背景性质对7-10岁自闭症谱系障碍儿童面孔搜索与加工的作用

The Role of Background Nature in Face-Searching and Processing of Children with Autism Spectrum Disorder Aged 7-10

为了考察背景性质对ASD者搜索面孔的影响,设计两个眼动实验任务,要求14名7～10岁ASD儿童和20名同龄正常儿童观看图片。实验一采用将面孔嵌入风景图片引起语义不一致的刺激;实验二采用含有面孔的无意义背景乱序图片刺激。结果发现:(1)面孔与背景语义不一致并不能促进ASD儿童对面孔的搜索;(2)乱序背景对ASD儿童面孔搜索与加工未产生干扰作用,但使正常儿童的搜索时间变长;(3)一旦觉察到面孔,ASD儿童对面孔的注视时间少于正常儿童。表明正常儿童对面孔的搜索与加工受背景性质的影响,而ASD儿童不受背景性质的影响;一旦发现面孔,ASD儿童的注意维持较短,但面孔加工模式与正常儿童相似。

One of the core issues in Autism Spectrum Disorder（ASD） is problematic social interaction（Geschwind,2009）.Faces may be the most ＂social＂ visual stimuli.From faces,and especially from eyes,humans are prone to extract social information like emotional disposition or communicative intent during conversation with others（de Wit,Falck - Ytter, von Hofsten,2008）.Detecting a face within the scene is a crucial step in attending to the information portrayed by that face,such as communicative facial signals.So the face capture becomes particularly important（Riby Hancock,2008b）. To explore the role of background nature in the face-searching and the processing with ASD,two experiments were involved in the current research that required 14 ASD children and 20 typical developing individuals,aged 7-10,to look at a range of pictures while having their gaze behavior monitored.In Experiment 1,a 2（participant;ASD vs.TD）×2（embedded object;face vs.earth） mixed design was employed.The semantic inconsistency involved scenes with embedded faces or earth images.In Experiment 2,a 2（participant： ASD vs.TD）×3（face：human face,dog＇ s face,back of head） mixed design was employed.The task involved scrambled pictures of a person or a dog with meaningless background. The results showed that there were no facilitation of semantic conspicuity background in face searching of ASD children.They consistently spent significantly longer time to locate at the face than those in the control group.And they spent less time to search faces than searching the inanimate objects.There were no interference of meaningless scrambled background on the face-searching of ASD children, but prolong that of TD.Across the two experiments,once their faces were looked,children with ASD spent less time on the nose and mouth than the typical developing group.But the fixation durations on the eyes did not differ between the two groups.It suggested that the face-searching and the processing of the ASD children were not affected by the background nature.The ASD children made a significantly less visual attention on the face than the individuals without autism.But their face-searching and the processing patterns aere similar to the typical group.