PROJECT SUMMARY
Children with language impairment (LI) comprise nearly 20% of the population receiving special education
services (Tomblin et al., 1997) and are six times more likely to have a reading impairment than their peers with
typical language development (Stoeckel et al., 2013). Whereas most children with LI have poor reading
comprehension (Catts et al., 2002), fewer than half have poor word-reading abilities, commensurate with
dyslexia (Catts, Adlof, Hogan, & Weismer, 2005). In two large-scale studies that examined longitudinal reading
outcomes in children with LI, factors could not be identified that reliably distinguished kindergarten children with
LI who would go on to have good word reading abilities versus those who would go on to have dyslexia in 2nd
grade and beyond (Catts et al., 2005; Bishop et al., 2009). The inability to distinguish future word-reading
outcomes for young children with LI creates a critical barrier to efficacious treatment and prohibits
optimal use of limited therapy time to address individual children's needs.
Contemporary models of typical reading development center on a reciprocal relation between orthographic
processing (letters and letter patterns) and phonological processing (sounds and sound patterns). In these
models, early phonological processing underpins acquisition of the alphabetic principle (that letters represent
sounds) and subsequent word reading, and in turn, orthographic knowledge impacts phonological processing
(Share, 1995; Ziegler & Ferrand, 1998). Accordingly, orthographic and phonological processing are correlated
in emerging typical readers and continue to develop in tandem with increasing word reading abilities (Hogan,
Catts, & Little, 2005; Wagner et al., 1997). However, contemporary models cannot explain why more than half
of children with LI develop good word reading skills despite early phonological processing weakness (Catts,
Adlof, Hogan, & Weismer, 2005). Despite its significance to typical reading development, orthographic
processing has largely been ignored in studies of children with LI. Our compelling pilot data are the
foundation for our hypotheses that: a) initially weak phonological processing is compensated for by
orthographic strengths in children with LI, and b) these early orthographic strengths will predict who
among young children with LI will go onto have good word reading versus those who will go on to
have dyslexia.
Our specific aims are: 1) to determine the impact of exposure to orthography on the acquisition of new
orthographic and phonological forms during word learning and how this changes over time in children with LI
and their typically developing peers; 2) to characterize profiles of orthographic and phonological processing in
children with LI and their typically developing peers from kindergarten to 2nd grade; and 3) to determine
predictors of development in orthographic processing, phonological processing, and word reading in children
with LI and their typically developing peers. Our aims fill a theoretical gap in which orthographic processing has
been overlooked in reading and word learning studies involving children with LI, and they address
methodological limitations that have negated conclusive findings on the reciprocity between phonological and
orthographic processing.
Our rigorous approach combines longitudinal research with carefully controlled experimental work. The
innovation of this project includes our use of a novel, dynamic word learning paradigm, which captures
phonological and orthographic knowledge and learning in a single task. Our findings will have broad clinical
and theoretical impact by contributing to our long-term goals a) to create more precise tools for early
identification of reading impairments in children with LI; b) to reveal theory-based mechanisms for the
interrelated development of orthographic processing, phonological processing, and word reading; and c) to
quantify orthographic and phonological learning profiles to inform individualized reading interventions.
