Thillay Alix, Lemaire Mathieu, Roux Sylvie, Houy-Durand Emmanuelle, Barthélémy Catherine, Knight Robert T, Bidet-Caulet Aurélie, Bonnet-Brilhault Frédérique
UMR Institut National de la Santé et de la Recherche Médicale U930, Université François-Rabelais de Tours Tours, France.
UMR Institut National de la Santé et de la Recherche Médicale U930, Université François-Rabelais de ToursTours, France; Centre Universitaire de Pédopsychiatrie, CHRU de ToursTours, France.
Front Neurosci. 2016 Jul 8;10:317. doi: 10.3389/fnins.2016.00317. eCollection 2016.
Resistance to change is often reported in autism and may arise from an inability to predict events in uncertain contexts. Using EEG recorded in 12 adults with autism and age-matched controls performing a visual target detection task, we characterized the influence of a certain context (targets preceded by a predictive sequence of three distinct stimuli) or an uncertain context (random targets) on behavior and electrophysiological markers of predictive processing. During an uncertain context, adults with autism were faster than controls to detect targets. They also had an enhancement in CNV amplitude preceding all random stimuli-indexing enhanced preparatory mechanisms, and an earlier N2 to targets-reflecting faster information processing-compared to controls. During a certain context, both controls and adults with autism presented an increase in P3 amplitude to predictive stimuli-indexing information encoding of the predictive sequence, an enhancement in CNV amplitude preceding predictable targets-corresponding to the deployment of preparatory mechanisms, and an earlier P3 to predictable targets-reflecting efficient prediction building and implementation. These results suggest an efficient extraction of predictive information to generate predictions in both controls and adults with autism during a certain context. However, adults with autism displayed a failure to decrease mu power during motor preparation accompanied by a reduced benefit in reaction times to predictable targets. The data reveal that patients with autism over-anticipate stimuli occurring in an uncertain context, in accord with their sense of being overwhelmed by incoming information. These results suggest that adults with autism cannot flexibly modulate cortical activity according to changing levels of uncertainty.
自闭症患者通常表现出对变化的抗拒，这可能源于他们在不确定情境中无法预测事件。我们对12名自闭症成年人和年龄匹配的对照组进行了一项视觉目标检测任务，并记录了他们的脑电图，以此来研究特定情境（在目标出现之前有三个不同刺激的预测序列）或不确定情境（随机目标）对预测处理的行为和电生理指标的影响。在不确定情境中，自闭症成年人比对照组更快地检测到目标。与对照组相比，他们在所有随机刺激之前的关联性负变（CNV）振幅增强，这表明准备机制增强；对目标的N2波出现得更早，这反映了信息处理更快。在特定情境中，对照组和自闭症成年人对预测性刺激的P3振幅均增加，这表明对预测序列进行了信息编码；在可预测目标之前的CNV振幅增强，这与准备机制的部署相对应；对可预测目标的P3波出现得更早，这反映了有效的预测构建和实施。这些结果表明，在特定情境中，对照组和自闭症成年人都能有效地提取预测信息以生成预测。然而，自闭症成年人在运动准备期间未能降低μ波功率，同时对可预测目标的反应时间受益减少。数据显示，自闭症患者过度预测不确定情境中出现的刺激，这与他们被传入信息淹没的感觉相符。这些结果表明，自闭症成年人无法根据不确定性的变化灵活调节皮层活动。
