phineas gages impairments of his brain deficit was that his was impaired by that specific brain injury so what is the conscience anyone let's just want throw out this conscious was impaired in my opinions it's my opinion but so what do we mean by conscience and what about Jiminy Cricket okay so it kind of a plane up helps you the right between the wrong and it's a Jiminy Cricket where it's a cognitive thing where it's like you know the rules are wrong or is it like an emotional thing that stops you from doing what you think is right or wrong it could be both but what do you think is more important yeah anyone have this thing where you know you're in the middle of a you know kind of a deserted town in the middle of the night and you're stopping this traffic light at the red light no there's no cops around right well what what do most of us do we're glued to that red traffic light right we're not going forward even though we know there's no chance we're going to get caught so what is it that's stopping us a big brain okay by explaining for people who don't know with lemon green is yeah I would argue that it's sort of like the bad feeling in your body that you get automatically when confronted with these kind of kinds of dilemmas and it's that bad feeling I would argue might be more important than be rational I know this is wrong kind of you know cognitive thinking so you know the weird thing the interesting thing about Phineas Gage is he seems to have suffered an injury that impairs that part of the brain which allows you to call up bad feelings in response to something that you know is wrong so we'll get that back to us that gets back to that in a moment but let's just go over some basic neuroanatomy so this is the picture of the brain that you know many of us are familiar with you know this is a cerebral cortex you can see this is tough with a split screen here I only have one pointer so so you know this is a fumarole cortex we can see that if this is the surface of the brain we can see it split into various lobes there's the frontal lobe in the front there's a temporal lobe next to the temple the back of the brain is called the occipital lobe and the parietal lobe is in between and here is a top-down view so we're looking from top down you see the eyeball so it's like the brain is paint pointed this way and you can see you know an odd thing about the brain is that you know what's the left the right side of your brain controls the left half of your body and the okay the left side of your brain controls the right side of your body so you guys probably know people who've suffered strokes and the interesting thing is that the that's the site of the injury often results in deficits on the opposite side of the body these two halves of the brain are connected by a bridge called the corpus callosum it's a huge series of connections that connect the right and left halves of your brain and then copy Bragg ask me about split brain experiments and you know neurosurgeons have actually cut this bridge and turns out what happens is that that splits you into two different be people that live in the same body so it's a really fascinating thing that we're not going to go into more in the talk but there's a big bridge called the corpus callosum and then this is a picture of the brain looking as if the brain is looking right at you and so you can see the corpus callosum mrs. bridge and you can see that there is stuff buried underneath the cortex right so that's really a really important point so the brain is not just what you see on the on the surface there's stuff buried underneath there oh another thing is you can see if the brain has lots of convolutions and the bumps are called gyri and the dips are called sulci and why do you think we have all these convolutions and dips and sulci and stuff like that what does that do increase the surface area right so if the brain is kept in a computer you can pack more computing machinery into that same area and actually if you look evolutionarily these are different kinds of primates in the relative sizes so here's humans and we have the biggest brains but we also have the wrinkly of brains so when you look back in evolutionary history the brains get smoother and smoother so it's a very interesting thing that we get more brain machinery stuffed in there by all those folds so okay so another key point is that the brain is a multi-layered structure it's not just the cortex what you see on the surface there's lots of machinery underneath there so a lot of us know about this theory called the triangle brain which is put forward to the 70s by a Harvard psychologist named Rick mcclain basically he posited that when you look at the modern human brain you can you can conceptualize it as being constructed of three different layers what do you call the reptilian layer so the limbic system and then the neomammalian which is cerebral cortex so if you look at a MRI and here is the nose looking forward here's the brain we consider the the first most primitive part of the brain to be called the reptilian complex which is the brainstem on top of that is built series of structures called the limbic system on top of that we have the covering called the cortex cortex literally means covering so okay so here's the cortex and what the cortex in general does is it manages all the computations required for higher cognition stuff like language stuff like higher-order object recognition telling the difference between Van Gogh and a Rembrandt consciousness being consciously aware of your thoughts consciously aware of your feelings all that fancy stuff that we consider being human this tends to be computed and instantiated in the cerebral cortex if we get rid of that upper layer we see underneath in a series of very complex series of structures that I'm just going to simplify and call the limbic system for the hardcore neuroscientist I know that that's kind of a simplification but let's just call this middle layer the limbic system