Neurobehavioral Investigation of Tactile Features in Autism Spectrum Disorders

描述（由申请人提供）：感觉症状是自闭症谱系障碍（ASD）最常见的相关特征之一。感觉能力比社交和沟通能力发展得更快，因此，如果在ASD中更好地理解它们的功能障碍，就可以在早期识别和干预中发挥重要作用。触觉敏感性的改变是感觉特征最典型的变体之一，但相对于ASD的听觉和视觉，它的研究却自相矛盾地不足。婴儿早期的触觉为整个发展过程中沟通和社会奖励的发展奠定了基础。因此，更好地了解ASD的触觉功能障碍是至关重要的。大多数实验研究的是手掌表面（通常是指尖）的判别触摸。亲和或情感触摸被认为是由一种独特的体感传入纤维（CT纤维）介导的，这种纤维在手掌中是不存在的。本项目采用行为学、神经生理学和神经解剖学的方法研究ASD患者的情感触觉感知。触觉防御的观察测量将与表征丘脑皮质回路强度的扩散张量成像（DTI）数据以及功能磁共振成像（fMRI）和事件相关电位（ERP）的反应相关联，这些数据将分别阐明ASD患者对情感触觉刺激的神经反应的空间和时间特征。本研究对ASD中情感触摸的神经行为基础的研究，将补充现有的以辨别触摸为主的实验文献，并通过探索神经机制来补充现有的行为文献。更好地了解ASD的触觉敏感性对开发早期识别的生物标志物具有重要的潜力，并为基于感觉的ASD治疗的疗效研究奠定基础。

DESCRIPTION (provided by applicant): Sensory symptoms are among the most commonly reported associated features of autism spectrum disorders (ASD). Sensory abilities develop more rapidly than social and communication skills, and thus if their dysfunction is better understood in ASD, could serve an important role in early identification and intervention. Altered tactile sensitivity is one of the most typical variants of sensory features, but is paradoxically understudied relative to hearing and vision in ASD. The sense of touch in early infancy lays the foundation for the development of communication and social reward throughout development. Thus, a better understanding of tactile dysfunction in ASD is critical. Most experimental work has investigated discriminative touch on the palmar surface of the hand, usually the fingertip. Affiliative or affective touch is believed to be mediated by a unique class of somatosensory afferent (CT fiber) that is absent in the palm. The proposed project undertakes the examination of affective tactile perception in ASD using converging behavioral, neurophysiological, and neuroanatomical techniques. Observational measures of tactile defensiveness will be correlated with diffusion tensor imaging (DTI) data characterizing the strength of thalamocortical circuits, as well as responses from functional magnetic resonance imaging (fMRI) and event-related potentials (ERP) that will elucidate the spatial and temporal characteristics, respectively, of neural response to affective tactile stimuli in ASD. This study of the neurobehavioral basis of affective touch in ASD will add to the existing experimental literature that is primarily focused on discriminative touch, and will complement the existing behavioral literature by exploring neural mechanisms. A better understanding of tactile sensitivity in ASD has significant potential for developing biomarkers for early identification and as a foundation for efficacy studies of sensory-based treatments of ASD.