Wagner Lauren, Banchik Megan, Tsang Tawny, Okada Nana J, Altshuler Rebecca, McDonald Nicole, Bookheimer Susan Y, Jeste Shafali S, Green Shulamite A, Dapretto Mirella
University of California, Los Angeles.
Ahmanson-Lovelace Brain Mapping Center.
Res Sq. 2024 Dec 3:rs.3.rs-5190659. doi: 10.21203/rs.3.rs-5190659/v1.
Language difficulties are common in autism spectrum disorder (ASD), a neurodevelopmental condition characterized by impairments in social communication as well as restricted and repetitive behaviors. Amongst infant siblings of children with an ASD diagnosis - who are at higher likelihood for developing ASD - a high proportion also show difficulties and delays in language acquisition.
In this study, we used functional magnetic resonance imaging (fMRI) to examine atypicalities associated with language processing in 9-month-old infants at high (HL) and typical (TL) familial likelihood for ASD. Infants were presented with native (English) and novel (Japanese) speech while sleeping naturally in the scanner. Whole-brain and region-of-interest analyses were conducted to evaluate neural differences in language processing based on likelihood group and language condition.
HL infants showed attenuated responses to speech in general, particularly in left temporal language areas, as well as a lack of neural discrimination between the native and novel languages compared to the TL group. Importantly, we also demonstrate that HL infants show distinctly atypical patterns of greater rightward lateralization for speech processing. Limitations: The sample size, particularly for the TL group, is relatively modest due to the challenges inherent to collecting auditory stimulus-evoked data from sleeping participants, as well as retention and follow-up difficulties posed by the COVID-19 pandemic. Additionally, the groups were not matched on some demographic variables; however, the present findings held even after accounting for these differences.
To our knowledge, this is the first fMRI study to directly measure autism-associated atypicalities in native language uptake during infancy. These findings provide a better understanding of the neurodevelopmental underpinnings of language delay in ASD, which is a prerequisite step for developing earlier and more effective interventions for autistic children and HL siblings who experience language impairments.
语言障碍在自闭症谱系障碍（ASD）中很常见，ASD是一种神经发育障碍，其特征是社交沟通受损以及存在受限和重复行为。在被诊断患有ASD的儿童的婴儿兄弟姐妹中——他们患ASD的可能性更高——很大一部分在语言习得方面也存在困难和延迟。
在本研究中，我们使用功能磁共振成像（fMRI）来检查9个月大的、患ASD的高（HL）和典型（TL）家族可能性婴儿中与语言处理相关的异常情况。婴儿在扫描仪中自然睡眠时，会听到母语（英语）和新语言（日语）的语音。进行了全脑和感兴趣区域分析，以评估基于可能性组和语言条件的语言处理中的神经差异。
与TL组相比，HL婴儿总体上对语音的反应减弱，尤其是在左侧颞叶语言区域，并且在母语和新语言之间缺乏神经辨别能力。重要的是，我们还证明HL婴儿在语音处理方面表现出明显非典型的更大程度的向右偏侧化模式。局限性：由于从睡眠参与者收集听觉刺激诱发数据存在固有的挑战，以及COVID-19大流行带来的保留和随访困难，样本量相对较小，尤其是TL组。此外，两组在一些人口统计学变量上不匹配；然而，即使考虑了这些差异，目前的研究结果仍然成立。
据我们所知，这是第一项直接测量婴儿期母语吸收中与自闭症相关异常情况的fMRI研究。这些发现有助于更好地理解ASD中语言延迟的神经发育基础，这是为患有语言障碍的自闭症儿童和HL兄弟姐妹制定更早、更有效干预措施的先决条件。
