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The Education of DyslexicChildren from Childhoodto Young AdulthoodSally E. Shaywitz,1 Robin Morris,2and Bennett A. Shaywitz31Department of Pediatrics, Yale University School of Medicine, New Haven,Connecticut 06510; email: [email protected] of Psychology, Georgia State University, Atlanta, Georgia 30302;

email: [email protected] of Pediatrics and Neurology, Yale University School of Medicine,New Haven, Connecticut 06510; email: [email protected]

Annu. Rev. Psychol. 2008. 59:45175

The Annual Review of Psychologyis online at http://psych.annualreviews.org

This articles doi:10.1146/annurev.psych.59.103006.093633

Copyright c 2008 by Annual Reviews. All rights reserved

0066-4308/08/0203-0451$20.00

Key Wordsaccommodations, classication, learning disabilities, neuroimagspecic reading disability, reading remediation, readingintervention, dyslexia

Abstract

The past two decades have witnessed an explosion in our understaing of dyslexia (or specic reading disability), the most commomost carefully studied of the learning disabilities. We rst rethe core concepts of dyslexia: its denition, prevalence, and dopmental course. Next we examine the cognitive model of dysespecially the phonological theory, and review empiric data suging genetic and neurobiological inuences on the developmendyslexia. With the scientic underpinnings of dyslexia servingfoundation, we turn our attention to evidence-based approachediagnosis and treatment, including interventions and accommotions. Teaching reading represents a major focus. We rst revthose reading interventions effective in early grades, and then view interventions for older students. To date the preponderancinterventionstudies have focusedon word-levelreading;newer sies are beginning to examine reading interventions that have beyond word reading to affect reading uency and reading comhension. The article concludes with a discussion of the criticalof accommodations for dyslexic students and the recent neurological evidence supporting the need for such accommodations

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Fluency: the ability to read wordsaccurately, rapidly,and with goodintonation

ContentsBACKGROUND AND

DEFINITION.. . . . . . . . . . . . . . . . . . 452Historical Roots. . . . . . . . . . . . . . . . . . 452Denition: Core Constancy

Amid Renements . . . . . . . . . . . . . 453EPIDEMIOLOGY OF

DYSLEXIA. . . . . . . . . . . . . . . . . . . . . . 455Prevalence . . . . . . . . . . . . . . . . . . . . . . . 455Developmental Course . . . . . . . . . . . 455Sex Differences in Dyslexia . . . . . . . 456

COGNITIVE MODEL OFDYSLEXIA AND ITSIMPLICATIONS... . . . . . . . . . . . . . 456Phonological Theory . . . . . . . . . . . . . 456Dyslexia in Different

Orthographies . . . . . . . . . . . . . . . . 457ETIOLOGY. . . . . . . . . . . . . . . . . . . . . . . . 458

Genetic Inuences . . . . . . . . . . . . . . . 458Neurobiological Inuences . . . . . . . 458

DIAGNOSIS AND TREATMENT . . . . . . . . . . . . . . . . . . 461Diagnosis of Dyslexia. . . . . . . . . . . . . 461 Teaching Reading to Dyslexic

Students . . . . . . . . . . . . . . . . . . . . . . 462Early Intervention. . . . . . . . . . . . . . . . 462Interventions for Older Students . . 463

Beyond Word Accuracy . . . . . . . . . . . 463 Treatment Resisters . . . . . . . . . . . . . . 465Response to Intervention . . . . . . . . . 465Summary of Interventions . . . . . . . . 466 Accommodations . . . . . . . . . . . . . . . . . 466

BACKGROUND ANDDEFINITION

Forgood readers, gaining meaning from print quickly and effortlessly, like breathing andspeaking, is a natural part of life. For thesemen and women, it is almost unimaginablehow something that seems to come so nat-urally could be difcult for others. Without doubt, since ancient times when man learnedto use printed symbols to convey words andideas, there have been those who struggled

to decipher the code. Just how many arefected, the basis of the difculty, and mostportantly, the most effective, evidence-baapproaches to educatingdyslexic children young adults were questions that had to until quite recently for resolution. We be

by reviewing the core concepts of dyslincluding its denition, epidemiology, cnitive model, and etiology, especially neubiological inuences. We next consider scic evidence-based reading interventions word-reading accuracy, uency, and comphension and then the exciting neurobiolical ndings that together have given to and must inform contemporary, evidenbased approaches to the education of dyslchildren. We conclude with a discus

of the critical role of accommodationsdyslexic students and the new neurobioical evidence supporting the need for saccommodations.

Historical RootsDyslexia has been described in virtuallyery ethnic group, language, and geograpregion. The original report, published asCase of Congenital Wordblindness on Novemb

7, 1896, was prompted by the experienca British physician, W. Pringle Morgan, whis patient Percy F., age 14, for whom he vided the following description:

. . . He has always been a bright and intelligent boy, quick at games, and in no wayinferior to others his age. His great dif-culty has beenand is nowhis inability tread. He has been at school or under tutorssince he was 7 years old, and the greatest efforts have been made to teach him to read

but, in spite of this laborious and persistenttraining, he can only with difculty spell ou words of one syllable. . . .

. . . I might add that the boy is bright andof average intelligence in conversation. Hiseyes are normal. . . and his eyesight is good The schoolmaster who has taught him forsomeyearssaysthathewouldbethesmartest

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lad in the school if the instruction were en-tirely in oral . . . (Morgan 1896, p. 1378).

What is so striking is the similarity of Percy F. to the children we continue to see tothis day. Such clinical descriptions from ev-ery corner of the globe attest to the invari-ance of dyslexia over both time and place. Inhis clinical vignette, Dr. Morgan captures theessenceof dyslexia: an unexpecteddifculty inreading.

Denition: Core Constancy AmidRenementsCurrent denition. The basic notion of dyslexia as an unexpected difculty in read-ing has remained constant across denitionsof dyslexia (Critchley 1970, Lyon 1995) asevidenced by the most current denitionprovided by a working group meeting in Washington, D.C., in 2002:

Dyslexia is a specic learning disability that is neurobiological in origin. It is character-ized by difculties with accurate and/or u-ent word recognition and poor spelling anddecoding abilities. These difculties typi-cally resultfroma decitin thephonological

component of language that is often unex-pected in relation to other cognitive abili-ties and the provision of effective classroominstruction . . . (Lyon et al. 2003, p. 2).

Renements from prior denitions.Dyslexia (also referred to as specic readingdisability) is a member of the family of learning disabilities; in fact, reading disability is by far the most common learning disability,affecting over 80% of those identied as

learning disabled (Lerner 1989). Althoughthe recognition of dyslexia as a discrete entity dates back over a century, the concept of alearning disability is relatively new.

