汉语发展性阅读障碍儿童的视觉快速加工能力

Visual temporal processing in Chinese children with developmental dyslexia

目的:探查汉语发展性阅读障碍儿童大细胞通路的视觉快速加工特性。方法:依据识字量测试和瑞文智力测试得分筛选出14名阅读障碍(DD)儿童,并按年龄、智力水平匹配出17名同年龄对照组(CA)儿童,同时按识字量得分和智力水平匹配出16名同阅读水平对照组(RL)儿童。采用轮廓幻影范式测查3组儿童在大、小细胞通路条件下的时间分辨率,借此探查儿童的视觉快速加工能力。同时还对所有被试进行了阅读流畅性、阅读准确性、语音意识、正字法技能等测试。结果:在大细胞条件下,DD组儿童的时间分辨率低于CA组和RL组[(16.2±4.9)vs.(23.8±11.2),(23.5±9.3),均P<0.05],而RL组和CA组之间差异无统计学意义;在小细胞条件下,三组被试差异无统计学意义[(18.5±5.7)vs.(19.1±10.6)vs.(18.7±3.9)]。相关分析显示,大细胞通路的时间分辨率与阅读流畅性(r=0.32,P<0.05)、语音意识测试(r=0.33,P<0.05)的成绩正相关;而小细胞通路与各汉字阅读测试得分相关均无统计学意义。结论:汉语阅读障碍儿童存在大细胞通路的视觉快速加工缺陷,且视觉大细胞通路的这一功能特性与汉字的阅读速度和语音加工过程联系紧密。

Objective：To examine the visual temporal processing of magnocellular stream in Chinese children with developmental dyslexia （DD）.Methods：According to scores of the vocabulary test and Raven＇s Standard Progressive Matrices （RSPM）,14 primary school students were selected as DD group.Meanwhile,17 children were selected as chronological-age control （CA） group matching in age and RSPM scores,and 16 children were selected as reading-level control （RL） group according to the vocabulary test and RSPM scores.In the present study,the phantom contour paradigm were applied to test the temporal resolution in magnocellular （M） and parvocellular （P） condition,reflecting the skills of visual temporal processing.All participants took part in reading fluency,reading accuracy,phonological awareness,and orthographic processing skill tests.Results：In M condition,children in DD group had a lower temporal resolution than those in RL and CA groups [（16.2 ±4.9） vs.（23.8 ± 11.2）,（23.5 ±9.3）,P ＜0.05],while there was no difference between RL group and CA group; as to the P condition,there were no differences among the 3 groups [（18.5 ± 5.7） vs.（19.1 ± 10.6） vs.（18.7 ± 3.9）].The correlation analysis showed that the temporal resolution in M condition was positively correlated with the scores in reading fluency （r =0.32,P ＜0.05） and phonological awareness （r =0.33,P ＜0.05） tests.Conclusion：Chinese dyslexic children have a deficit in visual temporal processing of their magnocellular stream,and the M function in temporal prcoessing is closely associated with the reading speed and phonological processing of Chinese characters.