- 學位論文
視覺注意力成份分析： 弱讀兒童與一般兒童的比較
Visual attention in normal and poor readers
摘要
過去有關閱讀障礙的研究普遍認為聲韻覺識與快速唸名為閱讀困難的重要成因，但也有不少學者顯示視覺注意力才是影響閱讀困難的關鍵因素。有關視覺注意力的研究大多著重於低階層視知覺，較少探討高階的認知注意力控制，而探討視覺注意力廣度的研究，實驗設計卻大多牽涉到口語能力（Showman & Ahissar, 2006），難以區辨閱讀困難到底是聲韻覺識問題抑或是視覺注意力問題。 本研究嘗試以單純的視覺判斷刺激且不需要口語登錄能力的注意力作業檢驗過去混雜的問題。實驗一為含括探討重要注意力成份的注意力網絡作業，實驗二為採用修改後可檢視轉換虧損與混作虧損的轉換作業。希望透過更嚴謹的實驗設計與操弄，探討弱讀兒童在視覺注意力成份上是否異於一般人的缺陷，最後以相關與階層迴歸分析探究各注意力指標與閱讀能力的關係。在本研究實驗一與實驗二中，皆加入與弱讀組同樣閱讀能力，但年齡較小之兒童的「同閱組」，以控制閱讀能力發展對結果的影響。 實驗一結果發現弱讀兒童在衝突抑制能力的表現和一般兒童沒有顯著差異；在警覺性的表現有異於一般兒童，反映弱讀組兒童可能對調節外來刺激的警覺度有困難；在導向性的表現與同閱組一樣，皆有異於一般兒童的表現，在給予導向性的提示下無法帶來增益，顯示弱讀兒童的導向性系統有異於一般人的缺陷或發展遲緩的問題。 實驗二結果發現弱讀兒童在混作虧損的表現並沒有異於一般兒童，顯示弱讀組兒童在持續性認知控制能力和一般兒童比較起來沒有明顯缺陷。但在轉換虧損有異於一般人的轉換問題，在重複嘗試項獲得的助益不多。相關與階層迴歸結果分析顯示注意力網絡作業的衝突抑制力能有效預測識字的表現，而轉換虧損及混作虧損能有效預測弱讀兒童的閱讀理解能力。 建議可再進一步針對弱讀兒童在警覺性、導向性及轉換虧損方面的注意力缺陷進行相關認知訓練作為補救教學方向，也可運用弱讀兒童沒有受損的持續性認知控制能力作為補償策略教導方向。
並列摘要
Studies have suggested that children with reading difficulties may have deficits in phonological awareness and naming speed. However, recent studies have debated the extent and nature of the role of visual attention in reading disabilities. Most research in visual attention focused on the perceptual level (i.e., orthographic coding), instead of the cognitive level requiring additional executive control. Furthermore, most studies of visual attention applied language stimuli (Showman & Ahissar, 2006), making it difficult to separate the influences of visual attention from those of linguistic processes. To examine the role of visual attention on reading difficulties, the present study applied visual attention tasks with stimuli of simple visual features. In Experiment 1, the attentional network test (ANT), which could separately measure three components of attention (i.e., alerting, orienting and conflict), was applied; in Experiment 2, a modified task-switching paradigm, which could separately examine the switch cost and mixed cost, was adopted. Analyses of correlation and hierarchy regression were also conducted to examine the relationship between visual attention and reading abilities. Besides a control group matched on age-level, the present study also included a control group with reading-level matched, to control the developmental influences of reading abilities. The results of Experiment 1 suggested that poor readers had deficits in components of alerting and orienting, whereas their conflict component remained preserved. In Experiment 2, the mixing cost of poor readers was equivalent to that of normal controls, suggesting that abilities of sustained executive control in poor readers remained preserved. However, the switching cost of poor readers was different from that of normal controls, indicating that poor readers benefited less from repetition trials. The results of multiple regression analysis suggested that the conflict component in ANT was a good predictor of word recognition for both poor and normal readers, whereas the mixing cost and the switching cost were both good predictors of reading comprehension in children with poor reading abilities. Based on the present findings, cognitive training on abilities of alerting, orienting, and sustained executive control was suggested in related remedial programs.