Saturday, March 1, 2014

The paradox of the Visual Word Form Area


 
Luke the Evangelist (source: British Library). In the past, only a minority could read long texts of cursive writing. But many more could read short texts of block writing.
 

The Visual Word Form Area (VWFA) is a specialized part of the brain that helps us recognize written words and letters. If it is subjected to a surgical lesion, the patient will suffer a clear impairment to reading ability but not to recognition of objects, names, or faces or to general language abilities. There will be some improvement over the next six months, but reading will still take twice as long as it had before surgery (Gaillard et al, 2006).

Most of the initial skepticism over the existence of the VWFA has disappeared. There does seem to be, however, much variability in its size. An area that may fall within this mental organ in one person may fall outside it in someone else (Glezer and Riesenhuber, 2013).

In addition to word recognition, the VWFA may participate in higher-level processing of word meaning:

[It seems that] the VWFA would not only be recruited at an early stage for allowing low-level (script processing) word processing as has been previously instantiated (Pammer et al., 2004; Dehaene and Cohen, 2011), but also at a later stage for gating high-level (lexico-semantic) processing. Such late semantic gateway would not be selective to the VWFA but rather emerge in the posterior LOT and extend anteriorly to the VWFA. (Levy et al., 2013)

The VWFA is described in the above study as a “bottleneck to consciousness.” It helps us not only to recognize words on a page but also to understand what the words mean. To me, this makes sense. I’m better at thinking through an idea and its implications if I can write it down and then read it. There thus seems to be a single mental pathway that does double duty: processing character strings (words) and processing higher-level concepts.

 
Population differences 

The VWFA functions differently in different human populations. The difference is striking between people who use alphabetical script, where each symbol represents a sound, and those who use logographic script, where each symbol represents an idea. Chinese subjects process their idea-based symbols with assistance from other brain regions, whereas Westerners process their sound-based symbols only in the VWFA (Liu et al., 2008). Similarly, dyslexics activate this brain region in ways that differ by linguistic background, apparently because of differences in spelling and writing (Paulesu et al., 2001).


Hardwired or softwired?

For Dehaene and Cohen (2011), the VWFA is not a hardwired mental organ. They argue that it occupies the same area of the brain because that is where we can most easily recruit neurons when learning to recognize words. But why, then, does this recruitment happen so fast in young children? When kindergarten children were asked to play a grapheme/phoneme correspondence game, their VWFAs preferentially responded to pictures of letter strings after a total of 3.6 hours over an 8-week period. It is worth noting that only a few of these children could actually read, and even then only at a rudimentary level (Brem et al., 2010; Dehaene et al., 2010).

But the alternative view, hardwiring, is also hard to accept. Reading began not in the Paleolithic but in historic times, less than 6,000 years ago. Widespread literacy is even more recent, and there are still many societies where most people cannot read or write. How could an entirely new mental organ have evolved over so short a time?

Yet this alternative view may not be so farfetched. Let’s examine the two main objections.


Was there not enough time for natural selection to work?

The VWFA did not evolve out of nothing. It seems to be a population of neurons that originally served to recognize faces (Dehaene and Cohen, 2011). This sort of recycling is a common pathway for natural selection and explains much of the apparent rapidity of evolution. A complex mental adaptation may take a long time to evolve, but much less time is needed to develop an exaggerated version of it or to alter when and how it becomes activated (Harpending and Cochran, 2002).

Indeed, parallel to the way alphabetical reading ability has spread historically and geographically, there is a similar spread of the latest variant of ASPM, a gene implicated in the regulation of brain growth. In humans, a new variant arose about 6,000 years ago in the Middle East. It eventually became more prevalent in the Middle East (37-52% incidence) and Europe (38-50%) than in East Asia (0-25%) (Frost, 2011; Mekel-Bobrov et al., 2005). 


Would it have benefited too few people to have been favored by natural selection?

There is some debate over the relative recentness of literacy. It is true that before the modern era only a small minority could read long texts of cursive writing. But the ability to read short texts of block writing was much more widespread, as evidenced by the prevalence of graffiti and storefront signs. We should also keep in mind that the literate few contributed disproportionately to the gene pool of subsequent generations. Clark (2007) has shown that the English lower class is largely descended from people who were middle or upper class a few centuries ago. In the ancient world, there was a perception that scribes enjoyed reproductive success. The Book of Sirach [39: 11] states: “If [a scribe] lives long, he will leave a name greater than a thousand.” 