The term learning disabilities, as ini-tially proposed by Samuel Kirk (Kirk 1963)and later operationalized in the FederalRegister (U.S. Ofce Educ. 1977), refers to abroad group of difculties involving listening,

Accommodationsadaptations withinthe classroom, usassistive technoloor provision of extime allowinglearning-disabledstudents todemonstrate theirfull knowledge

Decoding:determining thepronunciation of word by analyzinthe vowels andconsonant combinations with

the word

speaking, reading, writing, and mathematics.In contrast to this undifferentiated construct,the current denition explicitly categorizesdyslexia asa specic learning disability.New to the current denition over the previousone is reference to dyslexias neurobiologi-

cal origin, reecting the signicant advancesin neuroscience, particularly the brain imag-ing of reading and dyslexia that is discussed indetail below.

New, too, is the incorporation of, and em-phasis on, the importance of uent reading:the ability to read text not only accurately,but also rapidly and with proper expression(Rep. Natl. Reading Panel 2000). Thus, theprevious reference to single word decodingis now supplanted by reference to difcul-

ties with accurate and/or uent word recogni-tion, acknowledging converging data point-ing to the critical lack of the development of uent reading as a hallmark of dyslexia that persists into adolescence and then adulthood,even when accuracy improves.Thelack of u-ent reading is observed clinically by readingthat is effortful and slow; it is often consid-ered the sine qua non of dyslexia, especially in young adult and adult readers (Bruck 1998,Ley & Pennington 1991, Shaywitz 2003).

This renewed appreciation of the importanceof uencyshould encourage its measurement;otherwise, many dyslexic children who canread accurately, but not uently, will continueto go unnoticed (and untreated) within theclassroom (Katzir et al. 2006).

As in the prior denition (Lyon 1995),emphasis is on the phonological weaknessgiving rise to the reading (and speaking)difculties characterizing dyslexia. A rangeof studies has indicated phonological dif-

culties as the most robust (Fletcher et al.1994,Shaywitz et al.1999,Stanovich& Siegel1994) and specic nding (Morris et al. 1998)in dyslexic children and adolescents, sup-porting the phonological-core variable differ-ences model proposed earlier by Stanovich(1988). Critical to the notion of a phonolog-ical weakness as causal in the development of the concatenation of difculties observed in

www.annualreviews.org Education of Dyslexic Children 453

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dyslexia has been the repeated demonstrationthat remediation of the phonological weak-ness leads to the amelioration of the decod-ing and word-reading weaknesses in dyslexia(Bradley & Bryant 1983; Byrne & Fielding-Barnsley 1995; Byrne et al. 2000; Foorman

et al. 1998; Hatcher et al. 1994; Schneideret al. 1997; Torgesen et al. 1999, 2001).

Core denitional concept: an unexpecteddifculty in reading. Perhaps the most con-sistent and enduring core of any denition of dyslexia is the concept of dyslexia as an un-expected difculty in reading. Unexpectedrefers to the presence of a reading difculty in a child (or adult) who appears to have all of the factors (intelligence, motivation,exposure

to reasonable reading instruction) present tobe a good reader but who continues to strug-gle (Shaywitz 1998). More challenging hasbeen the question of how to operationalizethe unexpected nature of dyslexia. Thus, us-ing differing methods and criteria, denitionshave attempted to capture the unexpectednature of dyslexia by requiring a discrepancy of a certaindegree between a childs measuredIQ andhis reading achievement. Forexample,schools have typically relied on criteria based

on an absolute discrepancy, most commonly one or one-and-one-half standard deviationsbetween standard scores on IQ and readingtests; others, includingmany researchers,pre-fer regression-based methods adjusting forthecorrelationofIQandreadingachievement (Reynolds 1984, Stuebing et al. 2002).

We want to emphasize that the difculty has been not with the notion of a discrep-ancy, but rather with the real-life practicaleffect of implementing this model in a pri-

mary school setting. For example, children who were clearly struggling as early as kinder-garten or rst grade had to wait, often untilthird grade or later, until their failure in read-ing was of such a magnitude that they met discrepancy requirements. And so it is under-standable why this approach has often beenreferredtoasawait-to-failmodel.Attemptstoclarify the criteria by meta-analyses compar-

ing discrepant to simply low-achieving preaders (dened on the basis of a readscore below a certain cut point, e.g., bea standard score of 90) nd overlap betwthe two groups on reading-related construbut not on IQ-related measures (Stueb

et al. 2002). In addition, both low-achievand discrepant readers demonstrate comrable growth rates in word reading durthe school years (Francis et al. 1996). Knedge of long-term adult outcome may slight on possible differences between the groups not captured by studies during chhood; such efforts are now under waying data from the Connecticut LongitudiStudy(Ferreretal.2007,Shaywitzetal.200Not only do poor readers identied by eit

discrepancy or low-achievement criteriasemble one another on measures of readand growth rates of reading, but each gralso differs along multiple dimensions fgroups of typically achieving boys and (Fletcher et al. 1999, Lyon et al. 2001).

These ndings have strong educatioimplications: It is not valid to assume thatcrepant children require instructional stragies that differ from those for low-achievreaders. It also is not valid to deny the

ucation services available for disabled orisk readers to low-achieving, nondiscrepchildren. On the other hand, the observsimilarity of the discrepant and low-achievgroups in reading-related constructs argfor identication approaches that inclboth low-achieving children and those strgling readers who are discrepant but whonot satisfy an arbitrary cut point for desigtion as low achieving. Seventy-ve percechildren identiedby discrepancy criteria a

meet low-achievement criteria in reading;remaining 25% who meet only discrepacriteria may fail to be identied and yet be struggling to read (Shaywitz et al. 199

A recognition of these difculties cbined with accumulating data indicathe importance of early intervention (Lyet al. 2001; Torgesen et al. 1999, 2001) prompted researchers andeducators to sear


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for alternative approaches that would pro-mote earlier intervention or prevention forat-risk readers. Onesuch approach focuses ona more dynamic assessment, particularly ap-plicable to early grades, where the ongoingdevelopment of uency in component read-

ing skills (e.g., letter recognition, word read-ing) is measured frequently and is compared with expected norms (Kameenui et al. 2000). Another approach, termed response to intervention (RTI;Fuchs & Fuchs 2006),has gen-erated considerable interest. Here, all chil-dren are rst provided with evidence-basedreading instruction and their progress is fre-quently monitored; those whoare not makingprogressareselected to receiveadditional sup-port (see below for fuller discussion of RTI).

