Variability in reading retardation

Abstract

It is argued that much of the confusion which has arisen as to the nature of dyslexia is because retarded readers have so frequently been studied as if they formed a qualitatively homogeneous group. It is suggested that in fact reading is not a unitary process, but that it involves the acquisition of a succession of skills; and that different retarded readers may break down at different stages in the acquisition of these. There may be types of retarded reader who are unable (1) to analyse complex visual shapes; or (2) to analyse whole word sounds into phonemes; or (3) to make simple regular grapheme-phoneme associations; or (4) to grasp irregularities in these; or (5) to group single words into phrases and sentences. Each of these disabilities may be associated with a particular type of deficiency in conceptual thinking.

Specific reading retardation and working memory: A review

“…Many authors argue that specific reading retardation cannot be treated as a unitary disorder (e.g. Vernon, 1979). Certainly, OOO7-1269/83/030311-32 $02.00/0 0 1983 The British Psychological Society the possibility of subtypes of reading retardation must be kept in mind when reviewing the literature, but in this review reading retardation will be treated as though it were a unitary problem for two reasons.…”

Continuity between childhood dyslexia and adult reading

“…Whether or not dyslexia can be considered a discrete disorder relative to normally poor reading, one may ask whether reading disabilities are unitary or heterogeneous in their nature and causes. Several subtypes, each characterized by particular combinations of processing deficiencies, have been postulated to differentiate among dyslexic subjects (Ingram, 1960;Boder, 1973;Mattis et al, 1975;Doehring & Hoshko, 1977;Vernon, 1979;Decker & DeFries, 1981) and among cases of 'acquired dyslexia' (Marshall & Newcombe, 1973;Patterson & Marcel, 1977;Saffran & Marin, 1977). Several of the dyslexic adults in the present study appeared to show such selective processing decrements to some degree in either phonic analysis or in visual recognition.…”

Epidemiology and Etiology of Mental Retardation

“…It has been shown for the general population that IQ scores are relatively stable (Vernon, 1979;Zigler & Butterfield, 1966). Changes in scores greater than one standard deviation are usually attributed to removal of deprivation followed by intervention involving social and learning stimulation during early childhood (Clarke & Clarke, 1976;Dennis, 1973;Lazar & Darlington, 1982).…”