Ilha do Desterro: A Journal of English Language, Literatures in English and Cultural Studies E-ISSN: 2175-8026 [email protected] Universidade Federal de Santa Catarina Brasil

Achy Almeida, Fabiana Vanessa; Marchese Winfield, Claudia Dehaene, Stanislas. Reading in the Brain. USA: Penguin group, 2010. Ilha do Desterro: A Journal of English Language, Literatures in English and Cultural Studies, núm. 63, julio-diciembre, 2012, pp. 215-233 Universidade Federal de Santa Catarina Florianópolis, Brasil

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REVIEWS/RESENHAS of cognitive neuroscience with a particular interest in language and number processing, and he is the http://dx.doi.org/10.5007/2175- author of several books on the topic, 8026.2012n63p215 such as “The number sense”. he is a Dehaene, Stanislas. Reading in the professor of Experimental Cognitive Brain. USA: Penguin group, 2010. Psychology at the Collège de France, and the director of the Cognitive by Fabiana Vanessa Achy Almeida, neuroimaging Unit in Saclay, and Claudia Marchese Winfield France. Universidade Federal de Santa Catarina Reading in the brain works at different levels; including up-to- The art of reading has fascinated date scientific information, and researchers from different fields reviews of significant studies in the of interest as it is considered a field of neuroscience and cognitive paramount aspect of human psychology, expressing them in development. now not only language that is not too specialized, researchers, but lay readers may and also with suggestions for further benefit from a contemporary and well- readings. dehaene includes useful informed publication on cognitive illustrations, examples, explanations neuropsychology, Reading in the and interesting metaphors that brain, by Stanislas dehaene. The capture complex processes in easier basic premise of the book lies on the to read language. Unfortunately, the assumption that cerebral plasticity illustrations in this issue are in black yields an adaptive process of our and white, although the author neuronal circuits to operationalize sometimes refers to colored parts cultural and educational inventions in them. as a whole, these textual such as reading and writing, which strategies make the book accessible are characteristic of the society we to a wide readership. belong to. nevertheless, dehaene does not Stanislas dehaene is a well- minimize the complexity of reading, established researcher in the field which he accurately depicts as

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cognitive activity involving several that compare our brain to a tabula subprocesses, of a vastly parallel rasa, which would be shaped nature, which interact as reading by environment, culture and takes place in the human brain. The experience. In fact, according to author points out that neuroscience research findings the author argues research has offered findings that brain architecture is similar from brain imaging enabling the across human beings regardless of identification of the brain areas their culture. In response to those involved in reading, although still views, Dehaene proposes a theory controversial. These findings, in of neurocortical interactions, in turn, have helped to establish a new other words, the neuronal recycling theory of reading, whose main claim hypothesis. rests on the notion that neuronal networks in the human brain are Although the author also considers “recycled for reading”. According how literacy has affected the brain, to Dehaene, this new theory can he claims that evolution works cause a dramatic change to our on a random path, therefore the understanding of the human brain, plasticity view of the brain as its involvement in reading and other being constructed by our previous complex cognitive activities. experiences and environment is seen as too simplistic. Actually, Moreover, he states that the author states that the period in neuroscientific data offerwhich human beings have been able contributions to pedagogy and to read and have developed reading pedagogical actions for reading is not long enough to warrant the problems such as dyslexia. For argument that our brain has evolved instance, by challenging literacy via reading – this is what the author approaches such as the “whole calls the “reading paradox”. word” approach, and confirming that the systematic use of the phonics In response to this paradox, approach benefits the learner to Dehaene claims that neuroscience a greater extent. And, in the near findings indicate that the adult brain future, neuroscientific findings presents circuits that are specialized about how the “brain learns to read” in recognition of writing. Yet, the could inform literacy teaching. brain has evolved over millions of years, and reading only appeared a Dehaene refutes the empiricist view few thousand years ago, which leads and the social sciences perspective the author to suggest that the human Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 217

