Sanjeevan Teenu, Hammill Christopher, Brian Jessica, Crosbie Jennifer, Schachar Russell, Kelley Elizabeth, Liu Xudong, Nicolson Robert, Iaboni Alana, Day Fragiadakis Susan, Ristic Leanne, Lerch Jason P, Anagnostou Evdokia
Holland Bloorview Kids Rehabilitation Hospital, Toronto, ON, Canada.
Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada.
Front Hum Neurosci. 2020 Dec 10;14:587019. doi: 10.3389/fnhum.2020.587019. eCollection 2020.
: There is significant overlap in the type of structural language impairments exhibited by children with autism spectrum disorder (ASD) and children with attention deficit hyperactivity disorder (ADHD). This similarity suggests that the cognitive impairment(s) contributing to the structural language deficits in ASD and ADHD may be shared. Previous studies have speculated that procedural memory deficits may be the shared cognitive impairment. The procedural deficit hypothesis (PDH) argues that language deficits can be explained by differences in the neural structures underlying the procedural memory network. This hypothesis is based on the premise that the neural structures comprising the procedural network support language learning. In this study, we aimed to test the PDH in children with ASD, ADHD, and typical development (TD). : One hundred and sixty-three participants (ages 10-21): 91 with ASD, 26 with ADHD, and 46 with TD, completed standardized measures of cognitive and language ability as well as structural magnetic resonance imaging. We compared the structural language abilities, the neural structures underlying the procedural memory network, and the relationship between structural language and neural structure across diagnostic groups. : Our analyses revealed that while the structural language abilities differed across ASD, ADHD, and TD groups, the thickness, area, and volume of the structures supporting the procedural memory network were not significantly different between diagnostic groups. Also, several neural structures were associated with structural language abilities across diagnostic groups. Only two of these structures, the inferior frontal gyrus, and the left superior parietal gyrus, are known to be linked to the procedural memory network. : The inferior frontal gyrus and the left superior parietal gyrus, have well-established roles in language learning independent of their role as part of the procedural memory system. Other structures such as the caudate and cerebellum, with critical roles in the procedural memory network, were not associated with structural language abilities across diagnostic groups. It is unclear whether the procedural memory network plays a fundamental role in language learning in ASD, ADHD, and TD.
自闭症谱系障碍（ASD）儿童和注意力缺陷多动障碍（ADHD）儿童所表现出的结构性语言障碍类型存在显著重叠。这种相似性表明，导致ASD和ADHD结构性语言缺陷的认知障碍可能是相同的。先前的研究推测程序性记忆缺陷可能是共同的认知障碍。程序性缺陷假说（PDH）认为，语言缺陷可以通过程序性记忆网络背后的神经结构差异来解释。该假说基于这样一个前提，即构成程序性网络的神经结构支持语言学习。在本研究中，我们旨在对患有ASD、ADHD和发育正常（TD）的儿童进行程序性缺陷假说的测试。
163名参与者（年龄在10 - 21岁之间）：91名患有ASD，26名患有ADHD，46名发育正常，完成了认知和语言能力的标准化测试以及结构磁共振成像。我们比较了不同诊断组之间的结构性语言能力、程序性记忆网络背后的神经结构，以及结构性语言与神经结构之间的关系。
我们的分析表明，虽然ASD、ADHD和TD组的结构性语言能力存在差异，但支持程序性记忆网络的结构厚度、面积和体积在诊断组之间没有显著差异。此外，几个神经结构与不同诊断组的结构性语言能力相关。其中只有两个结构，即额下回和左上顶叶，已知与程序性记忆网络有关。
额下回和左上顶叶在语言学习中具有既定作用，与它们作为程序性记忆系统一部分的作用无关。其他结构，如尾状核和小脑，在程序性记忆网络中起关键作用，但与不同诊断组的结构性语言能力无关。目前尚不清楚程序性记忆网络在ASD、ADHD和TD的语言学习中是否起基本作用。