Denitional framework of dyslexia: cate-gorical or dimensional. How best to morebroadly conceptualize dyslexia has long beenof theoretical interest to investigators and of more practical import to educators who must set policies to identify struggling readers inneed of support. Earlier views, mainly stem-ming from the inuential Isle of Wight study (Rutter & Yule 1975, Yule & Rutter 1985),positeda categoricalviewof dyslexia envision-

ing reading ability as bimodally distributed, with children with specic reading retarda-tion (dyslexia) forming a so-called hump at the lower tail of the distribution (Rutter & Yule 1975, Yule & Rutter 1985). In con-trast, more recent data from an epidemio-logic sample, the Connecticut LongitudinalStudy, suggests that reading difculties, in-cluding dyslexia, occur as part of a continuumthat includes nonimpaired as well as disabledreaders (Shaywitz et al. 1992b). Other investi-

gators, too, have pointed out methodologicalaws in the British study (van der Wissel &Zegers 1985) or failed to replicate its ndings( Jorm et al. 1986, Rodgers 1983, Silva et al.1985,Stevenson1988).TheimportanceoftheConnecticut data is that these ndings placedyslexia within the same dimensional framework as other important disorders that affect the health and welfare of children and adults.

RTI: response tointervention

Evidence-basedreading instruction

programs andmethods for whicthere is reliable a valid evidencepublished in apeer-reviewed journal of effectiveness inteaching childrenread

Thus, like hypertension and obesity, dyslexiaoccurs in degrees of severity. A dimensionalmodel also argues that although cut pointsare placed to help dene groups, these are ar-bitrary and may have no biological validity;those on one or the other side of such a cut

point will differ from one another by degree,but not kind. Clinically, for school identica-tion of children forspecial services, this meansthat childrenwhodo notmeet these arbitrar-ilyimposedcriteriamaystill require andprot from special help in reading (Shaywitz et al.1992b, p. 149).

EPIDEMIOLOGY OF DYSLEXIA

Prevalence

Reading difculties are highly prevalent; thespecic prevalence rate will reect the par-ticular denition and cut points established ascriteria for identication. Forexample, resultsof the 2005 National Assessment of Educa-tional Progress indicate 27% of high schoolseniors are reading below the most basic lev-els (minimum level at which a student candemonstrate an understanding of what sheor he has read) (Grigg et al. 2007). Evenmore primary grade students36% of fourthgrade childrenare reading below basic lev-els (Perie et al. 2005). In our epidemiolog-ical Connecticut Longitudinal Study samplein which each participant was individually as-sessed, we found that 17.5% of students werereading below age or ability levels (Shaywitzet al. 1994).

Developmental Course

Converging data indicate that reading dif-culties are persistent and do not remit withage or time (Francis et al. 1994, Shaywitz et al.1995) (Figure 1 ).

This should put an end to the unsupported,but unfortunately, too widely held notion that reading problems are outgrown or somehow represent a developmental lag. The implica-tion is that reading problems expressed early


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Phonemes:elemental particles of speech; the smallest unit of speechdistinguishing onespoken word fromanother

must be addressed or they will persist withtime. Here, also, it is important to keep inmind that the expression of the difculty may change, so that difculties with reading ac-curacy, especially in very bright children, of-ten evolve into relatively accurate, but not

uent, reading. Given the knowledge of theunremittingcourse of dyslexia, earlyinterven-tion takes on a newurgency; particularly sincethe data strongly indicate a much more pos-itive response to interventions that are provided in the very rst few years of school com-pared with those delivered in the later yearsof primary school (Torgesen et al. 2006).

Sex Differences in Dyslexia

The belief that reading difculties affect predominantly or exclusively males reectsthe overwhelmingly larger number of boyscompared with girls identied by schoolsas having a reading problem. However, aseries of epidemiological studies, includingones that compare school-identied disabledreaders with objective, individually assessed,criterion-identied disabled readers, in-dicate that a referral bias favors boys inschool-identication procedures reecting

boys disruptive classroom behavior (Shay- witz et al. 1990). Since boys are generally more active and impulsive, they are morelikely to be identied through traditionalschool-identication procedures, whereasgirlswho are generally quiet and who may struggle to readoftengo unnoticed.A rangeof data now indicate that although there aresomewhat more boys, signicant numbers of girls struggle to read (Flynn & Rahbar 1994,Shaywitz et al. 1990). Awareness of a students

reading difculties should not be dependent on overt signs of a behavioral difculty; theincreased reliance on ongoing monitoring of reading uency (for example, use of dynamicindicators of basic early literacy skills, orDIBELS; Kameenui et al. 2000) should helpto ensure that all children who are failing tomake progress will be identied and receiveappropriate interventions.

COGNITIVE MODEL OF DYSLEXIA AND ITSIMPLICATIONS

Phonological Theory

Print emerged from the language system,

the relationship between print and spoklanguage is perhaps best captured by thestament, Writing is not language, but mere way of recording [spoken] language by ble marks (Bloomeld 1933, p. 21). Ofseveral theories suggested, an explanationecting what is known about the relatiship between spoken and written languathephonologicalmodel,hasreceived themsupport (Hulmeet al. 2005, Ramus et al. 20Rayner et al. 2001, Shaywitz 2003, Snow

2000). Most contemporaryapproaches to diagnsis and to teaching dyslexic children to derive from a phonological model of hchildren gain access to print. In particuknowledge of this model enables the reato understand the basis and logic of currevidence-based reading instruction. Here discuss the nature and educational impltions of this model; in a later section, cic evidence-based approaches to reading

tervention are presented. To understand wprint has meaning and why reading presenchallenge, we rst consider the language tem and then discuss why reading is morecult than speaking.

The language system. The language stem is conceptualized as a hierarchy of cponent modules (Fodor 1983); at the lowlevel is the phonological module, dedicto processing the elemental units of langu

phonemes. Language is generative; diffecombinations of just 44 phonemes in the glish language produce tens of thousand words (Abler 1989). The phonological muleassemblesthephonemesintowordsforspeaker and disassembles the words backphonemes for the listener. Reecting a pcess referred to as coarticulation, spoken guage appears seamless to the listener, w


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Functionalmagneticresonance imaging (fMRI): using themagnetic propertiesof blood to measureblood ow andlocalize brainprocesses whilesubjects perform acognitive task

relationship between letters and sounds(e.g., especially English, but also Danish,Portuguese, and French) (Caravolas 2005,Goulandris 2003, Ziegler & Goswami 2005). Although dyslexia occurs in all languages, variations in the consistency of the mapping

of the orthography to the phonology will in-uence reading acquisition and strategies, re-sulting in differences in reading development among languages (Ziegler & Goswami 2005).Of importance from an educational perspec-tive is that the more consistent the letter-sound mappings are, the easier it is for chil-dren to learn to read words accurately. Thus,the initial steps of literacy acquisition oc-cur earlier and with more ease in languagessuch as Finnish and Italian, where there is

greater predictability of sound-symbol link-ages. Variations in consistency, in turn, willinuence theexpressionof dyslexia across dif-ferent languages. For example, in orthogra-phies that are more consistent, learning toread words accurately generally occurs read-ily in dyslexic as well as in good readers. Asa result, in these readers, dyslexia may not present itself until later on in school, perhapsafter fourth grade or so, and may be expressedonly as a problem in reading uency, with

reading accuracy relatively intact (Ziegler &Goswami 2005). The inconsistencies betweenthe sounds and their spellings, not surpris-ingly, also affect dyslexic children and causedifculties in spelling. Ziegler & Goswami(2005) posit that these variations will affect how well dyslexic children develop phonemicawareness once literacy instruction begins. They argue that consistent phonemic-letterlinkages tend to be held and kept in memory more easily so that they are better instanti-

ated in response to reading instruction; as aresult, dyslexic children demonstrate phono-logical decits only very early on in these lan-guages. In contrast, in languages such as En-glish, with more unpredictable letter-soundsmappings, decits in phonemic awareness arenoted early on in school and persist throughadolescence (Shaywitz et al. 1999) and intoadulthood (Bruck & Treiman 1992).