and what this kind of you know and let me sum does many things but one of the key things it does is core evaluation so you know our brains evolved to keep us alive and what the limbic system does with core evaluations is it scans everything on the outside hearing sight sounds touches feelings inside our body and it just scans for anything that you might want to pay attention to because it's going to help you survive so things like donuts things like spiders things like sexual partners right so if it sees you know constantly scanning to see something that that's going to help you survive in some way they go ding a ling a ling a ling ling and tell us excludable cortex then you can actually go towards that doing that away from the spider away from the right and it doesn't and you know that that message was that message feel like it doesn't feel like a message a text message upon your phone it feels like the feeling of craving like the feeling if you want to go towards something or feeling of Terror or fear to move away so these core evaluations are computations done at a very low level that scans the entire external and internal environment in order to give your cerebral contour your cortex a signal to to move towards things and move away from things and those signals feel like feelings under if we get rid of the limbic system underneath that we have the brainstem which has such a basic life support so the brainstem is actually the upper extension of the spinal cord can you guys see okay here I feel bad because my pointer doesn't show up on this thing so sorry maybe I'll be like like a bono I went to a u2 concert and he knows a circular stage that has a constant use this way and they're happy with the place maybe Midway I'll switch over so the brainstem is the upper extension of the spinal cord and it has a lot of basic life support there are centers they're controlled respiration heart rate and basic sensory processing there are sensors there that are constantly sampling the chemical environment of your blood to make sure there's enough oxygen in it for instance so lots of basic life supports them there if you ever stroke in your brainstem you generally die like you know and you don't have breathing you die okay so there's a brain stem on top of that we have limbic system it's kind of costly looking out for things at a low level to help you survive core evaluations on top of that we have the thinking brain the cortex now another key principle at the brain is hierarchically organized so you know you are not aware of most of the things your brain is doing right anyone here consciously beating their heart or you can you forget how to breathe not really right that's because your brain the lower center is the brainstem the limbic system they're doing lots of things underneath your underneath consciousness they're helping you stay alive and you're a coach is only notified when it's just like a corporation you have your underlings do most of the grunt work answering the low-level emails and anytime there's something he you know I think the boss needs to know about this because there's two conflicting emails and I'm not quite sure how to resolve it that doesn't think it's bumped up to the next level of a higher so for instance your brain stone has basic life support systems including sensors for oxygen levels in your blood so if there's a low level of oxygen you're in you know the oxygen level in this room drops down these centers are going to start getting very excited saying or something around here something wrong here I need to notify the boss the brain stem is boss limbic system let me take some this is it's monitoring everything even step outside of your awareness and that's that's really cool like you're not aware of you know the feeling of you know the air on the back of your left hand right I mean now you are you point before but I guarantee you if there is a feeling of some fuzzy legs walking on that on the arm suddenly the big sis would say this is important I need to tell the boss and you become aware of it okay so if you have dropped a note too that tells the limbic systems let me sit some sampling lots of things including the feeling the back of your hand but if it gets a message saying your o2 levels dropping it says I need to tell the boss about this this just can't go on right and so then it sends signal to the cortex tortoise cortex us yes oh I do feel like I'm suffocating and so I'm going to get out of here and possibly go outside but please stay in the room so this is a busy diagram this is a diagram from one of the references we put in the briefing book one of the latest issues articles about the brain circuitry of drug addiction and so you know don't get overwhelmed it's easy to get overwhelmed with these kinds of diagrams I just want you to pay attention to three different areas the amygdala the ventral striatum and the orbital frontal cortex right so I have to give some love to this side the amygdala the ventral striatum and the orbital frontal cortex now the amygdala and the Metro striatum a part of the limbic system doing those core evaluations the main lot tends to be scanning for things that could possibly be threatening to you and you need to move away from and when the amygdala activates that feels like fear getaway the ventral striatum is locally known as the pleasure center of the brain and these are all oversimplifications every green area kind of does everything but just to keep things a bit more simple the ventral striatum is closed called a pleasure area of the brain and it tends to be looking out for things like Jonah sexual partners it gets excited when it's these things that you might be interested in moving towards and that feels like pleasure feels like anticipation if it activates and the thing isn't there like if you're crate if you see you want to donate but there's no doing out there if that activation feels like craving now um obviously you don't want to act on every single impulse your amygdala