Dyslexics are impaired on implicit higher-order sequence learning, but not on implicit spatial context learning
Dyslexics are impaired on implicit higher-order sequence learning, but not on implicit spatial context learning
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DOI：
10.1016/j.neuropsychologia.2005.10.015
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发表时间：
2006-01-01
期刊：
影响因子：
2.6
通讯作者：
Eden, Guinevere F.
中科院分区：
文献类型：
--
作者：
Howard, James H., Jr.;Howard, Darlene V.;Eden, Guinevere F.
发展性阅读障碍的特点是阅读能力差，语音加工和感觉信息加工等一系列任务受损。最近的一些研究发现了使用序列反应时任务的内隐序列学习的缺陷，但其他人没有。其他技能，例如全局视觉空间处理，甚至可能在诵读困难者中得到增强，尽管也注意到了缺陷。本研究比较了两个内隐学习任务，交替串行响应时间任务中存在的顺序依赖关系，在非相邻元素和空间上下文学习任务中，显示器的全局配置线索的搜索目标的位置，有读写障碍和非读写障碍的大学生。已有的证据表明，这些内隐学习任务是基于不同的脑系统，额-纹状体-小脑回路用于序列学习，内侧颞叶用于空间背景学习。结果显示双重分离：阅读障碍者表现出受损的序列学习，但上级空间背景学习。与此组间差异相一致的是，阅读能力（单个真实的和非单词阅读）与序列学习之间存在显著正相关，而这些测量与空间背景学习之间存在显著负相关。外显知识的测试证实，学习是内隐的两组在这两项任务。这些结果表明，阅读障碍大学生在某些内隐学习上受到损害，但在其他方面没有受到损害。他们的学习缺陷的具体性质是一致的生理和解剖差异的个人与诵读困难的额叶和小脑结构的报告。(c)2005爱思唯尔有限公司保留所有权利。
Developmental dyslexia is characterized by poor reading ability and impairments on a range of tasks including phonological processing and processing of sensory information. Some recent studies have found deficits in implicit sequence learning using the serial reaction time task, but others have not. Other skills, such as global visuo-spatial processing may even be enhanced in dyslexics, although deficits have also been noted. The present study compared dyslexic and non-dyslexic college students on two implicit learning tasks, an alternating serial response time task in which sequential dependencies exist across non-adjacent elements and a spatial context learning task in which the global configuration of a display cues the location of a search target. Previous evidence indicates that these implicit learning tasks are based on different underlying brain systems, fronto-striatal-cerebellar circuits for sequence learning and medial temporal lobe for spatial context learning. Results revealed a double dissociation: dyslexics showed impaired sequence learning, but superior spatial context learning. Consistent with this group difference, there was a significant positive correlation between reading ability (single real and non-word reading) and sequence learning, but a significant negative correlation between these measures and spatial context learning. Tests of explicit knowledge confirmed that learning was implicit for both groups on both tasks. These findings indicate that dyslexic college students are impaired on some kinds of implicit learning, but not on others. The specific nature of their learning deficit is consistent with reports of physiological and anatomical differences for individuals with dyslexia in frontal and cerebellar structures. (c) 2005 Elsevier Ltd. All rights reserved.