Department of Psychology, Mount Saint Vincent University, Halifax, Canada.
Montreal Neurological Institute-Hospital, Azrieli Centre for Autism Research, McGill University, Montreal, Canada.
Autism Res. 2022 May;15(5):834-846. doi: 10.1002/aur.2701. Epub 2022 Mar 29.
A growing body of research suggests that consistency in cortical activity may be a promising neurophysiological marker of autism spectrum disorder (ASD). In the current study we examined inter-trial coherence, a measure of phase consistency across trials, in the theta range (t-ITC: 3-6 Hz), as theta has been implicated in the processing of social and emotional stimuli in infants and adults. The sample included infants who had an older sibling with a confirmed ASD diagnosis and typically developing (TD) infants with no family history of ASD. The data were collected as part of the British Autism Study of Infant Siblings (BASIS) study. Infants between 6 and 10 months of age (M = 7.34, SD = 1.21) performed a visual face processing task that included faces and scrambled, "face noise", stimuli. Follow-up assessments in higher likelihood infants were completed at 24 and again at 36 months to determine diagnostic outcomes. Analysis focused on posterior t-ITC during early (0-200 ms) and late (200-500 ms) visual processing stages commonly investigated in infant studies. t-ITC over posterior scalp regions during late stage face processing was significantly higher in TD and higher likelihood infants without ASD (HRA-), indicating reduced consistency in theta-band responses in higher likelihood infants who eventually receive a diagnosis of ASD (HRA+). These findings indicate that the temporal dynamics of theta during face processing relate to ASD outcomes. Reduced consistency of oscillatory dynamics at basic levels of infant sensory processing could have downstream effects on learning and social communication. LAY SUMMARY: We examined the consistency in brain responses to faces in infants at lower or higher familial likelihood for autism. Our results show that the consistency of EEG responses was lower during face processing in higher likelihood infants who eventually received a diagnosis of autism. These findings highlight that reduced consistency in brain activity during face processing in the first year of life is related to emerging autism.
越来越多的研究表明，皮质活动的一致性可能是自闭症谱系障碍（ASD）的一种有前途的神经生理标志物。在目前的研究中，我们检查了跨试验相干性，这是一种跨试验相位一致性的度量，在 theta 范围内（t-ITC：3-6 Hz），因为 theta 已被牵连到婴儿和成人处理社会和情感刺激。该样本包括有一个被确诊为 ASD 的哥哥或姐姐的婴儿和没有 ASD 家族史的典型发育（TD）婴儿。数据是作为英国自闭症婴儿兄弟姐妹研究（BASIS）的一部分收集的。6 至 10 个月大的婴儿（M=7.34，SD=1.21）进行了一项视觉面部处理任务，其中包括面部和混乱的“面部噪声”刺激。在高可能性婴儿中进行了后续评估，在 24 个月和 36 个月时再次进行，以确定诊断结果。分析集中在早期（0-200 毫秒）和晚期（200-500 毫秒）视觉处理阶段的后 theta-ITC，这是婴儿研究中常见的阶段。在晚期面部处理期间，TD 和无 ASD 的高可能性婴儿（HRA-）的后头皮区域的 t-ITC 显著更高，这表明最终被诊断为 ASD 的高可能性婴儿（HRA+）的 theta 波段反应一致性降低。这些发现表明，在处理面部时，theta 的时间动态与 ASD 结果有关。在婴儿基本感觉处理中，振荡动态的一致性降低可能会对学习和社会交流产生下游影响。
我们检查了在自闭症家族可能性较低或较高的婴儿中，大脑对面部反应的一致性。我们的研究结果表明，在最终被诊断为自闭症的高可能性婴儿中，在处理面部时，脑电图反应的一致性较低。这些发现强调了在生命的第一年中，面部处理过程中大脑活动一致性降低与自闭症的出现有关。