ETIOLOGY

Genetic Inuences

Dyslexia is both familial and heritable: disorder is found in 23% to 65% of the cdren of parents who are dyslexic, and 4

of the siblings of a dyslexic child are alsfected (Pennington & Gilger 1996). Intereingly, a higher heritability for dyslexiabeen reported in children with higher I(Olson et al. 1999, Wadsworth et al. 20Genetic transmission is complex, with brecessive anddominant transmission obserin different cases, with at least 50% or mof the variance explained by genetic facand the remainder attributed to environmetal inuences (Olson & Byrne 2005). L

age studies have implicated genes on chromosomes2, 6, 15, and 18in dysl(Fisher & DeFries 2002). At least nine have been reported to be associated withdisorder. Much attention has recently ctered on DCDC2, located on the short a(p) of chromosome 6 in band 22 (6p22),its association with dyslexia has been ipendentlyreported by twodifferent investitive groups (Meng et al. 2005, Schumacet al. 2006). These ndings of a strong

netic inuence have educational implicatiIfachildhasaparentorsiblingwhoisdyslethat child should be considered at risk and oserved carefully for signs of a reading dculty. It is also important to emphasize thgenetic etiology does not constrain a posiresponse to reading intervention (Torgesen Mathes 2000; Wise et al. 1999, 2000); oidentied, dyslexic children deserve andbenet from evidence-based interventions

Neurobiological Inuences Within the past two decades, the developmof neuroimaging,particularly functionalmnetic resonance imaging (fMRI), hasproviinvestigators and clinicians with the opptunity to examine and treat learning disabties at a previously dreamed of, but unattable, level of understanding (Anderson


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Gore 1997, Frackowiak et al. 2004, Jezzardet al. 2001). Using this technology, neurosci-entists have been able to identify and local-ize several interrelated left hemisphere neuralnetworks in reading: an anterior network inthe inferior frontal gyrus (Brocas area), long

associated with articulation that also servesan important function in silent reading andnaming (Fiez & Peterson 1998, Frackowiak et al. 2004), and two in left hemisphere pos-terior brain regions, one around the parieto-temporal region serving word analysis, theother in the left occipito-temporal region,the word form area, critical for skilled, u-ent reading. A number of functional brainimaging studies in disabled readers convergeto indicate a failure of left hemisphere poste-

rior brain systems to function properly dur-ing reading (Brunswick et al. 1999; Heleniuset al. 1999; Horwitz et al. 1998; Paulesu et al.2001; Rumsey et al. 1992, 1997; Salmelinet al. 1996; Shaywitz et al. 1998) (Figure 2 ). This neurobiological evidence of dysfunctionin left hemisphere posterior reading circuitsis already present in reading-disabled chil-dren and cannot be ascribed simply to a life-time of poor reading (Seki et al. 2001, Shay- witz et al. 2002, Simos et al. 2000, Temple

et al. 2000). Anterior systems, especially involving regions around the inferior frontalgyrus, have also been implicated in disabledreaders in reports of individuals with brainlesions (Benson 1994) as well as in func-tional brain imaging studies (Brunswick et al.1999, Corina et al. 2001, Georgiewa et al.2002, Paulesu et al. 1996, Rumsey et al. 1997,Shaywitz et al. 1998). Although dyslexic read-ers exhibit a dysfunction in posterior readingsystems, they appeartodevelopcompensatory

systems involving areas around the inferiorfrontal gyrus in both hemispheres as well asthe right hemisphere homologue of the left occipito-temporal word form area (Shaywitzet al. 2002).

Malleability of neural systems for read-ing. A number of investigators have focusedon whether the neural systems for reading

are malleable and whether the disruption inthese systems in struggling readers can be in-uenced by a reading intervention. Specicinterventions are discussed below; here, wefocus on brain imaging as a tool to inter-rogate the plasticity of these systems and to

examine the inuence of reading instructionon thedevelopment or reorganization (repair)of these neural systems. For example, in astudy of second- and third-grade dyslexic andnonimpaired readers, compared with dyslexicreaders who received other types of interven-tion, children who received an experimentalevidence-basedphonological interventionnot only improved their reading but also demon-strated increased activation both in left an-terior (inferior frontal gyrus) and left poste-

rior (middle temporal gyrus) brain regions(Shaywitz et al. 2004). These ndings in-dicate that teaching matters and that how children are taught can foster the develop-ment of those automatic neural systems that serve skilled reading.Other investigators, too,have found that reading interventions inu-ence neural systems in brain. For example,onestudy in adults demonstrated greater activation in the left prefrontal cortex after train-ing compared with before training (Temple

et al. 2000). Other studies in children havereported intervention-associated changes in-cluding fMRI changes in left inferior frontaland posterior areas as well as in right hemi-sphere and cingulate cortex (Temple et al.2003); changes in lactate concentration dur-ing magnetic resonance spectroscopy in theleft frontal regions (Richards et al. 2000);fMRI changes in left frontal and left posteriorregions (Aylwardet al. 2003);changes in mag-netoencephalographyin the left superior tem-

poral gyrus (Simos et al. 2002); and changesin fMRI in dyslexic adults in posterior readingsystems (Eden et al. 2004). Still to be deter-mined is the precise relationship among thetype of intervention, changes in brain activa-tion, and clinical improvement in reading.

fMRI and mechanisms of reading. fMRIhas also been very useful in understanding


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LPMOT: left posterior and medialoccipito-temporalregion

LALOT: left anterior and lateraloccipito-temporalregion

the mechanisms of reading, knowledge that offers the possibility of providing more indi- vidualized interventions to dyslexic childrenand adults. Neurobiological evidence is be-ginning to emerge to support behavioral dataindicating that many dyslexics are not able to

make good use of sound-symbol linkages asthey mature, and instead, they come to rely on memorized words. Behavioral studies in-dicate phonologic decits continue to charac-terize struggling readers, even as they enteradolescence and adult life (Bruck & Treiman1992, Shaywitz et al. 1999). In addition, per-sistently poor adult readers appear to read words by memorizationso that they are able toread familiar words buthave difculty readingunfamiliar words. Brain imaging now reveals

that such readers demonstrate an aberrant neural connectivity pattern. Thus, in nonim-paired readers, functional connections wereobserved between the left occipito-temporal word form area and other components of thelefthemisphere reading system. Incontrast, inpersistently poor readers, functional connec-tions were observed between the left occipito-temporal word form area and right frontalneural systems regions associated with mem-ory (Shaywitz et al. 2003).

