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Jpn. J. Spec. Educ., 45 (6), 383-404, 2008.
invited PaPerCurrent Topic
The Multiple Systems Model of Reading:Understanding Reading Disabilities andTheir Effect on Academic Achievement
Across Individuals and Orthographies
Rauno PARRILA
The present paper contends that for a fu11 understanding of reading develop-ment and disabilities, both within and across languages, a better meta-theoretical
framework is needed in order to guide research and interpret research findings
so that they can be applied to educational practice. The framework presented,called the
`Cmultipic systems model of reading'], views development as contingent
cycles of construction and reconstruction that developmental resources at various
levels of functioning (genetic, neural, psychological, behavioral, and environmen-
tal) contribute to. The model makes two key assumptions: (a) reading abilities are
continuously distributed, and (b) the developmental process has distributedcontrol; every observed outcome is jointEy determined by multiple factors, includ-ing the developing organism itself. Ramifications of these assumptions for both
research and educational practice are discussed. Educational practicc is well
served by respecting the complex, and sometimes idiosyncratic, nature of' the
developing organism, and by not a]locating causal responsibility, or all the
remedial eflbrts, of possible reading problems to any single cause.
Key Werds: reading disabilities, dyslexia, multiple system modcl, core deficit
Introduction
Reading disabilities in general and developmental dyslexia in particular are
conceptualized and assessed variably both within and across linguistic contexts,
leading to both definitional and 'theoretical
cenfusion. The present article proposesthat a theoretical framework is needed that encompasses multiple Ievels of function-
ing, in order to enhanee the knowledge of why individuals (both within and across
linguistic contexts) fail to develop suMcient word-reading or text-level reading skMs,
and how such skills are related to each other and to academic outcomes. Specifically,
to understand probabilistic relationships between possible cognitive deficits, word-
and text-level reading problems, and difflirent academic and remedial outcomes,
University of Nberta
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rnodels adhering to the principles of developmental systems theory (DST; e.g.,
Oyama, GriMths, & Gray, 2001) provide better meta-theoretieal frameworks than any
single (or dual) core deficit model that is currently relied on. One such model, the
Multiple Systems Model of Reading (MSMR), will be presented.
In what foIIows, shortcomings ot' theories of reading disabilities, mainly of
dyslexia, wil1 be discussed, after which devclopmental systems theory and the
Multiple Systerns Model of Reading will be presented. Seme recent studies guided bythe Multiple Systems Model of Reading wM be described, and its educational
implications wM be discussed.
Theories of Reading Disabilities
A great deal of research on children and adults with. reading disabilities has
focused on identifying the source or corc deficit of the reading disability on the
cognitive Ievel of analysis. The majority of these studies have fbcused on English-
speaking individuals with word-level reading problems, or dyslexia, and have aimedat verifying or refuting the existence of some qualitative difi'erences between the
individuals who are dyslexic and control groups.
For the large part, studies with individuals who are developmental dyslexics (asopposed to neuropsychological studies with peop}e who are acquired dyslexics) have
been guided by single-factor theeries, most of which posit a specific impairment in the
ability to manipuiate, retrieve, and/or store phonological information as the cognitive
level core deficit responsible for poor reading (e.g., Frith, 1999; Ramus & Szenkovits,
2008; Snowling, 2001). When other explanatory constructs have been examined, their
purpose has been either to provide a neuroLogical and/or perceptual level explanation
for the cognitive level phonological deficits (e.g., Ahissar, 2007; Goswami, Thomson,
Richardson, Stainthorp, Hughes, Rosen, & Scott, 2002; Nicolson & Fawcett, l990;
Tallal, Miller, Jenkins, & Merzenich, 1997) or to provide an alternative explanation
for the performance of a subgroup of individuals who are dyslexic whose deficits may
not involve, or are not limited to, phonologica] tasks (e.g., Badian, 1997; Bosse,
Tainturier, ・& Valdois, 2007; Ho, Chan, Tsang, & Lee, 2002; Wolf & Bowers, 1999).
For example, researchers have reported that many, but not all, individuals who
are dyslexic perform poorly on rapid naming (e.g., Ho, Chan, Lee, Tsang, & Luan,
2004} Miller-Shaul, 2005) and orthographic processing tasks (e.g,, Badian, 1997; Ho
et aL, 2004; Meyler & Breznitz, 2003), and have problems proccssing visual infbrma-
tion using the magnocellular pathway (e,g,, Buchholz & McKone, 2e04). Other
researchers have reported that at least some individuals with dyslexia show depressed
levels of perlbrmance in diflbrent auditory processing (e.g., King, Lombardino,
Crandell, & Leonard, 2003) and visual attcntion span tasks (Bosse et al., 2007),experience mQtor-coordination (e.g., Rack, 1997) and implicit learning (e.g., Howard,Howard, Japikse, & Eden, 2006) difficulties, and report high levels of visual stress
(e.g., Singleton & Trotter, 2005).
Without going into detail on how plausible any of' these cleficits is as the core
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deficit (see, e.g., Ramus, Rosen, Dakin, Day, Castellote, White, & Frith, 2003; Ramus,2006), or how reliably each has been linked to reading outcomes Csee, e.g., Ahissar,
2007), existing studies sufler from notable methodological and theoretical problems,in the opinion of the present author. Methodologically, most studies on develop-
mental dyslexia have sulfered from (a) relatively srnall and heterogeneous samples
(e.g., Joanisse, Manis, Keating & Seidenberg, 2000; Reid, Szczerbinski, Iskierka-
Kasperek, & Hansen, 2007), (b) inconsistent sample selection proccdures (e.g.,compare Leikin & Zur-Hagit, 20e6, and Szenkovits & Ramus, 2005), (c) selection
procedures that have included aspects of the examined cause ln thern (e.g., use of
spelling and word attack scores as selection criteria and then examining phonologicalawareness), (d) variabLe measures of purportedly the same constructs (e.g., timed and
untimed mcasures of phonological awareness), (e) poor or nonexistent control of
potential confounding lactors (e.g., Giraudo, 2001), and (fi inconsistent selection
criterion fbr comparison groups (compare, e.g., Egan & Pring, 2004, and Bosse et al.,
2007; see also Goswami, 20e3, for a further discussion of methodological issues),
In addition, the theoretical assumption of qualitative rather than quantitativedifferences has led to simplistic study designs (group comparisons with small sample
sizes assuming, rather than examining, within-group homogeneity) and data analysis
methods, Even when more than one construct has been examined and individual
level data presented (e,g., Parrila, Georgiou, & Corkett, 2007; Rack, 1997; Ramus et
al,, 20e3), each of them has been explored separately without relating as much as the
number of deficient areas to observed reading levels (see Birch & Chase, 2004;Kinsbourne, Rufo, Gamzu, Palmer, & Berliner, I991, fbr notable exceptions). No
published study that we could find has exarnined, fbr example, the possibility that
several subclinical cognitive deficits may jointly produce a clinically significant
reading deficit. Contrary to what has been suggested (see, e,g., Vellutino, Scanlon, &
Tanzman, 1991), such alternatives are not ruled out simply by adopting IQ as an
exclusionary criterion for reading disabilities.
Theoretically, the assumption that developmental disorders, such as develop-mental dyslexia or specific reading comprehcnsion deficit, can have a single cau,se at
any !eve! of analysis has been challenged recently by multifactorial etiological models
(e.g., Gottlieb & Halpern, 2002; Pennington, 2006; see, however, Morton, 2004, and
Ramus, 2006, fbr multifactQrial etiological models that assume a single cognitive level
eause), Pennington (2006) argues that probabilistic multiple deficit models are needed
to providc realistic accounts of developmental disorders and the nondeterministic
relationship between disorders and their causes. He suggests further that such modcls
have to include (a) both protec:tive and risk factors, (b) multiple levels of analysis (hisown general model includes etiologic (with both genetic and environmental i'actors),
neural, cogni,tive, and behaviora] levels), (c) bidirectional connections between con-
structs within each level, and Cd) bidirectional connections between the levcls to
account for interactions between protective and risk factors functioning at diflerent
levcls ot' analysis (see also Ferd & Lernct', 1992; Gottlieb, 1983, 1997; Gottlieb,
Wahlsten, & Lickliter, 2006).