brain may have specialized cortical is presented, in the tradition of mechanisms that are attracted scientific research reports, whereby to written input. On one hand, knowledge acquisition is seen as our brains apparently have pre- cyclic and continuous. representations, which are used to help us deal with our environment Dehaene starts chapter 1, How do we and with variable situations, and read?, explaining some fundamentals there is flexibility in the brain in of the functioning of reading by this sense. On the other hand, there discussing the specificities of the are constraints, in the sense that the organ responsible for receiving pre-representations are minimally visual input – the eye. The author altered to meet new demands – describes how the retina deals with limited to those circuits that are visual information, stressing the amenable to change. role of the fovea that contains high- resolution cells and is located in the All in all, the discussions developed center of the retina. Thus, Dehaene about the implementation of emphasizes that eye-movement in reading processes in the brain are reading is characterized by fixations well-developed throughout the and saccades, which, ultimately, book. The organization of the book affects reading gaze and time. facilitates and guides reading about this complex theme as is divided The anatomical aspect of reading into an introduction, eight chapters, is subsequently related to the and a conclusion. It also contains reading processes of decoding author’s notes, the bibliography, the and encoding, which are seen as index and figure credits all presented simultaneous processes. The author at the end of the book, thus not emphasizes the issue of “invariance” distracting the audience from their in processing of written input, that reading. However, not all references is, letter recognition is not affected are listed in the bibliography, either by varying letter shapes or sizes, in the useful general sources or in the apparently; we recognize letter detailed references, unfortunately. common traits, and these are the Each chapter is structured with “invariants” in letter and in word a brief introduction followed recognition. by headings and subheadings that Dehaene uses when posing The key to understanding how the questions to orient reading. More human brain deals with invariance information on further research may reside in the hierarchical 218 Reviews/Resenhas

organization of decoding He further explains that encodings subprocesses of reading in each realized by neurons in the primary letter, grapheme, phoneme, in visual form area are progressively morpheme recognition and the recoded to be finally related to a use of affixes in word formation. mental lexicon, as if the input could Dehaene’s hypothesis is: “every find its mental address in a the mental written word is probably encoded lexicon. In addition, the author by a hierarchical tree in which discusses two possible routes for letters are grouped into larger size word recognition, the phonological units, which are themselves grouped route and the direct lexical route, into syllables and words” (p. 22). which are subsequently presented According to Dehaene, we naturally in chapter 2, where the author focus on morphemes in word explains that those routes represent recognition processes, i.e. we focus the dual-mode model. According to on finding meaning, but we move the author, the phonological route through levels of representation to refers to the mechanism via which get to meaning. we relate form to sound, letter to sound, grapheme to phoneme, while Having said that, Dehaene the direct lexical route refers to the analyzes the neural behavior in mechanism we have for associating dealing with this hierarchical written input to its meaning. meaning searching process, and Dehaene acknowledges that there he claims that we have neurons is a consensus regarding the dual- with a specific function as abstract mode model, apparently both letter detectors. In order for such routes may function simultaneously, abstraction process to be carried working in parallel. out, there is a filtering mechanism consisted of a feature detector In sum, in chapter 1 Dehaene neurons that differentiates upper describes reading by using case from lower case letters. In theoretic advances from cognitive this sense, abstract letter detector psychology, exploring reading neurons associate upper case and behavior, and bringing forth an lower case of a given letter as two analytical view of spelling systems possible forms of that letter, thus across cultures. Additionally, representing an abstract code he posits the important issue of that guides the brain towards invariance in letter recognition its corresponding sound and and explains reading processes at meaning. the level of decoding, including Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 219

neuroscience considerations (MEG), and positron emission Important information about tomography (PET). In this sense, what we know about reading chapter 2 focuses on the role of the is presented by the author in a occipito-temporal region in the reader friendly manner using left hemisphere –which the author metaphors such as “the silent refers to as the brain’s letterbox. The voice”, the metaphorical proposal metaphor is very fortunate since it that “every word is a tree”, the does express the properties of that idea of “competing neurons” to cortical region, also referred to as explain parallel processing, which the visual form area. Moreover, together allows the lay reader, as the concept of this cerebral well as the novice researcher, to letterbox guides the second chapter, deal with abundant information suggesting a specific property of the about complex processes, and left occipito-temporal region. at the same time “refreshes the memory” of more experienced When comparing old readers in the topic. neurobiological models of reading to the modern vision of the cortical In chapter 2, The Brain’s Letterbox, networks for reading, Dehaene uses Dehaene reviews findings from illustrations that nicely summarize brain imaging studies, and how the development of findings about they may provide support for the the implementation of reading neuronal recycling hypothesis processes in the brain (p. 63). and the importance of what he However, as previously mentioned, calls the brain’s letterbox. The the figures are in black and white in studies presented in this chapter the book, although the author refers offer a suitable overview of the to them as if they had been presented contributions of neuroscience to the in color in the aforementioned field of reading, in particular at the figures. The illustrations are available level of decoding, using techniques in http://readinginthebrain. and technological advances that pagesperso-orange.fr/figures. afford visualizations of the cerebral htm, address which, unfortunately areas involved in reading, ranging is not mentioned in the book. from post-mortem to modern Nevertheless, the author adequately methods such as functional reminds the reader that nowadays we magnetic resonance imaging have a more complex representation (fMRI), electroencephalography of the reading process, which is very (EEG), magnetoencephalography fast and parallel in nature, different 220 reviews/resenhas

