The development of phonological and orthographic processing strategies in readers with a specific reading disability compared to normally achieving readers

摘要

The self-teaching model of reading acquisition proposed by Share (1995, 1999)udsuggests that phonological decoding may be the principal means for becoming skilledudat word recognition. Given that individuals with a specific reading disability (SRD)udhave been shown to have a phonological processing deficit (Rack et al., 1992), theudlack of proficiency in these skills could have detrimental effects on orthographicudprocessing skills. In contrast, Lennox and Siegel (1994) argue that the cognitiveudprofile of children who have a specific reading disability (SRDs) might includeuddeficient phonological skills and superior orthographic skills. In a two-yearudlongitudinal study, SRDs in Grades 3, 5, and 7 and their chronological age (CAMs)udand reading age (RAMs) matched controls (N=98) performed a range of standardisedudand experimental tasks to investigate the development of phonological and orthographic component processing skills. Although SRDs made significant gains onudisolated word recognition tasks over time, they did not improve to the same extent asudRAMs. This was largely attributed to a phonological processing deficit given that, inudcomparison to controls, SRDs were significantly less accurate on nonword reading,udphoneme deletion, and phonological coding tasks and did not improve significantlyudover time for the latter two tasks. SRDs demonstrated a particular difficulty withudphonological analysis of visual stimuli and were more likely than controls to use anudorthographic strategy to perform this task. Although SRDs did not demonstrate auddeficit for synthesis tasks, they did show an atypical developmental pattern comparedudto RAMs. SRDs in Grade 3 had difficulty discriminating between real word targetsudand pseudohomophone foils on an orthographic coding task compared to controlsudwhereas older SRDs performed similarly to RAMs. Although all SRDs improved onudthis task, the youngest group appeared to develop less accurate orthographic representations. In discriminating between nonwords containing legal letter stringsudand those containing letter strings in positions that never occur in the Englishudlanguage, all groups performed similarly indicating that the participants had attaineduda sufficient level of orthographic knowledge required to perform this task.udOrthographic strategy use and coding skills appeared to be relatively intact inudcomparison to phonological processing skills for SRDs. However, there wasudinsufficient evidence to conclude that SRDs compensate for their phonological deficitudwith superior orthographic skills given that there were no orthographic tasks whereudSRDs performed better than would be expected given their reading age. Furthermore,udin addition to an atypical developmental pattern for phonological processing skills,udSRDs showed a protracted developmental course for some measures of orthographicudprocessing. These findings support Share's (1995, 1999) idea that the acquisition ofudorthographic representations is largely dependent on phonological processing skills.