SAiL Publications

This research focuses on the language and cognitive foundations of reading development and reading disabilities, with a focus on developmental language disorder (DLD), dyslexia, and their frequent co-occurrence. Across longitudinal, behavioral, neuroimaging, and school-based studies, the work demonstrates that oral language, working memory, and multifactorial risk processes play a central role in reading outcomes, challenging single-deficit models of dyslexia. The research identifies early precursors and protective factors that shape risk and resilience, clarifies heterogeneity in learner profiles, and advances understanding of word learning and memory mechanisms underlying reading difficulty. A strong translational emphasis links these findings to educational practice, highlighting early identification, interdisciplinary collaboration, and evidence-based service delivery in schools. Collectively, this scholarship informs theory, assessment, prevention, and equitable literacy instruction within the science of reading.

This body of research focuses on developmental language disorder (DLD) and poor reading comprehension, emphasizing how language, cognition, and environmental factors shape literacy development across childhood. Collectively, these studies demonstrate that many children with reading difficulties—particularly poor comprehenders—have underlying language impairments that often go unidentified in school systems. The research clarifies the complex relationships among oral language, working memory, attention (including ADHD), and reading outcomes, highlighting substantial heterogeneity and frequent comorbidity with dyslexia. Across longitudinal, experimental, and mixed-methods studies, this work identifies early language precursors to later comprehension problems, advances screening and classification practices, and evaluates instructional and service-delivery approaches responsive to children with language comprehension deficits. A strong translational emphasis connects caregiver and educator perspectives, school-based implementation, and equity-oriented advocacy, underscoring the importance of early identification, language-informed instruction, and interdisciplinary collaboration to improve outcomes for children with DLD and poor comprehension.

These articles collectively demonstrate that reading comprehension is fundamentally language driven and develops from multiple interacting skills that emerge well before formal reading instruction. Across longitudinal, experimental, and intervention studies, this work shows that oral language, listening comprehension, vocabulary, inference making, and working memory are critical predictors of later reading comprehension, extending and refining the Simple View of Reading across development. Findings from the Let’s Know! intervention studies provide strong evidence that language-focused classroom instruction in prekindergarten and early elementary grades improves comprehension-related skills, with effects on reading comprehension mediated through gains in language. Additional studies clarify the multidimensional nature of comprehension processes, distinguishing local and global inferences and demonstrating that attention and working memory contribute differentially to listening versus reading comprehension. Together, this research advances theory by moving beyond simplistic models of reading, identifies early predictors of comprehension difficulty, and provides empirical support for early, language-based instruction as a key lever for improving reading comprehension outcomes.

This body of research examines how early language skills—particularly vocabulary, grammar, and listening comprehension—develop from prekindergarten through the elementary years and contribute to later reading outcomes. Using longitudinal modeling and advanced analytic approaches, these studies show that language ability is multidimensional, with distinct but related components that follow different developmental trajectories and exert differential influence on reading comprehension and word reading. Findings refine and extend the Simple View of Reading by demonstrating that prekindergarten language skills predict later comprehension in nonlinear and heterogeneous ways, with “pressure points” where language weaknesses disproportionately constrain reading success for some children. Collectively, this work highlights listening comprehension as a critical, separable construct, identifies early profiles of lexical quality that shape later reading development, and underscores the importance of early, comprehensive language assessment for identifying children at risk for persistent reading difficulties.

This line of research investigates how phonological and lexical characteristics of words—such as speech perception, phonotactic probability, neighborhood density, and word frequency—shape phoneme awareness, word learning, and reading development, particularly in children with dyslexia and language-related speech difficulties. Across experimental and developmental studies, the work demonstrates that phonological awareness is not a unitary skill but is strongly influenced by the structure and statistical properties of words, and that these influences differ for children with typical development, dyslexia, developmental language disorder, and persistent speech delay. Findings show that children with dyslexia exhibit distinct speech perception and phonological processing profiles, and that lexical factors interact with phonological representations to affect learning and awareness. Collectively, this research advances theoretical models of phonological development, refines assessment of phonological awareness, and highlights the importance of considering word-level properties when evaluating and supporting reading and language development.

This research examines how attention-deficit/hyperactivity disorder (ADHD) interacts with developmental language disorder (DLD) to influence language and reading outcomes. Across these studies, findings show that ADHD does not simply add global impairment but exerts specific, domain-dependent effects, particularly on word reading and functional language performance. Children with DLD and co-occurring ADHD demonstrate greater challenges than peers with DLD alone, yet their reading and language profiles remain distinct from those of children with primary reading disorders such as dyslexia. Collectively, this work clarifies the unique and combined contributions of language impairment and attentional regulation, highlighting the need for differential diagnosis and tailored intervention that address both language and attention rather than attributing academic difficulties to a single underlying cause. 