A more recent fMRI study (Shaywitz et al.2007) also demonstrates the importance of memory systems in dyslexic readers. Thisstudy found that brain regions developing with age in dyslexic readers differ from thosein nonimpaired readers, primarily in beinglocalized to a more left posterior and me-dial (LPMOT), rather than a more left ante-rior and lateral (LALOT) occipito-temporalregion. This difference in activation pat-terns betweendyslexic andnonimpaired read-

ers has parallels to reported brain activationdifferences observed during reading of two Japanese writing systems, Kana and Kanji.Kana script employs symbols that are linkedto the sound or phoneme (comparable to En-glishandotheralphabetic scripts);Kanji script uses ideographs where each character must be memorized. In the imaging study of these writing systems, LALOT activation, similar

to that seen in nonimpaired readers, occurduring reading Kana. In contrast, LPMOactivation, comparable to that observeddyslexic readers, was noted during readof Kanji script (Nakamura et al. 2005), gesting that the LPMOT region functio

as part of a memory-based system. Togeththese behavioral and recent neurobiologndings lead us to suppose that as dyslchildren mature, this posterior medial syssupports memorization rather than the pgressive sound-symbol linkages observenonimpaired readers.

Implications of brain imaging studies. The brain imaging studies reviewed abprovide neurobiological evidence that i

minates and claries current understandof the nature of dyslexia and its treatmForexample, brain imaging has taken dyslfrom what had previously been considerhidden disability to one that is visiblendings of a disruption in posterior readsystems are often referred to as a neuralnature for dyslexia.

Important, too, is the demonstration odisruption in the occipito-temporal or wform system, a system that converging b

imaging studies now show is linked toent (automatic, rapid) reading. Disruptionthis system for skilled reading has veryportant practical implications for the dyslreaderit provides the neurobiological dence for the biologic necessity for addititime on high stakes tests (see Accommtions section below).

Studies demonstrating the effects oreading intervention on neural systems reading have important implications for p

lic policy regarding teaching children to re The provision of an evidence-based readintervention at an early age improves reing uency and facilitates the developmof those neural systems that underlie skireading (see section on interventions). fMstudies focusing on the mechanisms of ring indicate that poor readers rely on meoryratherthan understanding howletters li


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to sounds. Furthermore, these studies under-score the importance of uency; many bright but struggling readers memorize words andcanread them relatively accuratelybutnotau-tomatically, and so they read slowly and withgreat effort.

Thus, evidence is beginning to emerge toindicate that many dyslexics compensate fortheir poor reading by memorizing words.Theproblem, of course, for poor readers, is that memory has a limited capacity. For exam-ple, by third or fourth grade, a reader comesacrossperhaps3000ormorenewwordsayear. Many of these words are difcult to memo-rize because they are long, complicated, new,or rare words. Those typical readers who havelearned about the sound-symbol organization

of written language are able to analyze wordsbased on the letter-sound linkages and havea distinct advantage over the dyslexic reader. The reliance on memory systems in thesepopulations of older disabled readers may have implications for treatment of dyslexia.For example, it suggests that more pragmaticinterventions focusing on sight words (suchas those occurring in assigned reading mate-rials) and provision of accommodations suchas aural presentation of literature (e.g., books

on tape; see Accommodations section be-low) might take on a more signicant rolein these older dyslexic individuals than wouldan approach used in younger students that is based primarily on teaching sound-symbolassociations.

DIAGNOSIS AND TREATMENT

Diagnosis of Dyslexia

Dyslexia is more than simply a score on areading test. Reecting the core phonolog-ical decit, a range of downstream effectsis observed in spoken as well as in writtenlanguage. Phonological processing is criticalto both spoken and written language. Al-though most attention has centered on theprint difculties (and they are the most severe), the ability to notice, manipulate, and

Phonologicalprocessing: acategory of orallanguage processiinvolved withaccessing the spesounds making upspoken words

retrieve phonological elements has an impor-tant function in speakingfor example, in re-trieving phonemes from the internal lexiconand serially ordering them to utter the spo-ken word. Thus, it should not be surpris-ing that problems with spoken language, al-

beit more subtle than those in reading, areoften observed. These include late speaking,mispronunciations, difculties with word re-trieval, needing time to summon an oral re-sponse, and confusing words that sound alike,for example, saying recession when the in-dividual meant to say reception. A rangeof problems are noted in reading (especially small function words and unfamiliar words,slow reading);difculties in spelling;ability tomaster a foreign language; handwriting; and

attention(Shaywitz 2003).The lack of readinguency brings with it a need to read manu-ally (a process consuminggreat effort) ratherthan automatically; the cost of such reading isa tremendous drain on attentional resources. This is often observed in the classroom whenstruggling readers, asked to read quietly, de-plete their attentional resources as they strug-gle with the print, and consequently appearto be daydreaming or not attending to the as-signed reading. Some have posited that the

need to call upon exceptional attentional re-sources duringreading leads to theclinical ap-pearance of attentional difculties, in this in-stance, secondary to the reading difculty andnot primary (Pennington et al. 1993). That is, it is to be viewed as distinct from a pri-mary attentional problem. In addition, it haslong been known that there is also a highcomorbidity between dyslexia and attentiondecit/hyperactivity disorder, ranging from15% to 50% (Biederman et al. 1996, Shaywitz

et al. 1994). Therefore, both primary and sec-ondary attentional difculties are often notedin individuals who are dyslexic.

In contrast to these difculties, other cog-nitive abilities, including thinking, reasoning, vocabulary, and listening comprehension, areusually intact. Intact higher-level abilities of-feranexplanationof whyreading comprehen-sion is often appreciably above single-word


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National Reading Panel:Congressionally mandated in 1998 toreview researchliterature onteaching reading,and in 2000 reportedon the most effectivemethods andapproaches

Phonics: anapproach to early reading instructionemphasizingletter-sound linkages

reading accuracy and uency in dyslexia (reviewed in Shaywitz 2003).

