Development of Word-Level Reading and the N400 Component of the ERP

描述(由申请人提供)：根据美国政府的统计数据，只有大约三分之一的美国四年级学生的阅读水平达到了熟练水平。四年级是小学的关键一年，因为课程通常要求学生从学习如何阅读的基础知识转向以成年人的方式使用既定的阅读技能，以获得和建立新的知识。行为数据表明，在典型的发展中读者中，对简单、高频单词的上下文无关识别在四年级时是自动的，但神经数据很稀缺。这项针对三、四、五年级学生的研究既使用了各种阅读技能(拼写、语音、语义和理解)的标准化行为测量，也使用了神经文字处理的测量，神经文字处理是事件相关电位(ERP)波形的N400成分。在之前对成年人的研究中，N400已经被证明可以索引文字处理的词汇语义和更高层次的方面。这里，N400将被记录为以列表形式呈现的简单实词(例如，Bed)、伪词(例如，BEM)、不可发音的字母串(例如，MBE)和类似字母的刺激串(例如，BEM)。据预测，只有拼写和语音上合法的刺激(单词和伪词)才会在较大的儿童/更好的读者中引发N400，而所有类型的刺激可能会在尚未将与阅读相关的较低水平的过程自动化的较小儿童/较差的读者中引发N400；与此一致，大脑和行为测量之间的相关性预计会随着发育时间的推移而改变。这一发现模式将表明，神经认知文字处理系统对语言可能性的开放程度更高，在处理年幼儿童/较差读者的候选单词串时选择性较低，这表明一些小学后期的儿童确实可能还没有像成年人那样处理单词和类似单词的刺激。这样的见解可能会对课堂上的教学产生影响，特别是对许多处于危险之中、在小学后期难以阅读的儿童。从更广泛、更长远的角度来看，这类使用神经和行为测量方法对儿童和成人进行的单词水平处理的研究，将提供汇聚和限制证据，有助于更好地、多层次地理解作为阅读技能核心的文字处理系统的发展。 公共卫生相关性：阅读能力差的儿童面临脱离学校并最终导致学业失败的风险，从而导致其他公共卫生风险。如本文所述，从大脑和行为两个方面考察单词阅读技能发展的基础研究，可以更好地理解阅读技能的发展过程。这种理解上的科学进步最终可以在课堂上用于更好的教学和学习，并为贫困读者设计补救计划。

DESCRIPTION (provided by applicant): According to U.S. Government statistics, only about one-third of American fourth-graders are reading at a proficient level. Fourth grade is a pivotal year in elementary school as the curriculum typically requires students to shift from learning the basics of how to read to using established reading skills in an adult-like manner, to gain and build new knowledge. Behavioral data suggest that context-free recognition of simple, high frequency words is automatic by the fourth grade in typically developing readers but neural data are scarce. The proposed research with groups of third-, fourth-, and fifth-graders uses both standardized behavioral measures of various reading skills (orthographic, phonological, semantic, and comprehension) and a measure of neural word processing, the N400 component of the event-related potential (ERP) waveform. In previous studies with adults, the N400 has been shown to index both lexicosemantic and higher-level aspects of word processing. Here, the N400 will be recorded to simple real words (e.g., bed), pseudowords (e.g., bem), nonpronounceable letter strings (e.g., mbe), and strings of letter-like stimuli (e.g., BEM) presented in list form. It is predicted that only orthographically and phonologically legal stimuli (words and pseudowords) will elicit an N400 in older children/better readers, while all types of stimuli may elicit an N400 in younger children/poorer readers who have not yet automatized lower-level processes related to reading; consistent with this, correlations between the brain and behavioral measures are predicted to change over developmental time. This pattern of findings would indicate a neurocognitive word processing system that is more open to linguistic possibility and less selective in processing strings as word candidates in younger children/poorer readers, showing that some children in late elementary school indeed may not yet be processing word and word-like stimuli similarly to adults. Such insights might have implications for teaching and learning in the classroom, particularly for the many children at risk and struggling to read in late elementary school. In a broad, long-term view, such investigations of word-level processing using both neural and behavioral measures in children and adults will provide converging and constraining evidence that will lead to a better, multilevel understanding of the development of word processing systems that are at the core of reading skills. PUBLIC HEALTH RELEVANCE: Children who are poor readers are at risk for disengagement from school and eventual school failure, leading to other public health risks. Basic research that investigates the development of word reading skills in terms of both brain and behavior, as proposed here, can lead to a better understanding of the developmental course of reading skills. Such scientific advances in understanding can eventually be used in the classroom for better teaching and learning, and for design of remediation programs for poor readers.