Gene-culture co-evolution?

There may have been positive feedback between reading ability and the cultural opportunities it created. One example is the scientific revolution in Western Europe (15th - 18th centuries), which took off once a critical mass of scholars could read each other’s papers. In short, reading and writing are advantageous to the extent that other people can read and write. While this kind of feedback loop is self-evident, its biological implications may be less so. The same feedback loop would have steadily ratcheted up selection for the VWFA and, subsequently, for higher-level faculties. This might explain why the VWFA evolved beyond word recognition per se and towards lexico-semantic tasks.


Future research

One priority would be to study the VWFA in populations that have become literate only in recent times. What form, if any, does it take in such people? A study in New York elementary schools found that VWFA activation varied with socioeconomic status. In students from high SES families, activation seemed to be more hardwired and less dependent on familiarity with the way sounds are visually represented. Unfortunately, there was no attempt to break the data down by ethnic background (Noble et al., 2006).

At present, high VWFA activation is attributed to an environment where reading material is accessible and parents very supportive, this being in turn attributed to high SES. Yet reading material is ubiquitous nowadays. And how crucial is parental support? As a child, I read almost always on my own with little encouragement at home or school. My teachers were in fact annoyed by my habit of sneaking into the small storage room where old textbooks and encyclopedias were kept (we had no library). “If you’ve finished your assignment, stay at your desk. Is that clear?!”

Nonetheless, I read voraciously, even when I couldn’t understand half of what I read. Strange new words were a source of pleasure, and I would often read and reread the same texts simply because I liked the flow of the words and the images they conjured up.
 

References 

Brem, S., S. Bach, K. Kucian, T.K. Guttorm, E. Martin, H. Lyytinen, D. Brandeis, and U. Richardson. (2010). Brain sensitivity to print emerges when children learn letter-speech sound correspondences, Proceedings of the National Academy of Sciences U.S.A., 107, 7939–7944.
http://psyserv06.psy.sbg.ac.at:5916/fetch/PDF/20395549.pdf

Clark, G. (2007). A Farewell to Alms. A Brief Economic History of the World, Princeton University Press, Princeton and Oxford.

Dehaene, S. and L. Cohen. (2011). The unique role of the visual word form area in reading, Trends in Cognitive Sciences, 15, 254-262.
http://www.cnbc.pitt.edu/~plaut/VisCog/papers/DehaeneCohen11TICS.VWFA.pdf  

Dehaene, S. et al. (2010). How learning to read changes the cortical networks for vision and language, Science, 330, 1359–1364.
http://gondabrain.ls.biu.ac.il/Neuroling/courses/877/Dehaene_Science2010.pdf

Frost, P. (2011). Human nature or human natures? Futures, 43, 740-748.
http://dx.doi.org/10.1016/j.futures.2011.05.017  

Gaillard, R., Naccache, L., P. Pinel, S. Clémenceau, E. Volle, D. Hasboun, S. Dupont, M. Baulac, S. Dehaene, C. Adam, and L. Cohen. (2006). Direct intracranial, fMRI, and lesion evidence for the causal role of left inferotemporal cortex in reading, Neuron, 50, 191-204.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.76.7620&rep=rep1&type=pdf

 
Glezer, L.S. and M. Riesenhuber. (2013). Individual variability in location impacts orthographic selectivity in the “Visual Word Form Area”, The Journal of Neuroscience, 33(27), 11221–11226.
http://www.jneurosci.org/content/33/27/11221.full  

Harpending, H., and G. Cochran. (2002). In our genes, Proceedings of the National Academy of Sciences USA, 99(1), 10-12.
http://www.wcas.northwestern.edu/nescan/2008-2009%20papers/harpending%20-%20in%20our%20genes.pdf  

Levy, J., J.R Vidal, R. Oostenveld, I. FitzPatrick, J-F. Démonet, and P. Fries. (2013). Alpha-band suppression in the Visual Word Form Area as a functional bottleneck to consciousness, NeuroImage,78C, 33-45.
http://hal.inria.fr/docs/00/81/96/67/PDF/Levy_et_al.pdf  