from its sequential representations concerning the exact regions in of the past. however, the role of the brain that compute cognitive regions in the occipital lobe, as the processes are neither conclusive, primary visual area, has not been nor homogenous, extreme challenged because it had just begun caution should be exercised when to be understood with post-mortem analyzing brain imaging results studies. rather, the role of the left not to make broad generalizations, occipito-temporal region is further since millimeters in the brain may explored and better understood. underline a major difference. dehaene reviews findings from The aspect of invariance is revisited brain research from the nineteenth with dehaene presents EEG, and century up to current neuroscience MEG studies with real-time data studies, including seminal studies, that support this problem in letter, such as the one conducted by grapheme and word recognition déjerine (1887) and his patient Mr. that are characteristics of decoding C, exemplifying results with the processes in reading. Findings from brain’s letterbox area hypothesis. those studies once more confirmed research has shown a relationship the hierarchical organization in between the left occipital temporal the occipito-temporal area with lobe and letter recognition, based on neuronal activity from the posterior findings from examinations of brain- to the anterior sections of that cortical lesioned patients, particularly of region with increasing abstraction, those suffering from alexia and pure which the author interprets as alexia. The author acknowledges evidence of neuronal adaptation. that advances in methods, such as in reviewing the studies presented EEG, PEt, fMri and MEG, have in chapter 2, dehaene argues for enabled in depth examinations cultural adaptation to alphabetical of the functioning of the left- conventions and arbitrariness of occipito-temporal area. indeed, the relationship between upper case dehaene provides the lay reader and lower case letters. he advocates with simple explanations regarding for the possibility of hemispheric the methodologies and procedures specialization, since empirical data underlying those technological indicate that the left hemisphere devices, as well as he leads students shows a particular ability to abstract and researchers to complementary letters regardless of case, shape reading on fundamental literature. or size; while the right has not nonetheless, while results shown the same potential, with the Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 221

latter responding mostly to image Italian (transparent) or English similarities. (opaque), to Chinese and Japanese languages, with variance in terms Concerning the role of the corpus of transparency and directionality callosum (the region that links of reading as well. Dehaene briefly left and right hemispheres), considers the reading paradox, for Dehaene brings forth evidence this common role of the letterbox from neuroscience that nervous area cannot be explained in evolution connections sent from visual theories, since reading is a recent regions of the right hemisphere to phenomenon in evolutionary terms. the left occipito-temporal region The author concludes that there is travel through the corpus callosum, a consensus about the visual form a process that is compromised when area, the letterbox, which is present the corpus callosum has a lesion, as in the human brain in roughly the empirical data show. Thus, the reader same location in individual across can infer that the corpus callosum different cultures, from western to is part of the reading pathway. eastern ones. Additionally, other studies confirm the existence of such pathway from In addition to the role of the visual left occipito-temporal region to form area, i.e., the letterbox, brain Wernicke’s area and Broca’s area. imaging studies confirming the phonological and the direct lexical Studies across participants from routes are analyzed. Amongst them, different nationalities, thus users of Dehaene cites studies with words language that have alphabetic and and pseudo-words confirming the non-alphabetic writing systems; and dual-mode model with transparent also distinct cultural background and non-transparent words. As characteristics are included by regards the lexical route, studies Dehaene. They point to the show that the temporal and the remarkable conclusion that the role middle temporal regions are of the left occipito-temporal region involved in semantic processing is confirmed across participants with regardless of the input mode. Areas distinct first languages. The author in the temporal lobe and in the pre- discusses the role of the visual form frontal cortex were shown to be area with participants ranging from involved in sentence processing. In western languages with varying short, brain imaging results support degrees of transparency, such as the dual-mode model. 222 Reviews/Resenhas

