you'd welcome to contemporary science issues and innovations tonight we focus on language and the brain the acquisition and processing of language cognitive scientists study the uniquely human language phenomenon in many ways but in an unusual resource for such investigations is the rare ability to acquire dozens of languages the few people with that capability are known as hyper  expert is cognitive scientists a veteran go doctor federico ism sister professor at harvard medical school in mass general hospital and the director of the ev lab at mit recently she was featured in a new fourteen she joined the faculty at harvard medical school and g h her lab investigates the brain regions associated with both normal and impaired language processing and she uses an array of methods that will hear about tonight we are most fortunate to introduce dr elina fettering go welcome thank you very much effect to be here and i think to maybe start off we should get an idea of language just generally so one of the things that we see commonly now is language of dolphins and language of birds and so on is there a difference between what we mean by human language communication there is indeed all animal species communicate in some way so there's transfer of information but one thing that humans can do and arguably a lot of other species don't do to the same extent is being able to take a range of communicative signals we have like words and phrases and we combine them in new ways to make new complex meanings so i can share with you any arbitrary thought i have about the world and  most other animal communication systems the range of meanings that gets across is just much much more limited animal sophisticated animal communication forms have  syntax like you would have in human language so that's that's debated so syntax is basically a set of rules for how bits of communication signals combine  and there is certainly some structure in a lot of animal communications so two things that make human language very different is one the range of communication signals that we have so for example the number of words that we have which refer to all sorts of diverse concepts and this kind of ability to create almost an infinitude of new meanings  present whether different bits of meaning refer to distinct concepts and then get recombined into a complex meaning that we just don't know yet and it's really hard to study because it's hard to know what birds talk about well can report what they had for dinner talk about two weeks from now they're going to do which is very common with a lot of assume not yeah but a lot of that you know some animal researchers would just say look we just don't know presumably people learn these different types of languages could you remind us about these different types like case and sure yes so languages differ in many different ways so one fundamental distinction that so i should also i should start by saying that there are over six thousand languages around the world and a lot of them are very poorly studied and not at all studied by cognitive scientists a neuroscientist and there is some kind of linguistic descriptions of those languages but you know no empirical work trying to understand the processing of those languages so whatever we've learned comes from you know a handful of families and a handful of languages but even from that sample that we have been quite extensively studying we know that there is a big distinction between languages that use word order primarily to convey complex meanings so in english if i say mary kids john you know that it's mary that's doing the kissing and john and even if i say some implausible sentence like the pizza ate the boy and ice and i ask people what do you think it means they'll say well it's a crazy meaning but it means the people john it's  d the boy or something like that and other languages use a very different system to convey complex meanings and that is they mark the roles that the words play in an event in the words themselves so they would have something like mary actor mark or kissed john receiver mark or something like and having those markers allows those languages to move words around in any which way so for example  languages like russian my native language or other similar languages like finnish for example i can move words around very flexibly so yeah i can say merry kids john mary john kissed kiss john mary and i can languages use pitch and process international conference right so my pitch goes up and down as i talk to a convey different aspects of meaning so i can say i went to the store or i can say i went to the store right and those are different meanings but languages like chinese also use pitch to differentiate word meanings so the classic example is ma which with a particular told means mother with another tone it means horse and then there's two other version of that and so that's also something that you know as a kid learning that language you have to learn that bridge and that language can distinguish meanings which is you know similar to how sounds can distinguish meaning in say english is just a different feature of the stick signal but they could make it just quite difficult for people to learn after that optimal agent and so on then so we have those different types of languages and we come back with that and then in terms of language acquisition there are many cases where for whatever reason children have not learned at the optimal time the brain changes as it matures what there has been a rich topic of study for many years and it does seem that there is a certain age after which some aspects of language are especially hard and those tend to be accent learn a language late in life you tend to have an accent in a foreign language and interestingly other aspects of language learning seem to go just fine if you learn a language later for example learning new words so rather be unaffected in general it seems like the earlier a child gets exposed to a language the easier it is for them to learn this mapping between because language is effectively a mapping between a set of communicative signals and meanings right through to learn how words map onto a particular concepts in the world and we learn how combinations of words map onto some complex meanings and that seems to be easiest to learn when you're little and yes can we go to the language areas of the brain and for things like accent does is is there anything about the maturing of the brain that process that affects your ability so people