Cortical Activation to Faces and Objects in Infants at High-Risk for ASD

描述（由申请人提供）：拟议的研究将检查与婴儿期面部处理相关的ERP成分的皮质来源，其中包括一组典型发育（TD）婴儿和一组ASD高危婴儿（ASIBS）。面部处理缺陷是与ASD相关的常见损伤。患有自闭症谱系障碍的成年人在观看面部时表现出与典型成年人不同的神经反应模式，面部N170潜伏期更长就证明了这一点。然而，关于大脑发育的早期差异如何导致面部处理的这些差异，人们知之甚少。这项拟议的研究将调查ASIBS和TD婴儿在6至12个月的面部专业化发展期间的潜在差异。两个ERP组件已被确定为前光标的脸敏感的成人N170，婴儿N290和P400。面部特化的证据可以从这些面部敏感组件的振幅和延迟的差异中检测到，当观看面部而不是物体时。此外，这些组件是敏感的反转（这表明专门处理的脸）的12个月大的TD婴儿。没有研究检查ASIBS是否在这个年龄显示出面部倒置效应，但对成人的ERP研究表明，N170对ASD成人的面部倒置不敏感。 这项研究将确定婴儿期面孔敏感ERP成分的皮质发生器。将使用基于个体婴儿MRI的头部模型进行皮质源定位。这种方法可以对头部内部的组织进行更准确的分类，这在研究种群时特别重要。 (such如婴儿），即使在特定年龄组内，头部大小和形状也存在很大差异。使用真实模型来计算头部内的电流密度将允许更准确地估计皮质激活源，这可以允许在组之间进行更细粒度的区分。最终，这将使我们能够识别TD婴儿和ASIBS在面部处理过程中活跃的大脑区域，并记录在面部专业化的关键时期出现的任何差异。

DESCRIPTION (provided by applicant): The proposed research will examine cortical sources of ERP components associated with face processing in infancy with a group of typically developing (TD) infants and a group of infants at high-risk for developing ASD (ASIBS). Deficits in face processing are a common impairment associated with ASD. Adults with ASD demonstrate patterns of neural response distinct from typical adults when viewing faces, as evidenced by longer N170 latencies to faces. However, relatively little is known about how early differences in brain development contribute to these differences in face processing. The proposed study will investigate potential differences between ASIBS and TD infants at a time when specialization for faces is developing, from 6 to 12 months. Two ERP components have been identified as pre-cursors to the face-sensitive adult N170, the infant N290 and P400. Evidence of face specialization can be detected from differences in the amplitude and latency of these face-sensitive components when viewing faces as opposed to objects. Additionally, these components are sensitive to inversion (which indicates specialized processing of faces) by 12 months of age in TD infants. No study has examined whether ASIBS show a face inversion effect at this age, but ERP studies with adults have shown that the N170 is not sensitive to face inversion in adults with ASD. The proposed research will identify the cortical generators of face-sensitive ERP components in infancy. Cortical source localization will be performed using head models based upon individual infants' MRIs. This method allows for more accurate classification of tissue within the head's interior, which is of particular significance when studying populations (such as infants) where there is a great deal of variability in head size and shape, even within a specific age group. Using realistic models to calculate current density within the head will allow for more accurate estimation of cortical sources of activation, which may allow for more fine-grained distinctions to be made between groups. Ultimately, this will allow us to identify brain regions active during face processing in TD infants and ASIBS, as well as document any differences emerging during this critical time period for face specialization.