Dehaene
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Stanislas Dehaene holds the chair of Experimental Cognitive Psychology at the Collège de France, and he is also the director of the INSERM-CEA Cognitive Neuroimaging Unit at NeuroSpin, France’s most advanced neuroimaging research center. He is best known for his research into the brain basis of numbers, popularized in his book, “The Number Sense.” In his new book, “Reading in the Brain,” he describes his quest to understand an astounding feat that most of us take for granted: translating marks on a page (or a screen) into language. He answered questions recently from Mind Matters editor Gareth Cook.
COOK: How did you become interested in the neuroscience of reading?
DEHAENE: One of my long-time interests concerns how the human brain is changed by education and culture. Learning to read seems to be one of the more important changes that we impose to our children's brain. The impact that it has on us is tantalizing. It raises very fundamental issues of how the brain and culture interact.
As I started to do experimental research in this domain, using the different tools at my disposal (from behavior to patients, fMRI, event-related potentials, and even intracranial electrodes), I was struck that we always found the same areas involved in the reading process. I began to wonder how it was even possible that our brain could adapt to reading, given it obviously never evolved for that purpose. The search for an answer resulted in this book. And, in the end, reading forces us to propose a very different view of the relationship between culture and the brain.
COOK: What is this “new relationship”?
DEHAENE: A classical, although often implicit, view in social science is that the human brain, unlike that of other animals, is a learning machine which can adapt to essentially any novel cultural task, however complex. We humans would be liberated from our past instincts and free to invent entirely new cultural forms.
What I am proposing is that the human brain is a much more constrained organ than we think, and that it places strong limits on the range of possible cultural forms. Essentially, the brain did not evolve for culture, but culture evolved to be learnable by the brain. Through its cultural inventions, humanity constantly searched for specific niches in the brain, wherever there is a space of plasticity that can be exploited to “recycle” a brain area and put it to a novel use. Reading, mathematics, tool use, music, religious systems -- all might be viewed as instances of cortical recycling.
Of course, this view of culture as a constrained “lego” game isn't that novel. It is deeply related to the structuralist view of anthropology, as exemplified by Claude Levi-Strauss and Dan Sperber. What I am proposing is that the universal structures that recur across cultures are, in fact, ultimately traceable to specific brain systems.
In the case of reading, the shapes of our writing systems have evolved towards a progressive simplification while remaining compatible with the visual coding scheme that is present in all primate brains. A fascinating discovery, made by the American researcher Marc Changizi, is that all of the world's writing systems use the same set of basic shapes, and that these shapes are already a part of the visual system in all primates, because they are also useful for coding natural visual scenes. The monkey brain already contains neurons that preferentially respond to an “alphabet” of shapes including T, L, Y. We merely “recycle” these shapes (and the corresponding part of cortex) and turn them into a cultural code for language.
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19 Comments
Add CommentI read the post and wonder how neither culture nor disease has left an imprint on the organisation brain structures use to operate. I always thought that the brain's hemispheres held some sway, I.E. left handed or Asian's reading right to left.
Reply | Report Abuse | Link to thisI don't pretend to know what makes us tick or whether perfoming tasks a certain way cause neurons to form like excercising builds muscle but do tend to believe that physiology differs from textbook examples. As much as I'd like to believe that brain function follows rules, there is too much to disuade me from accepting that what makes us creative has no variance.
Perhaps the rules are imbedded in stem cells at the onset of life. Life, by it's own virtue, has a tendancy to be different!
Does it mean, the languages we are speaking today were predestined long long ago, since the particular part of cortex formed in the brain?
Reply | Report Abuse | Link to thisAnd again, does it mean that we can predict the general frame or outlook of the novel things that would come in the future by studying the structure of the brain?
Essentially, the brain did not evolve for culture, but culture evolved to be learnable by the brain. I can not actually catch the meaning of the sentence ,especially after reading the later sentences. The Human brain is gradually evolving with the environment , also including the culture, the brain and culture are all evolving in the progress of the interaction.
Reply | Report Abuse | Link to thisWhenever I see the words "evolve for" or "evolved to be", loud alarm bells start ringing in my prefrontal cortex.
Reply | Report Abuse | Link to thisThere is nothing purposeful about evolution. It is a remorseless process of pure chance. Those that survived, bred. Those that died before they bread died out.
We seem to have evolved biologically or culturally to believe that everything must have a purpose. Is this so and if so, why, I wonder?