many different things when they talk about language so language involve two directions of communication right there is comprehension so as i'm talking you're understanding what i'm saying and right now i'm producing language so at the very broad level production is taking a thought in my head and converting it into a linguistic code a code which somebody else can understand and in comprehension you're taking a linguistic signal and then you're trying to extract presumably the intended thought from it sometimes this fails but most of the time it works and that's why we can communicate successfully and so this conversion between thoughts and linguistic utterances is what i have mostly focused on and that's shown kind of in the red box and that's what i refer just kind of high level aspects of language but then there's a lot of kind of helper mechanisms right so before we start inter breeding linguistic signals we have machinery in our speech cortices auditory mechanisms the deal with just processing of the speech signal so those areas in the brain for example don't care if you're listening to your native language or a foreign language they respond just as strongly so they care about the features but then once you're able to interpret the signal a something meaningful then these higher order areas will kick in which i'll show you in just a little bit and similarly in individuals who have acquired written language and literacy they have they developed parts of their visual cortex that now specialize for processing letters that's very clear to you that there's a difference yes yes so eleven way in which this specialized visual region has been important isn't showing that you can develop these highly specialized bits of the brain as a function of experience right so oftentimes people say oh if we have something in your brain that is specialized for a particular function it must be innate and that's just not true at all we now see very clearly that there is these regions which are highly specific they respond to letters but not to letters in a script that you don't know and clearly those we have learned when we were learning to read and need to distinguish between these little black things that all look really similar you know different very important ways and we can use them to convey linguistic messages as well so that's on the side of perception and then on the side of production we can output language through our ticket leaders so there is but i think the most exciting part of language is this ability to convert complex abstract thoughts into this code that we can share with one another and that arguably has laid the foundation of human culture an ability to teach each other skills and transfer knowledge over generations and so that's what i mostly focus on here i'm showing you a set of regions that are active when we produce and understand language and so these are the what i refer to as high level language features so these are the regions that translate between thoughts before that can you just tell us which side of the brain is sorry so here i'm showing a projection of language activation so this is from a whole large number of participants from two hundred and twenty participants that we've scanned on a language homologs of those regions which is also quite poorly understood but it's there with the reason that we know that these the left hemisphere region so more important is that when you have damage to your left hemisphere you're more likely to end up with language ok and so that's where the actually being so there's your pretty left hemisphere so does that i mean that's right so so these are basically regions that are active so the contrasts that you can use to find these regions are contrasts between meaningful and structured language and some control condition which is matched perceptually but doesn't have meaning or structure so you can for example contrast people listening to a story in their native language versus to a story in an unfamiliar language and right where they're getting a lot of the same similar perceptual input but they just can't map it on to any representation so meaning and so does that mean that if they the if i listen to you in russian and if i don't the same areas get activated by say music you know so that's a very good question there's been a lot of debate and come to science for many years about the extent to which other forms of complex thought cognitive complex munda processing cher's machinery with language so there's a lot of there's a long philosophical tradition where people have argued that basically language laid the whole fall foundation for a lot of complex thought including things like arithmetic and logic and maybe the ability for complex hierarchical planning of action sequences and a lot of things like that and people have also noted parallels between say language and music as you mention because music is also complex hierarch language especially sperling because to understand what the language mechanisms do it's really important understand how selectively they engage in processing language was another kind of similar life because the kinds of computations that go on would be very different if a region brain region performs a process as both language and music compared to if it processes just language and non music so those are little fundamentally distinct theoretical construe alls and so on and o mechanisms are shared between cognitive process and so we can say take a language task find reagents in your brain that respond during that language task and then ask do the very same regions respond when you listen to seems like all of the other forms of complex thought go on elsewhere in the brain now there's a little bit of a cabinet such that we don't know whether language may be important in the development of those capacities and to do those kinds of experiments you would want access to kids who didn't get linguistic input unfortunately that right right right right right right but down in an adult brain it seems like the mechanism the process language do not process other complex  's do not engage in other forms of complex thought and it's very consistent now with also evidence from very severe aphasia ok so there as you know many people have heard of aphasia as basically referring to general going to language problems that occur in adulthood after stroke damage or head trauma or something like that and a very interesting case of aphasia from the point of view of cognitive scientists it's a very devastating condition