Zamzow Rachel M, Christ Shawn E, Saklayen Sanjida S, Moffitt Amanda J, Bodner Kimberly E, Higgins Katherine F, Beversdorf David Q
a Interdisciplinary Neuroscience Program , University of Missouri , Columbia , MO , USA.
J Clin Exp Neuropsychol. 2014;36(4):431-45. doi: 10.1080/13803395.2014.904844. Epub 2014 Apr 14.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social communication impairments and restricted, repetitive behaviors. Whereas current pharmacological interventions for ASD focus primarily on psychiatric symptoms, including agitation and obsessive behaviors, few agents target core symptomatology. It has been previously hypothesized that abnormalities in facial scanning, such as reduced eye contact or increased mouth fixation, contribute to social communication deficits in ASD. In addition, previous reports have suggested elevated stress and anxiety in ASD, symptoms that are believed to impact facial scanning patterns.
The present pilot study sought to explore the effects of pharmacological intervention via propranolol, a nonselective β-adrenergic antagonist and known anxiolytic, on facial scanning in ASD. Specifically, we wished to determine whether there is an increase in eye contact and a decrease in mouth fixation with administration of propranolol.
A sample of 14 participants with ASD and 14 matched controls participated in two study sessions in which propranolol and placebo were administered in a counterbalanced, double-blinded manner. At each session, ocular fixation data were collected during presentation of video stimuli of 16 human faces. Fixation time on the eye, nose, and mouth regions of the face stimuli was analyzed.
The baseline fixation patterns for the ASD and control groups did not significantly differ; however, administration of propranolol was associated with a significant reduction in mouth fixation for the ASD group. Additionally, mouth fixation was positively related to nonverbal communication impairment in the ASD group.
Although eye fixation in ASD appears typical in the present study, the effect of propranolol in reducing mouth fixation suggests an important focus for further research. Future studies are needed to better characterize the relationship between stress and anxiety and facial scanning in ASD, as well as the effects of pharmacological intervention.
自闭症谱系障碍（ASD）是一种神经发育障碍，其特征为社交沟通障碍以及局限的、重复的行为。尽管目前针对ASD的药物干预主要集中于精神症状，包括烦躁和强迫行为，但很少有药物针对核心症状。此前有假说认为，面部扫描异常，如眼神接触减少或对口部的注视增加，会导致ASD患者的社交沟通缺陷。此外，先前的报告表明ASD患者的压力和焦虑水平升高，这些症状被认为会影响面部扫描模式。
本试点研究旨在探讨通过普萘洛尔（一种非选择性β-肾上腺素能拮抗剂且已知具有抗焦虑作用）进行药物干预对ASD患者面部扫描的影响。具体而言，我们希望确定服用普萘洛尔后眼神接触是否增加以及对口部的注视是否减少。
14名ASD参与者和14名匹配的对照组参与了两个研究阶段，在这两个阶段中以平衡、双盲的方式给予普萘洛尔和安慰剂。在每个阶段，在呈现16张人脸的视频刺激时收集眼部注视数据。分析对面部刺激的眼睛、鼻子和嘴巴区域的注视时间。
ASD组和对照组的基线注视模式没有显著差异；然而，普萘洛尔的给药与ASD组对口部的注视显著减少有关。此外，ASD组对口部的注视与非言语沟通障碍呈正相关。
尽管在本研究中ASD患者的眼部注视看起来正常，但普萘洛尔减少对口部注视的作用提示了一个重要的进一步研究方向。未来需要开展研究，以更好地描述压力和焦虑与ASD患者面部扫描之间的关系，以及药物干预的效果。