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I propose here that to understand the probabilistic relationships between
possible cognitive deficits, word- and text-level reading problems, and diflerent
academic and remedial outcomes, models adhering to the prineiples of developmental
systems theory (DST; e.g., Oyama et al., 2001) provide better meta-theoretical
frameworks than any single (or dual) core deficit model. In general, developmental
systems theory views development as contingent-but more or less reliable-cycles of
construction and reconstruction that dif{erent developmental resources contribute to.
One of the key underlying assumptions is that the developmentai process has
distributed control; every observed outcome is jointly determined by multiple factors,
or interactants, including the developing organism itself, Implicit in this assumption
is the important idea that the significance of any particular factor is dependent upon
the state of the rest of the system, thus making it necessary to consider other risk and
protective factors as well as changes in importance of diff'erent factors both over time
and across contexts.
The Multiple Systems Model of Reading
Based on developmental systems theory and earlier work by Gottlieb (198S),Frith (1999, 2002) and Pennington (2006), my associates and I have been developing
a probabilistic multiple systems model of reading (MSMR) to guide our research
efforts. This rnodel aims to understand reading development and disabilities across
the life span in diflerent orthographies (see, e.g., Georgiou, Parrila, & Liao, in press;Georgiou, Parrila, & Papadopoulos, in press; Kirby, Silvestri, Alligham, Parrila, & La
Fave, 2008; Liao, Georgiou, & Parrila, in press; Parrila et aL, 2007; Stephenson,Parrila, Georgiou, & Kirby, 2008). The full model, depicted in Fig. 1, assumes
bidirectional influences between five levels of analysis or systems-genetic, neural,
psychological, behavioural, and environmental-and several functionally identifiable
subsystems in each Ievel (see, e.g., Gottlieb et aL, 20e6, and Oyarna et al., 2001, for
related models). The present article will explicate some specific connections betweep
risk and protective factors both betwcen and within the behavioral, psychological,and environmental systems, including the language that the individual is learning toread. Note that the assignment of factors (or "interactants")
to any levels, systems,
and categories is always arbitrary and exemplifies only one possible assignment
among many, The one used here was chosen only to promote discussion, not to irnply
any fundamental ontological dichetomies. An alternative depiction of the simplified
three-level multiple systems model is shown in Fig. 2,
The three-level Multiple Systems Model of Reading makes several assumptions
derived from the principles ef developmental systems theory (Oyama et al., 2001),Frith (1999), Penning'ton (2006), and from continuous abilities theories of reading
(e.g., Olson & Gayan, 2001; Shaywitz, Escobar, Shaywitz, Fletcher, & Makuch, 1992;
Stanovich, 1988; Vellutino et al., 1991) that also have rejected the validity oS"
qualitative difi'erences between readers of difi'erent abilities. These assumptions
include:
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(I) Any system or subsystem (e.g., cognitive risk and protective factors) can be the
focus of study by itself, but full expianations of reading and acadcmic out-
comes require simultaneous consideration of multiple risk and protective
fhctors operating at more than one level of analysis (for example, the eflect of
cognitive factors on reading is mediated by environmental factors, such as
language, e.g., Georgiou, Parrila, & Papadopoulos, in press, and instructional
methods, see, e.g., IJanderl, 2000; Papadopoulos, 2001);
(2) Distributions of risk factors, protective factors, and reading outcomes are
continuous (see, e.g,, Olson & Gayan, 2001; Shaywitz et aL, 1992; Stanovich,
Main Leve]s efActivit},
Environmcnt
Behaviour
Psychelogical
Neural
GcnctLc
BidiTectionalInfiuences
.
FIG.
Individual Development
1 Schematic Representation of the Diflerent Levels of Analysis
Multiple Systems Model of' Reading (Modified From Gottlieb,in
the1992)
Behaviour(actiens,interaction$it)
wa..
,
Environment(physicai,secial,cultural)
di k .i u,.
! }'t
/ x 1,,
g F
.,K.
)'/pa Vif./.g/><hlll."k
,/
l'.{・'fg.v.!a.f・.//・ `esM-um-ma----cpt [Eii.i.E:Etl・:'illFIG. 2 Three-Levcl Multiple Systems
-
Reading &academic
outcomes
Model of Reading
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1988), and any decision of' when the pertbrmance is regarded as clinically
depressed, subclinically depressed, or not depressed is necessarily arbitrary;
(S) Connections between risk factors, protective factors, and reading outcomes are
bidireetional (for example, protective factor motivation to read results in a high
level ofprint exposure which then leads to better reading skills and, further, to
higher motivationl see, e.g., Fink, 1998);
(4) Connections between risk t'actors, protective factors, and reading outcomes are
probabilistic rather than deterministic. No single risk factor is 1ikely a sufiicient
or necessary cause for a reading disability, and the presence of multiple risk
l'actors (in the same or difi'erent systems) may be necessary for reading
disability to occur (see also Pennington, 2006);
(5) In the absence of protective factors within a system (for example, strong
orthographic or semantic skills moderating the eff'ect of poorer phonological
skills on word reading) or in other systems (for exampie, strong motivation to
succeed moderating the effect of slow text reading rate), the effbct of any risk
factor or a combination of risk factors is accentuated;
(6) Conneetions between risk faetors, protective factors, and reading and academic
outcomcs are not equally weighted across individuals or languages (fbr exam-
ple, the role of phonological deficit is not equal across languages; compare Ho
et al., 2e02; Lyytinen, Aro, Eklund, Erskine, Guttorm, Laakso, Leppanen,
Lyytinen, Poikkou, & Richardson, 2004; and Morris, Stuebing, FIetcher,
Shaywitz, Lyon, Shankweiler, Katz, Francis, & Shaywitz, l998), or across
developmental periods (e.g,, Parrila, Kirby, & McQuarrie, 2004).
According to this conceptualization, reading disabilities may result (but do not
necessarily result) from a spccific deficiency in a particular reading-related cognitive
ability Csuch as representation, e.g., Snowling, 2000, or processing, e.g., Ramus &
Szenkovits, 2008, of phonological information), as qualitative diflerence theories
would predict. Note, however, that thc impact of a phonological deficit is probabilisticand depends upon the state of the rest of the system, such as the presence or absence
of other risk and protective factors, the language being learned, and the instructional
methods employed, In addition, a reading disability can result from a lcss than
adcquatc mix of diflerent cegnitivc abilities (as quantitative differencc, continuous
abilities theories of reading disability would predict), or from a suboptimal interaction
between the cognitive subsystem, other psychological subsystems, and the environ-
mental system (see also, Frith, 2002).
The distribution of weights, however, is not assumed to be equal within and
between systems, or across developrnental periods, languages, or individuals. For
example, the existing evidence suggests that for cxplaining a word reading deficit in
a population of elementary school students receiving generally effective instruction
(such as synthetic phonics if they are learning an alphabetic language), the psycholog-ical system carries more weight than any other system, and within the psychologicalsystem, the cognitive subsystem and phonological processing are more importantfactors than, say, general intelligence, motivation, or attention (see reviews in Adams,
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1990; Vellutino, Fletcher, Snowling, 8t Scanlon, 2004). However, the samc weighting
may not be optimal or even appropriate tbr elementary school students learning toread Chinese (e,g., McBride-Chang, Shu, Zhou, Wat, & Wagner, 2003; Shu,
McBride-Chang, Wu, & Liu, 2006) or Greek Ce,g., Georgiou, Parrila, &
Papadopoulos, in press), or tbr older students whose phonological skills have reached
a plateau but whose reading skills may continue to develop (e.g., Andreassen,
Knivbcrg, & Niemi, 2006).
Research Implications
The multiple systems model of reading is best viewed as a meta-theory that can
guide creation of more specific theories, research designs, and firameworks fbr
planning and implementing educational programming. One immediate research
ramification that the Multiple Systems Model of Reading has is that the assumption
of universality ol' any theoretical explanation is a working hypothesis at best and
requires verification across contexts (for example, across diffttrent languages, or in
empirical studies that involve factors frorn several systems). A second ramification is,
as stated above in assumption (1), that studies should attcmpt to include predictorsfrom diflerent systems and subsystems in order to understand better how these jointlycontribute to the development of any particular target skM. When trying to under-
stand the performance of individuals with learning disabilities, it may be particularlyimportant to examine both protcctive and risk factors to account better for the
probabilistic relationship bctween what is frequently regarded as the core deficits and
the academic outcomes they are expected to aflect.