but basically lose all of their mappings between thoughts and language and as of a few years ago a lot of people beam and they would argue that that would leave you unable to engage in any form of complex thought and that just turns out  so those individuals are perfectly fine doing math and reasoning about how there is mind and engaging in solving logic problem it seems like the only thing they lose is this code this ability to transfer thoughts into a code that we can share with one and ok that enough but that's that's been on like the books for a long time these were these things are very specifically organized in the brain so that's quite good to know since you brought up the aphasia issue it seems as though that's been an area that has been particularly rich in showing some of the specific areas of the brain anyway tell us about it would you that the some of the i don't know which kinds you look at which articulation to a spending plan of the whole range of possible problems the evidence that we've had from aphasia over you know the many years and that's kind of the evidence that started the whole field of cognitive science from  and beyond what methods like f m r i can tell us those methods can tell us whether something is causally important right so if i damage your brain region and following that damage you are unable to perform a certain function it says ok this region was really fundamental these things so there is many forms of aphasia and there is no i would say in the field of psychology so the field of come to signs that focuses on patient evidence i don't think there is clear agreement right now about classically referred to as broca's aphasia in though it's not clear whether damage to broca's area as it is a guy i say it is right right right but symptomatically the problem is that they show is that they can't seem to out put language ok they can understand things just fine you can talk to them you can you know pro there are comprehension you can do tasks which have comprehension and they'll be pretty much fine understanding almost all of language but they have a hell of a time getting language out ok and it's really frustrating yes illit dating it often is accompanied by depression because it's really difficult when you can't express yourself is there a sort of parallel between most of this go through you can't recall a name you can't recall the term for something and then it comes to you at three o'clock in the morning or something like that but you can almost tell how many syllables maybe what it starts with is that similar to what we're talking about here costly each bit of information they each bit of signal they produce they have to pay for it this is really really difficult and so if you if you may have maybe have heard the term telegraph expedient it's exactly referring to that analogy such that when you only have a little bit of signal that you can output your resort to producing this kind of not you know it's language like i would put it but it's not full language right you're reducing words you're compressing you're getting rid of all of the function words you're you know maybe manipulating order in a way that i making things at least possible to convey something you don't do these when you with that kind of an impairment to people sort of know what they want to say but of the other common type of patients is patients with comprehension problems so there they basically it seems like they can't extract information from the linguistic signal and they can output speech just fine in access to words but they seem to have lost the relationship between words and meanings ok you can't make that linkage that ok all right so there are areas sort of specific for these capabilities and that is it's so that i guess more rare as you as you go along but you stumbled on this for you burner tell us about that was that yes oh so this this topic was  the topic of in general language expertise has been of interest to me ever since i started looking at languages disorders in some way i say because it's kind of the extreme case right so languages orders lead to some difficulties with some aspects of  language and maybe we're going to send something about how the system is broken by also looking at people who are really really good at some of that language and what it means to be a language expert can be defined in many different ways right some people have vast mcabee larrys some people are really really articulate and don't make speech errors when they speak and are really you know compelling and conveying ideas or something like that but one form of expertise is this seeming ability to acquire many many forms of more but instead they're in these societies where there's one dominant language and somehow they get interested in where launching a website in the near future that will advertise to the polyglot communities once  it's up where we're trying to just get basic information on what drives people to do this seems like there's quite a lot of variability and why people get started on this kind of as a as a not hobby or they start learning a language and that just really easy for them and they're like ok i'll try another one some people seem to want to read literature in other languages and that's kind of what he rates them to try to learn all these different languages but there's no real systematic review as of yet but  write that we will have enough information soon to to do that but yes and so so the questions were interesting as you know are these people different somehow from the typical popular their brains different their processing mechanisms different of course it's like what when you say this you have to keep in mind that there is a range of professions i understand i understand older people have such vast now they'll have you know and sometimes quite a few languages at which they're really quite proficient but then there is a long tail of language where they learn something would not be able to kind of fully converse with a native speaker so for starters what we were interested in looking at is just the basic properties of the language architecture so remember i mentioned that  the way that we find the language system is we contrast the processing of structured and meaningful sentences or short stories to kind of perceptually match but meaningless information like for example more and language and so we've now collected that contrast on a very large number off typical individual so we have in our database we have over seven hundred participants