Helland Turid
Department of Biological and Medical Psychology, University of Bergen, 5020 Bergen, Norway.
Brain Sci. 2024 Aug 31;14(9):893. doi: 10.3390/brainsci14090893.
During the period in which children learn to read and write, a gradual shift from right to left hemisphere dominance for language is typically seen. However, in children with dyslexia, a deviant pattern is described in the literature. As part of a larger longitudinal study (The Bergen Longitudinal Dyslexia Study), the present study aimed to assess this development from an early age before children learn to read and write. Dichotic listening (DL), which is a non-invasive test, was used to assess the development of brain laterality in a Typical group and a Dyslexia group. The participants received yearly sessions of evidence-based literacy training at ages 5 to 7. The Typical group showed increasing ear scores and a shift from no ear advantage in the Pre-literacy stage (age 6), indicative of no hemisphere dominance, to a right ear advantage, indicative of a left hemisphere dominance, in the Emergent literacy stage (age 8) and the Literacy stage (age 11). The Dyslexia group showed a different pattern, with a significant right ear advantage at age 6, indicative of a right hemisphere dominance, and increasing ear scores at ages 8 and 11; however, no ear dominance was observed in the Literacy stage. The results point to an effect of relevant, evidence-based training affecting both right and left hemispheres in dyslexia, which should form a basis for further research.
在儿童学习读写的阶段，通常会观察到语言优势半球从右半球逐渐向左半球转移。然而，在患有诵读困难症的儿童中，文献中描述了一种异常模式。作为一项更大规模纵向研究（卑尔根纵向诵读困难症研究）的一部分，本研究旨在从儿童学习读写之前的早期阶段评估这种发展情况。双耳分听（DL）是一种非侵入性测试，用于评估典型组和诵读困难症组的脑侧化发展。参与者在5至7岁时每年接受基于证据的读写能力训练课程。典型组的耳得分增加，且从读写前阶段（6岁）无耳优势（表明无半球优势），转变为在读写萌芽阶段（8岁）和读写阶段（11岁）出现右耳优势（表明左半球优势）。诵读困难症组表现出不同的模式，在6岁时具有显著的右耳优势（表明右半球优势），在8岁和11岁时耳得分增加；然而，在读写阶段未观察到耳优势。结果表明，相关的基于证据的训练对诵读困难症患者的左右半球均有影响，这应为进一步研究奠定基础。
