RAN and double-deficit theory.

Lervag and Hulme's neuro-developmental theory and Wolf and Bowers's double-deficit hypothesis were examined in this longitudinal study. A total of 130 children were tested in preschool and followed through fifth grade, when 84 remained in the study. During preschool and kindergarten the participants were given tests of end-sound discrimination (phonological awareness; PA) and the rapid naming of objects (rapid automatic naming; RAN) and were placed into the four groupings of the double-deficit hypothesis. The growth curves for the four groups with the subtests of word reading, pseudoword reading, and comprehension supported the double-deficit hypothesis. The RAN objects scores of preschool and kindergarten predicted reading at every age level and offered support for Lervag and Hulme's neuro-developmental theory. It was concluded that both RAN and PA predicted reading in the English language throughout the elementary school years and that the early assessments of these variables were more diagnostic than measures at later ages.