The Multiple Systems Model of Reading: Understanding ... - J-Stage

The JapaneseAssociation The Japanese Association

of of Special Special Education Education

Jpn.J.Spec.Educ.,

45

383-404, (6),

2008.

invited PaPer Current Topic

The Multiple Systems Model of Reading: Understanding Reading Disabilitiesand Their Effect on Academic Achievement Across Individuals and Orthographies Rauno The present framework so

for a fu11understanding

that

contends

disabilities, both within

and

ment

paper is needed

that they

called

the

cycles

of

can

in

be

order

applied

`Cmultipic

develop-

of reading

languages, a better meta-theoretical to guide research and interpret research findings The framework to educational practice. presented, across

and

systems

model

and

reconstruction

construction

PARRILA

of reading'],

views

development as

contingent

that developmental resources

at various

levelsof functioning(genetic, neural,

and environmenpsychological,behavioral, to. The model makes two key assumptions: (a)reading abilities are distributed, and the developmental (b) process has distributed

tal) contribute continuously control;

every

observed

research

and

by

served

respecting

remedial

Key

eflbrts,

Werds:

of

reading

itself. Ramifications practice

educational

developing organism,

isjointEy determinedby

outcome

ing the developingorganism

the complex, and

by

are and

not

possible reading

multiple

of these

factors, includforboth

assumptions

discussed.Educational practicc is well idiosyncratic,nature

sometimes

a]locating

causal

problems to

dyslexia, multiple disabilities,

any

responsibility, single

system

or

of'

the

all the

cause.

modcl,

core

deficit

Introduction in general and Reading disabilities conceptualized

and

assessed

variably

developmentaldyslexia in particularare both within and across linguisticcontexts,

'theoretical leading to both definitional and cenfusion. The present article proposes that a theoretical framework is needed that encompasses multiple Ievelsof functioning, in order to enhanee the knowledge of why individuals(bothwithin and across contexts) failto develop suMcient word-reading or text-level reading skMs, linguistic and how such skills are related to each other and to academic outcomes. Specifically, to understand relationships between cognitive deficits, wordpossible probabilistic remedial and text-level reading difflirent academic and outcomes, problems, and

University

of

Nberta 383-

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The JapaneseAssociation The Japanese Association

of of Special Special Education Education

R. Parrila

developmental systems theory (DST;e.g., Oyama, GriMths, & Gray, 2001)provide bettermeta-theoretieal frameworks than any single dual) core deficit model that is currently relied on. One such model, the (or 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 SysternsModel of Reading will be presented.Seme recent studies guided by the Multiple Systems Model of Reading wM be described,and itseducational

rnodels

adhering

implications

wM

to the principles

of

be discussed.

Theories

of

Reading

Disabilities

A great deal of research on children and adults with. reading disabilities has focused on identifyingthe source or corc deficitof the reading disabilityon the cognitive Ievelof analysis. The majority of these studies have fbcused on Englishspeaking individualswith word-level reading and have aimed problems, or dyslexia, at verifying or refuting the existence of some between the qualitativedifi'erences individualswho are dyslexicand control groups. For the large part,studies with individualswho are developmental dyslexics(as opposed to neuropsychological studies with have dyslexics) peop}e who are acquired been guided by single-factor theeries, most of which posit a specific impairment in the ability to manipuiate, retrieve, and/or store phonologicalinformation as the cognitive levelcore deficitresponsible for poor reading Frith,1999; Ramus & Szenkovits, (e.g., Snowling, When other explanatory constructs have been examined, their 2008; 2001). and/or purpose has been either to provide a neuroLogical perceptuallevelexplanation Ahissar, 2007; Goswami, Thomson, forthe cognitive levelphonological deficits(e.g., 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 dyslexicwhose 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). researchers For example, have reported that many, but not all, individualswho are dyslexicperform poorly on rapid naming Ho, Chan, Lee, Tsang, & Luan, (e.g., Miller-Shaul, 2005) and orthographic Badian, 1997; Ho 2004} processingtasks (e.g,, et aL, 2004; Meyler & Breznitz,2003), and have problems proccssingvisual infbrmation using the magnocellular Buchholz & McKone, 2e04).Other pathway (e,g,, researchers have reported that at leastsome individualswith dyslexiashow depressed levels of perlbrmance in diflbrentauditory King, Lombardino, processing (e.g., Crandell, & Leonard, 2003) and visual attcntion span tasks (Bosseet al., 2007), mQtor-coordination experience Rack, 1997) and implicitlearning(e.g., Howard, (e.g., Howard, Japikse, & Eden, 2006) difficulties, report high levels and of visual stress Trotter, Singleton & 2005). (e.g., Without going into detailon how plausibleany of' these cleficits is as the core - 384 -