and eventual striatum saying you want to you know unless you're a presidential candidate you uh you know you see a attractive sexual partner you go you know here we going to really want to say you know I couldn't resist I'm sorry but that's when your port X comes into your orbital frontal cortex is involved in evaluating the signals coming from the amygdala and eventual Freud and saying it adds context to what those drives are telling you to do it well maybe not we we shouldn't you know grope that person or maybe we shouldn't have that you know six donut you know or you know the regula it's like a little its limit you look like a scared little kid that everything freaks you know that little kids I'll you know see the spider let me like goes oh my god there's a spider spider it gets very active and excited and the orbital frontal cortex adds context it says you know what there's a cage around that's better we're actually in the view so you don't so calm down a Bigelow it's going to be fine or you know you know the Rachel's freedom gets very excited we're seeing a donut and the overall Central Square just says you know the last keep the clip of time you kind of just overdid it with the donut and you felt really bad so it kind of helps modulate inhibit those drives that come from underneath and limbic systems well guess part what part of the brain was damaged in Phineas Gage the orbital frontal cortex the toppling rod went straight to that area that's the area that gives emotional context to the drives and can inhibit appropriately the drives that should be inhibited and so Antonio Damasio and his wife Anna enjoyed DiMaggio is one of the geniuses of neuroscience he's a neurologist excused to be in Iowa I think he's moved around he said USC now some great folks with USC and he did a he studied that area to bring called events so it's the orbital frontal cortex his Phineas gages tamping iron it went through and here is a side view of the brain with the brain looking forward this way and then underneath the ventral surface of the brain I ball to be here so you looking underneath this section of the brain is called the orbital frontal cortex it's also called the ventral medial prefrontal cortex that was the area that was damaged in Phineas Gage and he his lab was really instrumental in studying stroke patients to understand what this part of the brain was doing because the fascinating thing is if you're damaged as part of the brain your memory is fine you know where you are your use of language is fine your cognition is fine and also your emotions are fine they're expose still happy and sad but they no longer seem to care about about inhibiting things that we would find socially kind of repulsive right so I would argue that that's what keeps us from urinating in public even though we have a really full bladder we're just not going to do it the reason we don't do it again we know what's wrong but with the other reason is we know we would die of embarrassment right and that feeling is it's a feeling that stops us it's a feeling of I feel really bad in my body contemplating doing this and that's what generally stops us from doing things that and what did that feeling come from how do we get that feeling in our brain where we any of your baby so they have problems urinating public we don't have that right it's a series of learned emotional response like we did something your need in public and then you felt bad somehow mommy said don't do that and you feel bad in your body over time you develop an emotional linkage of an estate of your body with a certain context that is exactly what this part of this brain is doing so people with damage in this part of the brain that helped me called emotional amnesia they can feel emotions but they just don't store it so they can't form those linkages between a context and a feeling in their body that would ordinarily stop many of us from doing stuff like marinating public or groping people okay so DiMaggio the way he put it is this area of rain holds linkages between the facts that compose a situation and the emotion previously paired with it and I would say that is actually a major part of what the consciousness this is where this is one of the main brain areas where constant during the conscience is instantiated okay and you know in general Phineas Gage was an important of someone who has suffered a specific brain injury it had a specific deficit thereby showing a key principle at different parts of the brain do different things that's the principles called functional specialization and actually the best thing there Michael Posner is one of the key people who have established that that principle in the brain and so you know this idea that different parts of the brain do different things that might sound like a really obvious idea to modern-day people but it was not an obvious idea 100 years ago in fact there was a raging debate between the whole list and the local list so Pierre Flourens was one of the premier friends of holism which said like you know the brain is a computer and all parts of it are undifferentiated so really you know impairments have to do don't have to do with the location of the impairment has to do the size of the impairment above the damage right so everybody Rain cards kind of interchangeable Franz Joseph gall was opponent of localism said no no brainy areas are highly specialized in Kent different parts of the brain do different things but he took it a little too far he's the main guy between the theory of phrenology which you guys knew phrenology right bumps on their surface of your head means you're a criminal you means you're a good person I have a very bumpy head I don't know what that I shaved my head to go to meditation retreat a few years ago and I was like oh my god I'm very shaving it why my hair is kind of like you know I God would hate me but he took it too far and he said you know the brain is divided into areas and there's an area for acquisitiveness and there's a