Prior studies have demonstrated that infants and toddlers who later go on to develop autism spectrum disorder (ASD) show atypical functional connectivity as well as altered neural processing of language and other auditory stimuli, but the timeline underlying the emergence of these altered developmental trajectories is still unclear. Here we used resting-state fMRI (rsfMRI) during natural sleep to examine the longitudinal development of functional connectivity in language-related networks from 1.5 to 9 months of age. We found that functional connectivity of networks that underlie the integration of sensory and motor representations, which is crucial for language development, is disrupted in infants at high familial risk (HR) for developing ASD as early as 1.5 months of age. By 9 months of age, HR infants showed hyperconnectivity between auditory and somatosensory regions whereas low risk (LR) infants displayed greater intrahemispheric connectivity between auditory cortex and higher-order temporal regions as well as the hippocampus. Furthermore, while LR infants showed robust changes in functional connectivity during the first year of life with increasing long-range connectivity accompanied by decreasing short-range connectivity over time, HR infants displayed limited developmental changes. Our findings demonstrate that early disruptions in the development of language-related network connectivity may provide an early marker for the later emergence of ASD symptomatology.

先前的研究表明，后来继续发展自闭症谱系障碍（ASD）的婴儿和幼儿表现出非典型的功能连接性以及语言和其他听觉刺激的神经加工改变，但是这些改变的发展轨迹出现的时间轴仍然存在不清楚。在这里，我们使用自然睡眠期间的静止状态功能磁共振成像（rsfMRI）来检查1.5到9个月大的语言相关网络中功能连接的纵向发展。我们发现，对于在1.5个月以内出现ASD的高家族风险（HR）婴儿来说，构成语言和语言发展至关重要的感觉和运动表征整合基础的网络功能连接受到了破坏。到9个月大时，HR婴儿在听觉和躯体感觉区域之间表现出高度的连通性，而低风险（LR）婴儿在听觉皮层和高阶颞区域以及海马之间表现出更大的半球内连通性。此外，尽管LR婴儿在生命的第一年中显示出强大的功能连接性变化，随着时间的推移，远程连接性增加，而短程连接性下降，而HR婴儿的发育变化有限。我们的发现表明，与语言相关的网络连接性发展的早期中断可能为ASD症状学的较晚出现提供早期标志。