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of of Special Special Education Education

Understanding

Reading Disabilities

deficit e.g., Ramus, Rosen,Dakin,Day, Castellote, White, & Frith, 2003;Ramus, (see,

has been linked to reading outcomes e.g., Ahissar, Csee, and theoretical problems, 2007),existing studies sufler from notable methodological in the opinion of the present author. Methodologically,most studies on developmental dyslexia have sulfered from (a)relatively srnall and heterogeneous samples Manis, Keating & Seidenberg, 2000; Reid, Szczerbinski, Iskierka(e.g., Joanisse, Kasperek, & Hansen, 2007), (b) inconsistentsample selection proccdures (e.g., compare Leikin & Zur-Hagit, 20e6,and Szenkovits & Ramus, 2005), (c)selection cause ln thern (e.g., use of procedures that have included aspects of the examined and spelling word attack scores as selection criteria and then examining phonological 2006), or how

reliably

(d)variabLe

awareness),

each

measures

of

purportedly the

same

constructs

timed (e.g.,

and

of phonological (e)poor lactors (e.g., Giraudo, 2001),and (fiinconsistentselection potentialconfounding criterion fbr comparison e.g., Egan & Pring, 2004,and Bosse et al., groups (compare, issues), 2007; see also Goswami, 20e3, fora furtherdiscussion of methodological In addition, the theoretical assumption of qualitative rather than quantitative differenceshas led to simplistic study designs (groupcomparisons with small sample sizes assuming, rather than examining, within-group homogeneity) and data analysis methods, Even when more than one has been examined individual construct and leveldata presented (e,g., Parrila,Georgiou,& Corkett, 2007; Rack, 1997; Ramus et relating al,, 20e3),each of them has been explored separately without as much as the number of deficientareas to observed reading levels(seeBirch & Chase, 2004; Kinsbourne, Rufo, Gamzu, Palmer, & Berliner,I991, fbr notable exceptions). No fbr example, the possibility that published study that we could find has exarnined, several subclinical cognitive deficitsmay significant jointly produce a clinically reading deficit. Contrary to what has been suggested e,g., Vellutino,Scanlon, & (see, Tanzman, 1991), such alternatives are not ruled out simply by adopting IQ as an exclusionary criterion for reading disabilities. Theoretically,the assumption that developmentaldisorders, such as developuntimed

mental

mcasures

of

dyslexia or !eve!of analysis

specific

awareness),

reading

comprehcnsion

or

nonexistent

deficit, can have a

control

single

cau,se

at

has been challenged recently by multifactorial etiological models Gottlieb & Halpern, 2002; Pennington, 2006; see, however, Morton, 2004, and (e.g., Ramus, 2006,fbr multifactQrial etiological models that assume a single cognitive level eause), Pennington (2006) argues that probabilistic multiple deficitmodels are needed to providc realistic accounts of developmental disordersand the nondeterministic relationship between disorders and their causes. He suggests furtherthat such modcls levels of analysis have to include (a)both protec:tiveand risk factors,(b)multiple (his own model includes etiologic both and environmental i'actors), general (with genetic between conneural, cogni,tive, and behaviora]levels),(c)bidirectional connections any

level, and between the levcls to Cd)bidirectional connections for interactions between protectiveand risk factorsfunctioning at diflerent account levclsot' analysis (seealso Ferd & Lernct',1992; Gottlieb,1983, 1997; Gottlieb, Wahlsten, & Lickliter,2006). structs

within

each

-385-

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of of Special Special Education Education