Recent studies in my laboratory on predictors of reading development have been
guided by the Multiple Systems Model of Reading. For example, my associates and
I (Stephenson ct al., 2008) recently reported a iongitudinal study that examincd how
home litcracy (shared book reading, parent teaching activities, and books in the
home), parents' belief's in and expectations of their children's reading and academic
abi].ity, and children's task-focused behavior during everyday learning situations were
associated with the dcveloprnent ef two emergent literacy skills phonological sensi-
tivity and letter knowledge in kindergarten and of word reading in both kindergar-
ten and first grade. There is substantial evidence that at least somc aspects of each
of these i'actors contribute to reading development (see, e.g., Aunola, Nurmi, Niemi,Lerkkanen, & Rasku-Puttonen, 2002; Bus, van IJzendoorn, & Pellegrini, 1995; de
Jong & van der Leij, 1999; Entwisle & Hayduk, 1988; Kirby, Parrila, & Pfeiflbr, 2003;Parrila et al., 2004), thus making them good candidates for interactants in the reading
acquisition process. However, most existing studies have focused on onc or the other
of them and, as a result, there is little understanding of the joint contributions that
the different environmental and psychological subsystems makc to successfu1 reading
acquisition. The results from my }aboratory show that parents' teaching activities at
home prior to kindergarten (but not shared book reading), parents' beliefs about their
children's reading ability, and children;s task-focused behavior were signilicant
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predictors of at least seme early literacy skMs, but also that much of the eflect that
these variables have on early word reading skills is mediated by two highly correlated
emergent literacy skills, phonological awareness and letter knowledge. These results
suggest that the cumulative developmental cycle between task-focused behavior,
parents' expectations and literacy practices, and difEerent literacy and cognitive skMs
likely starts years before children enter into any kind of formal educational environ-
ment. We argue that a better understanding of relationships between diffbrentenvironmental factors, children's task-focused behavior, and emergent literacy skills
is necessary for a more comprehensive theory of reading acquisition.
In a related study, my associates and I (Manolitsis, Georgiou, Stephenson, &
Parrila, 2008) exarnined whether the relationship between parents' home literacy
instruction and childrenis performance is moderated by the language children are
learning to read. We chose two alphabetic languages, English and Greek, that differ
greatly in the consistency of their grapheme-phoneme correspondences and, subse-
quently, on the demands they impose on the first grade learner. Learning to read
Greek poses only a moderate challenge (see, e.g., Ellis, Natsurne, Stavropoulou,Hoxhallari, van Daal, Polyzoe, Tsipe, & Petalas, 2004; Seymour, Aro, & Erskine,2003), and we speculated that this alone might aflbct the frequency and nature of
home literacy activities that parents engage in with their children, In general, our
findings indicated that the Greek parents reported doing home literacy activities less
oftcn with their children than did the Canadian (English-speaking) parents, and the
Greek children did poorer in tasks measuring emergent literacy skills in kindergartenthan the English-speaking Canadian chitdren.
However, the most interesting finding was that for the Greek children, the
firequency of home literacy activities was negatively correlated with phonologicalawareness, whereas the opposite was true for the Canadian children learning to read
English. We suspect that the explanation for this counterintuitive (at least tbr thoseof us who work in North America) finding is that Greek parents, in general, do not
believe that what they do at home wM have much impact on how easily their children
learn to read (and most Greek children did indeed learn to read in first grade with
no problems) and they only get actively involved when they have a specific reason to
expect diMculties (see Silinskas, Leppanen, Aunola, Parrila, & Nurmi, 2008, fbr
similar results with children who were Iearning to read another highly consistent
orthography, Finnish).
In a separate series of studies, we have been examining the moderating role of
orthography to how speeific cognitive subsysterns are related to reading, The theoreti-
cal impetus for these studies has been the idea that carefu11y selected cross-linguistic
comparisons often provide excellent contrasts for testing different theoretical accountsof reading acquisition, because languages vary in critical aspects, such as size of the
optimal decoding unit (see also Ziegler & Goswami, 2005), orthographic consistency
and transparency, and morphological complexity.
Liao et al. (in press) examined the relationship between rapid naming speed
(RAN) and Chinese character recognition accuracy and fiuency. This study was
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motivated by reports that rapid naming speed tasks may predict Chinese character
recognition better than they predict English word recognition, and that as a functionof increased reading sk-, the relationship between rapid naming speed and reading
becomes stronger in Chinese (see, e.g., Tan, Spinks, Eden, Perfetti, & Siok, 2005), a
result that challenges most theoretical accounts of the rapid naming speed-reading
relationship developed to explain the performancc patterns observed when children
are learning to read English. The Tesults of Liao et al. (in press) indicated that while
some of the relations observed between rapid naming speed tasks and reading in
English were replicated in Chinese (for example, graphological rapid naming speed
tasks were better predictors of reading than non-graphological rapid naming speed
tasks), others were not, More specifically, similar to Tan et al. (2005), Liao et al. (inpress) found that the importance of rapid naming speed increased from second to
fourth gradc, evcn aftcr controlling for age, nonverbal intelligence, phonologicalsensitivity, short-term memory, and orthographic processing.
In an extension of the Liao et aL (in press) study, Georgiou, Parrila, and Liao
(in press) showed that when the dependent variable (either an accuracy or a fluencymeasure) was comparable across languages, there were no statistically significant
diffbrences in the correlations between rapid naming speed and reading in fourth
grade students, across three orthographies: English, Greek, and Chincse.
However, the results also indicated that diflbrent components of the rapid
naming speed tasks may be responsible for the rapid naming speed-reading relation-
ship across languages. More specifically, while pause time (the average time between
two articulations in the series) was a less important predictor of word reading than
articulation time (the average time to say the names ot' the stimuli) in English and
Grcek, the oppesite was true fbr orthographically less transparent Chinese, This result
raises the possibility that what underlies the rapid naming speed-reading relationship
may vary across languages.
Thus, when rapid naming speed is fiagged as an important indicator of reading
difliculties in different languages (see, e.g., Ho et al., 2004, in Chinese, and Torppa,
Tolvanen, Poikkeus, Eklund, Lerkkanen, Leskinen, & Lyytinen, 2007, in Finnish, and
Badian, DuffY, Als, & McAnulty, 1991, in English), it is possible that the underlying
cognitive deficits and how they impact reading are very diflbrent across those
languages. An interesting possibility that fo11ows from this reasoning is that rapid
naming speed may be related differently to the different writing systems used in
Japanese. One prediction from the above studies is that the rapid naming speed-kana
reading relationship would likely resemble that observed in alphabetic orthographies
(and be based more on articulation speed with older readers, but not necessarily with
younger readers, see, e.g,, Georgiou, Parrila, & Kirby, 2006), whereas the rapid
naming speed-kanji relationship would likely resemble that observed in Chinese (andwould likely be based more on lexical access speed),
Currently, we are expanding the Multiple Systems Model of Reading research to
examine which interactants play a role in determining the academic outcomes of
adults with learning disabilities. This line of research was initialIy motivated by the
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observations (e.g., Jackson, 2005) that in post-secondary students, reading skills and
academic outcomes are not highly correlated, and that studcnts who are successfu1 in
their post-secondary studies can have very deficient basic reading skills (Parrila et al.,
2007). Existing studies of post-secondary students with learning disabilities, most of
which were done with very small and non-representative samp!es, suggest that
protective factors include use of good study and learning strategies, good motivation
and attitude towards the teaching/learning process, good interpersona] skills, being
perslstent and goal-oriented, and having environmental aceommodations, such as
lighter course' loads (e.g., Corkett et al., 2008; Corkett et al., 2006; Keim et al,, 1996;
Kirby et al., 2008; Reis, McGuire, & Neu, 2000; Ruban, McCoach, McGuire, & Reis,
2003; Vogei & Adelman, 1992), Vogel and Adelman (1990), in turn, suggest that poormotivation, poor attitude, substance abuse, dcnial erlearning disability, and unrealis-
tic expectations are risk lactors for university students with LD.