Retaking the paradox, Dehaene and the human brain. The author argues for the universality of the refers to Brodmann’s subdivision left occipito-temporal region as the of the cortical areas to explain that region where people from all cultures correspondence. However, Dehaene recognize words, and he reiterates does not explain the importance of this universality, in particular for the Brodmann’s classifications to the issue of invariance Also, he agrees field, leaving those less experienced that decoding is a vastly parallel readers at a disadvantage. process across cultures, with an array of neurons in activation when Nevertheless, Dehaene draws the decoding takes place, and that the reader’s attention to many relevant two reading routes exist in both issues, in particular the fact that western and eastern cultures, with apes apparently are endowed with variations in tendency towards the a primary visual area like human phonological route or the direct beings. Having said that; in humans, lexical route related to the degree of the occipito-temporal region, as transparency and organization of a already discussed, is very connected given language. to reading, so much so, that is called the brain’s letterbox. In apes, the Despite the abovementioned occipito-temporal region is devoted conclusions, Dehaene refrains from to the recognition of faces and objects. solving the paradox just yet, and suggests further considerations. Another very relevant aspect is In fact, he proposes revisiting our invariance in face recognition primate origins and examining other exhibited by apes (Tanaka, primates’ brains by recollecting Tomonga, & Matsuzawa, 2003). studies that examined the brain of Findings from that research showed apes. This examination is carried that monkeys were able to cope out in chapter 3, The Reading Ape, with face rotation, and they did so in which Dehaene defends the by adjusting their view to a certain argument that the human brain can angle. The neuronal rationale is read due to our brain architecture based on neuronal specialization, and neuronal circuitry. with some neurons being more sensitive to rotation and others This idea is supported by findings being more prone to abstract to an about the brain of apes. An interesting object irrespective of the angle at similarity is the correspondence which it is presented. between areas of the monkey’s brain Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 223

This characteristic of primate letters”. The author revises other brains is seen by Dehaene as studies leading to the conclusion indicative of our ability to deal with that the primate brain in fact, holds shape, size and position variances an “innate shape lexicon”. However, in letter and word recognition. he expresses a doubt concerning Connecting that to human the nature of the shape lexicon by processes, the author revises a admitting that in human beings, study by Rolls (2000) that proposes the lexicon could be learned a hierarchical organization of the Additionally, this recognition occipito-temporal areas which is of basic shapes allows for the seen as vital for understanding combination of a wide variety of primate visual systems. Rolls’s shapes primates may encounter, and research is particularly interesting shapes used in combinations are for it is about face-recognition of likely to be those more frequently an epilepsy patient who seemed present in a given environment. to have neurons that recognize Alternatively, shapes may be taught, Hollywood superstar Jennifer in which case, they have a chance Aniston presented in different ways of being encoded in higher-level – color photograph, caricature, neurons in the primate brain. close-up picture and even her written name. The primate brain Considering the possibility that the ability to deal with variance primate brain learns to recognize the is therefore understood as the shape of a T, Dehaene suggests that “predecessor of reading”. this shape may represent the edge of an object, assuming that same “T” Dehaene relies on Tanaka et al. a monkey may use to recognize an (2003) to propose the idea of a object, humans use to symbolize neuronal alphabet in the monkey letters. As a matter of fact, these brain, i.e., neurons dedicated to shapes are processed in the occipito- shape fragments. The study used temporal region, the same area that images that were simplified to what humans use to process letters, thus the researchers considered to be DDehaene proposes that while their basic shapes, and there were humans use the occipito-temporal neurons that responded to basic region to recognize words, apes use shapes, in particular shapes that that same area to process shapes, were simplified to a Y or to a T ultimately concluding that the shape, which Dehaene calls “proto- human brain did not evolve to read, but our writing systems instead, 224 Reviews/Resenhas

have stemmed from cerebral In chapter 4, Inventing Reading, characteristics. Dehaene discusses more specifically how the neuronal recycling Having in mind the assumption hypothesis may account for brain proposed by the neuronal recycling constraints in the development and hypothesis that brain structure acquisition of writing systems. The constrains sets of writing systems author briefly reviews the evolution to be learned, Dehaene proposes of writing systems citing researches two other questions to be addressed and bringing figures, providing in the next four chapters (chapter the reader with an overview of the 4, Inventing Reading; chapter 5 – evolvement from cave paintings Learning to Read; chapter 6 – The to the alphabet we know today. Dyslexic Brain; and chapter 7 – Despite the fact that writing systems Reading and Symmetry): Question may vary greatly, Dehaene suggests (1) “How did humans discover that that they all share many features their visual cortex could be turned and proposes the magic formula into a text comprehension device?”; of three strokes per character, a Question (2) “How does this recycling combination that can be easily process recur in the brain every processed by neurons in the visual time a child learns to read?”, while area in a pyramidal shape. For considering three consequences of instance, writing systems present the neuronal recycling hypothesis. characters formed of two, three, or First, the evolution of writing, in four shapes and strokes, and such the sense that past and present hierarchical combinations create writing systems should carry some sounds, syllables, or words. Besides, common cross-cultural regularity, location and size of characters are in agreement with our brain irrelevant, but not rotation, which organization constraints. Second, should be restricted to a maximum the evolution of human abilities, since of forty degrees, a limitation for learning new abilities, such as reading our visual neurons that is followed and writing, may happen at the across writing systems. expense of losing others. And third, the acquisition of reading, on the basis Dehaene starts chapter 5, Learning that learning to read depends both to read, using the terms ‘learning’ on the amount of cortical recycling to read and ‘acquiring’ reading required and the compatibility of as interchangeable concepts, teaching methods and the structure of which may not be a common our cerebral networks. understanding in the second and Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 225

