ISSN 1671-3710
CN 11-4766/R

心理科学进展 ›› 2022, Vol. 30 ›› Issue (2): 343-353.doi: 10.3724/SP.J.1042.2022.00343

• 研究前沿 • 上一篇    下一篇


李何慧1,2,3, 黄慧雅1,2, 董琳1,2, 罗跃嘉1,3,4, 陶伍海1,2()   

  1. 1深圳大学脑疾病与认知科学研究中心
    2深圳大学心理学院, 深圳 518060
    4北京师范大学心理学部, 北京 100875
  • 收稿日期:2021-04-15 出版日期:2022-02-15 发布日期:2021-12-24
  • 通讯作者: 陶伍海
  • 基金资助:

Developmental dyslexia and cerebellar abnormalities: Multiple roles of the cerebellum and causal relationships between the two

LI Hehui1,2,3, HUANG Huiya1,2, DONG Lin1,2, LUO Yuejia1,3,4, TAO Wuhai1,2()   

  1. 1Center for Brain Disorders and Cognitive Sciences, Shenzhen University, Shenzhen 518060, China
    2School of Psychology, Shenzhen University, Shenzhen 518060, China
    3State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
    4Faculty of Psychology, Beijing Normal University, Beijing 100875, China
  • Received:2021-04-15 Online:2022-02-15 Published:2021-12-24
  • Contact: TAO Wuhai


发展性阅读障碍(下文简称为“阅读障碍”)不仅会影响个人的终身发展, 还会对社会造成沉重的经济负担, 深入探讨相关的神经机制, 对实现阅读障碍的早期预测和干预十分重要。以往关于阅读障碍神经机制的模型多集中于大脑, 近些年的研究发现, 阅读障碍也与小脑异常有关, 但到目前为止我们仍不清楚两者的关系。通过总结最新的研究进展, 我们发现小脑在阅读障碍中可能发挥着多种功能, 且小脑异常与阅读障碍可能互为因果。在此基础之上, 我们提出了“阅读中小脑与大脑的功能映射假说”, 旨在从一个全新的角度揭示小脑与阅读的关系, 以及两者与大脑的关系。相关内容对全面揭示阅读障碍的神经机制, 以及小脑在高级认知加工中的作用, 具有重要的启示意义。

关键词: 发展性阅读障碍, 小脑异常, 阅读的神经机制, 功能映射假说, 因果关系


Developmental dyslexia (hereafter referred as "dyslexia") will not only affect the lifelong development of individuals but also impose an additional financial burden on society. Digging into the relevant neural mechanisms contributes to the early prediction and intervention of dyslexia. Established models of the neural bases of dyslexia primarily focused on the cerebrum. In recent years, extensive studies have shown that dyslexia is also associated with cerebellar abnormalities. However, it remains unclear about the relationships between the two.

By summarizing recent findings, we found that the cerebellum could play multiple roles in reading. First, it could influence reading in different ways. Cerebellar dysfunctions could impair reading by affecting motor or motor-related skills (such as oculomotor control, automatization, or articulation), or by disturbing linguistic-related processes (such as phonological or semantic processing). Second, different subtypes of dyslexia are associated with abnormalities in distinct cerebellar regions. For example, dyslexic readers with automatization deficits showed abnormal neural activities in the anterior parts of the cerebellum, which were responsible for motor processing, whereas dyslexic readers suffering from visual and phonological deficits were associated with the abnormalities in the gray matter volume of the posterolateral areas of the cerebellum, which were mainly responsible for high-level cognitive processing. These results indicate that the relationship between dyslexia and the cerebellum is not unitary. There may exist multiple cerebellar areas being targeted by dyslexia, which also contribute differently to reading.

The causal relationships between cerebellar abnormalities and dyslexia might be bi-directional. Previous literature found that structural deficits in the posterolateral parts of the cerebellum were only associated with dyslexia compared to other development disorders (i.e., ADHD, autism) that may coexist with dyslexia. This result suggests that neural abnormalities in these areas were due to deficits in reading abilities rather than other comorbidities. Additionally, these regions vary in their causal relationships with dyslexia. For example, activation in the anterior parts of the right lobule VI, responsible for motor processing, showed greater activation or functional connectivity with the cerebrum in dyslexic readers compared to normal readers. These increased neural activities may be the compensatory mechanisms of dyslexia and a by-product of reading difficulties. In contrast, neural activities of the cerebellar areas responsible for linguistic processing (i.e., the right lobule VII) could predict future reading abilities, indicating that the functional state of the cerebellum in early developmental stages may influence reading development. Moreover, functional deactivations in the cerebellar linguistic areas have been observed in preschool readers with a high risk of dyslexia, suggesting that cerebellar abnormalities have occurred before formal reading instruction. These results jointly support that cerebellar abnormalities may be the cause of dyslexia.

The results mentioned above illustrate that the cerebellum is more than a reading-related hub. There could be multiple cerebellar regions that are engaged in reading, with different regions supporting different cognitive processes and having distinct causal relationships with dyslexia. Accordingly, we introduced the "cerebro-cerebellar mapping hypothesis of word reading", which proposed that reading-related regions in the cerebellum map to their functional correspondence areas in the cerebrum. Regions with the same functions across the cerebrum and cerebellum synchronized in neural activities and collaborated during reading. Dysfunctions of this collaboration may lead to dyslexia. This new framework aims to reveal the relationship between reading, the cerebellum, and the cerebrum from a new perspective, and offers important insights into the neural mechanism of dyslexia and the role of the cerebellum in high-level cognitive processing.

Key words: developmental dyslexia, cerebellar abnormalities, the neural mechanisms of reading, mapping hypothesis, causal relationship