UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.
CNRS (Integrative Neuroscience and Cognition Center, UMR 8002), Paris, France.
Transl Psychiatry. 2019 Dec 18;9(1):341. doi: 10.1038/s41398-019-0672-6.
Atypical sensory behaviours represent a core symptom of autism spectrum disorder (ASD). Investigating early visual processing is crucial to deepen our understanding of higher-level processes. Visual evoked potentials (VEPs) to pattern-reversal checkerboards were recorded in ASD children and age-matched controls. Peak analysis of the P100 component and two types of single-trial analyses were carried out. P100 amplitude was reduced in the ASD group, consistent with previous reports. The analysis of the proportion of trials with a positive activity in the latency range of the P100, measuring inter-trial (in)consistency, allowed identifying two subgroups of ASD participants: the first group, as control children, showed a high inter-trial consistency, whereas the other group showed an inter-trial inconsistency. Analysis of median absolute deviation of single-trial P100 (st-P100) latencies revealed an increased latency variability in the ASD group. Both single-trial analyses revealed increased variability in a subset of children with ASD. To control for this variability, VEPs were reconstructed by including only positive trials or trials with homogeneous st-P100 latencies. These control analyses abolished group differences, confirming that the reduced P100 amplitude results from increased inter-trial variability in ASD. This increased variability in ASD supports the neural noise theory. The existence of subgroups in ASD suggests that the neural response variability is not a genuine characteristic of the entire autistic spectrum, but rather characterized subgroups of children. Exploring the relationship between sensory responsiveness and inter-trial variability could provide more precise bioclinical profiles in children with ASD, and complete the functional diagnostic crucial for the development of individualized therapeutical projects.
非典型感觉行为是自闭症谱系障碍 (ASD) 的核心症状之一。研究早期视觉处理对于深入了解高级过程至关重要。在 ASD 儿童和年龄匹配的对照组中记录了棋盘格模式反转的视觉诱发电位 (VEPs)。对 P100 成分的峰分析和两种类型的单次分析进行了研究。ASD 组的 P100 幅度降低，与之前的报告一致。分析 P100 潜伏期范围内具有正活动的试验比例，测量试验间（不）一致性，可以识别 ASD 参与者的两个亚组：第一组与对照组儿童一样，表现出高试验间一致性，而另一组则表现出试验间不一致性。分析单试 P100(st-P100)潜伏期的中值绝对偏差揭示了 ASD 组的潜伏期变异性增加。两种单次分析都揭示了 ASD 儿童亚组中变异性增加。为了控制这种变异性，仅包括正试验或 st-P100 潜伏期均匀的试验来重建 VEPs。这些对照分析消除了组间差异，证实了 ASD 中 P100 幅度降低是由于试验间变异性增加所致。ASD 中增加的变异性支持神经噪声理论。ASD 中存在亚组表明，神经反应变异性不是整个自闭症谱的真正特征，而是具有特征性的儿童亚组。探索感觉反应性和试验间变异性之间的关系可以为 ASD 儿童提供更精确的生物临床特征，并为个体化治疗项目的发展完成关键的功能诊断。