While very few of these studies have specifically fbcused on post-seeondarystudcnts with reading disabilities, it seems reasonable to assume that (a) there is
significant heterogeneity in the reading disabled population in behavioral, psychologi-cal, and environmental systems, (b) dilfercnt combinations of risk and protectivelactors can be associated with similar academic outcomes, both successful and
unsuccessfu1, and (c) both the deployment and the utility of environmental accomme-
dations vary as a function of behavioral and psychological risk and protectivefactors.
In an ongoing study, we are testing these assumptions alld examining how
specific cognitive (phonological sensitivity, naming speed, orthographic processing,and working memory) and noncognitive (attention, motivation, selfieMcacy) psycho-logieal risk and protective factors interaet with reading ability (decoding, word
reading, and reading comprehension), study and learning strategies, and environ-
mental accommodations (e.g., lighter course loads, use oi' family and friends as
readers and/or note takers, use ol' support services) in determining aeademic
achievement.
While the above studies are simple in their design and data analysis methods,
they are presented here as examples ot' research resulting from questions that the
assumptions of the Multiple Systems Modcl of Reading can lead us to consider. On
the simptest teveL, we could be examining the rnediating and moderating effects of
interactants frorn other systems or subsysterns, whereas more complex longitudinal
designs could bc aimed at modeling the cyclcs oi' contingencies that lcad to normative
outcomes, and the variations in the constellation and weighting of diflbrent inter-
actants that lead to individual differences, including learning disabilities.
In all approaches, the multiple systems model encourages inclusion of a wider
variety of participanrs and tasks, so that the joint contributions of various potentialrisk and protective ±
'actors can be assessed.
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Educational Implications
The multiple systems model of reading has important ramifications in terms of
how we identit'y individuals who require educational accommodations and intcrven-
tions, the factors that should be considered when designing accommodations and
interventions and, further, how we assess the efllrctiveness of those accommodations
and interventions.
Traditionally, the process of identifying students as having learning disabi]ities
has, at least in North America, relied on an assessunent ot' whether a specific student
qualifies for some specific Iabel defined on the basis of some arbitrary criteria, such
as a two standard deviation diiference between an achievement test result and an
intelligence test result (see Fletcher, Lyon, Fuchs, & Barnes, 2007, {br a review ol' the
aptitude-achievement discrcpancy models), More recently, and at least partly as a
rcsult of criticisms of the aptitude-aehievement discrepancy models (e.g., Siegel, 1992),
several jurisdic]tions have moved towards models that rely on low achievement
together with some cxclusionary criteria (e.g., normal vision, hearing, inte"igence,
educational experiences) in order to maintain the idea that learning disabilities are
unexpectcd and result from an uneven patterns of intra-individual development.
Finally, the most recent models, driven in part by the 2004 reauthorization of the
Individuals with Disabilities Education Act (IDEA) in the U.S., combine low achieve-
ment and examination of how the individual responds to additional targeted interven-
tions, possibly leading to repeated cycles of assessments and interventions (see, e.g.,
Fletcher et al., 2007; Vellutino, Scanlon, Small, & Fanuele, 2006).
The Multiple Systems Model of Reading challenges each of these approaches,
First, no matter what approach is taken, it is necessary to acknowledge that distribu-
tions of all the assessed abilities are continuous, and the decision as to what the cut-off
score is for low achievement is nccessarily a financial dccision whose purpose is to
control aecess to additional educatienal resources, rather than to identify children
whose pcrformancc is somehow qualitatively diflbrcnt firorn the rest, It is not an
educational decision so long as we do not have data to show that, ibr example,
children whose performance fa]Js outside of the cut-off would not benefit from the
same reseurces. Being clear on this /issue is important for the discussion of how
existing resourccs are dividcd.
Second, whatever the criteria fbr low achievement, initial identification should
take place on the basis of the individual;s low achievement on the target academic (orpre-academic in the case of younger learners) skilL without any additional exclusionar-
y or inclusionary eriteria. This fo11ows from the idea of distributed control of the
developrnental process: academlc outcomcs arejointly determined by multiple factorsincluding the developing organism itself.
No interactant should be assumed to have a causal priority. All discrepancy
definitions and definitions that includc exclusionary criteria make this assurnption,
either directly or inadvertentty. Letting such assumptions guide identification leads to
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absurd conclusions, such as that children with low IQ cannot have dyslexia: because
since beth IQ and reading ability (however dyslexia is defined) are normally distribut-ed, it fo11ows that some children wru fa11 at the low end of both distributions bychance alone. The same logic applies to the presumed impossibility of children having
both hearing impairments and dyslexia, or vision impairments and dyslexia. Once the
initial identification is completed on the basis of low achievement, the task then is to
try to identify and understand al1 the interactants that possibly affect the low
achievement of the particular individuai. Here it is partieularly important to include
both protective and risk factors to better account fbr the probabilistic relationship
between what we frequently regard as primary deficits and the academic outcomes,
and to enhance planning of interventions that address the problem simultaneously on
multiple levels.
Third, because performance is jointly determined by multiple interactants, and
because many of these interactants are distributed continuously in the population, it
follows that categorical classifications, such as "dyslexia'',
are dithcult to defend on
any grounds other than low performance of the target academic skill (where they are
ultimately defended on financiai grounds). This is because locating cases in specific
regiens of a multivariate space requires both making a somewhat arbitrary decision
as to what variables should be included and using arbitrary cut-offs tbr each ofthose
variables. Inciuding more than two variables quickly leads into a multiplication of
categories, whereby it quickly defeats the purpose of categorical classification.
This is not to say that such classifications cannot be usefu1 for research purposes.For example, assurning a phonologicaL processing deficit (rather than poor word
reading) as the core deficit in dyslexia has served research well in terms of under-
standing the interactants that impact word reading in poor readers who have a
phonological deficit (see, e.g., Frith, 2002; Ramus, 2006; Snowling, 2000). However,
poor word reading (whether defined on the basis of accuracy, a reasonable criterion
fbr children in English, or automaticity, perhaps the only reasonable criterion in more
consistent orthographies; sec, e.g., Yamada & Banks, 1994) is not necessarily associat-
ed with any single interactant, and determining the possible active interactants
(including phonological processing) for each individual is the precise task of educa-
tional assessment; a task that has to be guided by the best available data on what
variables aflbct word reading performance.
Finally, as a result of the observed low achievement being aflbcted by multiple
continuously distributed interactants (possibly with variable weightings), we should
expect large differences between individuals and few prototypical cases, That is,
heterogeneity rather than homogeneity is to be expected (see also Erskine & Seymour,
2005). The solution to the diversity is likely not better subtyping (e.g., increasing thenumber of categories; see above), but rather assessment and intervention planningthat acknowledges the role that multiple interactants can play in affecting behavior.
To guide assessment and intervention planning, we could develop checklists of
possible interactants (both risk and protective) that should be considered in order to
obtain a better understanding of the entire system when an individual is identified
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with a low aehievement on a specific aeademic task. Such checklists would initiallyconsist of all possi,ble interactants, as determined by the best available research
evidence, and the goal of the assessment would be to come up with a shorter list of
active interactants, some or all of which could then be targeted fbr intervention, The
selection of interventions should naturally also be guided by the best available
research evidence, however limited that is for any givcn approach.
Exaniple of the multiple n'sk and Proteetive foctors involved in word readiag deevelopment.
The discussion of risk and protective factors in what fbllows is not meant to exhaus-
tive but rather to iliustrate how many interactants may be involved in determining
performance level even in a relatively simple academic task. Readers familiar with
current assessment practices can also consider how many of the suggested inter-
actants are covered in such practices. Much of what is rcported below has been wellestablished with English-speaking participants. Some evidence wiIl also be reported
from studies conducted with participants learning to recognize words in orthograph-
ically more consistent alphabetic languages and in languages that do not use an
alphabetic writing system. However, caution should be exercised before making
generalizations to any specific language or writing system.