Dyslexia is a clinical diagnosis, best madeby an experienced clinician who has taken acareful history, observed the child or youngadult reading, and administered a battery of

tests that assess the childs cognitive abil-ity, academic skills including reading accu-racy, uency, and comprehension, spelling,and mathematics (an area in which skillsare often high), and language skills, partic-ularly phonological processing (Marzola &Shepherd 2005, Shaywitz 2003). The unevenpeaks and valleys of both cognitive and aca-demic functioning contribute to the clinicalpicture of dyslexia: a weakness in phonolog-ically based skills in the context of often-

stronger cognitive and academic skills innonreading-related areas. As children mature, compensation often

occurs that results in relatively accurate, but not uent, reading. Awareness of this devel-opmental pattern is critically important forthe diagnosis in older children, young adults,and beyond. The consequence is that suchdyslexic older children mayappear to performreasonably well on a test of word reading ordecoding; on these tests, credit is given irre-

spective of how long it takes the individualto respond or if initial errors in reading arelater corrected. Accordingly, tests of readinguencyhow quickly and accurately individ-ual words and passages are readand tests as-sessing reading rate are keystones of an as-sessment for, and an accurate diagnosis of,dyslexia.

Teaching Reading to DyslexicStudents Within the past decade, an evidence-basedapproach to teaching children (includingdyslexic children) to read has emerged. Muchof the evidence base was synthesized by theNational Reading Panel established by theU.S. Congress in 1998 with a mandate toreview existing research on teaching chil-dren to read and then to present the data

in a Report to Congress. The panel workfor two years reviewing the extant datateaching children to read published in pereviewed journals, performing meta-analy where the data allowed, and reportingCongress onits ndings inApril 2000. Asa

sult of its exhaustive review, the panel fothat ve essential elements should be inporated into effective reading instructiophonemic awareness,phonics, uency, voculary, and comprehension (Rep. Natl. ReingPanel 2000)and that these are optimataught systemically and explicitly. These pirically rooted ndings converge with w we know about why print has meaningnoted above, a core decit in phonologprocessing is observed in a majority of

dren and adults with developmental dysl(Liberman & Shankweiler 1991). Thus, not surprising that a majority of the manycent well-controlled research studies havecusedonpreventing or remediating thesecphonological decits.

Early Intervention Probably the most hopeful research has bearly intervention studies of children

risk for dyslexia based on their prob with phonological processing or initial widentication skills (Lonigan 2003) in kingarten or the rst grade. Both classroolevel interventions (Adams & Carnine 2Foorman et al. 1998, Fuchs & Fuchs 20and pullout remedial approaches (Blachm1997, DAgostino & Murphy 2004, Torgeet al. 1999, Vellutino et al. 2006) combinations of classroom and pullout proaches (OConnor 2000, Simmons et

2003, Vaughn et al. 2003) have reported pitive results. Although denitions of readdisabled or dyslexic subjects in these stu varied, on average, large effects sizes (> 0. were reported. Together, these studies sgest that prevention programs that explicfocus on phonemic awareness, phonics, meaning of text in the earliest grades of ring instruction reduce the base rates of at-


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students to below 5%. Although one can-not explicitly dene such children as havingdyslexia because they are typically just learn-ing to read, and it is difcult to dene a word-reading decit at this level of readingdevelopment, it appears that these systematic

programs cansignicantly improve core read-ing skills in the weakest readers at these ages.

Interventions for Older StudentsFor older students the remedial research lit-erature includes a range of intervention pro-grams, including those described as direct in-struction and those that are more strategy based (Swanson et al. 1999). Here, the ev-idence is less encouraging than for younger

children. Investigations using remedial interventions that begin after the second grade in-dicate it is more challenging to bring chil-dren or adults up to expected grade levelsonce they fall behind, although signicant improvements in reading can still occur (ef-fect sizes> 0.60). As an example, Lovett et al.(2000) combined a program referred to as anexplicit, scripted direct-instruction approach(based on Reading Mastery; Engelmann &Bruner 1988) that focused on phonologi-

cal analysis and blending of phonemes witha strategy-based program (an expanded andadapted version of the Benchmark program;Gaskins et al. 1986) that focused on teachingchildren metacognitive strategies to assist in word identication. This combined program,and adaptations of it for different grade levels,have been evaluated with severe dyslexic stu-dents in both elementary and middle schoolin randomizedexperimentaldesigns withcon-trolgroups.Resultsofimplementationofsuch

combination programs indicated that this ap-proach resulted in signicantly better stan-dardized reading measure outcomes than theindividualcomponentsaloneor othercontrast programs (Lovett et al. 2003).

In an intensive eight-week evaluation of two different phonologically based programs, Torgesen et al. (2001) focused on older el-ementary students with word-reading abili-

ties below the fth percentile. The investiga-tors showed that these explicit programs re-sulted in signicant improvements in readingon standardized reading measures followingthe interventions, and many of the studentstested in the average range on word identi-

cation measures (but not uency measures). More importantly, the gains made in wordidentication lasted for more than two yearspost intervention.

These and many other studies (for morecomprehensive reviews, see Fletcher et al.2007; Shaywitz 2003; Swanson et al. 1999,2003) have provided theevidence that phono-logically based decoding and word recog-nition skills are teachable aspects of read-ing for most children (Moats & Foorman

1997, p. 188). This corpus of evidence in-dicates that focused, intense, systematic, andexplicit interventions can positively impact word-reading development, with some ex-pected transfer impacting comprehension, ineven the most severely disabled dyslexic read-ers and that many different types of remedia-tion programs can be effective. This is an im-portant nding, for there is often a tendency to search for the one (magical) program that will address all struggling readers difculties.

Current knowledge supports several types of intervention programs as effective. Evidenceis not yet available that would allow the selec-tion of one specic program over others or tosupport the choice of an individual programthat would be specically more benecial toparticular groups of dyslexic readers.

Beyond Word Accuracy Fluency. The consistent improvement in

phonologically based word attack and de-coding skills has not always generalized toaccurate, uent text reading or adequatereading comprehension, the ultimate goal of all reading interventions (Lovett et al. 1989, Torgesen et al. 1997). Moats & Foorman(1997) review this problem and state, gener-alization and transfer of decoding prociency to uent word recognition and better reading


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Scaffolding: ateaching strategy where the teacherprovides scaffolds(supports) that facilitate the childsability. For example,the teacher reads apassage slightly moredifcult than thechild is able to readby him/herself. Thechild then reads thesame passagerepeatedly andgradually learns toread this previously difcult section withfacility

comprehension was not automatic. . . (p. 188), a conclusion that has continued tobe echoed by other studies and reviews (Lyon& Moats 1997, Rayner et al. 2001, Rep. Natl.Reading Panel 2000, Snow 2002, Torgesenet al. 1997).

These results and questions have more re-cently raised signicant interest in whetheruency decits can be treated in reading-disabled and dyslexic subjects and whethersuch interventions (see Kuhn & Stahl 2003,Rep. Natl. Reading Panel 2000 for morecomprehensive reviews) should be focusedon connected-text or word-level strategies. Meyer & Felton (1999) found that most u-ency programs use repeated reading of con-nected text, although some newer programs

focus on broader developmental models of uency encompassing both building semanticknowledge and orthographic pattern aware-ness (Wolf et al. 2000).