This body of research investigates how early speech sound production, speech perception, motor control, and working memory relate to later language and reading development, with particular attention to children with speech sound disorders, childhood apraxia of speech (CAS), dyslexia, and overlapping profiles. Across longitudinal and experimental studies, the work shows that early speech production differences are indirectly linked to later reading outcomes through preliteracy skills, rather than serving as a direct cause of reading difficulty. Findings also clarify heterogeneity within speech sound disorders, demonstrating that deficits in speech perception, motor control, and working memory vary by diagnosis and task demands and are not uniformly present across groups. Genetic, motor, and cognitive factors are shown to interact over development, shaping speech consistency and learning trajectories. Collectively, this research refines theoretical models linking speech, language, and literacy, and underscores the importance of early, multidimensional assessment to distinguish pathways from speech difficulties to later reading risk.

This line of research examines language, cognitive, and learning processes in Spanish–English bilingual children, with a focus on phonological vulnerability, word learning, executive function, and the structure of oral language across languages. Across experimental and large-scale modeling studies, findings show that bilingual children may exhibit phonological vulnerabilities in one or both languages that reflect differences in input and experience rather than disorder, underscoring the need for language-specific and developmentally sensitive assessment. Studies of novel word learning demonstrate that bilingual children learn new words differently from monolingual peers, influenced by phonological memory and lexical knowledge, while evidence for a broad executive function advantage is limited and task dependent. Dimensional analyses further reveal that oral language in bilingual children is multidimensional and language specific, mirroring patterns seen in monolingual development. Collectively, this work advances theory on bilingual language development and provides critical guidance for distinguishing typical bilingual variation from language impairment in educational and clinical contexts.

Hogan, T.P. & Bridges, M.S. (2025). From idea to impact: Funding for implementation research in communication sciences and disorders. In L. Olswang, N. Douglas, & J. Feuerstein (Eds.), Implementation Science in Communication Sciences and Disorders. Baltimore, MD: Brookes Publishing.

Thompson, D.M., Nelson, N., Snowling, M., Hulme, C., and Hogan, T.P. (2025). From research to practice: The Nuffield Early Language Intervention (NELI)'s journey across the Atlantic. In B. Cook & T. Landrum (Eds.), Advances in Learning and Behavioral Disorders: Case Studies of Research-Based Practice. Cambridge, MA: Emerald Publishing.

Curran, M. & Hogan, T. (2024). Serving children with exceptionalities as they climb the ladder of reading and writing: DLD. In N. Young & J. Hasbrouck (Eds.), The Ladder of Reading and Writing. Benchmark Education Company LLC.

Curran, M. & Hogan, T. (2024). Developmental language disorder: What it is and why it matters. In S. Cabell, S. Neuman, & N. Patton Terry (Eds.), Handbook on the Science of Early Literacy. Guilford Press.

Nelson-Strouts, K., Hogan, T.P., & Bridges, M.S. (2024). Preschool children with developmental language disorder. In S. Chabon, E.R. Cohn, & D. Lee-Wilkinson (Eds.), The Communication Disorders Casebook: Learning by Example, Second Edition. Plural Publishing.

Hogan, T.P. (2019). Integrative Commentary of Section II: Typical Language (Spoken and Written) Development. In E. Grigorenko, Y. Shtyrov, & P. McCardle (Eds.), All about Language: Science, Theory, and Practice (pp. 76-79). Baltimore, MD: Brooks Publishing.

Cabbage, K.L. & Hogan, T.P. (2014). Phonological Awareness (Development of). In P. Brooks & B. Kempe (Eds.), Encyclopedia of Language Development (pp. 451-454). Thousand Oaks, CA: SAGE Publications.

Hogan, T.P., Cain, K., & Bridges, M.S. (2012). Young children’s oral language abilities and later reading comprehension. In T. Shanahan & C. Lonigan (Eds.), Literacy in Preschool and Kindergarten Children: The National Early Literacy Panel and Beyond (pp. 217-232). Baltimore, MD: Brooks Publishing.

Bridges, M.S., Justice, J.M., Hogan, T.P., & Gray, S. (2012). Promoting lower- and higher-level language skills in early education classrooms. In R.C. Pianta, W.S. Barnett, L.M. Justice, & S.M. Sheridan (Eds), Handbook of Early Childhood Education (pp. 177-193). New York, NY: Guilford Press.

Hogan, T.P., Bridges, M.S., Wymer, C., & Volk, R. (2010). Tessa: A preschool child with a specific language impairment. In S. Chabon & E. Cohn (Eds.), The communication disorders casebook: Learning by example (pp. 142-156). Boston, MA: Allyn & Bacon.

Catts, H.W., Hogan, T.P., & Adlof, S.M. (2005). Developmental changes in reading and reading disabilities. In H.W. Catts & A.G. Kamhi (Eds.), The connections between language and reading disabilities (pp. 25-40). Mahwah, NJ: Lawrence Erlbaum Associates.