How the Brain Learns to Read - Prof. Stanislas Dehaene

[Music] hello my name is Stanislas danan I am a French cognitive neuroscientist I study the brain and today I would like to tell you about uh our research on how the brain learns to read and why it is pertinent for Education um my uh laboratory situated uh just south of Paris Specializes in uh viewing the brain through various means and I think you are aware now that we have a growing panoply of brain Imaging methods which include functional magnetic resonance imaging as well as electrography and Magneto craphy to track the Dynamics of brain activity um

you may not be aware that these techniques are now available also to study education and to study the child's brain is entirely feasible these days with training with a mock scanner and welcoming of children inside that scanner to have excellent images of the child's brain as it is learning uh even to do repeated scannings and these children are extremely happy uh to come to the lab and participate in this research all they need to be told is that they are like astronauts inside this spaceship and that uh in uh not moving which is very important

for us uh they contribute to science but also contribute to the spaceship not moving um so uh with this we can study how education changes the brain I would like to mention in this slide what I think brain science can bring to education uh I it's a very simple point I think it's a shame that teachers know more about the workings of their car than they know about the working of the brain of their children um and I mean it I think if you want to change a system you have to understand how it works

what are the rules of operation and um I believe that empowering teachers with the appropriate knowledge of the principles of brain plasticity and education will lead to better classroom practices there's a lot we know already in cognitive Neuroscience which is relevant the competencies of the young child for vision language numbers many others how Learning Works the role of attention the role of reward the role of sleep the importance of sleep for consolidation of learning the transfer from explicit to implicit knowledge many other topics are relevant I also think that cognitive science can help measure um

progresses in education and experimentation is absolutely essential in order to test education protocols and to quantify their effects on behavior and on the brain and finally I believe also that cognitive neurosciences can participate in development of teaching devices such as school curricular manuals or software I'll give an example of that at the end so today I want to talk specifically about the topic of reading and what we understand about it from the brain's point of view if you had not learned to read any page of text would look to you like this Stone a texture

but no meaning but because you've learned to read you can have a conversation with the deceased you can speak to the dead you can listen to the Dead with your eyes because you can read what they wrote 2,000 years ago you can communicate thoughts to the Mind through the eye which is the great invention of the world according to link so how does that work well this is a picture of your left hemisphere the left hemisphere of the brain is most essential for language and reading and um just to orient you this is the back

of the brain this is the front of the brain it's been slightly inflated so you can see inside uh the folds and now I want to show you the activation of the brain as you read one word we see it in time so let me start this here we go and you have the word unfolding from the back of the brain to the front of the brain uh it will Loop several times you can see the information enters into the occipital pole which is the visual side of the brain moves into the vental areas and

then explodes into the left hemisphere uh distributed activity I have no time of course to explain to you all of the details of this brain activity but I want to show you a sort of caricature that you can remember and this very simply that reading starts as any other visual stimulation in these generic visual areas of the the occipital pole of the brain but then very quickly moves into an area that we have discovered which concentrates the recognition of the written word I have called it the brain's letter box because it is where we store

our knowledge of letters and from there what you have seen is this explosion of activity into at least two networks one that concerns the meaning of the words and another that concerns the pronunciation and the articulation of the word and so we can say essentially from the brain's point of view that learning to read consists first in recognizing the letters uh and how they combine into written words and second connecting them to this systems coding for speech sounds and for meaning and what is rather remarkable is that all of the areas in Orange and in

green here already exist for spoken language they are shared between spoken language and written language so uh not only that but they already exist in a young child um we can image the brain of young babies even when they are extremely young few months of age we have various message for that and when we have them listen to language we already see these network of regions which exist also in the adult brain and that process spoken language so we may say that reading is not creating something completely novel reading consist essentially in connecting uh creating

an interface between vision and and the language system the spoken language system when the child comes to uh the reading school it already has a very sophisticated spoken language system it already has a very sophisticated visual system but it needs to create this interface this visual word form area this brain's letter box and to connect it appropriately and in doing so it needs also to change some of these Target systems how does this work exactly we've conducted a large number of studies and many other labs in the world have conducted many studies that look at

