Sequential Versus Simultaneous Processing Deficits in Developmental Dyslexia

Abstract

Despite the large number of studies conducted on developmental dyslexia, the cause(s) of the disorder still remain(s) unclear.Researchers in this field still struggle to understand the reason why abnormal reading acquisition occurs in children who receive appropriate environmental opportunities to achieve a good education, and present normal intellectual efficiency.This introduction will focus on the presentation of the phonological hypothesis, and then move onto the presentation of the visual attention span hypothesis, which predicts at least two proximal causes to developmental dyslexia.Setting the theoretical framework for these hypotheses will help to understand why sequential and simultaneous dimensions for visual and auditory processing may have independent roles to play in typical and atypical reading development. The phonological hypothesis: The only core deficit of the reading disorderThe phonological hypothesis (e.g., Snowling, 2000), probably the most well-known hypothesis among those formulated so far, predicts that an impairment in various phonological components (e.g., phonological short-term memory, phonological awareness, and phonological fluency) and sub-lexical processing (i.e., at the level of units smaller than the word such as graphemes, syllables or morphemes) would be detrimental for the acquisition of the skills necessary to decode new words, and acquire fluent reading (see Vellutino et al., 2004 for a review).This hypothesis suggests that difficulties in acquiring phonological awareness and the alphabetic principle would prevent letter-to-sound mapping from developing normally.Consequently, a phonological disorder would affect reading acquisition, impairing the abilities necessary to map sub-lexical and lexical orthographic forms to their auditory counterparts.In support to the phonological deficit hypothesis, studies on typical children provided reliable evidence for a causal link between phonological skills development and reading acquisition (see however Castles & Coltheart, 2004 for a counter-argument about this causality).For example, longitudinal studies have shown that phonological skills predict later reading performance (e.g., Hulme et al., 2002).Phonology-based training www.intechopen.com

Cite this work

No public copy is stored for this record, so only the metadata is cited.

Stored only when both papers are in the corpus — 27 citations exist upstream.

Papers that cite the same references — the relational fallback while embeddings are still backfilling.