Stoodley Catherine J, Ray Nicola J, Jack Anthea, Stein John F
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
Ann N Y Acad Sci. 2008 Dec;1145:173-83. doi: 10.1196/annals.1416.003.
Developmental dyslexia is diagnosed when children fail to acquire literacy skills despite adequate education and intellectual ability. There is evidence of impaired implicit learning in dyslexia, and it is possible that poor implicit learning in dyslexic children affects their acquisition of complex skills such as reading. To assess whether children with dyslexia show evidence of poor implicit motor learning, 45 dyslexic children completed a serial reaction time task (SRTT). Age-matched controls (n= 44) and nondyslexic poor readers ("garden-variety" poor readers, n= 20) were used as comparison groups. The inclusion of the garden-variety poor-reader group allows us to address the specificity of implicit learning deficits to dyslexics, as opposed to poor readers who do not have a discrepancy between their intellectual and literacy skills. There were no significant differences between the three groups in performance accuracy. However, whereas the controls and garden-variety poor readers showed good implicit learning (measured by a significant reduction in response times from a block of random to a block of sequenced trials), the dyslexic group did not. These data suggest that implicit motor learning deficits may underlie the laborious learning seen in developmental dyslexia. Because garden-variety poor readers were as able as control children to use the sequence cues to achieve better task performance, there may be differences in how garden-variety poor readers and dyslexic children acquire knowledge. This has important implications for remediation programs that are specific to children with dyslexia and for distinguishing among varieties of poor readers.
当儿童尽管接受了足够的教育且具备智力能力，但仍未能掌握读写技能时，就会被诊断为发展性阅读障碍。有证据表明阅读障碍患者存在内隐学习受损的情况，阅读障碍儿童内隐学习能力差可能会影响他们对阅读等复杂技能的掌握。为了评估阅读障碍儿童是否存在内隐运动学习能力差的证据，45名阅读障碍儿童完成了一项序列反应时任务（SRTT）。年龄匹配的对照组（n = 44）和非阅读障碍的阅读能力差的儿童（“普通”阅读能力差的儿童，n = 20）被用作比较组。纳入普通阅读能力差的儿童组使我们能够探讨内隐学习缺陷对阅读障碍儿童的特异性，这与智力和读写技能没有差异的阅读能力差的儿童形成对比。三组在表现准确性方面没有显著差异。然而，对照组和普通阅读能力差的儿童表现出良好的内隐学习（通过从一组随机试验到一组序列试验的反应时间显著缩短来衡量），而阅读障碍组则没有。这些数据表明，内隐运动学习缺陷可能是发展性阅读障碍中学习困难的潜在原因。由于普通阅读能力差的儿童与对照儿童一样能够利用序列线索来提高任务表现，普通阅读能力差的儿童和阅读障碍儿童获取知识的方式可能存在差异。这对于针对阅读障碍儿童的补救计划以及区分不同类型的阅读能力差的儿童具有重要意义。