foreign language research literature, activation in the left hemisphere in which the learning-acquisition areas, such as the left superior dichotomy have different meanings. temporal region, the temporal lobe, The purpose of chapter 5 is to and the left inferior frontal region advocate for a new perspective (Broca’s area) can be seen. And when of reading mechanisms and their they are from six to twelve months implications for teaching. old, their brains systematically select and classify segments of speech According to the neuronal so that they recognize regularities recycling hypothesis, learning to in speech. Two-year-olds learn an read connects two brain regions average of ten to twenty words a day, already present in infancy: (1) and by the time they have their first object recognition system; and reading lesson, at the age of five or six, (2) language circuit, regions they are phonology ‘experts’, having a that after years of practice are large vocabulary and understanding refined, such as the left-occipito- the basic grammar rules of language, temporal letterbox area, onto the as Dehaene supports. adult reading network. Thus, the prediction is that reading gradually At the same time, the visual system concentrates on the left-occipito- is organized in a way that the temporal letterbox area, as well as baby is capable of perceiving one other areas, as the child masters object within the visual scene, and the writing process. A denser follows it as it moves around it. discussion is presented based on Some features help the baby, such the three stages for learning to read as texture, contours, and internal proposed by Frith (1985), which organization of the object. Besides, provides a description of children’s the visual system organization also learning curve, and followed influences the different viewpoints by pedagogical implications on the baby uses to see the object, teaching reading. making inferences about it. It has not been determined yet exactly when In an interesting description, the recognition of faces, places, and author accounts for the development objects that activate brain regions of the baby brain considering speech in babies reaches the adult format. comprehension and invariant visual For instance, the ability to recognize recognition aspects. Babies are able faces at two months old activate the to perceive linguistic contrasts and occipito-temporal cortex used in the rhythm of their L1 in the utero: adults too, which may be enhanced 226 Reviews/Resenhas

over time as babies recognize faces Dehaene observes that the first around them. What is known is that years of formal reading teaching at five or six years of age, the visual are crucial for children’s efficient recognition process is ready, however development and the author still plastic enough to foster for emphasises that the key element learning of new information, such as in learning to read is ‘phonemic letter as this is the time when children awareness’. He stresses that it is go to school to learn how to read. necessary to explicitly teach children that speech is made of phonemes, As regards the first stage of learning and when phonemes are combined, to reading (Frith, 1995), the they create words. Dehaene’s view logographic or pictorial stage takes is based on the assumption that place at five or six years, before learning graphemes and phonemes formal reading instruction. The happen simultaneously since these visual system recognizes words two processes constantly interact as faces and objects, and it relies in a ‘spiral causality’, with attention on visual features, such as shape, drawn to both speech sounds colour, and letters to identify them. and understanding of letters in Becoming aware of phonemes a continuum process. Yet, brain happens during the second phase, imaging has shown discrepancies the phonological stage, in which between literate and illiterate brains, the child decodes words into letters on the account that learning to read and connects letters to sounds, that greatly alters the brain architecture. is, the development of grapheme to Indeed, Castro-Caldas (1999) phoneme. In this phase, the child reported differences not only in focuses on isolated letters or on participants’ performance but also relevant letter groups, and practices in the brain structure, for example linking graphemes to speech sounds the corpus callosum – the region to form words. Finally, the third stage that links both hemispheres – is corresponds to the orthographic stage, thicker in literate participants, in which the child has a large lexicon which may indicate a more intense of visual units and reading time is exchange of information between determined by word frequency, rather the hemispheres. than word length, i.e., rare words are read more slowly whereas more Although imaging tools used in frequent ones are read faster. research have not allowed scientists, at least not yet, to fully observe the reading progress, the neuronal Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 227