area for Sublett ever sublimity is and an area for mercifulness and he very there's one area of the brain that does that and that that's nonsense that's taking it too far because when you think about it any task that you do like let's say you're reading right when you think about what that task involves involves looking at looking at words so there's a visual system involvement right then it's understanding the word so there's some you know there's processing of what that visual signal means it might be invoke memories right so and those memories might invoke kind of behaviors and decisions you might might want to make each of those different qualities of that task is done in different parts of the brain so you something as simple as reading a single word activates different parts of the brain associated with those elementary tasks does that make sense that's what dr. Posner's work with his colleagues of the wash at Washington University established in a series of super elegant studies I love reading those studies whenever you does studies I feel like I understand the brain okay so actually the you know localism taking it too far holism is also taking it too far this is in between things called distributed processing and that's the principle that I just elucidated where you know it's not that there's one part of the brain that does you know a single thing but they're you know any task that you have has elementary cognitive operations and each of those elementary operations are done by different parts of the brain to make sense so it's a collection of specialized modules it gets invoked dynamically depending on the task that's at hand right okay good nodding heads good now Phineas Gage was a loss-of-function study you know tab BRE went through a certain part of his brain you know and he lost some ability and so people started to make correlations between parts of the brain and the parts then what you know what kind of functions are done by that part of the brain many of us are probably familiar with strokes strokes stroke patients so that's another loss of function study where part of your brain gets knocked out and by studying what kind of impairments results from that you can make inferences about what that brain area is useful for right make sense in fact you know from the seminal studies early studies on brain localization work had to do four phases or language deficits and so you guys heard of Broca and wernicki these are a two famous scientists of neurologists around the turn of the century who studied some fascinating pair of patients who had language deficits in different parts of their brain we go over here for a little bit so broke up pure of Broca was a French neurologist who found that a bunch of his patients lost ability to vocalize language so they could understand language when you spoke to them and they could do execute commands you know you know if you said send them to them to do something indicating that they understood language but they were they had a really hard time generating languages speaking so he discovered that these patients had a damage in the area of the cortex called Broca's area and interestingly that Broca's areas right next to the part of the brain that controls the motor muffled of the lips and tongue so damaged this area results in impairments where patients can understand language but have a hard time generating language boy is it that landing down [Music] I can go in English for throttling I'm resting cookie jar right yes damage broken area now there's another area called Wernicke's area which is close to the auditory cortex where it's a pot with the part of the main processes of incoming sound signals damage is Wernicke's area and results in a language deficit in which people can generate language just fine they're talking up a storm but once you but they can't understand language spoken language they can understand written language which comes in through a different pathway through the visual cortex but they can't understand spoken language so when you ask them to do something in a verbal command they respond with very fluent nonsense so here's an example what are you doing today we see with the water over here at the moment to talk with the people over them over there they're diving for them at the moment without saving the moment he of water person for him with look for him so we're on a cruise and we're that weight will be water right here and those save their hands right there for them a moment so that's Broca's area so early study for super interesting important for establishing again the different parts of the brain do different things since also around the turn of the century a guide named Broadman had a microscope a novel technology at the time and by studying he by sampling little core samples from different areas of the cortex and looking at them under the microscope he could see that cells look different in different parts of the brain and he hypothesized that the reason those cells look different is because those these brain areas are specialized and do different things so this is a Broadman map and you must many of you must have seen this we still use this map of brain areas which he numbered like area 17 is primary visual cortex and you're a scientist still refer to Broca's areas so it's another indication that if you look at the microscopic level different parts of the brain it looks different and that that supports the theory that different parts of the brain do different things any questions so far yeah this is all guys ok so now broken and I should I learn this thing trigger alert juror alert I hadn't heard before yesterday I need to warn you phrasing that but might potentially be traumatic and my tone of voice was a little sarcastic yet I don't mean that but we're Nikki and Broca you know they discovered were thus to where the damage was and their patients brain by that's a wait until those patients died and then they had to slice up those brains literally with a knife and