Core deficits and variable differences in Dutch poor readers learning English.

To examine phonological core deficits and variable orthographic competence, Dutch poor readers were investigated as they began instruction in reading in English (at about 14 years of age). A subgroup of poor readers with good orthographic competence in English (Poor/Good) and a subgroup with poor orthographic competence in English (Poor/Poor) were identified. Verbal and reading tasks in Dutch and English were assessed twice within a 10-month interval, and the scores of the two measurements were combined to gain stability. For both subgroups, we found indications that phonological core deficits and variable differences in orthographic competence transferred across the two languages. However, the Poor/Good subgroup did not show the weaknesses in serial rapid naming and semantic fluency of the Poor/Poor subgroup in both languages. Moreover, the Poor/Good readers were relatively good in reading skills and verbal learning in English. They had a specific reading disability at the phonemic level but also had compensatory skills at the level of syllables and words that help them to acquire English as second language. In contrast, the Poor/Poor subgroup had a more general reading disability, most prominently present in L2. The results are discussed in terms of orthographic differences between Dutch and English, the phonological-core variable-differences model, and "subtypes" of dyslexia.