Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zurich, Neumuensterallee 9, 8032, Zurich, Switzerland.
Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
Sci Rep. 2020 Oct 30;10(1):18728. doi: 10.1038/s41598-020-75111-8.
The visual word form area (VWFA) in the left ventral occipito-temporal (vOT) cortex is key to fluent reading in children and adults. Diminished VWFA activation during print processing tasks is a common finding in subjects with severe reading problems. Here, we report fMRI data from a multicentre study with 140 children in primary school (7.9-12.2 years; 55 children with dyslexia, 73 typical readers, 12 intermediate readers). All performed a semantic task on visually presented words and a matched control task on symbol strings. With this large group of children, including the entire spectrum from severely impaired to highly fluent readers, we aimed to clarify the association of reading fluency and left vOT activation during visual word processing. The results of this study confirm reduced word-sensitive activation within the left vOT in children with dyslexia. Interestingly, the association of reading skills and left vOT activation was especially strong and spatially extended in children with dyslexia. Thus, deficits in basic visual word form processing increase with the severity of reading disability but seem only weakly associated with fluency within the typical reading range suggesting a linear dependence of reading scores with VFWA activation only in the poorest readers.
左腹侧枕颞（vOT）皮质中的视觉词形区（VWFA）是儿童和成人流畅阅读的关键。在阅读障碍者的印刷处理任务中，VWFA 激活减少是一个常见现象。在这里，我们报告了一项多中心研究的 fMRI 数据，该研究涉及 140 名小学生（7.9-12.2 岁；55 名阅读障碍者，73 名典型阅读者，12 名中等阅读者）。所有参与者都进行了视觉呈现单词的语义任务和符号串的匹配控制任务。通过这个大型儿童群体，包括从严重受损到高度流畅的读者，我们旨在阐明阅读流畅性与视觉词处理期间左 vOT 激活之间的关联。这项研究的结果证实了阅读障碍儿童左 vOT 中单词敏感激活减少。有趣的是，阅读技能与左 vOT 激活之间的关联在阅读障碍儿童中尤其强烈且空间扩展。因此，基本视觉词形处理的缺陷随着阅读障碍的严重程度而增加，但与典型阅读范围内的流畅性仅呈弱相关，这表明阅读分数与 VFWA 激活之间仅存在线性关系，仅在最差的阅读者中。