Liu, C., W-T. Zhang, Y-Y Tang, X-Q. Mai, H-C. Chen, T. Tardif, and Y-J. Luo. (2008). The visual word form area: evidence from an fMRI study of implicit processing of Chinese characters, NeuroImage, 40, 1350-1361.
http://psychbrain.bnu.edu.cn/teachcms/res_base/teachcms/upload/channel/file/2010_4/11_25/6hlcggx7rk3z.pdf  
Mekel-Bobrov, N., S.L. Gilbert, P.D. Evans, E.J. Vallender, J.R. Anderson, R.R. Hudson, S.A. Tishkoff, and B.T. Lahn. (2005). Ongoing adaptive evolution of ASPM, a brain size determinant in Homo sapiens, Science, 309, 1720-1722.
http://ftp.eebweb.arizona.edu/faculty/nachman/Archived%20Research%20Papers/mekel_bobrov_et_al_2005.pdf  

Noble, K.G., M.E. Wolmetz, L.G. Ochs, M.J. Farah, and B.D. McCandliss. (2006). Brain–behavior relationships in reading acquisition are modulated by socioeconomic factors, Developmental Science, 9, 642–654.
http://www.cumc.columbia.edu/dept/sergievsky/fs/publications/Noble-et-al-2006-2.pdf  

Paulesu E., J.F. Démonet, F. Fazio, E. McCrory, V. Chanoine, N. Brunswick et al (2001). Dyslexia: cultural diversity and biological unity, Science, 291, 2165–2167.
http://www.drru-research.org/data/resources/42/Paulesu-et-al-2001.pdf

28 comments:

Anonymous said...

My step-father used to read trashy westerns, but he used to read.

However, there was little encouragement for us to read, except that he bought, for some strange reason, an encyclopedia. I devoured it.

Sean said...

It seems to me that this post has a bearing on the Whole Language method of teaching reading, which is an educational method developed by a historically selected-for-literacy population, ie the WASPS of Columbia Teachers College. No doubt the continuing failure of children from certain groups to read properly, despite using the method favoured by progressives, will entrench the liberal tradition in their belief an ineffable discriminatory miasma is to blame. Expect ever more intense efforts to achieve the only kind of integration that eliminates the achievement gap: genetic.

"One example is the scientific revolution in Western Europe (15th - 18th centuries)"

Germany was the first country where substantial regions had universal literacy. Processing of higher-level concepts in Germany has been in advance of other countries, German philosophy is an obvious example. Germany is using wind turbines to replace nuclear weapons (the ability to build nuclear weapons). They are lost in a prison of words.

Historically, Russian has been illiterate and backward. Russia gave assurances to Ukraine if it got rid of its nukes, Russia would not attack, and Ukrainians under the influence of the US and Britain's (as well as alcohol obviously) promising to defend then, ignored Mearshiemer's warning.

Selection for reading ability leads to creatity, and then murmurations of reifying intellectuals.

Sean said...

It is well established that the 'whole word' method of teaching reading works well for high SES families, a hardwired VWFA would explain that. Which suggests reading should be taught differently for certain groups. Sadly, literate creativity has long since overheated among western Europeans. Our society is in the hands of an intellectual murmuration, and they are not going to break formation.

Anonymous said...

The difference is striking between people who use alphabetical script, where each symbol represents a sound, and those who use logographic script, where each symbol represents an idea. Chinese subjects process their idea-based symbols with assistance from other brain regions, whereas Westerners process their sound-based symbols only in the VWFA (Liu et al., 2008).

Chinese and Japanese are the only extant logographic scripts. Japanese uses a mix of logographic script and syllabaries. The rest of the world uses alphabetic scripts. Korean uses an alphabet although it's designed to appear like logographic script by grouping syllables into blocks.

Is this difference in processing due to the scripts themselves or due to differences in processing writing in general between Chinese and Westerners?

Reader said...

There are languages where the spelling of words is wildly unpredictable, with bizarre variations and silent letters: English, of course, but also French is a well-known culprit, as well as Dutch.

I've always wondered whether the speakers of these non-phonetic, highly "flexible" languages possess some kind of unique traits or brain mechanisms, in contrast to speakers of more phonetic languages.

