Developmental dyslexia (DD), a severe and frequent disorder of reading acquisition, is characterized by a diversity of cognitive and motor deficits whose interactions still remain under debate. Although deficits in the automatization of sensorimotor control have been highlighted, internal action representation allowing prediction has never before been investigated. In this study, we considered action representation of 18 adolescents with pure DD and 18 age-matched typical readers. Participants actually and mentally performed a visually guided pointing task involving strong spatiotemporal constraints (speed/accuracy trade-off paradigm). While actual and mental movement times of typical readers were isochronous and both conformed to Fitts’ law, the movement times of dyslexics differed between conditions, and only the actual movement times conformed to Fitts’ law. Furthermore, the quality of motor imagery correlated with word reading abilities. This suggests that the process of action representation is impaired in pure DD and supports the sensorimotor perspective of DD. Theoretical implications are discussed.

中文翻译：

---

发展性阅读障碍青少年的行动表征缺陷

发育性阅读障碍 (DD) 是一种严重且频繁的阅读障碍，其特征是认知和运动障碍的多样性，其相互作用仍存在争议。尽管已经强调了感觉运动控制自动化的缺陷，但之前从未研究过允许预测的内部动作表示。在这项研究中，我们考虑了 18 名纯 DD 青少年和 18 名年龄匹配的典型读者的行为表现。参与者实际上和精神上执行了一个视觉引导的指向任务，涉及强时空约束（速度/精度权衡范式）。虽然典型读者的实际和心理活动时间是等时的，都符合菲茨定律，但阅读障碍者的活动时间因条件而异，只有实际的运动时间符合菲茨定律。此外，运动意象的质量与单词阅读能力相关。这表明动作表征过程在纯 DD 中受损，并支持 DD 的感觉运动观点。讨论了理论意义。