There is a general consensus among researchers that word reading problems
(often equated with dyslexia) in English are associated with problems in phonologicalawareness, that is, one's ability to reflect on and manipulate the phonemes in spoken
language (see, e.g., Share, 1995, for a review). Frith (1999), for example, estimated
that roughly 80% of British children with dyslexia have such problems. Although this
number may be an over-estimate (it was based on a sample of children already
diagnosed with a specific learning disability), the importance of phonological aware-
ness to learning and of being able to use grapheme-phoneme correspondences
fiuently, is well established in the English language.
In addition to phonological awareness, we know that several other cognitive level
variables can contribute to word reading difi,culties. These include rapid naming
speed and verbal short-term memory problems. Although these are often regarded as
being different expressions of the same underlying phonological deficit that also is
responsible for phonological awareness problems (see, e.g., Morton, 2004i Ramus,
2006), this interpretation is not universally accepted (see, e.g., Wolf & Bowers, 1999).Similarly, thc eflbct of hearing impairments on reading could be mediated by a
phonological deficit resulting from impoverished input to the phonological systern.
Rerated arguments can be made for temporal and cercbellar processing deficits (see,e.g., Frith, 1999; Morton, 2004; however, see Galaburda, 1999, for a diflerentinterpretation).
We also know that diMculties in learning to read words can be associated with
language factors that are not clearly phonological in nature, such as semantic deficits
(e.g., Shu, Meng, Chen, Luan, & Cao, 2005), morphological processing deficits (e.g.,Schiff & Raveh, 2007), and orthographic processing deficits (e.g., Badian, 1997, 2005;
Ho et al., 2004), as well as factors outside of the language system such as visual
memory (Ho et al., 2004), visual attention span (Bosse et al,, 2007), and motivation
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(e.g., Lepola, Poskiparta, Laakkonen, & Niemi, 2005; Stephenson et al., 2008). Inaddition, the ease with which children learn to read words may be aflbcted by at least
some aspects efthe home environment (e.g., Burgess, Hecht, & Lonigan, 2002; Evans,
Shaw, & Bell, 2000; Stephenson et al., 2008), the severity of their difilculties, and the
teaching methods employcd at their school (e,g., Landerl, 20001 Papadopoulos, 2001).The point of this list is not to be exhaustive but rather to illustrate that even when
we are looking at an academic task that Hkely has a strong biological and neurological
basis, the list of factors that can negatively aflect individuals' performances, and that
may need to be addressed in order for an intervention to be successfu1 (Andreassen,Knivsberg, & Niemi, 2006; Niemi, Poskiparta, & Vauras, 2001), is likely to be much
tonger than the usual lists of causal factors.
Hewever, many individuals with phonological problems do Iearn to read words
(e.g., Bishop & Adams, 1990; Parrila et al,, 2007; Wilson & Lesaux, 2001). What,
then, are the protective factors that allow at least some individuals to develop
functional word reading skills? On theoretical grounds (see, e.g., Coltheart, Curtis,
Atkins, & Haller, 1993), an obvious candidate for a cognitive protective factor is
orthographic knowledge, While the current evidence on this is mixed, several studies
have reported orthographic knowledge as a relative strength (e.g., Mrucr-Shaul, 2005;
see also Siegel, Share, & Geva, i995) or as a possible compensatory tool (Leinonen,MUIIer, Leppanen, Aro, Ahonen, & Lyytinen, 2001; van der Lelj & van Daal, 1999),
makirig it likely that it is a protective factor for at least some individuals.
Elbro (1993), in turn, suggested that the ease of lexical access determines thedegree to which individuals with reading disabilities can compensate for their primary
phonological deficit by using more whole-word oriented strategies. Elbro (1993)provided preliminary evidenec for this position by showing that adolescents with
dyslexia who used more whole-word oriented reading strategies aiso had faster
picture naming times. In a second study, Elbro (1993) showed that this relation did
not extend to readers who were not dyslexic.
Yet another possibility is that relatively intact morpholo.ifical knowledge compen-
sates for poorer phonological skMs. Here again, the evidence is mixed, with sorne
studies showing at least reading-age appropriate pcrformancc level on morphological
tasks (e.g., Elbro & Arnbak, 1996; Leong, 1999) and others not (e,g., Deacon, Parrila,
& Kirby, 2006; Joanisse et al., 2000), with one possible explanation fbr those
difflerences being the aspects of morphology that each study fbcused on (see Deacon,Parrila, & Kirby, in press, for a review). In addition to possible protective factors
within the cognitive system, we know that good home literacy environment (Torppa,Poikkeus, Laakso, Tolvanen, Leskinen, Leppanen, Puolakanaho, & Lyytinen, 2007),early interventions (e.g., Byrne & Fielding-Barnsley, 1995), and motivational orienta-
tion can have a positive impact on future readang development, so that these f'actorsshould perhaps be added to the list of interactants whose status is assessed. Needlesste say, as research on word reading development progresses, some of the current and
perhaps poorly defined interactants will be replaced by better defined ones, some wiIIbe dropped, and new ones will be added.
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In summary, several systerns have been implicated as possible risk and protectivefactors in word reading development. While the phonological subsystem is likely moreheavily weighted than any other, it cannot be assumed to have entire control of the
developmental process. Therefore, for assessment to be maximally infbrmative and
the resulting interventions maximally efiective, multiple systems need to be addressed.
Note that in order to increase the chances of future success, this is true even if a
phonological deficit is identified and remediated (see, e.g., Niemi et al., 200I).
Summary and Conclusions
The present article has argued that in order to understand reading development
and disabilities fu11y, both within and across diffk}rent Ianguages, a better meta-
theoretical t'ra'mework is needed to guide both the research itself and also the
interpretation of research findings in relation to educational practice. One such
framework, the multiple systems model ofreading, was presented briefly. This model
looks at normal reading developrnent and disabilities as diflbrent states of the same
complex developing system, with no single interactant being allocated the entire
causal control of the developmental process.
This does not mean that researchers should give up the search fbr specific
genetic, neural, or cognitive mechanisms that contribute to reading development, or
the development of theories that explain the contribution of these mechanisms. Onthe contrary, such work is necessary and has greatly increased our understanding of
the genetic, neural, and cognitiVe factors that should be included in a cemprehensive
model (see, e,g,, Ramus, 2006, for a review). What the multiple systems rmodel of
reading contends, instead, is that theories will be enriched if' they conceptualize
development at all levels as construction and focus on identifying the interactants ofthis process (see, e.g., Galaburda, LoTurco, Ramus, Fitch, & Rosen, 2006, f'or an
example in the genetic-neural level), and that none of these theories per se constitutes
a sufEcient explanation for the development of the target behavior, reading,
In particular, educational practice is well served by respecting the complex, and
sometimes idiosyneratic, nature of the developing organism, and by not allocating
causal responsibility and all the assessrnent and remedial e'flbrts of possible reading
problems to any single cause.
Author Note
I would like to thank John Kirby, Jari-Erik Nurrr]i, Robert Klassen, JenniferBarber, Sancly Lai and Hisao Maekawa fbr their comments on the earlier draft of this
paper. The preparation ol' the ideas presented in this paper has been partiallysupported by grants from Social Sciences and Humanities Research Council of
Canada, Killam Research Fund, and Faculty of Education, University of Alberta. All
correspondence regarding this paper should be addressed to Rauno Parrila at rauno.
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References
Adams, M. J. (l990) Beginning to read. MIT Press, Cambridge, Massachusetts.Ahissar, M, (2007) Dyslexia and the anchoring-deficit hypothesis, TYends in Cbgnitive S2:iences,
11, 458-465.
Andreassen, A, B., Knivsberg, A, M., & Niemi, P, (2006) Resistant readers 8 months later:
Energizing the student's lcarning milieu by targeted counselling. Dystexia, 12, 1 15-138.
Aunola, K., Nurmi, J.-E., Niemi, P., Lerkkanen, M.-K., & Rasku-Puttonen, H. (2002) Developmental dynamics of achievement strategics, reading performance, and paren-
tal beliefs. Reading Researoh qpaarterly, 37, 310 327.Badian, N. A. (1997) Dyslexia and the Double Deficit hypothesis. Annats of' Qysimia, 47,
69-88.Badian, N. A. (2005) Does a visual-erthographic deficit contribute to reading disability?