recycling hypothesis presupposes suggests that reading is based on that the visual system gradually processes of automaticity and specializes, modifying the brain unconsciousness. The child does not architecture, as it develops when start at that level, though, because learning to read. Thus, at the she ought to be made explicitly pictorial stage, when words are aware of the components involved seen as pictures, there is no brain in reading. The author strongly specialization and both hemispheres recommends that in order to set contribute to reading. However, as an efficient neuronal hierarchy, the child becomes more expert, the in which reading may develop, activation gradually concentrates on it is necessary to establish a solid the left occipito-temporal letterbox foundation first by recognizing area. Dehaene hypothesises that letters and graphemes, and after each reading lesson underpins a linking them to speech sounds, so neuronal re-organization in the that more elaborate processes may sense that some visual neurons that emerge, such as spelling, vocabulary, primarily recognized objects and and meaning, to name a few. faces now recognize letters, and a similar gradual development is true Dyslexia is the theme of chapter for phonemic awareness, which 6. According to Dehaene, develops to more refined structure. dyslexic children demonstrate a Another speculative finding brought disproportionate difficulty in learning by the neuronal recycling hypothesis, to read that is not caused because and also extremely controversial in of mental retardation, sensory the field, is that the brain would lose difficulty, or underprivileged family some cognitive capacity when we background. The author criticizes learn to read, on the grounds that the criteria used as a threshold to neuronal circuits once dedicated to define reading impairment since the other cognitive functions would be boundaries to distinguish between now totally devoted to reading. good and poor readers are not clear, which hinders the diagnostic process When it comes to neuroscience and of dyslexic children. It is highlighted teaching, Dehaene acknowledges that dyslexia is no longer seen as a the huge gap that there is between social or a cultural problem, but a theoretical laboratory knowledge pathology that runs in the family and classroom practice. Dehaene and carries genetic heritability of proposes a definition of reading reading abilities. Dehaene sustains ascertain what reading is not, and that dyslexia may be caused by both 228 Reviews/Resenhas

visual and language deficits; however, most literature tends to agree with the question of whether dyslexia such results. Some studies also show refers to the cause or the consequence that dyslexic children may have of learning disability still remains, deficits in their visual and auditory apart from the extensive research processing too, but this finding is conducted on the topic. still being hotly debated. Reading is complex process that requires The author posits dyslexia as both low and high level cognitive referring to the reading deficit resources, resources which may in single word decoding due to also be involved in other cognitive impairment in grapheme-phoneme processes. Hence, it has not been conversion, considering that most demonstrated yet whether such dyslexics suffer from a deficit in deficits exist due to dyslexia or phoneme processing. Most up- they co-occur as coincidental to-date literature understands associations with dyslexia. dyslexia as impairment in speech processing, rather than a reading Dehaene cites several studies problem. Children with dyslexia do on dyslexia, examining children not have phonemic awareness and and adults, as well as animal show deficiencies in rhyming or studies conducted with rodents. recognizing and combining sounds- Among them, he brings forth letters, blending, segmentation, the investigation conducted by manipulation, and alliteration, Heikki and colleagues, in Finland, among other deficits. with a large potential population of dyslexics over many years. In Pioneer studies on the theme general, results show a link between conducted by Morgan, early phonological abilities and the Hinshelwood, and Orton believe ease to later acquire reading. This is dyslexia to be an eye movement explained because dyslexic children problem or an inappropriate use of suffer from a ‘faulty representation of sentence context – the “congenital speech sound’, which prevents them word blindness”. Nonetheless, from accurately processing spoken research has produced consistent words and then pairing these words evidence on the origins of dyslexia with visual symbols. Along with that as an anomaly in the phonological study, Dehaene mentions Paulesus’ processing of speech sounds, with a group, in France, which examined smaller number of dyslexic children Italian, French, and English dyslexic with spatial attention deficits, and participants, and found insufficient Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 229

