报告题目：汉语阅读困难儿童的注意障碍（Attentional deficits in Chinese dyslexic children）
报 告 人：王治国博士（SR Research，Canada）
摘要：Reading depends heavily on the efficient shift of attention. Mounting evidence has suggested that dyslexics may have deficits in attentional orienting. However, it remains unclear whether the attentional deficit in dyslexic individuals is restricted to covert attentional orienting or it also affects overt attentional orienting. With the majority of relevant studies carried out in alphabetic writing systems, it is also unclear whether the attentional deficits observed in dyslexics are restricted to a particular writing system. Here I will present a set of studies in which we examined inhibition of return (IOR) – a major driving force of attentional shifts – in Chinese dyslexic children. In the first study, robust IOR effects were observed in both covert and overt attentional tasks in two groups of typically developing children, who were age- or reading ability-matched to the dyslexic children. In contrast, the dyslexic children showed IOR in the overt but not in the covert attentional task. These findings suggest that covert attentional shift is selectively impaired in dyslexic children. Importantly, this impairment is not restricted to alphabetic writing systems, within which attentional shifts play a much more important role in phonological and orthographical processing. In a second study, the time course of attentional orienting was examined with the same covert attentional task. The onset time of IOR in dyslexic children was found to be much later than that in age- and reading ability-matched controls, indicating that the attentional deficit in dyslexic children is rooted in a dysfunction in attentional disengagement. To further verify this finding, the dyslexic children were tested with a second attentional task, within which a salient visual cue was used to facilitate attentional disengagement. IOR effect appeared much earlier in this task, with an onset time that is comparable to the healthy controls. Furthering this line of study, we also examined the time course of attentional orienting in children with mathematical learning difficulties (MLD). This study showed that the onset time of IOR is later in MLD children, compared to healthy controls. These findings together suggest that sluggish attentional disengagement is likely a general cognitive impairment in all forms of learning disabilities.