Annats of' D)slexia, 55, 28-52.Badian, N. A,, Duffy, F, H., Als, H,, & McAnulty, G. B. (1991) Linguistic profiles of
dyslexlc and good readers. Annals of I]tyslexia, 41, 221 245.Birch, S. & Chase, C. (2004) Visual and language processing deficits in compensated and
uncempensated eollege students with dyslexia. .lburaat
qf Leaming Disabilities, 37, 389-
410,
Bishop, D. V. & Adams, a. (1990) A prospective study of the relationship between specific
language impairment, phenological disorders and reading retardation. Jburnal of C:hild llsJcholegy and Rtychiat[); and Allied Disoptines, 31, 1027-1050,
Bosse, M.-L., Tainturier, M. J., & Valdois, S. (2007) Developmcntal dyslexia: The visual
attention span deficit hypothesis. Cbgnition, 104, 198 230,Buchholz, J. & McKone, E. (2004) Adults with dysLexia show deficits on spatial t'requency
doubling and visual attention tasks. Ilyslkxia, 10, 24-4S.
Burgess, S. R,, Hecht, S. A., & Lonigan, C. J. (2002) Relations of the home literacy
environment (HLE) to the developmcnt ufreading'-relatcd abilities: A olle-year longitu-
dinal study. Reading' Research Qztarterly, g7, 408-426.
Bus, A, G,, van IJzendoorn, M. II., & Pcllegrini, A. D. (1995) Joint book reading makes fbr
success in learning to read: A meta-analysis on intergencrational transmission of
literacy. Review of Edttcational Research, 65, 1-21.
Byrne, B., & Fielding-Barnsley, R, (1995) Evaluation of a program to teach phonemic
awareness to young children: A 2- and 3-year fo11ow-up and a new preschool trial.
.lburnal of Educational RsJchology, 87, 488-503.
Coltheart, M., Curtis, B., Atkins, P., & Haller, M, (l993) Models of reading aloud:
Dual-route and parallel-distributed-processing approaches. Ils"choiQgical Review, 100,
589-608.Corkett, J. K,, Hein, S. F,, & Parrila, R. (2008) 7Jhe role of Personal characterdstics in comPensat-
ing for reading dijficulties: A gualitative inevestigation of' universiip students' espen'encas.
Manuscript submittcd for publication.Corkctt, J, K., Parrila, R., & Hein, S. F, (2006) Learning and study strategies of university
students who report a significant history of reading difficulties. Deveiopmental Disabitities
Bultetin, 34, 57-79J
--
398
The Japanese Association of Special Education
NII-Electronic Library Service
The JapaneseAssociation of Special Education
Understanding Rcading Disabilities
de Jong, P. F. & van der Leij, A. (1999) Specific contributions of phonQlogical abilities to
early reading acquisition: Results from a Dutch latcnt variable Iongitudinal study.
.lburnal of Educational RiJtholqgy, 91, 450 476.
Deacon, S. II., ?arrila, R., & Kirby, J. R. (2006) The status of morphological processing in
compcnsated dyslexics. Annats of Qystkxia, 56, 103-128.Deacon, S. H., Parrila, R., & Kirby, J, R. (in press) A review of the evidence on
rnorphological processing in dyslcxics and poor rcaders: A strength or weakness? In F.
Manis, A. Fawcett, G. Reid, & L. Siegel (Eds.), Pyslexia handbook. Sage Publications,
London.Egan, J. & Pring, L. (2004) The processing of infiectional morphology: A comparison of'
children with and without dyslexia. Reading and uaitin.a, 17, 567 -591, .
Elbro, C. (1993) Dyslexic reading strategies and lexical access: A comparison and validation
of' reading strategy distributions in dyslexic adolescents and younger, normal readers.
In R. M. Joshi & C. K, Leong (Eds.), Reading disabilities: Diagnosis and component Processes. KIuwer, Dordrecht, 239-251.
Elbro, C. & Arnbak, E. (1996) The role ef morpheme recognition and morphological
awarencss in dyslexia, Annats of l]lyslexia, 46, 209 2<LO,Ellis, N. C., Natsume, M,, Stavropoulou, K., Hoxhallari, L,, van Daal, V. H., Polyzoe, N,,
Tsipe, M.-L., & Petalas, M. (2004) The eflects of orthographic depth on learning to
read alphabetic, syllabic, and logographic scripts. Reading Research Quarterly, 39,
438-460.Entwisle, D. R. & Hayduk, L, A, (1988) Lasting eflects of elementary school, Sociolagv qf Education, 61, 147-159.Erskinc, J. M, & Seymour, P. H. K. (2005) Proximal analysis of developmental dyslexia in
adulthood: The cognitive mosaic modcl. Jlburnag qf Eduaational Rsycheiogy, 97, 406-424.
Evans, M. A,, Shaw, D,, & Bell, M, (2000) Home literacy activities and their influence on
early literacy skills. thnadian .lburnal
of ]ExPerimental RsJchellzg], 54, 65-75.
Fink, R. P. (1998) Literacy development in successfu1 men and womcn with dyslexia. Annats
of I]lvslexia, 48, Sl1-346.Fletcher, J, M., Lyon, G. R., Fuchs, L. S., & Barnes, M, A. (2007) Learning disabiibties: thom
idbtztofication to intervention. Guiltbrd Press, New York. '
Ford, D. H, & Lerner, R. M, Cl992) DeveloPmental spstems theot:y: An intugnitioe aPPreach. Sage,
Newbury Park, Calithrnia.Frith, U. (]999) Paradoxes in the definition of dyslexia. Ilystdria, 5, 192-214.
Frith, U. (2002) Resolving the paradoxes of dyslcxia. In G. Reid & J. Wearmouth CEds,), l]b,slewia and titeraay,' Theotv and Practice. Wiley, Chichester, UK, 45-68,
Galaburda, A. M. (1999) Developmental dyslexia: A multilevel syndrome. L!pusllaxia, 5,
183 -191.
Galaburda, A. M., LoTurco, J., Ramus, F., Fitch, R. H., & Resen, G, (2006) From genes
to behavior in developmental dyslexia. JVketure dearoscience, 9, 1213-1217.
Georgiou, G. K., Parrila, R,, & Kirby, J, (2006) Rapid naming speed components and early
reading acquisition. Scientijic Stntdies qf Reading, 10, 199-220.
Georgiou, G. K., Parrila, R., & Liao, C.-H. (in press) Rapid naming speed and reading
across languages that vary in orthographic consistency. Reading and uaiting.Georgiou, G. K., Parrila, R., & Papadopo'ulos, T. C. (in press) Predictors of werd decoding
-399-
The Japanese Association of Special Education
NII-Electronic Library Service
The JapaneseAssociation ofSpecial Education
R. Parrila
and reading fiuency across languages varying in orthographie consistency. .foumal
qf
Educational RF]thology,.
Giraudo, H. (2001) R61e et repr6sentation de I'inibrmation morphologique chez Papprenti
lecteur et 1'enfant dyslexique (The role and representation of morphologieal infbrma-
tion in the beginning reader and in dyslexic children). Annates Ilyssen, 16, 81-90. (in French)
Goswarmi, U. (2003) Why theories about developmcntal dyslexia require developmental
designs. 71ends in Clognitive S2riences, 7, 534-540.Goswami, U., Thomson, J., Richardson, U., Stainthorp, R., Hughes, D,, Rosen, S., & Scott,
S, K, (2002) Amplitude envelope onsets and developmental dyslexia: A new hypothe-
sis. PLIVIAS, 99, 10911-10916.
Gottlieb, G. (198B) The psychobiological approach to developmental issues. In M, M.
Haith & J. J. Campos (Eds.), lldndbook of child Pspchelogy (4th ed., VoL 2). Wiley, New
York, 1・-26.
Gottlieb, G. (l997) Synthesicing nature-nurture: Prenatal roots qf' instinctieve behaevior, Lawrenee
Erlbaum Associates, Mahwah, New Jersey.Gottlieb, G. & Halpern, C. T. (2002) A relational view of causality in norrnal and abnormal
development. Dewetopment and RsJchopathology, 14, 421-435.
