Vernon M D
Br J Psychol. 1979 Feb;70(1):7-16. doi: 10.1111/j.2044-8295.1979.tb02135.x.
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.