activation in the left temporal lobe, germinal zone to different cortex which appears in MRI images as layers, but some travel beyond the systematically disorganized. proper position and crash, others never achieve their final destination Having brought the evidence and accumulate in ill-shaped cortical provided by those studies, Dehaene cell layer (dysplasia) or forming starts discussing the anatomy of a miniature folds (microgyri). dyslexic brain. Broadly speaking, he sustains that MRI images of dyslexic Dehaene defends the theory of brains reveal the basic layout of neuronal recycling hypothesis the cortex and its connections to considering another topic that be disorganized. He explains that may also corroborate such Paulesus’ group used the technique understanding: reading and of voxel-based morphometry, via symmetry. According to the author, which it is possible to measure the on one hand, visual circuits display amount of gray matter at any point several efficient characteristics in the cortex, that is, its thickness for reading, on the other hand, and folds of the cortex. And that was other features hinder the process: carried out by the aforementioned generalizations of mirror images, group, which found a disorganized that is, when children see letter such left temporal cortex, as well as as “b” and “d” as the same object to a rarefied gray matter in same from two different perspectives. places, whereas others were denser In his recycling hypothesis, the than normal. He also found that “mirror stage” is part of our reading dyslexics had more gray matter in development and it vanishes with the left middle temporal gyrus, in time. Dehaene explains that the proportion to their reading speed distinction between right and left deficit. The amount of more gray begins in the dorsal visual pathway, matter in one place and less in others the brain region responsible for may be explained by ‘ectopias’, that gestures in space, and gradually is, neurons that were not placed moves to the ventral visual pathway correctly. According to Dehaene’s that accounts for object recognition. reasoning, much of dyslexia may be explained due to what happens with In an appealing analogy, the neurons during pregnancy. Neurons dissociation between right and are expected to travel immense left refers to object orientation as distances in the fetal brain to reach “manual worker” and object identity their appropriate places, from the as “collector”. For Dehaene, the 230 Reviews/Resenhas

manual worker acts, compares, and Dehaene asserts that human manipulates the image, but it is not memory “suffers” from perceptual capable of distinguishing the object; priming effect, that is, the visual whereas the collector recognises and system in the brain processes an labels the image, but it pays little abstraction of the scene, an image attention to location and orientation that is a translation of the symmetry. in space. His understanding of That means that although we live in a how the symmetry between right three-dimensional world, including and left disappears is based on the (1) vertical axis; (2) from front to assumption that children first see back reference; and (3) from left- letters in a limited perspective of to-right axis, the image is recorded two-dimensional curves and not in agreement with two main axes, in three-dimensional perspectives from front to back, and vertical, that allows letters to rotate in space. both of which were more developed Then, images representing bigrams, in mobile species like us, and due to graphemes and morphemes are the gravity force. restricted to the left hemisphere and only for letters in left-to-right Besides, reading and symmetry orientation; thus, the expert reader may also shed some light on knows the statistics of letters in the controversial studies on ordinary writing, but not for mirror dyslexia, discussed in chapter 6. writing, which remains inoperative Dehaene attempts to elucidate the in an unexploited reading system. misunderstanding that dyslexic children would suffer from not From early animal studies conducted only a reading deficit, but also from by Pavlov and human studies dated a deficiency in distinguishing left back to Samuel Orton, both in the from right, due to the great number 1920s, to a more contemporary view of dyslexics who mix “p” with “q”, or proposed by Corballis and Beale “b” with “d”. However, the confusion (1970s), what is sustained in the of mirror letters can happen to any literature and experiments is that children, dyslexic or not, as the visual visual maps of occipital region of impairment may occur as the result the left and right hemispheres are of a phonological deficit. I ndeed, organized as mirror images of each “p” and “q”, or “b” and “d” are similar other: the right visual field projects plosive phonemes and difficulties in the image into the left hemisphere distinguishing them and projecting and the left visual field projects the mirror images from seven to ten image into the right hemisphere. Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 231

years of age may or may not be that behind cultural diversity characteristics of a dyslexic child. lays universal mental structures that feature similar restrictions. Final remarks about advances Furthermore, Dehaene’s review in neuroscience research into includes American philosopher reading are presented in Chapter Jerry Fodor, the proponent of the 8, Toward a culture of neurons, in a modularity of the mind, and the celebratory tone for the accuracy of cognitive scientist and French our understanding of the mapping anthropologist Dan Sperber. of reading processes in the brain. And Dehaene finally answers his Sperber posits that the brain holds proposed reading paradox. He innate modules that are universal states that human beings did not and, to a certain extent, Dehaene’s go through a biological evolution perspective conflates with Sperber’s towards reading, rather than that, in the sense that the human brain reading evolved to suit our brain. exhibits specializations. However, He grounds this assertion on the Dehaene contends that Sperber developments of writing systems may neglect the role of plasticity of presenting similarities across cultures, the brain, which Dehaene considers as discussed in previous chapters of to be fundamental to our cognitive his book. The neuronal recycling potentiality. For Dehaene, reading hypothesis rests on cortical areas does not stem from a specialized having adapted from initial visual visual system, rather than that recognition invariant objects to writing systems have changed our reading. His conclusion is that cultural brain functionality in such a way that constructions are restricted by our it has in fact, extended our cognitive cerebral structure, and with this potential. Therefore, he claims the assumption, it is possible to investigate modular view does not translate the neuronal recycling for other cultural full range of the cortical features, expressions besides reading. which present some specializations, but exhibit plasticity as well. He supports his assumption on previous research drawing on The more varied the complexity of diverse fields such as neuroscience, cultural or educational innovations, citing Jean-Pierre Changeaux, and the more the brain circuitry needs structural anthropology referring to to be re-organized. Plasticity Claude Levi-Strauss, who according seems to be what gives us our edge to Dehaene, initially suggested since it enables the creation and 232 Reviews/Resenhas