As examples of the repeated readingapproaches, Stahl & Heuback (2005) and Young and associates (1996) reported signif-icant gains in their poor readers text read-ing uency using connected text methods, whereas Levy and associates (1997) and Tan& Nicholson (1997) focused their interven-

tions at the word level and showed similar but less robust gains in connected text uency. A key aspect of most uency-focused interven-tion programs with dyslexic students is that they require signicant reading of connectedtext with scaffolding support by either peersor teachers. The conceptual framework be-hind these approaches is that as word identi-cation becomes more automatic, due to in-creasing orthographic awareness via practice,an improving reader requires less strategic at-

tention on the act of reading as it becomesautomatic and can direct more cognitive en-ergy and focus on comprehension of mean-ing. Kuhn & Stahls (2003) review of uency-oriented instructional approaches found that repeated reading of text with scaffolding typi-cally produces gains in uency and reading-related skills similar to reading the equiva-lent amounts of nonrepetitive text (average

effect sizes 0.350.50). This nding suggthat its the amount of reading that is ccal in supporting the development of uand automatic reading. Chard and associa(2002) review of studies specic to stud with dyslexia found slightly higher averag

fect sizes (0.500.70) for a range of intertion approaches focused on uency.

Reading comprehension. Although chdren and adults with dyslexia are denetheir word identication and decoding prlems, some may also have reading comhension difculties that are not due to an derlying oral language disorder. Becausthis, some researchers have focused on in vention programs aimed at reading comp

hension abilities. Most remedial approachave developed comprehension-related stegy instruction or specic comprehensirelated skill instructional types of prograStrategy-related programs have focuseddeveloping critical thinking skills relateunderstanding of text and constructingmeaning based on the readers prior knoedge, prediction of text, monitoring of tstructure, and question asking, as exampSkill-related programs focus more on nd

ideas and facts, developing multiple meaof words and increasing vocabulary, and smarizing text.

Several reviews ( Jenkins & OCon2003, Swanson et al. 1999, VaughnKlingner 2004) suggest that various typecomprehension-focused intervention studin reading-disabled children and adults, pticularly those usingexplicit, strategy-focuapproaches, were effective. Unfortunatbecause of the wide range of methodolo

used in these studies and the variety of grammatic approaches, the resulting rangeffect sizes seen in comprehension-focuintervention studies of dyslexic studentypically broad (0.200.70). It appears many of these studies support the efcacthe comprehension-focused remediationprgrams ability to teach their specic strgies, but the ability of students to apply th


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strategies innewtextreading andcomprehen-sion situations is less consistent.

Treatment ResistersIn their focus on treatment resisters,Torgesen

& Mathes (2000) highlighteda key setof nd-ings across all intervention studies: A numberof children and adults do not respond to pro-grams that are shown to be effective in theirpeers. Such results highlight the heterogene-ity of the dyslexia population, but also sug-gest that nooneexplicit remedial instructionalprogram, whether focused at the levelof wordidentication, uency, or comprehension, orany combination of these processes, will beable to successfully address the needs of all

such readers. The kinds of issues raised by suchconsistentndings of treatment-resistersacross different interventions focus on con-textual or procedural factors rather than con-tent itself. Questions include how best to un-derstand the role of (a) instructional intensity (length of intervention, hours of instruction,optimal ratios of teachers to students, read-ing time, etc.); (b) program integrity/delity;(c ) teacher ability/experience; (d ) programfocus/explicitness/multidimensionality; and

(e) individual student prior instructional ex-periences/exposure and reading abilities. The ways in which these factors, individually andtogether, affect treatment outcomes is just beginning to be addressed, particularly fortreatment resisters. The answers to theseunresolved questions will provide criticalinformation to better understand the ways in which effective instructional programs may affect any specic student with dyslexia.

Response to Intervention It has become increasingly apparent that sev-eral causes exist for students deciencies inreading. Such students may be instructionalcasualties resulting from poor, inappropriate,or noneffective reading instruction. On theother hand, some reading-decient studentshave received quality reading instruction but

still have not mastered reading due to theirunderlying individual core phonological andlinguistic decits. In addition, some studentshave experienced both factors. Such problemsare not easily addressed via one-time evalua-tions or interventions without some develop-

mental perspective and sequential evaluationsover time. The thrust of RTI frameworks (Fuchs &

Fuchs 2006) is to address these traditionallimitations in the treatment of persons withdyslexia by focusing on change over time. A typical model would screen all students oncoreacademicabilitiesinthis casereadingand identify those at risk using somewhat liberal criteria (resulting in more false posi-tives). These students are then followed us-

ing frequently repeated reading-focused eval-uation probes during an academic year (or years) while they are receiving systematicreading instruction. Those students who donot make adequate progress compared withtheir typically developing peers (comparingthe amount of change over a given time pe-riod) are then provided with increasingly in-tense and, as needed, alternative approachesto reading interventions and continue to bemonitored over time. Students who receive

the best available quality instruction and whodo not respond to these increasingly explicit,intense, and alternative approaches over time would then be classied as dyslexic or learn-ing disabled (Presid. Commiss. Excell. Spec.Educ. 2002).Clearly, such multitiered modelsstill depend on measures sensitive to change,denitions of adequate change, validated in-terventions of increasing intensity, instruc-tional integrity, and a systematic approachat the school/teacher level to ensure that

all students are monitored. McMaster andcolleagues (2005) have provided one of thebetter examples of this approach to childrenacross 33 classrooms. Less than 5% of thosechildren who, via the ongoing weekly mon-itoring of reading, received increasingly in-tense and ultimately one-on-one instruction were still considered not to have made ad-equate progress in reading, compared with


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nearly 15% of the control classrooms usingstandard reading instruction and practices. The use of RTI models is expected to be arapidly growing trend in the school identi-cation of reading difculties.

Summary of InterventionsExplicit, intense, systematic, and develop-mentally appropriate interventions are effec-tive and provide an evidence-based approachin treating dyslexia. Interventions focused at word decoding and single-word identicationlevels have had the most consistent evidenceand have been shown to be the most effective,particularly in preventionandearly childhoodstudies. Fluency-andcomprehension-focusedinterventions have had less investigation but have still shown signicant, albeit more vari-able, effects on reading outcomes in thesestudents. Programs that systematically inte-grate multiple-focused interventions are con-sidered the most effective, although their spe-cic sequencing, degree of overlap, and leveloffocusoneachcomponentduringeachphaseare still open to critical investigation. At thispoint, determining which instructional pro-gram works best is not necessarily important,but rather determining what program works

best for what kind of dyslexic student with what kind of characteristics in what kind of implementation.