Shakespeare got it right again! He lets Polonius interview Hamlet : What are you reading? "Words, words, words" is the reply. But evolution has the last say when it comes to explaining human habits, it seems: We automatically try to put a "meaning" to all our observations, because our brains still "collect & classify" words just like fruits - which were - and still are- our original food sources. So - to my mind -our search for meaning derives from a "fruitful purpose"- literally! Vide: Youthevity.com for an"evolutionary diet" concept
Reply | Report Abuse | Link to this"Theory, experiments on brain circuitry for reading, and education research all currently point to the superiority of grapheme-phoneme teaching methods. "
Reply | Report Abuse | Link to thisHowever, this should not be construed to mean that we should neglect the importance of reading in context by exposure to good books. Since the advent of No Child Left Behind, the education world has taken phonics instruction to an extreme level, to the point where many kindergarten and first grade teachers no longer have time to simply read to children. The goal of reading is no longer to derive meaning and enjoyment from books, but to pass a series of benchmark evaluations that may or may not be appropriate for an individual child's age/development level.
Many people don'tunderstand that Whole Language, when properly used, does indeed include phonics. It's a good system that was horribly misused for many years.
Reading instruction needs to include phonics AND good literature.
When students learn a new skill area, such as reading or the complexities of standard grammar, they seem to develop a new "organ" in the mind that handles that function. This organ operates below the level of consciousness -- e.g., automatically deciphering letters or matching subjects with verbs.
Reply | Report Abuse | Link to thisThe result is that good education changes students. Strangely, many college students today seem to resist being educated at the depth that changes them. Perhaps defensively, some try to maintain their current identity while merely tacking on additional skills, without realizing that those skills will transform them into subtly different persons -- the way reading transforms how a part of the mind works, or how writing causes us to see the world in terms of what can be written about, perhaps to the neglect of those things that are difficult to depict through writing.
So, in teaching kids to read, it may be crucial to continue to cultivate their non-verbal competencies, so that verbalizing does not colonize their minds to the exclusion of other modalities. Whole language, in my experience, was good in this respect.
Some visual learners seem to resist reading and writing, perhaps out of fear that the richness of their inner visual experience will be taken over by words. (Google "The Writing Problems of Visual Thinkers.")
I tried to find more about Marc Changizi's evidence of limited, shared letter/glyph shapes, no success, but read his idea that letters are shaped as they are for ease of reading, to the eye, rather than ease of writing, to the hand. Though at the same time Changizi notes that letters universally have 3 or fewer marks in them. Anyway, this question of the shapes of letters seems central, and I wonder what shapes are not used by any languages of the world. What would these shapes look like? Maybe a coiling line shape would be absurd to incorporate, but are there any simple letter shapes that we simply overlook and never use?
Reply | Report Abuse | Link to thisWriting is truly an amazing bridge between the visual senses and the analytic, grammatical, phonological system we associate with spoken communication. The lexical aspect of language is just the same- individual words can express "things", and in arrangements they can express the most complex abstractions. It's as though we're using various signals in our brains, and jumping back and forth between, say, imagining a "tree" and puzzling out the sentences of Kierkegard. In ptolemaic writing and hieroglyphs the graphemes are used for magical effect on walls, etc. to ward off evil, for blessings, etc. Have we permanently "evolved" from using pictoghraphs for written words?
I would also question how all reading in all languages uses the same part of the brain. ? How about the blind and braille?How about the deaf and sign language? Or is that not reading...
There is plenty of evidence suggesting activation of the occipital cortex in blind individuals performing tactile discrimination tasks (i.e., Braille reading). Interpretationally, there seems to be at least a pair of hypotheses to explain visual cortical activation during these tasks: long-term learning of Braille reading and sensory deafferentation. The latter appears to stand on more solid empirical grounds - Braille-naive blind subjects show increased occipital cortical activation in tactile discrimination tasks than sighted controls.
Reply | Report Abuse | Link to thisWhat could perhaps be seen as a behavioral correlate to altered cortical plasticity compensatory of loss of vision is an increased acuity of spacial resolution, which is relatively location-specific. So for instance, Braille-trained blind subjects (and, I would imagine, more so in those with more or earlier training) show greater spacial resolution capacity at the fingertips than controls.
I wonder if brain areas activated by auditory stimuli would show compensatory activation in response to visual input in deaf people. This http://www.snl-b.salk.edu/pdf/Finney-natureneuro01.pdf could be illuminating.
See also Van Boven et al.,2000; Sadato et al., 2004.
There is plenty of evidence suggesting activation of the occipital cortex in blind individuals performing tactile discrimination tasks (i.e., Braille reading). Interpretationally, there seems to be at least a pair of hypotheses to explain visual cortical activation during these tasks: long-term learning of Braille reading and sensory deafferentation. The latter appears to stand on more solid empirical grounds - Braille-naive blind subjects show increased occipital cortical activation in tactile discrimination tasks than sighted controls.
Reply | Report Abuse | Link to thisWhat could perhaps be seen as a behavioral correlate to altered cortical plasticity compensatory of loss of vision is an increased acuity of spacial resolution, which is relatively location-specific. So for instance, Braille-trained blind subjects (and, I would imagine, more so in those with more or earlier training) show greater spacial resolution capacity at the fingertips than controls.
