The Role of Letter-Speech Sound Integration in Typical and Atypical Reading Development

Book excerpt: Fluency is the quintessence of effective reading. To obtain socio-economic success, fluent reading is of primordial importance and reading is considered a crucial marker of an individual’s life course. Approximately 5% of children are affected by developmental dyslexia, exhibiting inaccurate word recognition, spelling, phonological decoding, and most importantly, severely dysfluent reading, which remains as their most characterizing and persistent deficit. Unable to attain society’s literacy demands, individuals with dyslexia are at severe risk for adverse academic, economic, and psychosocial consequences. Recently, it has been posed that the development of automatic letter-speech sound (LSS) integration is critical in the acquisition of fluent reading skills, and in particular that a failure to develop automatic LSS integration results in an impairment of reading fluency. In support, neurocognitive research has suggested that the development of automatized processing of LSS associations is an essential step in the formation of a functional neural network for reading. Furthermore, both neurocognitive and behavioural studies have suggested a less efficient LSS integration in children with dyslexia than in typical readers. Finally, results from intervention studies have suggested that training LSS might be a promising approach to ameliorate dysfluent reading in children with dyslexia. Nonetheless, there is still a considerable gap of knowledge in our understanding of the mechanisms by which learning LSS associations relate to (dys)fluent reading.