The reason I say this is that the non-phonetic languages tend to be clustered in Western Europe. But as you go East, toward Germany and the Slavic countries (as well as Hungary, Greece, etc.), all the way to Russia, the languages become extremely phonetic. For instance, in the Slavic languages (whether Roman- or Cyrillic-based, doesn't matter), it's very rare to find unusual or non-standard spelling. 99.9% of the time words are written exactly as they're pronounced.

Moreover, another thing that the Eastern-European languages will do is alter the spelling of foreign words to fit their standard. In Polish, "Clinton" will be spelled "Klinton" and "Bush" will be spelled "Busz." Can you imagine anyone in the West changing the spelling of proper names originally written in the Roman alphabet? Doesn't happen, ever. It's as if Westerners know that they can't assume anything about pronunciation, and are highly flexible and prepared to accept different ideas.

Reader said...

To add to my comment above, another remarkable thing that happens as you go from West to East in Europe is the grammar of languages grows in complexity.

I have no idea why all the Western-European languages have lost their "cases" (declension) while all the Eastern-European ones still retain it. German, which sits right in the middle between East and West, proves this rule: it keeps 4 "cases," which is much fewer than anything to the East, but still totally bewildering to speakers of any Western-European language.

Anonymous said...

I have no idea why all the Western-European languages have lost their "cases" (declension) while all the Eastern-European ones still retain it. German, which sits right in the middle between East and West, proves this rule: it keeps 4 "cases," which is much fewer than anything to the East, but still totally bewildering to speakers of any Western-European language.

The Western European languages are less inflected now. English especially. They rely more on prepositions and word order than inflection now.

Anonymous said...

Eastern European languages are more phonetic, because the spelling has been codified many centuries after french / english. So the time for split due to sound changes has been limited.

Additionally most of the languages had major spelling reforms in XIX and XXth centuries.

http://en.wikipedia.org/wiki/Reforms_of_Russian_orthography

panjoomby said...

Stanislas Dehaene shows we hijack the VWFA from an area previously used for facial recognition - wonder if nonliterate folks have better facial recognition? literate folks seem to have enough of it. he uses the term "neuronal recycling" where i said "hijack":) he discusses "mirror invariance" - b/c that part of the brain ID'd faces, initially it doesn't notice b & d are different - some brains take longer to notice b/p/d/q/9 are different (viz., the brains of dyslexics).

Anonymous said...

Is there something similar going on with math? Math also appears in historic times with the rise of reading and writing.

Is the VWFA or something similar also involved in processing math?

Lots of people say how their eyes glaze over and how they feel uncomfortable or dizzy or even get headaches when they see a page of math. Similar to how they feel when they look at a page of a foreign script they can't read. And these aren't illiterate or non intellectual people but often people who are highly literate in their native script.

Numbers and math symbols are logograms, and thus a form of writing, so perhaps there is something similar going on.

Peter Fros_ said...

Anon,

My mother would sometimes read from the Bible to me, but she was indifferent to the sort of stuff I preferred to read (comic books and, later, books on astronomy, prehistory, etc.).

Sean,

There have always been useful idiots among the chattering classes, but I don't think the real problem is there. The real problem is the increasingly predatory nature of modern capitalism and the shift to a shorter time horizon for profit making.

Anon,

Both. People have evolved different ways of processing these scripts apparently because different forms of mental processing are required.

Reader and others,

It's partly because English and French spelling were codified at an earlier date. English and French spelling thus tend to reflect older forms of pronunication that have ceased to exist. For example, we used to pronounce the 'gh' in the word 'night'. Now, we no longer pronounce it.

Another reason is resistance to spelling reform. Spanish spelling was codified at an early date, but there have been successive reforms to bring spelling into line with changes in pronunciation. This has happened much less in Great Britain and France.

Panjoomby,

Richard Russell might be better at answering that question. In theory, face recognition should decrease to the extent that face-recognition neurons are assigned to other uses.

Anon,

I was wondering myself. Where in the brain do we process numbers?

Magistra Mundi said...

My teachers were in fact annoyed by my habit of sneaking into the small storage room where old textbooks and encyclopedias were kept (we had no library). “If you’ve finished your assignment, stay at your desk. Is that clear?!”

