Dyslexia

Dyslexia is a brain-based language-learning disability affecting 15%–20% of the population. Reading and spelling skills are below population mean and expected levels based on verbal reasoning. Research has shown a genetic basis for dyslexia with multiple associated genes and often familial history. Differences in brain patterns between normal readers and those with dyslexia have been shown in structural and functional [Page 559]magnetic resonance imaging and studies examining the connectivity of brain regions.

Historically, this learning disability identified in the 1800s was called word blindness. Characterized by poor underlying phonological processing of heard and spoken words and orthographic processing of read and written words, dyslexia interferes with an individual’s ability to convert written words into spoken words (decoding) and spoken words into written words (spelling). Executive functions and working memory related to language are related deficits.

Most individuals show average or better expressive language and reading comprehension abilities despite difficulties with word reading and spelling. Dyslexia may present differently in each affected individual, although common characteristics are trouble with decoding unfamiliar words, which in turn affects rate and fluency of reading, and spelling, which in turn affects rate and fluency of composing. Some also have handwriting problems. The severity of these characteristics can vary among individuals.

Although dyslexia is thought of as a childhood disorder, it can present throughout the life span. Students may need accommodations and interventions from elementary school through college and beyond. Spelling issues tend to persist throughout the life span.

Dyslexia can be treated through explicit, systematic teaching at all levels of language: subword, word, and syntactic and text levels. Phonological, orthographic, and morphological awareness needs to be addressed. Research has shown brain changes and normalization of reading and/or spelling in children with dyslexia who undergo specialized reading and/or writing intervention. Individuals with dyslexia can exhibit different strengths and weaknesses in reading and spelling skills and often need individualized intervention to remediate their deficits. Some are twice exceptional, and their superior cognitive capabilities may mask their dyslexia unless they are carefully assessed.

See also Dysgraphia; Giftedness; Learning Disabilities; Literacy; Special Education Identification; Special Education Law