what has been changed in the brain of children or adults after they've learned to read and uh in particular I want to mention here a study that we did very recently which was published in the journal science where thanks to a large International collaboration we uh were able to scan illiterate and literate subjects of various level of literacy in Brazil as well as in Portugal bringing them to our lab in France um thanks to this experiment we managed to make a complete map of the areas that have been change by learning to read and as

all of you in this room know how to read you can consider that your brain has been dramatically changed um so I've told you about these areas for language the first major change that we see in the literate brain is this letter box area coming active only in people who have learned to read it will activate in direct proportion to the read reading score and it will activate to the letters that you know it will not activate for instance to Chinese if you don't know Chinese so it has learned the shapes of the letters it

is accompanied by Major change in the visual cortex in in your early visual areas which is generic and serves for all sorts of visual tasks you have changed the Precision of the coding in your visual cortex because you've learned to read but most importantly you have also changed your representation of speech sounds if you've learned an alphabetic language you have changed the way your cortex codes the phes of speech the Elementary uh components of speech and learning to read is to a large extent the capacity to attend to the individual fims of speech and to

attribute them different letters when we see this map of course we could think that the connection between these areas must must also be changed and I'm happy to say that with new methods for identifying the connections of the human brain we can also track these changes we can see even in a living person all of these fiber tracks that connect if your own brain areas we can see the micro structure and what we see is that indeed this particular connection uh bundle which exist in all brains is reinforced and is being changed in people who

have learned to read and there is a good likelihood that this bundle is involved in connecting the letters to the sounds bidirectionally when you hear a sound you can also think about his letters um this change is subtle but it is an anatomical change so the anatomy of the brain is also changed because uh children learn to read we make these essential changes that of course create a whole new modality of input of language um there are lots of things we've understood about the details of this process I want to give you a few the

first thing is what does this area do before we learn to read uh it's of course not an area that has involved for reading so it must be doing something else and what we have found is that this region reacts also to faces and to objects it is involved in visual recognition in all species actually in all primates at least and what we find is that as you learn to read so this is reading score on the x-axis here what you can see is that the response to strings of letters increases in this area but

the response to other categories decreases so there is a sort of competition in the brain of the reader and the new function of reading has to find some space in the cortex making room as it were and what we find also is that the representation of faces is therefore displaced to the right hemisphere words compete with faces in the reader's brain it's not a massive computation but it is a sort of reorganization which takes place when children learn to read um thanks to this understanding we can also uh explain puzzles of reading acquisition and um

one puzzle which we have been able to explain from the brain's point of view is something you might have seen in your children which is this notion of mirror reading and writing many children when they sign their drawings will write their names uh in the improper direction from right to left in this case um here is another example of a child who has written theodoro Ben okay and the child is writing left to right right to left alternating in the writing system which is called bedon which means how the ox flows this was the way

of writing in ancient Greece but of course children don't know about ancient Greece at that age so how are they capable of doing these things and many parents thinks is this dyslexia well we understand now what it is it is not dyslexia what it is is a trace of this old function of the system which is trying to learn to read we all have all primates have a symmetry mechanism which allows you to notice that these two faces are the same person even though on your retina they are completely different pictures but they are mirror

images of each other and this is an evolved system that we have to unlearn as we learn to read because it is not useful and we have to distinguish these things as two different words or potential words uh we have found indeed that the primary area which has the most sensitivity to this symmetry is precisely the area that I've called the brain's letter box which is trying to learn to read so essentially it's not a wonder that children have difficulties with mural reading and writing U this has nothing to do with dyslexia it is a

universal difficulty for all children that they have to overcome and we might teach them explicitly by the gestures of writing to help them to overcome their difficulty another thing that we understand a little bit better now is this very classical question of phonics versus whole word training uh you know there's been a lot of debate in Psychology and in education should we teach the whole word level or should we really teach every uh single letter and their pronunciation um is there anything such as the global shape of the word which is being used in Reading

