Abstract:
In autism spectrum disorder (ASD), atypical sensory experiences are often associated with irregularities in predictive coding, which proposes that the brain creates hierarchical sensory models via a bidirectional process of predictions and prediction errors. However, it remains unclear how these irregularities manifest across different functional hierarchies in the brain. To address this, we study a marmoset model of ASD induced by valproic acid (VPA) treatment. We record high-density electrocorticography (ECoG) during an auditory task with two layers of temporal control, and applied a quantitative model to quantify the integrity of predictive coding across two distinct hierarchies. Our results demonstrate a persistent pattern of sensory hypersensitivity and unstable predictions across two brain hierarchies in VPA-treated animals, and reveal the associated spatio-spectro-temporal neural signatures. Despite the regular occurrence of imprecise predictions in VPA-treated animals, we observe diverse configurations of underestimation or overestimation of sensory regularities within the hierarchies. Our results demonstrate the coexistence of the two primary Bayesian accounts of ASD: overly-precise sensory observations and weak prior beliefs, and offer a potential multi-layered biomarker for ASD, which could enhance our understanding of its diverse symptoms.
摘要:
在自闭症谱系障碍(ASD)中,非典型的感官体验通常与预测编码的不规则性有关,这表明大脑通过预测和预测误差的双向过程创建分层的感觉模型。然而,目前尚不清楚这些不规则性是如何在大脑的不同功能层次中表现出来的.为了解决这个问题,我们研究了丙戊酸(VPA)治疗诱导的ASD的马塞特模型。我们在听觉任务中记录高密度皮质脑电图(ECoG),并进行两层时间控制,并应用定量模型来量化两个不同层次结构中预测编码的完整性。我们的结果表明,在VPA治疗的动物中,感觉过敏和两个大脑层次结构的不稳定预测的持续模式,并揭示相关的时空神经特征。尽管在VPA治疗的动物中经常发生不精确的预测,我们观察到层次结构中低估或高估感觉规律的不同配置。我们的结果表明ASD的两个主要贝叶斯解释共存:过于精确的感官观察和弱的先验信念,并为ASD提供潜在的多层生物标志物,这可以增强我们对其不同症状的理解。