视觉复杂性和字间距调节汉语发展性阅读障碍儿童的视觉拥挤效应:来自眼动的证据

The Modulation of Visual Complexity and Character-Spacing on the Visual Crowding Effect of Chinese-Speaking Children with Developmental Dyslexia: Evidence from Eye Movements

采用眼动追踪技术,通过笔画数多少构成高低不同的视觉复杂性,操纵文本的字间距,来考察视觉复杂性和字间距对汉语发展性阅读障碍儿童的视觉拥挤效应的影响。结果发现,阅读障碍儿童阅读低视觉复杂性文本时,随着字间距的不断增加,字间距增加到一定程度时(+6 pt)阅读时间最长、总注视次数最多,随后在本实验字间距最大条件下(+12 pt)阅读时间变短、总注视次数变少,正常儿童不存在这种现象。结果表明,文本阅读中,字间距和视觉复杂性对阅读障碍儿童的视觉拥挤效应起到调节作用,低视觉复杂性文本可以降低阅读障碍儿童的视觉拥挤效应,阅读障碍儿童的视觉拥挤效应强度和字间距大小的数量关系呈非线性。

Visual crowding effect （VCE） is defined as the identification of a center letter being interfered by its flanking letters. Previous studies in alphabetical system languages showed that dyslexics are more influenced by VCE than controls due to their underlying visual deficits. Unlike English, Chinese is a densely-packed language and readers maybe more rely on visual processing to recognize characters, it has found that Chinese dyslexics might exhibit more pronounced visual crowding effect （VCE）. In experiment, we manipulate visual complexity of text and character-spacing （default. ＋3 pt, ＋6 pt. ＋12 pt） on Chinese dyslexic children to examine whether visual complexity and character-spacing modulated the VCE in Chinese sentence reading. The results showed that： 1） Chinese dyslexics＇ performances were more influenced by VCE than controls when they read low complexity and high complexity text; 2） Under low complexity text condition, with the character-spacing increased, spacing ＋6 pt led to worse reading performance for dyslexics, while spacing ＋12 pt didn＇t, indicating that enlarging character-spacing facilitates reading performances.The results indicated that 1） low complexity text and character-spacing facilitate the good reading performances for dyslexics; 2） visual complexity and character-spacing modulate the visual crowding effect of dyslexics; 3） the quantity relationship of character-spacing and the VCE need to be further studied.