Gettlieb, G., Wahlsten, D., & Lickliter, R. (2e06) The significance of biology fbr human
development: A developmcntal psychobiological systems view. In R, M. Lerner & W.
Damon (Eds.), Hbndbook of child Psychology (6th ed., Vo]. 1). Wiley, Hobokcn, New
Jersey, 210-257.Ho, C. S.-H., Chan, D. W,-O., Lee, S.-H., Tsang, S.-M,, & Luan, V, H. (2004) Cognitive
profiling and preliminary subtyping in Chinese dcvelopmental dyslexia. Cbgnition, 91,
4S-75.Ho, a. S.-H., Chan, D. W.-O., Tsang, S.-M., 8t Lee, S.-H. (2002) The cognitive profile and
multiple-deficit hypothesis in Chinese developmental dyslexia. Deveiopmental Rsychology,
38, 543-553.
Howard, J, H., Jr., Howard, D. V., Japikse, K. C., & Eden, G. F. (2006) Dyslexics are
impaired on implicit higher-order sequence learning, but llot on implicit spatial
context learning, Muropsycholagia, 44, 1I31-1144.
Jackson, N. E, (2005) Are university students' component reading skills related to their text
cemprehension and academic achievement? Learning and individual Diplrrences, 15,
113-139,
Joanisse, M. F,, Manis, F., Keating, P,, Seidenberg, M. S. (2000) Language specific deficits
in dyslexic children: Speech perception, phonology, and morphology. Jhurnal o.f
ErPerimental Child RsJchology, 77, 30-60.
Keim, J., McWhirter, J. J., & Bernstein, B. L. (1996) Academic success and university
accommodation fbr learning disabilities: Is there a relationship? .lburnal of Cbltage
Student DewelQPment, 37, 502- 509,King, W. M., Lombardino, L. J., Crandell, C. C., & I.eonard, a. M. (2003) Comorbid
auditory processing disorder in developmental dyslexia. Ear and Hlaan'ng, 24, 448-456,
Kinsbourne, M., Rufo, D. T,, Gamzu, E., Palmer, R. L., & Berliner, A. K. (l991) Neuropsychological deficits in adults with dyslexia. Deweiopmental Medicine and Child
.IV17urology, 33, 763-775. '
- 400
-
The Japanese Association of Special Education
NII-Electronic Library Service
The JapaneseAssociation of Special Education
Understanding Reading Disabilities
Kirby, J. R., Parrila, R. K., & Pfeifik]r, S. L. (2003) Naming speed and phonological awareness as predictors of reading development. Jbermal Qf Educationat Ilsyohotogy, 95,
453-4・64.
Kirby, J, R., Silvestri, R., Alligham, B,, Parrila, R., & La Fave, C, B. (2008) Learning
strategies and study appreaches of collcge and university students with dyslexia.
.lbumat qf Learning Disabitities, 41, 85-96.Landcrl, K. (2000) Influenc¢ s of' orthographic consistency and reading instruction on the
development of nonword reading skills. European Jbttrnal of Rg]chology qf Education, l5, 239-257,Lcikin, M. & zur Hagit, E. (2006) Morphological processing in adult dyslexia. .lburnal of Rgychok'nguistic Research, 35, 471-490,Leinoncn, S., Mti11er, K., Leppanen, P., Are, M., Ahoncn, T,, & Lyytinen H. (2001) Hetcrogeneity in adult dyslexic readers: Relating processing skills to the speed and
accuracy of oral text reading, Reading and vaniting, 14, 265-296.
Leong, C. K. (1999) Phonological and morphological processing in adult students with
learning!reading disabilities. .lburnat
of Learning Disabitities, 32, 224-238,Lepola, J., Poskiparta, E,, Laakkonen, E., & Niemi, P. (2005) Development ol' and relation-
ship between phonological and motivational processes and naming speed in predicting word recognition in Grade l, Sicientijic Studies of' Readiag, 9, 367-399,Liao, C.-H., Georgiou, G. K., & Parrlla, R. (in press) Rapid naming speed and Chinese
character recognition. Reading' and uaiting.Lyytinen, H., Aro, M., Eklund, K., Erskine, J., Gllttorm, T., Laakso, M.-L,, Lepptinen, P.
T., Lyytinen, P., Poikkou, S. A., & Richardson, U. <2004) The development ef children
at familial risk fbr dyslexia: Birth to early school age. Annals of Qysimia, 54, 184-220.Manolitsis, G., Georgiou, G., Stephenson, K., & Parrila, R, (submitted) Baginning to vaad
across laaguages vanying in orthagrophic consistenay: Comparin.cr the qi7i7cts qf' non-cagnitive and
cagnitive predictors. Manuscript submitted ['or publication.McBride-Chang, C., Shu, H., Zhou, A., Wat, C. P., & Wagner, R. K. (2003) Morphological
awareness uniquely predicts young children's Chinese charaeter recognition. Jburnal of Educational Rsychotog),, 95, 743-751.Meyler, A. & Breznitz, Z. (2003) Processing of phonological, orthegraphic and cross-modal
word representations among adult dyslcxic and normal readers. Reading. and maiting,
16, 785-803.
Miller-Shaul, S. (2005) The characteristics of young and adult dyslcxics readers on reading
and reading related cognitive tasks as coinpared to normat readers. L!ysZlrxia, 11, 132
151.
Monis, R. D., Stuebing, K. K., Flctcher, J. M., Shaywitz, S. E,, Lyon, G. R.,.Shankweiler,
D, P., Katz, L., Francis, D. J., & Shaywitz, B. A. (1998) Subtypes of reading disability:
Variability around a phonological core. Jlburnal of Educational Rtycholqgy, 90, 347-373.Morton, J. (2004) Uitderstandin.a devetQPmentag disotdkrs: A causat modeting approach. Blackwell
Publishing, Maldcn, Massachusetts,Nicolson, R. I. & Fawcett, A, J, (1990) Automaticity: A new framework for dyslexia
rescarchl/' Cbg'nition, 35, 159-182.Niemi, P., Poskiparta, E,, & Vauras, M, (2001) Benefits of training in linguistic awareness
dissipate by grade S? .lburnal of the Ubllenic RsJcholagical Society, 8, 330-337.
-401
The Japanese Association of Special Education
NII-Electronic Library Service
The JapaneseAssociation ofSpecial Education
R. Parrila
Olson, R. K. & Gayan, J. (2eOI) Brains, genes, and environment in reading development,
In S. B. Neuman & D. K. Dickinson (Eds,), Uitndbeok of early titeraay researth. Guiltbrd
Press, New York, 81 -94.
Oyama, S., Griffiths, P. E., & Gray, R. D. (20el) Introduction: What is developmental
systems theory? In S. Oyama, P. E. GriMths, R. D. Gray (Eds,), ([lyales oj' contingentl)J:
Deevelopmental systems and eevotution. MIT Press, Cambridge, Massachusetts, 1-11.PapadopoulQs, T. C. (2001) Phonological and cognitive correlates of word-reading acquisi-
tion under two different instructional approaches in Gr ¢ ck, European .lbumal of Rs]chology of Educatien, 16, 549-568.Parrila, R., Georgiou, G., & Corkett, J. (2007) University students with a significant history
of rcading diMculties: What is and is not compensated? Erccoptionality Education ( Zinado,
17, 195-220.Parrila, R., Kirby, J, R., & McQuarrie, L. (2004) Articulation rate, naming speed, verbal
short-term memory, and phonological awareness; Longitudinal predictors of early
reading development. Stientijc Studes qf Reading, 8, 3-26.Pennington, P. F. (20e6) From single to multiple deficit models of developmental disorders.
Cbgnition, IOI, S85-413.Rack, J. (1997) Issues in the assessment of dcvelopmental dyslexia in adulLs: Theoretical
and applied perspectives. .11?urnag of Research in Reading, 20, 66-76.