Intelligent children should have intelligent teachers. And too often they don't.

I wonder on the VWFA and language in general if they have some ancient link with the ability to track an animal. Tracks are meaningful and generally linear and can be broken into smaller units (e.g. a pawprint corresponding to a word or morpheme). Tracking is like following a narrative. So did it precede or co-evolve with language?

Anonymous said...

I'm really dubious about hard wiring. There are a lot of people in the world today who have few if any literate ancestors, and I would think it would be extremely obvious if such people were significantly handicapped when it comes to reading. For example, Polynesians children who went to missionary schools. Did they have an exceptionally hard time learning to read? Do native English speaking pure blooded Hawaiians today have any particular difficulty with reading. Not that I've ever heard.

Contrast this with intelligence. There has been a lot of comment about differences in intelligence between various peoples over the years. Such comments are politically unfashionable now days, and efforts are made to suppress them, yet they still get made, because people notice these differences first hand. If there had ever been any real differences between peoples' native abilities in such a low level skill as reading, don't you think it would have been noticed and commented upon at some point?

panjoomby said...

@ anonymous: correct, tho the brain is not hard wired to read, reading has high heritability. b/c some brains are more advantageously pre-set in such a way that they acquire reading more readily. (brains with greater auditory memory & more connections back to the VWFA for quicker retrieval). it's a trade off. e.g., some brains are preset (via heredity) to have better spatial at the expense of difficulty learning to read. in the past we probably selected for spatial (those with that skill kept us alive), but now we find that the pattern we selected for has some weaknesses that interfere with reading. one can't have everything:) PS - thank you for the richard russell tip!

Sean said...

There are reading differences by ethnicity, an initial step in the process of learning to read is hard wired, and thus look-say is easy for WASPs, very difficult for people descended from non literate ancestors. This was known in the 19th century. Overview of History of Reading education in the United States. It's the most literate sector that spawned the liberal tradition (Deweyite progressives of yesteryear) The liberal tradition will never accept children may best be taught differently, according to ethnicity. They see that as 'irrational'.

Arthur Jenson said that teachers refused to believe him about IQ because they had seen black children start at a new school, and learn to put the correct name to hundreds of faces in a very short time. Germany was the first country to have universal literacy in a substantial region. 2.5% of people in Germany have face blindness

Sean said...

If historically widespread literacy in Germany is the reason for its society being advanced in every way, the reason for 500 years of technological and commercial backwardness in Russia (mainly illiterate a century ago) becomes clear.

Germany is getting rid of all nuclear power and weapon potential, replaced with windmills. It has become the mulch cow of the EC; just shows where genetic pacification and literacy end up.

Ben10 said...

Well, anyways, those are things of the past.
'They' have dropped cursive out of the Elementary public school system in Texas. My 10 years old had her first taste of cursive last year at the end of her 3rd grade, for one or two weeks, not enough anyways to feel familiar with it.
So she can't read it very well and can't write it...
I guess it's an excuse so 'They' could re-write the Constitution of the United States in a more friendly 'Texting' form...LOL.
To fight the decrease in fluency in Elementary, kids now have to log in their reading time, signed by their parents (mine Kid cheats all the time on her Time, but dad's no fool)
Reading cursive is eh... so totally not cool.
'They' also dropped Algebra-II from High School. Too demanding for 'some' dudes, so 'They' wanted a curriculum a bit more compliant with race-gap reducing policies.
229 68522648

Sean said...

In China they have boarding kindergartens for the elite's children. There was a BBC WS program about it. An Australian woman who worked there as a teacher said she'd protested that the kids (as young as 3 years old) got up at 7 am, and were still having English lessons at 9pm.

Ben10 said...

Sean: don't they risk a burn out? learning saturation?
On the other hand, that's not much more than the time spent by kids on video games, if left on their own.

About this topic, Merovingian cursive is one of the more elaborate early cursive among medieval cursive. It's not that surprising that only people with special visual recognition abilities could read it. And the weird thing is that at the same time, medieval paintings and drawings show a lack of visual perspective and 3d-feeling in general (everything look flat and out of proportion in the paintings).

Sean said...