I wonder if brain areas activated by auditory stimuli would show compensatory activation in response to visual input in deaf people. This http://www.snl-b.salk.edu/pdf/Finney-natureneuro01.pdf could be illuminating.
See also Van Boven et al.,2000; Sadato et al., 2004.
Heh. And Kant's so-called "Copernican Revolution" is rediscovered. Again.
Reply | Report Abuse | Link to this"Hitherto it has been assumed that all our knowledge must conform to objects. But all attempts to extend our knowledge of objects by establishing something in regard to them a priori, by means of concepts, have, on this assumption, ended in failure. We must therefore make trial whether we may not have more success in the tasks of metaphysics, if we suppose that objects must conform to our knowledge."
Do differnent parts of the brain light up when we read on paper versus when we read on screens? This needs to be studied with MRI scans etc.
Reply | Report Abuse | Link to this"As Deheane and
Reply | Report Abuse | Link to thisothers have demonstrated, the brain is much more than the seat of the
soul -- it's also the fleshy source of our culture. By studying the
wet stuff inside our head, we can begin to understand why this
sentence has this structure, and why this letter, this one right here,
has its shape." says Jonah Lehrer in his review elsewhere. Yes! We need to study the wet stuff inside our heads with MRi scans and scholarly research to determine the differences between reading on paper surfaces and reading on screens, both the pro and the con, and to see if in fact different parts of the brain light up for retention and analysis and critical observation when we read on paper versus when we "read" on screens, which in my POV is not really reading. Scholars, go to it! Report back to us soon!
In such a case, I believe we need a new word for reading on screens, some call it screen-reading, others call it screening. It is a very different mental and emotional process from reading words on a paper surface, and future MRI scans research will show this to be true. Let the studies begin. I wrote to Dr D in Paris about by email at his lab, so he knows what I am doing too. I believe that reading on screens is INFERIOR to reading on paper, in terms of retention, processing, digesting, analysis and the use of critical thinking skills. Future studies will show this to be true, I believe. Research is already under way. It is not so much do you like reading on Kindles or nooks or iPhones, gadgetwise, what is important is HOW we read on paper vs HOW we read on screens, and I am sure there is a vast difference, and that reading on screens, while useful and convenient and cool and trendy, should not cause the disapperance of books and newspapers and magazines on paper print surfaces. We need both.
Reply | Report Abuse | Link to thisThis may be a ridiculous question. If all human writing systems are based on the same basic shapes due to the coding scheme of the primate brain, would that mean that if we were ever to encounter a truly alien writing system no human would be able to learn it?
Reply | Report Abuse | Link to thiswtpossum, thank you for your comments. I was thinking along similar lines for some of your questions. For example, I am thinking certain languages do not use letters, such as Chinese. Granted, written languages may utilize similar shapes as Dehaene noted, but are there certain shapes not used.
Reply | Report Abuse | Link to thisI also had the question of braille and whether the brain remembers the shapes in similar manners or if it would be very different.
Regarding sign language, I'm thinking that may be more picture-graph. I believe English written language is still taught at deaf schools.
I am not sure I can find this reference, but I remember reading that deaf readers "subvocalize" with their fingers, and is located in the same area of the brain that processing sounds is located, showing that the "organ of speech" is mutable. The piece of phonological processing we associate with reading writing systems is expressed through the fingers....even logosyllabic languages like Mandarin have a phonological component. That, too, may be a universal.
Reply | Report Abuse | Link to thisWe appear to be able to read words at a glance without being aware of each letter. But can a person read phrases at a glance without being aware of individual words?
Reply | Report Abuse | Link to thisI created an internet application, www.readspeeder.com, which divides text into its 'natural' phrases. It seems to me that by using this tool, the reader can indeed take in whole phrases at a single glance. The concept of the phrase seems to be immediately visualized without the reader actually being aware of each word.
I've noticed that comprehension also seems to be easier when reading by phrases. I think this is because a single word is just a symbol, whereas a phrase is a complete thought or idea. When I use readspeeder, the thoughts seem to be lifted right off the page into my mind. This is especially true when I manually advance to each phrase as soon as I grasp the current one.
I've also found that with practice, this habit of reading by phrases seems to carry over to reading printed text.
So I'm not sure. Is it really possible to read whole phrases at a glance, or does it just appear that way?
I wholly agree with your comment, jocwjocw. Evolution doesn't tolerate infinitives (e.g., "evolve TO ANALYZE"; "evolve TO READ"; etc...). I bet you'd like my blog, Modern Hermeneut: www.modern-hermeneut.blogspot.com
Reply | Report Abuse | Link to thisI'm writing about evolution right now and the punchline is essentially the same point as the one in your comment.