well um here there is something very important as adults we have forgotten how we were as children we have forgotten how difficult it was to learn to read and we think that we can just lay our eyes on a word and it immediately Pops to mind and indeed there is this notion of parallel reading we read all of the letters at the same time this gives us an illusion of whole word reading but in fact if we look at the brain the brain still processes every single letter and does not look at the whole shape

so whole word reading is a mess basically all what we have is letter processing but letter processing in parallel across all the all of the letters of the word the brain does not use the global work shape um and in fact in children it's even worse children require more and more time for more and more letters you can see this on this graph this is the number of letters in a word the reaction time of the children and in first grade they're very very slow and they need more and more time for each letter so

this is not at whole whole word reading it's slow serial one letter at a time and as children progress second grade third grade this goes away and give this illusion of whole world reading so I think we can be very clear on this point because there is a strong convergence with educational research to suggest that the brain has nothing to do with this sort of exercises that my child had of picking up the Ascender and descender letters and deciding that this corresponds to this word the global shape is not used few words of conclusion through

slides of conclusion I think neurosciences can help education um we understand now a lot about reading and we understand that in all cultures there is not so much variability we always have the same brain mechanisms reading always requires specializing the visual system for the shape of letters and connecting them to speech sounds even in Chinese by the way there are no letters but there are characters and some of them map statistically to the sound Teaching Letter to sound correspondences is therefore essential it's one of the main Pathways which is being transformed in the Brain Brain

Research converges with educational research teaching of letter to sound correspondences is the fastest way to acquire reading and comprehension not just you know uh being able to decode the words um how does this work because it works because there is a form of self-teaching once the correspondences are learned um children have this correspondence between letters and sounds then they can recognize the words auditorally using their auditory lexicon and then this more direct route between letters and meaning can be trained it can be self trained as the child reads by himself even without a teach teach

so uh this notion of two routes of reading play a very essential role in all contemporary models of the reading process cognitive Neuroscience can also lead to new software tools and in very briefly I want to mention that our colleagues from Finland have been developing over many years now uh this graphogame sophisticated software which is just looks like a game to Children where you have to select letters based on the sound that you hear and many training games of this sort and they have shown that just a few hours of training uh with this little

game suffices for preschool children to already begin to develop these visual word form system that I've been talking about so um with efficient tools that attract the child's attention and reward them for what they can do uh we get very quick changes in these plastic brains at this young age um I want to mention that this notion of re neuronal recycling the idea that some are are sufficiently plastic that we can shift their function slightly which is what occur during reading is a sort of General principle we all are like this caricature of Darwin we

are humans but we are also primates and as primates we inherit constraints on our brain uh our learning is constraints by the representations that we inherit from Evolution which concern not just language but also number space time and um teachers must take into account this early child's knowledge because if we understand what they have to displac in the child brain we can teach better um I want to mention that this is relevant to reading but also I think very strongly to mathematics we begin to understand that our brain the human brain just like uh other

monkeys is organized to understand concepts of the external work such as number and the same brain areas that are concerned with number in the monkey and in the human brain and on this basis we can begin to understand what is the foundation of intuition of number sense that uh develops later into a full system of arithmetic and so on the very same principle of this notion that there are old brain systems that need to be recycled we can propose an understanding beginning of an understanding of the development of arithmetic and I want to mention that

this is just uh culminating now in my lab in the development of software tools that are based on cognitive principles and that can help children develop a better sense of number and this number catcher software is just available today it's called the number cater.com and it's a new software that's freely available in order to help children develop their intuitions of number U finally I want to finish by saying that you can read about these topics uh in more detail I realize that 20 minutes is not sufficient to convey all of these ideas uh but uh

primarily now I think we can have a short discussion thank you very much for your attention so we we can take uh brief questions for a few minutes uh if you would please stand up and uh also mention who you are ah yes wait for the microphone sorry could we have a microphone for this gentlemen do you no no microphone okay speak up and I I may repeat the question maybe I have question excellent question maybe I I'll answer this one first uh so the question was can uh adult people or even old people learn