Rarnus, F. (2006) A neurological model of dyslexia and other domain-specific develep-
mental diserders with an associated sensorimotor syndrorne, In G. D. Rosen (Ed.), 7he
dystexic brain: Mw Pathways in neuroscience dircoverpJ. Lawrence Erlbaum Associates,
Mahwah, New Jersey, 75-IOI,Ramus, E, Rosen, S., Dakin, S, C,, Day, B, L,, Castellote, J. M., White, S., & Frith, U. (200S) Theories oi' developmental dyslexia: Insights from a multiple case study of dyslexic
adults. Brain, I26, 841-865.Ramus, F. & Szenkovits, G, (2008) "Jhat phonological deficit? Qpaarterly
.lburnal qf' ExPerimen-
tal Aychology, 61, 129-141,
Reid, A, A., Szczerbinski, M., Iskierka-Kasperek, E., & Hanscn, P, (2007) Cognitive prefilcs of adult developmental dyslexics: Theoretical implications. QysZkxia, 13, 1-24.
Reis, S. M,, McGuire, J. M., & Ncu, T. W. (2eOO) aompensation strategies used by
high-ability students with learning disabilities who succeed in college. G(fted enild
QFearterly, 44, 123-134,Ruban, L. M,, McCoach, D, B., McGuire, J. M,, & Rcis, S. M. (2003) The diflerential
impact of academic seltLregulatory methods on academic achievement among univer-
sity students with and without learning disabilities. .lburnal
of Leaming Disabilities, 36, 268-284.
Schiff R. & Raveh, M. (2007) Defieient morphological processing in adults with develop-
mcntal dyslexia: Another barrier to eMcient word recognition? Qptslaxia, 13, 1IO-129.Seymour, P. H. K., Aro, M., & Erskine, J. M, (2003) Foundation literacy acquisition in
European orthographies. British .lburnat
of Rtvehology, 94, I4S-174,Share, D. L. (1995) Phonological reeoding and selftteaching: Sine qua non of reading
acquisition. Cagnitien, 55, 151-218.
Shaywitz, S. E,, Escobar, M. D., Shaywitz B. A., Fletcher, J. M., & Makuch, R. (1992) Evidence that dyslexia may represent the lower tail ofa normal distribution of rcading
-
402 -
The Japanese Association of Special Education
NII-Electronic Library Service
The JapaneseAssociation ofSpecial Education
Understanding Reading Disabilities
ability, rvlrw En.aland .lbumal
of Medicine, S26, 145-150.Shu, H., McBride-Chang, C., Wu, S,, & Liu, II. (2006) Understanding Chinese develop-
mental dyslexia: Morphological awareness as a core cognitive construct. .lburnal of Educational ilrychotogy, 98, 122-,133,Shu, H., Meng, X., Chcn, X., Luan, H,, & Cao, F, (2005) Thc subtypes of developrmental
dyslexia in Chinese: Evidence from three cases. 1]tvsilexia, 11, Sl1-329.
Siegel, L. S. (1992) An evaluation of the discrepancy definition of dyslexia. .lburnal
qf Learning Disabilities, 25, 618-629.Siegel, I., S., Sharc, D., & Geva, E. (t995) Evidcnce for superior orthographic skills in
dyslexics. Rslcholagical Stience, 6, 250-254.Silinskas, G., Leppanen, U,, Aunela, K., Parrila, R. & Nurmi, J.-E, (submitted) (:iiiidrenle
academic skill Pvadicts Parental teac'hing. Manuscript submitted Ibr publicatien.Singleton, C. &. Trottcr, S. (2e05) Visual strcss in adults with and without dyslexia. .lburnal
of Research in Reading, 28, S65-378. '
Snowling, M. J. (2000) ,Qyslexia (2nd ed.). Blackwell, Oxford, England.
Snowling, M. J. C2001) From language to reading and dyslexia. Qyslexia, 7, 37-46,
Stanovich, K. E. (1988) Explaining the diff'erences between the dyslexic and the garden-
variety poor reader: The phonological-core variable-diflerence modei. .lburnag
of Learning Ddsabilities, 21, 590 604, 612.
Stephenson, K. A., Parrila, R. K., Georgiou, G, K., & Kirby, J. R. (2008) Effects of homc
literacy, parents' beliefs, and children's task-focused behavior on emergent literacy
and word reading skills. Stientipc Studies of Reading, 12, 24-50.Szenkovits, G. & Ramus, F. C2005) Exploring dyslexics' phonologieal deficit I: Lexical vs
sub-lexical and input vs output proeesses. Ilystexia, l1, 25S-268.Tallal, P., Miller, S. L,, Jenkins, W, M., & Merzenich, M. M. (l997) The role of temporal
processing in developmental language-based learning disorders: Research and clinical
implications. In B. A. Blachman (Ed.), Fbundations of reading acquisition and dyslexia: inzpiications for early intevaention, I.awrence Erlbaum Associates, Mahwah, N'ew Jersey, 49-66,
Tan, L. H,, Spinks, J. A., Eden, G. F., Perl'etti, C. A., & Siok, W. T. (2005) Reading dcp ¢ nds
on writing, in Chinese. PIV/AS, 102, 8781-8785.
Torppa, M., Poikkeus, A.-M,, I.aakso, M,-L., Tolvanen, A., Leskinen, E,, Leppljnen, P. II.,
Puolakanaho, A., & Lyytinen, H. (2007) Modeling the early paths of phonological
awareness and factors supporting its development in children with and without
f'amilial risk of dyslexia. SZ'ientijic Studies e.f Readirrg, 1], 7B-103.Torppa, M., Tolvanen, A., Poikkeus, A.-M., Eklund, K., Lerkkanen, M.-K., Leskinen, E.,
& Lyytinen, H. (2007) Reading developme]t subtypes and their early characteristics.
Annals of' IItvsimia, 57, S-S2.van der Leij, A. & van Daal, V. H, P. (1999) Automatization aspects of dyslexia: Speed
limitations in word identifieation, scnsitivity to increasing task demands, and ortho-
graphic compensation, Jburnal of' Leaming Disabilities, 32, 417-428.
Vellutino, F. R., FIetcher, J. M., Snowling, M. J., & Scanlon, D. M. (2004) Specific rcading
disability (dyslexia): What havc wc lcarned in the past four decades? .lburnal qf enild
AJchotogy and Ilslchiatrv, 45,2 40.Vellutino, F. R., Scanlon, D. M., & Tansman, M, S. (1991) Bridging the gap between
- 4e3
-
The Japanese Association of Special Education
NII-Electronic Library Service
The JapaneseAssociation ofSpecial Education
R. Parrila
cognitive and neuropsychological conceptualizations ofreading disability. Leamin,g and
inchvithtat Dij7ierences, 3, l81-203.
Vellutino, F. R,, Scanlon, D. M., Small, S,, & Fanuele, D. P. (2006) Response to intervention
as a vehicle fbr distinguishing between children with and without reading disabilities:
Evidence fbr the role ofkindergarten ancl first-grade interventions. Jrburnal of Learning Disabilities, 39, 157-169.Vogel, S. A. & Adelman, P. B. (1990) Intervention eff'ectiveness at the postsecondary level
fbr the learning disabled. In T, Scruggs & B. Wong (Eds.), intervention resean'h in leaming
daabitities. Springer-Verlag, New York, 329-344.
Vogel, S. A. & Adelman, P. B. (l992) The success of college students with learning
disabilities: Factors related to educational attainrnent, .lbumag
ctf Learning Disabifities,
25, 430-441.
Wilson, A. M, & Lesaux, N. K, (2eOl) Persistence of phonological processing deficits in
college students with age-appropriate reading skills, Jrburnat of Leaming Ddsabitities, 34, 394--400.Wolg M. & Bowers, P. G (1999) The Double-Deficit hypothesis fbr the developmental
dyslexias. Jrbumal qf Educational RyJchology, 91, 415-4S8.Yamada, J. & Banks, A. C1994) Evidence tbr and characteristics of dyslexia among
Japanese children. Annals of' P;vslexia, 44, 105-l19.
Ziegler, J. C. & Goswami, U. (2005) Reading acquisition, developmental dyslexia, and
skilled reading across lunguages: A psycholinguistic grain size theoTy. Rs2eholagical
Bulhetin, 131, S-29.
-・Received
January 31, 2008; Accepted February 23, 2008-
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