NEUROBIOLOGY OF FACIAL EXPRESSION IN AUTISM

这项拟议的研究将检验自闭症患者面部运动和情感表达能力受损的神经生物学基础。自闭症患者通常在情感表达方面有严重的障碍，包括有限的范围和不适当地使用面部表情来传达情感和意图。对自闭症患者面部模仿和神经功能的研究表明，情感面部表情的损害可能部分归因于潜在的运动功能障碍。这项拟议的研究将测试自闭症患者面部运动性受损的两种相互竞争的模型：控制面部表情肌肉结构的脑干结构障碍与皮质水平的神经功能障碍。这些目标将在两个样本中进行检验：高功能自闭症儿童与在年龄、VIQ、性别和种族方面匹配的典型发育儿童相比，低功能自闭症儿童与非特定精神发育迟滞儿童相似。面部运动性将通过对离散的面部动作以及这些动作在情感面部表情中的协调情况的量化分析来检验。无意义的面部表情将在模仿与面神经特定分支相对应的动作时进行评估。情感面部表情将在六种典型情绪的自发、诱导和模仿表情中进行测量。情感表达的交际价值也将通过由朴素评分员对参与者的表达进行定性分析来评估。将通过对脑神经功能的全面和定量评估，进一步检验神经参与面部表情能力的模型。最后，本项目将检查 一些早期发育基因在脑干和小脑的形成和功能中起重要作用，因此可能影响自闭症患者的面部运动异常。通过明确自闭症面部运动障碍的性质，这项研究将对早期干预产生影响，并可能有助于识别这种疾病的内表型。

The proposed research will examine the neurobiological bases of impaired facial movement and emotional expressiveness in autism. Individuals with autism typically have significant impairments in emotional expression, including limited range and inappropriate use of facial expressions to communicate affect and intentions. Research on facial imitation and neurological functioning in autism suggests that impairment in affective facial expression may be due in part to an underlying motor dysfunction. The proposed research will test two competing models of impaired facial motility in autism: dysfunction of brainstem structures that control the musculature of facial expression versus neurological dysfunction at a cortical level. These aims will be examined in two samples: children with high functioning autism compared to typically developing children matched on age, VIQ, gender, and race, and children with low functioning autism similarly matched to children with non-specific mental retardation. Facial motility will be examined through a quantitative analysis of discrete facial movements and the coordination of these movements in affective facial expressions. Nonmeaningful facial expressions will be assessed during imitation of movements that correspond to specific branches of the facial nerve. Affective facial expressions will be measured during spontaneous, elicited, and imitated expressions of six canonical emotions. The communicative value of emotional expressions will also be assessed through qualitative analyses of participants' expressions by na'fve raters. Models of neurological involvement in facial expressiveness will further be examined through a comprehensive and quantitative evaluation of cranial nerve function. Finally, this project will examine several early developmental genes that are important in the formation and function of the brainstem and cerebellum, and thus may influence facial movement abnormalities in autism. By specifying the nature of impaired facial motility in autism, this research will have implications for early intervention and may help in the identification of endophenotypes of this disorder.