then find little goobers and stuff that employee okay this thing looks to me where the problem is now you can Majan that's an incredibly slow process right like you have you know five really interesting patients and you have to wait ten or twenty years until they die or you know ethically hope the V died sooner now wouldn't wouldn't the whole enterprise be a lot more efficient if you could look to see what the damage was in the living person right that would be fantastic right and so that's what the imaging revolution has done to help us so I'm going to talk about the evolution of brain imaging so the extra we all know about x-rays invented or discovered by Rankin he reported in a meeting in 1895 that he discovered these x-rays and this is the very first x-ray you took of his wife's hand you can see the ring and his wife was reputed to have said I've seen my death when she saw this scan now x-rays are amazing x-rays worked by shooting high intensity waves called x-rays through a person's body and on the other side is a photographic plate and then something stopped x-rays more than others like bone stop x-rays and you know really well leading to light areas in the x-ray and tissues tend to soft tissues tend to stop and not so well they go through and so the photographic plate gets start which so they're called shadow pictures and here's a skull x-ray and you know the the dream was maybe we can see the brain with this x-ray stuff right but the problem was the brain is inside this thing called the skull and the skull is a really dense thing that stops most x-rays and so it's really hard to see also with an x-ray a three-dimensional thing is flattened into two dimensions it becomes really hard to tell anything apart that's why radiologists get paid the big bucks they see something exists and they can they can turn that into a three-dimensional image in their heads so for a long time the brain was called the Dark Continent we had no way of imaging it now I think around the 50s 60s someone had to buy the idea of injecting air into the branch of air is very not dense and compared to brain tissue we might be able to tell a difference in the x-ray so the the brain has a series of interconnected fluid canals called the ventricles so the ventricles makes three both spinal fluid and bave the brain and fluid someone has a bright idea of taking a big syringe of air injecting it through the brain and injecting air into this system and then you'd be able to see the bubble of air with an x-ray later on people said you know we actually don't need to go right to the ring we can go through the spinal cord with a spinal tap kind of procedure and that was a lot better but still these are the kind of images you get right it's going to be hard to tell problem you can tell some if someone has a major problem - ventricles you can tell something's going on but it's a low resolution image and I like seeing this to remind us how far we've come you inject us air bubble and then you there in this chair that kind of puts you in different positions and then you take x-rays and those different positions that was the error bubble moves to kind of this was supposed to be an incredibly painful procedure and the joke was that this this procedure was therapeutic just a patient in whatever their complaint was never came back to you again this is the sixties okay shooting ahead the cat scan it was invented in the 60s the beetles were incredibly important part of developing the Cascade the cat scan was developed by EMI which is also the record label the Beatles of the Beatles EMI ended up with it just a ton of money from the Beatles album says they said what can we do with all this money an engineer you know and EMI said I know what to do with that money with the rise of computing power I've conduct a new kind of x-ray that will take a series of x-ray images in a rotational manner and with my computer algorithms that can reconstruct a three to two dimensional and then a three-dimensional structure of the brain and you know amazingly it worked so when you look at a cat scanner this is the inside witness's is a spinning x-ray where you have an x-ray source that's spinning in a circle and there's a photographic plate and staking like a million x-rays all right and then magically if you do take a million different you know x-rays and different angles reconstruct out with computer you can now start to look at brain tissue so this is the first cat scan and can you see say anything here there's a dark spot so it's it's fantastic it's always great in the first cat scan shows something you can actually use something about so this has turned out to be a tumor that was resected and you know Hounsfield whence up 2011 it was all good the MRIs the technology that were most of us are familiar with it's our modern imaging method and it's a much bigger machine so here's a person here is you know and the MRI and it still takes you know hours of physics to explain exactly how it works but suffice it to say that the MRI can interrogate magnetic signals all throughout your brain and they tells your brain is made of different different you know compositions of water and fat and different kinds of molecules it can actually distinguish those magnetically so those have different magnetic properties that can be converted to an image and so and the my resolution is dependent on magnetic field strength so the early MRIs with 0.35 Tesla then there were 1.5 tesla then you went up to 3.0 Tesla then you went up Q the modern research scanners have 7 Tesla's and if you connected between 0.35 Tesla and 7-tesla there was a remarkable improvement resolution the world's most powerful MRI is being constructed there's a person inside there it's going to generate an almost 12 Tesla signal which is just enormous and with that it was had enormous magnetic strength the voxels or the brain elements that gets get image gets smaller and smaller so we're getting incredibly we're going to get incredibly high-resolution