and so i was interested whether relative to that distribution of people the language regions of hyper don't activate the same language system to the same extent and this is really interesting li parallel to what we've known about efficient processing and motor learning so there's  been a few studies over the last couple decades showing that when people learn a new complex motor task they activate large chunks of their motor cortex and as they get better and better and better that deviations kind of showing less energy  something but it seems like that's not the case and at least so far based on the you know the sample we have which is like twenty people it seems like they don't have to work their regions language regions quite as much that is really interesting thought so and another interesting thing is that it's not the case that they just have reduced activations for anything so we had also a control task which was a demanding working memory task where you had to remember a set of locations and for that task it looks very similar between  change that yes so that's that's interesting and there's you know there's many other questions that we're asking so we all so i asked looked at the processing of different languages and solid lots like different types of  generally find that there is kind of a drop off as people become less and less proficiency so to me this suggests that basically the activity in this language system indexes kind of how much meaning you can extract from the signal and so for example i don't know if you like a little bit of spanish maybe or something so if i talk to us in spanish maybe you would activate your language system a little bit less than english but  still a lot more than for example for russian which you may not know at all there is a level of expertise in the number of languages so they're not necessarily equal proficiency all the way through but  i'm not sure if it's easier for me to learn these languages i work very hard to learn i enjoy it i'm going to write this but it's not it's not you know i and then there's other polyglots who say yeah i find that it's kind of fun and no effort at all i just get this information and i can just easily pick it up and again so this is something that we're hoping to study using these behavioral surveys so if you know as many polyglots as we can access it's possibly correlated also with how people learn language and there are some learn from books or test looks like like i would st learn from a foreign foreign textbook and there's others who just go out to a market place and just start strike conversations with people who speak a different language and try to figure maybe they have a really good social skill such that they can leverage that in some way to extract some meaning and then eventually you know build off of that or something like that but again like i would like to be able to say that you know forty percent of all prefer learning this way and you know we just don't know yet that's good and another thing is just on that is that there might be a difference in the type of language like everyday language has a vocabulary this big and then reading language is much different the structure everything is much different so in that may work in there also but in our remaining time i would like to ask about your methods and you've mentioned f m r i a lot and so on but then we can also take just pictures of static anatomy and say you know how big is your inferior frontal gyrus or let's look at your bundles right and for a for looking at the wire bundles there's different kinds of sequel that we use but we can write that so you have a tumor in their liver and i can also look at two years of this so it's a versatile tool and we use it in different ways to look at for example brain anatomy versus brain function sometimes trying to lay those to each other but are different aspects of brain anatomy like you know thing that it's really lacking is being able to track the processing information really fast so it measures the signal that is related to blood flow changes yet when your particular brain region works cell speier and then they get depleted in oxygen and glucose and new oxygenated blood has to come in and bring new supplies to that area and that's the signal that we measure those changes and that takes a few seconds so if i show you a sentence it'll take about six seconds in the language regions to see an increase in whereas in the course we understand language on much faster i understand and so for questions where we're interested in when something happens as we're processing different kinds of information become available or become process and another method that's kind of becoming really really invaluable to cognitive science is intracranial recordings so every now and then patients with epilepsy would need to undergo surgery for resection i can and so while and basically what usually happens is that they have the st surgery and then they get implanted with some grids right on their brain ok sometimes there's also death recordings from certain things that are not accessible from the surface but a common thing is to put a grid right on the your brain right and and then you typically wait for the next seizure to happen to figure out where the epileptic genic cortex is so that you yeah it's great that this can happen and it's actually amazing how much of the brain you can cut out without it without problems but anyway while there i'm kind of in the hospital for a few days waiting for that next seizure you can come and kindly ask them to read some sentences or listen to music or do whatever task and then we can get very precise temporal and spatial information yes and that's just that's been and it's very precious data there's not many patients who undergo these difficult yes no question of yeah because we have no animal models so like with started this conversation right there is some aspects of language like the basic motor control of articulators or basically basic perception of the speech signal that you just there's so many many things that we don't understand i am interested in also how language which is evolutionarily quite a late invention yeah how it interacts with other systems that have been there for you know zero phylogenetically much longer  properties such that they tend to be in the left hemisphere yeah exactly and so we're currently trying to understand whether there is a relationship between for example how letter allies languages and people versus how letter allies math and