transmission of cultural objects, cortex and associated area exhibit which are features that are singular connections across cortical areas, to human beings. In terms of showing less specialization, hence transmission, Dehaene reviews more plasticity. Tomasello’s research on acquiring language. According to Dehaene, Yet, assumptions corroborate that Tomasello asserts that humans do higher level cognitive processes not simply imitate, they interact, and take place in the pre-frontal cortex. for that humans do not simply focus Resorting to ideas proposed in on the linguistic input they receive the tenth century by Avicenna, while interacting. Instead they Dehaene’s thinking presents novelty also perceive the intentions of use in the sense that the pre-frontal of a given linguistic input. Studies cortex seems to be specialized in with children during language memory and mental synthesis, acquisition phase showed that they which are ultimately linked to do not simply imitate words, but imagination, which, in turn, is linked when children are exposed to new to our aforementioned ability to words, they first figure out what the invent. These ideas are precursors of words refer to, only then do they current findings from neuroscience: assign meaning to the spoken word. multimodality of neurons – in Nevertheless, Dehaene contends that the presence of a current goal, Tomasello’s research so far explains neurons collect information from how we transmit knowledge, but not multiple sources of input coming how we create new knowledge. from sound, images our tactile information; the activation of As far as this issue is concerned, information in working memory, Dehaene focuses on brain functions and the constancy of brain activity. in the pre-frontal cortex that In other words, the brain is never show how connections break inactive, not even in resting states through modules! First, he points as confirmed by neuroscience data. out architectural changes in the pre-frontal cortex in terms of These findings have ledD ehaene expansion stemming from changes to conclude that they relate to in neuronal functionality. This leads human beings ability to integrate the discussion to characteristics of information from different the pre-frontal cortex, for although sources in different ways – we can modularity features in a great part synthesize information, we can of the primate brain, the pre-frontal consciously represent information Ilha do Desterro nº 63, p. 215-242, Florianópolis, jul/dez 2012 233

and reformulate it, unlike any explicit teaching children the other primate. In reading, Dehaene correspondence between letters and proposes that being literate speech sounds, and tries to distance implies being able to represent his ideas from ideological debate, and manipulate phonemes, this assuring the reader that this will expanded phonemic awareness is enable children to read extensively. achieved by explicit instruction on the association of grapheme Bearing in mind the perspective to phoneme – the teaching of the of beginning researchers, the alphabet. experience of Reading in the brain allowed us to have an overview of the In the concluding, chapter, entitled field and how his neuronal recycling The Future of Reading, Dehaene hypothesis fits into neuroscientific reiterates the importance of reading research in reading. The assumption to mankind, to its culture and to that the human brain is a blank slate, its mind. Above all, he posits that and that cultural evolution may plasticity explains how education influence writing and reading circuit and culture inventions are not fixed systems in the brain as proposed is and finite. Summing up his theory, refuted by Dehaene’s own response- it proposes that existing shape provocative position that “only a recognition structures within the stroke of good fortune allowed us to brain, which seem to be mainly read” (p. 302). concentrated in the occipito- temporal areas have been recycled to Dehaene’s reader-friendly book is an provide the network needed to enable invitation to discover neuroscience the acquisition and development of achievements regarding our writing. The principal opposition understanding of reading, which to this concept is that the brain extends to the general public, structure evolved concurrent with ranging from lay readers interested the evolution of writing. in scientific and cultural themes, as well as to students and researchers. Additionally, the author stresses the neuroscience advances about how [Received in 27/05/2012. Approved in reading processes are mapped into 18/06/2012] the brain may provide important contributions to reading pedagogy. Dehaene stresses that empirical data indicate the value of the