to read uh the the finding is that indeed the brain remains plastic maybe not quite as plastic as in young children but still plastic and we have especially studied people who were illiterate and then learned to read when they were adults we found the same brain changes by and large there were a few brain changes that were missing but most of them were present including this circuit I showed you today so people can learn when they're adults they're probably just a little bit slower I didn't say the same speed but can yes oh there is

a microphone that channeling of information from visual to analysis Etc is it a chemical reaction or is it neurologic what is it is it a chemical no it is a uh neurological transformation of information uh we believe that each brain area is uh Computing extracting some specific aspect of information so first you start with essentially local features in the image maybe a little stroke here and there then uh the brain extracts the presence of letters combinations of letters and finally it extracts the sound patterns in these other areas or the meaning patterns and the connections

essentially transmit this information from one stage to the next Can medicine can chemicals that we create accelerate this process or make it less can we learn faster with some medicine in the future that is a wonderful and difficult question at the moment there is no uh real proven smart drugs but they are effects for instance of attention uh I rather believe especially in the context of this education conference that we should modify the brain's inner chemical systems and they are inner chemical systems that help you focus your attention U and are sensitive also to reward

so when you give the child a reward you are changing its brain chemical composition in a way which reinforces the behavior makes the child happy of course sleep is a very essential component of this learning algorithm and I should mention that there are beautiful studies showing that giving children more sleep is one way to help them learn so uh in many cases especially in cases of attention disorders we can help children by giving them more sleep do we have time for perhaps another question Madame can we have the microphone oh oh you already have the

microphone so then we'll we'll take you second okay yes uh my question is about dyslexia uh I'm not dyslexic myself but there are dyslexic people in my family and Having learned in the French system I learn the letters cursive in writing and uh printed in reading and I have I'm a very bad speller but I'm left-handed and I'm very Visual and now that I use a computer I see my mistakes MH when I type I see them because I but they are printed but when I curse when I when I do cursives I don't see

them so uh I'm maybe I'm just revealing something to you that will help you in your research but did you uh research about um dyslexia yes there is a lot of research about dyslexia um and we understand now that it it is in to some extent we can see anomalies in the very circuits that I showed you today especially we think that the connection system of the brain may be abnormal in DST exia so maybe these connections are missing or in not sufficient number we also know that uh the setup of the brain quite early

on maybe even during pregnancy is not quite right in some of these areas not Dramatical so it can be compensated and I would like to mention since you mention cursive writing that this is something extremely important in teaching there is very beautiful research contrasting children who have been taught with or without cursive writing cursive writing is good for the brain it adds another circuit which has to do with recognizing the gestures of writing and it helps children learn to read uh this is very well demonstrated now perhaps perhaps because it helps break this symmetry that

I was talking about p's and q's become very different when you write them we don't exactly know the mechanism we backward children still write backward when they do cursive I mean yes but it helps them to write in the proper direction and as in for instance the montory system you can prepare children to learn to read preparation exercises include writing or just making drawings from left to right if you are in a left to right right system um making curves and also training exercises for phonics which are very well demonstrated so preschool should also be

preparing children for learning to read and phonics exercises can help a lot what about the left handed right-handed uh as opposed to using the right side of your brain well I think maybe we should give a chance to of another person maybe to ask a question but did you have a question or someone here yes you did yeah there are many questions so we have to decide maybe you have where are we oh uh yes I don't need to control anything about the questions go ahead okay uh I ask you about the um do the

environmental uh factors and cultural factors affect the way that children learn language or uh all uh all are the same all children all over the world are the same to learn uh that's a very nice question uh we think that the brain mechanisms are very Universal uh children have the same basic layout of the brain circuits but you mentioned culture and the environment and this is an essential component uh children the predictors of uh learning to read in young children are how well they are in phonics this understanding of the sound systems of language and

also what is the size of their vocabulary spoken vocabulary if they know a large number of words they will learn to read faster so these again these are cultural factors that can be improved and for instance they are very simple things but parents from low socioeconomic families sometimes need to be told that they need to speak to their children that they must have this systematic inter action which will enrich the children's language system and prepare them for reading so I think we can help reading way in advance even if we keep reading at the age

