CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
Dyslexia. 2022 Nov;28(4):431-447. doi: 10.1002/dys.1726. Epub 2022 Aug 12.
Dorsal stream is an important pathway for visual information transmission. As a part of the dorsal pathway, the middle temporal visual motion areas (V5/MT+) are mainly responsible for visual motion processing and the ability of visual motion processing is closely related to reading. Compared with alphabetic scripts, the visual structure of Chinese characters is more complex and there are no clear grapheme-phoneme correspondence rules. So the ability of visual analysis plays an important role in Chinese character processing. This study first investigated the brain activation of Chinese dyslexic children and children of the same chronological age when they observed coherent motion stimuli. ROI analysis indicated that only the activation of left V5/MT+ was significantly weaker in dyslexics than that in the control group. The activity of the magnocellular-dorsal stream was closely related to orthographic awareness in the combined data (two groups) and the typical children. In dyslexia group, the stronger the activation of V5/MT+ was, the worse the phonological awareness, rapid naming performance and orthographic awareness were. In short, Chinese dyslexic children were deficient in the activation of the left V5/MT+ and the activity of the magnocellular-dorsal pathway was closely related to orthographic awareness in Chinese pupils.
背侧流是视觉信息传递的重要途径。作为背侧通路的一部分，中颞视觉运动区（V5/MT+）主要负责视觉运动处理，而视觉运动处理能力与阅读密切相关。与字母文字相比，汉字的视觉结构更为复杂，且不存在明确的字形-语音对应规则。因此，视觉分析能力在汉字处理中起着重要作用。本研究首先考察了中文阅读障碍儿童和同年龄正常儿童在观察连贯运动刺激时的大脑激活情况。ROI 分析表明，阅读障碍者左 V5/MT+的激活明显弱于对照组。在合并数据（两组）和典型儿童中，大细胞-背侧流的活动与正字法意识密切相关。在阅读障碍组中，V5/MT+的激活越强，语音意识、快速命名表现和正字法意识越差。总之，中文阅读障碍儿童左 V5/MT+的激活不足，且大细胞-背侧通路的活动与中国小学生的正字法意识密切相关。