pictures of the brain and like many big science projects that you keep getting pushback now that's loss of function studies which are really useful but it's sort of a kind of like if you wanted to get how your iPhone work it's like if you took an ice pick and stabbed different parts of your iPhone and said oh well this doesn't seem to work anymore right it's kind of a slow laborious process so what we really like to do is study the intact functioning brain which is the normal function structure and function of the brain and so that's where functional imaging studies come in and that's really a revolution so the two main ways to visualize brain activity these days are with pet and with fMRI and a pet studies are amazing and the campion they can do things that they're from or can't do I'm going to focus mostly in fMRI which is used more pet requires ingestion of radioactive particles and a lot of patients kind of don't like that so much so fMRI is all downes magnets so it's safe and it's even holistically beneficial so fMRI so the thing with fMRI to really a key point is that you know although these pictures are very pretty and it looks like we're looking at brain activity we are not looking at brain activity we are looking at an indirect measure of brain activity we're actually looking at a vascular response to brain activity so the smy visualizes a vascular response to bring an activity not bring an activity itself and so you know the basic principle is if the part of your brain is working hard it's going to recruit more blood flow that extra blood flow is going to change the magnetic properties of that part of the brain and that can be visualized on the fMRI so the fMRI actually visualizes what's called a relative oxygenation level which is an indirect measure brain activity because your brain is working hard recruits more broad blood oxygen level goes up and that can be seen on the MRI now so this is an important slide and I you know I see the references of the briefing book in the skin you know there's many limitations of fMRI we're looking at a correlation of vascular response to brain activity and all correlations are imperfect and there's people who've made their careers studying how those things can be mismatched the other thing to really understand is that this is a highly processed image this was not just a photograph of your brain activity this is a highly refined image with many steps and statistical assumptions behind it there's a lack of standardization so that one last after my machine has a bunch of settings that aren't the same as another lab set for my machine so you can imagine if this gets into core its really been resisted in courts because you know 1:1 labs Ephrem I you know image can look very different from another ones of all the settings are different right it hasn't been standard in the same way that DNA analysis has been completely standardized from lab to lab and also some of the statistical assumptions have been shown to be faulty in fact it was a major paper this year that was incredibly disturbing Jeff from arrived researchers that showed that based on an obscure setting and the software of most fMRI software packages but up to 70% of the results might just be BS so it's still new technologies there'll be no 90s but it's still relatively new FM eyes is being used more and more in fact Sarah Felton Ewing will present I hope on her elegant studies showing forth I'm not going to tell her what she can but she's done very elegant work looking at adolescents engaging in therapy seeing what parts of their brain are active and using those F for my images to refine what kind of therapeutic interventions might be the most effective so different parts of the brain do different things that's how we get these colorful maps that you can see if you open up to any webpage another key principle brain areas are wired together right they talk they do these different things and they talk to each other they form these local circuits all right so this is a circuit that we've talked about it ready there is the amygdala this part of the limbic system that gets really excited over things that are scary the ventral striatum the part of the brain that gets excited over things like donuts and the orbitofrontal cortex it says hey maybe we should follow every impulse that we sense that we know that we might have and in fact we know what hooked what dr. Compton I think will talk about is how this circuit gets corrupted with as you develop a drug addiction when you look at the microscopic level of what these wires are composed of they're composed of brain cells so here's a high-resolution picture of a brain cell with a cell body a the wire which is called the axon and then the end of it which is called the axon terminal and so this is the basic computing unit of the brain and you know what's what's interesting about this is that this is a chemical electrical chemical system so the dendrite has the cell body has lots of extensions that sniff around the chemical environment looking for things that makes it excited chemical to make it excited if it gets excited it generates an electrical charge then gets sent down the axon in an electrical impulse at the other end it releases chemicals called neurotransmitters which then continues the brain communication that's why the brains are you can you can control brains with electrical you can put an electrode in someone's brain turn it on see weird things happen you can also give people of drugs right medication different kinds of chemicals and that will affect brain function let's big as it's affecting the the chemical environment which gets picked up by the neuron so make sense okay and this is a high-resolution view of what the end of one axon with the start of a new neuron so curious a - neuron circuit here's the axon the wire right and then connecting to the second neuron and this connection is called the synapse alright so I'm going to show you a high-resolution view of the synapse so