BACKGROUND Differences in non-social attentional functions have been identified as among the earliest features that distinguish infants later diagnosed with autism spectrum disorder (ASD), and may contribute to the emergence of core ASD symptoms. Specifically, slowed attentional disengagement and difficulty reorienting attention have been found across the lifespan in those at risk for, or diagnosed with, ASD. Additionally, the locus coeruleus-norepinephrine (LC-NE) system, which plays a critical role in arousal regulation and selective attention, has been shown to function atypically in ASD. While activity of the LC-NE system is associated with attentional disengagement and reorienting in typically developing (TD) individuals, it has not been determined whether atypical LC-NE activity relates to attentional disengagement impairments observed in ASD. OBJECTIVE To examine the relationship between resting pupil diameter (an indirect measure of tonic LC-NE activation) and attentional disengagement in children with ASD. METHODS Participants were 21 school-aged children with ASD and 20 age- and IQ-matched TD children. The study consisted of three separate experiments: a resting eye-tracking task and visual and auditory gap-overlap paradigms. For the resting eye-tracking task, pupil diameter was monitored while participants fixated a central crosshair. In the gap-overlap paradigms, participants were instructed to fixate on a central stimulus and then move their eyes to peripherally presented visual or auditory targets. Saccadic reaction times (SRT), percentage of no-shift trials, and disengagement efficiency were measured. RESULTS Children with ASD had significantly larger resting pupil size compared to their TD peers. The groups did not differ for overall SRT, nor were there differences in SRT for overlap and gap conditions between groups. However, the ASD group did evidence impairments in disengagement (larger step/gap effects, higher percentage of no-shift trials, and reduced disengagement efficiency) compared to their TD peers. Correlational analyses showed that slower, less efficient disengagement was associated with increased pupil diameter. CONCLUSION Consistent with prior reports, children with ASD show significantly larger resting pupil diameter, indicative of atypically elevated tonic LC-NE activity. Associations between pupil size and measures of attentional disengagement suggest that atypically increased tonic activation of the LC-NE system may be associated with poorer attentional disengagement in children with ASD.

中文翻译：

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自闭症谱系障碍儿童的注意脱离和蓝斑-去甲肾上腺素系统。

背景 非社会注意功能的差异已被确定为区分后来被诊断患有自闭症谱系障碍 (ASD) 的婴儿的最早特征之一，并且可能导致核心 ASD 症状的出现。具体而言，在那些有患或被诊断患有 ASD 的人的整个生命周期中发现注意力脱离速度减慢和注意力重新定向困难。此外，蓝斑-去甲肾上腺素 (LC-NE) 系统在唤醒调节和选择性注意中起关键作用，已被证明在 ASD 中发挥非典型作用。虽然 LC-NE 系统的活动与典型发育（TD）个体的注意力脱离和重新定向有关，尚未确定非典型 LC-NE 活动是否与在 ASD 中观察到的注意力分离障碍有关。目的 研究 ASD 儿童静息瞳孔直径（强直 LC-NE 激活的间接测量）与注意力脱离之间的关系。方法 参与者是 21 名患有 ASD 的学龄儿童和 20 名年龄和智商匹配的 TD 儿童。该研究包括三个独立的实验：静息眼动追踪任务和视觉和听觉间隙重叠范式。对于静止的眼球追踪任务，在参与者固定中央十字准线的同时监测瞳孔直径。在间隙重叠范式中，参与者被指示注视中央刺激，然后将他们的眼睛移动到外围呈现的视觉或听觉目标。扫视反应时间（SRT），测量了无轮班试验的百分比和脱离效率。结果 与 TD 同龄人相比，ASD 儿童的静息瞳孔大小明显更大。各组的整体 SRT 没有差异，组间重叠和间隙条件的 SRT 也没有差异。然而，与 TD 同龄人相比，ASD 组在脱离接触方面确实存在缺陷（更大的步距/间隙效应、更高比例的无轮班试验以及脱离接触效率降低）。相关分析表明，较慢、效率较低的脱离与瞳孔直径增加有关。结论 与之前的报告一致，ASD 儿童静息时瞳孔直径显着增大，表明强直性 LC-NE 活性异常升高。