Wagner Lauren, Banchik Megan, Tsang Tawny, Okada Nana J, Altshuler Rebecca, McDonald Nicole, Bookheimer Susan Y, Jeste Shafali S, Green Shulamite, Dapretto Mirella
Neuroscience Interdepartmental Program, University of California Los Angeles, Los Angeles, CA, 90095, USA.
Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA.
Mol Autism. 2025 Feb 3;16(1):6. doi: 10.1186/s13229-025-00640-w.
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 differences in 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 a priori 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 lateralization for speech processing, particularly during native speech processing, suggesting a failure to left-lateralize.
The sample size, particularly for the TL group, is relatively modest because of 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. The groups were not matched on some demographic variables, but 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，这是一种神经发育障碍，其特征是社交沟通受损以及行为受限和重复。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表现出困难和延迟。
在本研究中，我们使用功能磁共振成像（fMRI）来检查9个月大的婴儿在患ASD的高家族风险（HL）和典型家族风险（TL）情况下语言处理的差异。婴儿在扫描仪中自然睡眠时，会接触到母语（英语）和新语言（日语）的语音。进行了全脑和先验感兴趣区域分析，以评估基于风险组和语言条件的语言处理中的神经差异。
总体而言，HL组婴儿对语音的反应减弱，尤其是在左颞叶语言区域，并且与TL组相比，他们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组婴儿在语音处理方面表现出明显非典型的偏侧化模式，特别是在处理母语时，这表明未能向左侧偏侧化。
由于从睡眠中的参与者收集听觉刺激诱发数据存在固有挑战，以及COVID-19大流行带来的保留和随访困难，样本量相对较小，特别是对于TL组。两组在一些人口统计学变量上不匹配，但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的非典型性的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组兄弟姐妹开发更早、更有效的干预措施的先决条件。