Overall, signicant progress has beenmade in understanding the cognitive basis of dyslexia and in using this knowledge to in-form instructional practices.At thesame time,it must be kept in mind that we are only in the early stages of discovering and devel-oping specic reading interventions that willconsistently improve all components of read-

ing, including accuracy, uency, and compre-hension. Broad-stroke gains have been madein developing an overall template for providing reading interventions to dyslexic stu-dents; however, we await evidence to guidethe more ne-grained selection of specic in-terventions for individual struggling readersat all ages and at all levels of reading ability.

Accommodations A complete education for a dyslexic stuincludes evidence-based reading intervtions and accommodations. As noted abintervention data, although promising, h yet to indicate that the gap has been closethe ability of dyslexic students to read wuently beyond the rst few grades. Accingly, although dyslexic children will imptheir accuracy, decient uency continuebe a concern at all grade levels, and incringly so as children move up into midand high school and then into postsecondeducation.

Accommodations are of three gentypes: (a) those that by-pass the reading culty by providing information through

auditorymode,(b)thosethatprovidecompesatoryassistive technologies, and(c ) those tprovide additional time so that the dysureader can demonstrate his/her knowledge

First,beginningquite early in their schoing,dyslexic readers require alternativemoof acquiring information so that their voculary and fund of knowledge better retheir intellectual level than does their paired reading ability. Access to recorded terials, whether they are based on the sch

curriculum or reect what peers are readforpleasure,areanecessityforsuchchildrethey are to keep up with their classmates with their own intellectual curiosity andterests. Next,assistive technology, computandboth print-to-speechas well as speech-print software provide further compensatfor oft-noted difculties with handwritspelling, and lack of uency. A major vance has been the convergence of behavandneuroimagingdataprovidingevidence

the critical need for extra time on examtions for dyslexic students, particularly as tprogress toward high school graduation beyond. Behavioral data indicating the psistence of dysuent reading are now sportedby neurobiologicaldatademonstratthat the left anterior lateral occipito-tempo(word-form) region responsible for u


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rapid reading is disrupted in dyslexic childrenandadults(Dehaeneetal.2005;Shaywitzetal.1998, 2003). As the neurobiological data indi-cate, dyslexic readers develop compensatory neural pathways, and these systems support increased accuracy over time. However, the

word-form region does not develop (Shaywitzet al. 2007), and compensatory pathways donot provide uent or automatic reading. Ac-cordingly, if such students are to demonstratethe full range of their knowledge, provisionof additional time on examinations is a neces-sity to compensate for the lack of availability of the efcient word-form area. Currently, noquantitative data are available to serve as a re-liable metric for gauging the specic amount of extra time needed by a student, and this

determination is best guided by the studentsown experience over the years. Because thepersistence of the reading difculty is indi-cated by both behavioral and imaging longi-tudinal data, requiring that students in post-secondarysettings be tested every three orve years is not consistent with scientic knowl-edge. Furthermore, it is extremely expensiveand even problematic. As students progressthrough school to higher grades and compen-sate in reading accuracy, simple reading mea-

sures of word identication fail to capture dif-culties inuent reading and soare often mis-leading. In addition, since such nonautomaticreaders must call upon attentional resourcesduring reading, these students are highly sus-ceptible to noise and other distractions. Study

and test taking in quiet, separate rooms al-lowthese dysuent readers to concentrate andmake maximum use of their often strained at-tentional resources.

In summary, given that dyslexia representsa disparity between an individuals readingand intellectual abilities; accommodations arecritical to assure fairness and equity. Con-temporary management of dyslexia providesevidence-based accommodations; these in-clude access to recorded materials; computers

and print-to-speech software; and additionaltime on examinations, with the amount of time determined by the students experience(Shaywitz 2003). Such accommodations areprovided based ona students history, observa-tions of his/her reading aloud,andtest results. With the provision of such accommodations,dyslexic students are entering and succeedingin a range of professions, including journal-ism, literary writing, science, medicine, law,and education (Shaywitz 2003).

SUMMARY POINTS

1. The core concept of dyslexia as an unexpected difculty in reading has remainedinvariant over the century since its rst description; dyslexia is found in all languagesincluding both alphabetic and logographic scripts.

2. A decit in phonological processing, accessing the individual sounds of spoken words,represents the core weakness in dyslexia, and its remediation is the focus of early intervention programs for at-risk and struggling readers.

3. Dyslexia is a chronic, persistent difculty and is neither a developmental lag noroutgrown; the implication is that reading problems must be recognizedandaddressed

early.4. Evidence-based interventions are now available and have positive effects on reading.

The most consistent and largest effect sizes are associated with provision of preventionprograms explicitly focused on phonological awareness, phonics, andmeaning of text.

5. Intervention programs for children beyond second grade, though effective, are chal-lenging and have produced less-consistent results. Such evidence-based programsfocus on systematic, phonologically based instruction and teaching metacognitive


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strategies to assist in word identication. No single program is the most effectivmany types of remediation programs can be effective.

6. Fluency decits have proven much more difcult to remediate than word accuracproblems. Many children who respond to programs aimed at improving word identication skills remain dysuent, slow readers. Approaches that focus on repeateoral reading with feedback and guidance have shown the most consistent positive rsults. For readers who are not uent and cannot read individual words automaticallyreading remains effortful and slow.

7. Neurobiological studies have revealed differences in the neural circuitry for reaing between nonimpaired and dyslexic readers and identied a neural signature fodyslexia. Brain imaging has also indicated a target (the left occipito-temporal woform area) for intervention for skilled or uent reading and that these systems armalleable and respond to effective reading interventions. Such ndings demonstratthe importance and powerful impact of effective reading instruction.

8. Interventions, while promising, have yet to close the gap in the ability of dyslex

children to read uently; dyslexic children often remain accurate but slow readerNeurobiological evidence indicates that the failure of the word form area to functioproperly in dyslexic children and young adults is responsible for their characteristinefcient, slow reading. Accommodations, particularly the provision of extra timare essential for dyslexic students to fully demonstrate their knowledge.

FUTURE ISSUES

1. To identify which specic instructional components/programs work best for whichspecic types of dyslexic students and under what kinds of implementation practice

2. To identify which specic instructional elements in which specic combination improve uency and reading comprehension, particularly in older students.

3. To identify the role of attentional difculties in dyslexic readers.

4. To determine effective methods of identifying at-risk children earlier and more accurately.

5. To determine mechanisms by which the phonology and orthography are integratedin the word form region and how this process could be facilitated.

ACKNOWLEDGMENTS The work described in this article was supported by grants from the National Institute of ChHealth and Human Development (P50 HD25802, RO1 HD046171, and R01 HD057655)Sally Shaywitz and Bennett Shaywitz.

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www.annualreviews.org Education of Dyslexic Children C-1

Figure 1 Trajectory of reading skills over time in nonimpaired and dyslexic readers. Ordinate is Rasch scores(W scor

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