Saarland University, Clinical Neuropsychology Unit and Outpatient Service, Building A1.3, D-66123 Saarbruecken, Germany.
Neuropsychologia. 2013 Jun;51(7):1273-8. doi: 10.1016/j.neuropsychologia.2013.03.006. Epub 2013 Mar 22.
Neglect patients often omit or misread initial letters of single words, a phenomenon termed neglect dyslexia (ND). Omissions of whole words on the contralesional side of the page during paragraph reading are generally considered as egocentric or space-based errors, whereas misreading of the left part of a word can be viewed as a type of stimulus-centred or word-based, neglect-related error. The research of the last decades shed light on several effects of word features (such as written word frequency, grammatical class or concreteness) that modulate the severity of ND. Nevertheless, almost all studies about those modulating factors were case studies and some of them have not been replicated yet. Therefore, to date we do not know how relevant such effects of different word stimuli are for a population of ND patients. Knowing their incidence would improve our theoretical understanding of ND and promote the development of standardized ND assessments, which are lacking so far. In particular, case studies have shown that ND error frequency increases systematically with word length (word length effect, WLE) while other single case studies found contrary results. Hence, the existence of the WLE in ND is unsettled and its incidence and significance in stroke patients is unknown. To clarify this issue we evaluated the relation between word length and the extent (number) of neglected or substituted letters within single words in ND (neglect dyslexia extent, NDE) in a group of 19 consecutive ND patients with right hemisphere lesions. We found a clear WLE in 79% (15 of 19) of our ND patients, as indicated by significant correlations between word length and NDE. Concurrent visual field defects had no effect on the WLE in our sample, thus showing no influence of early visual cortical processing stages on the WLE in neglect dyslexia. In conclusion, our results suggest a clear relationship between word length and reading errors in ND and show that the WLE is a frequent phenomenon in ND.
忽略症患者经常遗漏或误读单词的首字母，这种现象被称为忽略性失读症（ND）。在阅读段落时，对侧页面上的整词遗漏通常被认为是自我中心或基于空间的错误，而对单词左半部分的误读则可以被视为一种以刺激为中心或以单词为中心的、与忽略相关的错误。过去几十年的研究揭示了几个影响单词特征（如单词的书写频率、语法类别或具体性）的因素，这些因素会调节 ND 的严重程度。然而，几乎所有关于这些调节因素的研究都是病例研究，其中一些尚未得到复制。因此，到目前为止，我们还不知道不同单词刺激对 ND 患者群体的相关程度。了解其发生率将有助于我们从理论上更好地理解 ND，并促进目前缺乏的 ND 标准化评估的发展。特别是，病例研究表明，ND 错误频率会随着单词长度的增加而系统增加（单词长度效应，WLE），而其他一些单一病例研究则得出了相反的结果。因此，ND 中是否存在 WLE 尚未确定，其在中风患者中的发生率和意义也尚不清楚。为了澄清这一问题，我们评估了在 19 名连续的右侧大脑半球损伤 ND 患者中，单词长度与 ND 中单个单词被忽略或替代的字母数量（忽略性失读程度，NDE）之间的关系。我们发现，在我们的 19 名 ND 患者中，有 79%（15 名）存在明显的 WLE，这表明单词长度与 NDE 之间存在显著相关性。同时存在的视野缺损对我们样本中的 WLE 没有影响，这表明在忽略性失读中，早期视觉皮层处理阶段对 WLE 没有影响。总之，我们的结果表明 ND 中存在单词长度与阅读错误之间的明显关系，并表明 WLE 是 ND 中常见的现象。
