Individuals with autism spectrum disorders typically exhibit reduced visual attention towards social stimuli relative to neurotypical individuals. Importantly, however, attention is not a static process, and it remains unclear how such effects may manifest over time. Exploring these momentary changes in gaze behaviour can more clearly illustrate how individuals respond to social stimuli and provide insight into the mechanisms underlying reduced social attention in autism spectrum disorder. Using a simple passive eye-tracking task with competing presentations of social and nonsocial stimuli, we examine the different ways in which attention to social stimuli evolves over time in neurotypical adults and adults with and autism spectrum disorders. Our temporal modelling of gaze behaviour revealed divergent temporal profiles of social attention in neurotypical and observers with autism. Neurotypical data showed an initial increase in social attention, a ‘decay’ and subsequent ‘recovery’ after prolonged viewing. By contrast, in individuals with autism spectrum disorder, social attention decayed over time in a linear fashion without recovery after prolonged viewing. We speculate that the ‘gaze cascade’ effect that maintains selection of social stimuli in neurotypical observers is disrupted in individuals with high autistic traits. Considering these temporal components of gaze behaviour may enhance behavioural phenotypes and theories of social attention in autism spectrum disorder.

Lay abstract

One behaviour often observed in individuals with autism is that they tend to look less towards social stimuli relative to neurotypical individuals. For instance, many eye-tracking studies have shown that individuals with autism will look less towards people and more towards objects in scenes. However, we currently know very little about how these behaviours change over time. Tracking these moment-to-moment changes in looking behaviour in individuals with autism can more clearly illustrate how they respond to social stimuli. In this study, adults with and without autism were presented with displays of social and non-social stimuli, while looking behaviours were measured by eye-tracking. We found large differences in how the two groups looked towards social stimuli over time. Neurotypical individuals initially showed a high probability of looking towards social stimuli, then a decline in probability, and a subsequent increase in probability after prolonged viewing. By contrast, individuals with autism showed an initial increase in probability, followed by a continuous decline in probability that did not recover. This pattern of results may indicate that individuals with autism exhibit reduced responsivity to the reward value of social stimuli. Moreover, our data suggest that exploring the temporal nature of gaze behaviours can lead to more precise explanatory theories of attention in autism.

中文翻译：

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自闭症患者社会注意力时间动态的差异

与神经正常个体相比，患有自闭症谱系障碍的个体通常表现出对社会刺激的视觉注意力减少。然而，重要的是，注意力并不是一个静态的过程，而且目前还不清楚这种影响如何随着时间的推移而显现。探索注视行为的这些瞬时变化可以更清楚地说明个体如何对社会刺激做出反应，并深入了解自闭症谱系障碍社会关注减少的潜在机制。使用简单的被动眼动追踪任务以及社交和非社交刺激的竞争呈现，我们研究了神经正常成年人和患有自闭症谱系障碍的成年人对社交刺激的注意力随时间演变的不同方式。我们的凝视行为时间模型揭示了神经正常人和自闭症观察者的社会注意力的不同时间特征。神经典型数据显示，社会关注度最初有所增加，随后在长时间观看后出现“衰退”和随后的“恢复”。相比之下，患有自闭症谱系障碍的人，社会注意力随着时间的推移以线性方式衰减，并且在长时间观看后也无法恢复。我们推测，在神经典型观察者中维持社会刺激选择的“凝视级联”效应在具有高度自闭症特征的个体中被破坏。考虑凝视行为的这些时间成分可能会增强自闭症谱系障碍的行为表型和社会注意力理论。

外行摘要

在自闭症患者中经常观察到的一种行为是，与神经正常个体相比，他们倾向于较少关注社会刺激。例如，许多眼球追踪研究表明，患有自闭症的人会更少看向人，而更多地看向场景中的物体。然而，我们目前对这些行为如何随时间变化知之甚少。追踪自闭症患者外表行为的每时每刻的变化可以更清楚地说明他们对社会刺激的反应。在这项研究中，患有和没有自闭症的成年人都会受到社交和非社交刺激的展示，同时通过眼动追踪来测量观看行为。我们发现，随着时间的推移，两个群体对社会刺激的看法存在很大差异。神经典型个体最初表现出较高的概率寻找社交刺激，然后概率下降，并且在长时间观看后概率增加。相比之下，患有自闭症的人最初表现出概率增加，随后概率持续下降，并且没有恢复。这种结果模式可能表明自闭症患者对社会刺激的奖励值的反应性降低。此外，我们的数据表明，探索注视行为的时间性质可以带来更精确的自闭症注意力解释理论。