R. Parrila I propose here that to understand deficits,wordand possible cognitive

between text-level reading problems, and diflerent remedial models academic and outcomes, adhering to the prineiples of developmental systems theory (DST; e.g., Oyama et al.,2001) provide better meta-theoretical frameworks than any single (ordual) core deficitmodel. In general,developmental more or lessreliable-cycles of systems theory views developmentas contingent-but construction

and

reconstruction

that

the

probabilistic

relationships

dif{erent developmentalresources

contribute

to.

One of the key underlying assumptions is that the developmentai process has distributedcontrol; every observed outcome isjointly determined by multiple factors, or interactants, includingthe developing organism itself, Implicitin this assumption is the important idea that the significance of any particularfactorisdependent upon risk and the state of the rest of the system, thus making itnecessary to consider other as well as changes in importance of diff'erent factors both over time protectivefactors and

across

contexts.

The

Multiple Systems Model

of

Reading

Based on developmental systems theory and earlier work by Gottlieb (198S), Frith (1999, my associates and I have been developing 2002)and Pennington (2006), a probabilistic multiple systems model of reading (MSMR) to guide our research aims to understand reading development and disabilities across efforts. This rnodel the lifespan in diflerentorthographies e.g., Georgiou, Parrila, & Liao, in press; (see, 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 fullmodel, depicted in Fig. 1, assumes influencesbetween five levelsof analysis or systems-genetic, neural, bidirectional several functionallyidentifiable psychological, behavioural,and environmental-and subsystems in each Ievel(see, e.g., Gottliebet aL, 20e6, and Oyarna et al., 2001, for related models). The present article willexplicate some specific connections betweep risk and factors betwcen and within the behavioral, both protective psychological, systems, including the language that the individualislearningto and environmental read. of factors(or to any levels,systems, Note that the assignment 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 dichetomies. An alternative any fundamental ontological depictionof the simplified three-level multiple systems model is shown in Fig. 2, The three-level Multiple SystemsModel of Reading makes several assumptions derived from the principlesef developmental systems theory (Oyama et al., 2001), Frith (1999), Penning'ton (2006), and from continuous abilities theories of reading Olson & Gayan, 2001;Shaywitz, Escobar, Shaywitz, Fletcher,& Makuch, 1992; (e.g., Stanovich, 1988; Vellutino et al., 1991) that also have rejected the validity oS" difi'erences between readers of difi'erent abilities. These assumptions qualitative include: "interactants")

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Understanding ReadingDisabilities

(I)Any

system

focus comes

of

simultaneous

fhctorsoperating cognitive

at

consideration

than

more

one

factors) can be the protective

risk and

by itself, but fullexpianations

require

language,

cognitive (e.g.,

or subsystem

study

levelof

of of

reading

multiple

analysis

and

acadcmic

risk

protective

and

(for

example,

out-

the eflect

of

factorson reading is mediated by environmental factors, such as e.g., Georgiou,Parrila, & Papadopoulos, in press,and instructional

IJanderl,2000; Papadopoulos, 2001); are (2)Distributionsof risk factors,protectivefactors,and reading outcomes continuous e.g,, Olson & Gayan, 2001;Shaywitzet aL, 1992;Stanovich, (see, methods,

see,

e.g.,

Main Leve]s ef

BidiTectionalInfiuences

Activit}, Environmcnt Behaviour Psychelogical Neural

GcnctLc

. Individual Development

FIG. 1

Schematic Representation of the Diflerent Levels of Analysis the1992) Multiple Systems Model of' Reading (Modified From Gottlieb,in

Environment

(physicai,secial,cultural) di k

.i

!

u,. }'t

/ x1,, -

Behaviour

(actiens,interaction$it) g wa.. .,K. ,

Reading

&academic outcomes

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