the electrical impulse called the action potential comes down at the end it releases chemicals called neurotransmitters in this case of siedel choline those neurotransmitters diffuses across the synapse and bind to receptors so here's a receptor it binds to the receptor and what that binding does is open up the pore which allows electrically charged molecules to come in which can continue the electrical process here's an incredibly impressive example of brain wiring diagrams called die strasse as the name should all be aware of he is 100% guaranteed to win the Nobel Prize one of the things his lab invented was a method of making the brain clear so this is a mouse brain and he made it clear once you make it clearer you can fluorescently label brain cells and look at circuitry at a whole brain level so here's one of the really impressive videos from his lab we're showing you the mouse brain he's showing you how they're taking to dementia you know two-dimensional slices which is they're going to feed into a computer to construct a completely accurate three-dimensional model high resolution model you zoom in you can see this is the whole brain these are the axons you can see you know axons coursing back and forth and it's all in the computer so you can rotate you can make parts of it transparent so now the computer is reconstructing the three-dimensional model which is done you can then rotate and you can spend fly through the brain look at cellular level resolution I mean imagine this 100 years ago this is an incredible incredible technology carl dr. ah yeah the part of the brain called the hippocampus which is important for memory and again he's just slicing through these are cell bodies you can see these wires or the axons here he's labeled different sets of neurons with different colors you can then take each slice reconstructed with the computer and make a three-dimensional model and this is not an artist rendition this is an actual part of the brain with all the wiring intact okay in the heat and the human beings we can image this with diffusion tensor imaging diffusion tensor imaging allows us to see the wires in the brain does that because when you look at neurons they they have water in them and water tends to go up and down the axon DTI imaging looks at the movement of water molecules and from that you can infer where the connections in the brain are so we have these very high-resolution DTI imaging knobs of different these are all the different kind of wires in the brain and we get we get those wires by looking at where molecule molecules of water are going back and forth okay I'm going to just finish up with one last slide so I talked about the brain it does core evaluation you know the limbic systems looking out for things that helps you survive Donuts sexual partners spiders move away from move towards right and then the upper parts of the brain the cortex puts those cord valuations into context it's cognitive context saying well you know you eat your six donut and you didn't feel so good mostl context where you fill that in your body when you over binge on donuts before so it says maybe we shouldn't listen to the core evaluation so much and that's built up through past experiences so if you see a donut you know your eventual sorry amigos ding a ling ling ding a ling a ling so that creates that feeling of drive of mugging to move towards that doing it and I'm from Portland so that's why there's only donut for my talk we have fantastic donuts you know and that's you know it brings up facts and reasons donuts are good you know it's a tasty doing this of 8,000 calories it also brings up emotional context of these linkages of what happened and how you fell previous times you eat donuts these are all connected in the circuit right and then from the activity of those of the circuit we come up with a decision either Dhoni and if there are defects in your brain areas or their connections you're going to have impaired decision-making and a lot of what happens with drug addiction is that this circuit gets corrupted over time so you make worse and worse decisions I just want to make a shout outs forward this is the last slide so you know how do we change the cogs the way we think about things we'll generally with psychodynamic therapy with therapy kind of reframing what's something with the cognitive meaning of something is right how do we work on the emotional context well we have therapies like CBT which changed the kind of emotions we actually linked to a certain situation and Sarah might talk about her worker dog but she's fabulous worth looking at different brain areas that are activated by different kinds of therapy to guide what really what are the active ingredients of make therapy effective now you can control the you know the core evaluations of medications and with new techniques but I hope our other speakers will talk about Mary and firemen are going to just going to talk about medications and it might affect the activity of these of these levels maybe turning down the ventral striatum activity a little bit so you have less craving and Virginia cruising Karlsson accepting grant I hope we'll talk about just some fabulous research using dreads which are designer drugs that can activate receptors and just specific very specific neural circuits to turn them up or down so imagine there was a tiny little spot in the ventral spot right striatum that led to craving for cocaine imagine there was just one spot there imagine you can selectively turn down the activity of just at one spot and get rid of craving for cocaine that's the promise of that there of the kinds of approaches that these guys are trying to do we have a great day ahead of us thank you so much for being here and also the pleasure to talk to you guys you

Channel: LawNeuro.org

Views: 117,212

Rating: 4.9106555 out of 5

Keywords: Science & Technology, law and neuroscience, neurolaw

Id: SvBfAqk70LU

Length: 46min 49sec (2809 seconds)

Published: Thu Mar 16 2017