of six or seven preparing children to learn to read at the age of three four five by enhancing their vocabulary and their sound system of language yeah thank you uh now can you bring the mic microphone thank you we have a few more minutes so maybe a short question it's GNA be a very short question hi my name is Diana and I'm working with a company that makes online games to teach children Arabic so my question is are there any specific practices that we need to avoid in a game so that we don't not divert

the brain from developing the right areas for reading ah very good point um I you point to the fact that we need to have children concentrate and I think actually games are very good for that even children who are said to have attention disorders when they are gaming they tend to be very concentrated but it is very important that we have them concentrate on the right level of representation and I have been arguing that the level of the letters and how they correspond to sounds is an essential level um I am worried indeed that part

of the problem with the whole word reading approach is that children are not attending to the appropriate level of letters they're trying to treat the whole word as if it was a face something that you could recognize globally like this um so I think it is important to have children concentrate on the L level first and then they can concentrate on the message later um I also think that it's important to avoid too much distruction so in the software but as well in the manuals when you have reading manuals that are full of pictures thousands

of items on the page this creates trouble especially for children with attention deficits so maybe we have time for one or two more questions uh Denise Conway from Seda over here where are you okay um yeah I just wanted to ask you about the role of parents or some literate person who uh reads to the child little uh story books before they have um an interest actually in in the words per se but Focus in on pictures and and then creating a love of or an interest in learning and then a motivation to understand that

there are letters and words that actually apply to some meaning in in the actual story book and my second question is around is there an age that is actually too early in which uh to try and get your child to learn uh to read MH so for motivation we know it's a important multiplier of learning in the brain you can think of the brain as having learning rules but the intensity of learning will be multiplied by factors such as attention concentration motivation and reward um so I would I would think that yes uh we already

know that the brains learning algorithm is very sensitive to uh the level of concentration of the child um now for your uh second question this is something that I've researched a little bit and I've not found much evidence to suggest that there is a critical age for learning to read as I was answering earlier even adults can learn to read and uh they do so with the same brain systems they might be a little bit slower we don't really know um because the learning experience of course is completely different when you're an adult so it's

very difficult to compare quantitatively in the other direction should children learn to read at the age of five or four there are some examples of this happening spontaneously in many families and as far as we can see it's not damaging and it's again teaching the same circuits um so I think the answer from science is just we don't know you know sometimes scientists has to be very modest and just say we don't know um I I really think that uh from what we know it there may be no damage at all being done by learning

to read earlier uh but at the same time I'm very sensitive to the idea that young children must be in these very creative years active um you know moving uh creating playing with mathematical objects or games so there's a lot more than reading and maybe reading can wait until the age of six or seven in the previous session it was mentioned that Switzerland tends to teach his children to read later and as far as we can see it's just as fine right there are many many questions we have one minute left so I think we

have time for one question uh whoever has the microphone always always close to it go ahead can you stand up and say who you are hi my name is z I'm from Pakistan I just want to know that there is a debate on language in education especially for the children who are from grade 1 to grade three that we suggest that the mother tongue should be the language of instructions with the other languages do you have any uh can you suggest us what how many languages a child can learn till gr like year 8 or

10 uh thank you um first of all I want to say that the speed of learning um is not something so easy to determine because it varies depending on the language and there there's beautiful research showing that Italian for instance can be learned in three months because it's a completely regular system every letter corresponds to a sound English is probably the world's worst alphabetic language I'm sorry to say that's the one we choose um because there are many irregularities and it is known that children will need two more years to achieve the same level as

in Italian or in other regular languages so but typically even in English after three years of training in grade three uh children should be readers and there is no reason for a pedagogy not to achieve success in Reading in one year for regular languages I was in Brazil recently and they say that they wanted to have training to read in three years and I kept telling them no in your language should be three months or maybe six months or one year but not more um at that age you can learn to read in other languages

which was your original question languages will combine into the same areas and we don't exactly know what's happening in bilinguals for the moment but we see no cost there seem to be rather savings when you have already learned one language you can read a second one faster thank you very much for your questions and your [Applause] attention