Neuropsychological processes related to persisting reversal errors in dyslexia and dysgraphia.

摘要

Despite research evidence to the contrary, a persistent belief exists among educators that the defining feature of dyslexia is a propensity to reverse (rotate on the vertical axis) letters when reading and writing. Educational practitioners are still mistakenly diagnosing dyslexia on the basis of reversals despite 6 decades of research evidence to the contrary. The purpose of this research is twofold: First, to examine whether reversals are more prevalent in a well-defined sample of adults and children with reading and writing disabilities than in non-reading and writing disabled individuals, and second, to identify the underlying neuropsychological processes that predict persistent reversal errors. The hypothesis will be tested that persisting reversal errors reflect deficits in underlying neuropsychological processes that contribute to dyslexia and/or dysgraphia. Measures of attention, automatization, working memory, executive functions, and reading and writing achievement were administered to 340 participants in a larger family genetics and learning disabilities study to determine the incidence of persistent written reversal errors in older children and adults with and without reading and writing disabilities and the relationship between these neuropsychological correlates and reversal error incidence. Finally, those processes that had a significant relationship with reversal error incidence were entered into multiple regressions to identify any unique variance they may contribute to reading and writing outcomes in children and adults with reading and writing disability who make reversal errors. The incidence (frequency or percentage) of individuals making reversals was significantly different for children who did and did not have dyslexia/dysgraphia, but not for adults who did and did not have dyslexia and dysgraphia. Reversal and non-reversal groups of children and adults were differentiated on the basis of specific neuropsychological, reading, and writing skills. Executive functions and orthographic and/or phonological coding in working memory contributed to some word-level reading processes in children who made reversals, but only accuracy of word reading contributed uniquely to their reading comprehension and only accuracy of spelling contributed uniquely to their written composition. In adults who made reversals, coding in working memory continued to predict some of their reading and writing skills, but executive functions did not.