Border collie puppies training at 8 weeks old, The real working bloodline Border collies do not make good pets I'm told, they get neurotic unless they are kept busy. I suppose kids from very high achieving backgrounds may be be something like that.

"School children may not be made to neglect (their studies) even for the building of the Temple" Shabbat 119b

The Ashkenazim regarding illiteracy with horror was not terribly significant in the evolution of that community's superior intelligence, or so we are led to believe. Yet participating in business required literacy from women, some of who were supporting their full-time scholar husband. See here

Peter Fros_ said...

Magistra,

To be honest, I don't feel I ever learned much from formal schooling.

The VWFA seems to have developed out of neurons that originally were used to recognize faces. I suspect that people with little or no VWFA end up using face-recognition neurons.

Anon,

Almost anyone can learn to read, but reading speed varies considerably among people. And the main problem isn't word comprehension. It seems to be the ability to process character strings. I used to do literacy volunteer work, and I remember people who fully understood the words on the page but who nonetheless had trouble processing them mentally.

Panjoomby, Sean,

Yes, there are trade-offs, and this is a major reason why people have trouble believing that most mental traits have a heritable basis. They see someone who does terrible academically, and yet he talks and acts normally. They then see someone who is great at school and yet he talks and acts like someone who is mildly retarded.

Ben,

Schooling is definitely being dumbed down. I'm surprised when I read elementary school textbooks from the late 19th and early 20th centuries.





Anonymous said...

Is there something similar going on with math? Math also appears in historic times with the rise of reading and writing.

A lot of our records of Babylonian writing come from clay tablets used by apprentice scribes. On these tablets they often had Sumerian or Akkadian vocabulary on one side and math tables and problems on the other. The scribes were trained and proficient in math as well as writing.

It's also been said that math ability is associated more with verbal IQ than spatial ability.

Anonymous said...

In Polish, "Clinton" will be spelled "Klinton"

Surely, that should be "Klingon"!

BTW, Both English and Chinese are regarded as analytic languages, as far as I am aware.

Anonymous said...

There are a lot of people in the world today who have few if any literate ancestors, and I would think it would be extremely obvious if such people were significantly handicapped when it comes to reading. For example, Polynesians children who went to missionary schools. Did they have an exceptionally hard time learning to read? Do native English speaking pure blooded Hawaiians today have any particular difficulty with reading. Not that I've ever heard.

I have been involved a small amount with helping Hispanic kids develop literacy. It didn't help much. They do not tend to have books in their houses nor do they read much for pleasure, probably because reading is not pleasurable to them. It is hard work.

My step-father was not a highly educated man and was a simple mechanic, yet he read lots of stuff. Of course, a lot of it was Louis Lamour Westerns, but those things were on the order of 50,000 to 100,000 words. He would read the whole thing in a couple of days or so.

Now, we can measure just how well they read by how many books those populations write. To write well takes a lot of reading beforehand.

Got any stats on how many books those populations have written?

Anonymous said...

"as well as...Greece, etc"

No, in contemporary Greek ει, οι, ι, η, and υ are the same sound. You might have had a point around 2k years ago, though.

Anonymous said...

Magistra

"I wonder on the VWFA and language in general if they have some ancient link with the ability to track an animal."

I wouldn't know about that but it made me wonder about early script symbols.

http://images.cpcache.com/merchandise/514_400x400_NoPeel.jpg?region=name:FrontCenter,id:9674884,w:16

Anonymous said...

I wonder on the VWFA and language in general if they have some ancient link with the ability to track an animal. Tracks are meaningful and generally linear and can be broken into smaller units (e.g. a pawprint corresponding to a word or morpheme). Tracking is like following a narrative. So did it precede or co-evolve with language?

Interesting point. In traditional Chinese legend, a man invented Chinese writing after seeing and being inspired by a hoof print:

https://en.wikipedia.org/wiki/Cangjie

More generally, the earliest writing was derived from pictures, and the earliest pictures drawn by man consist of animals.

haa said...

The visual word form area gets activated by reading practice. The ancients did not have printing, so long texts were beyond their reach. They probably all read at beginning grade 1, and scribes may have gotten to grade 2. So block and cursive print are a function of practice. A gene may have something to do with it, but there is a simpler explanation.