1Department of Counseling, Psychology and Special Education, Brigham Young University McKay School of Education, Provo, USA.
2Department of Radiology and Imaging Sciences, University of Utah School of Medicine, Salt Lake City, USA.
Mol Autism. 2018 Dec 27;9:67. doi: 10.1186/s13229-018-0248-y. eCollection 2018.
Functional neuroimaging research in autism spectrum disorder has reported patterns of decreased long-range, within-network, and interhemispheric connectivity. Research has also reported increased corticostriatal connectivity and between-network connectivity for default and attentional networks. Past studies have excluded individuals with autism and low verbal and cognitive performance (LVCP), so connectivity in individuals more significantly affected with autism has not yet been studied. This represents a critical gap in our understanding of brain function across the autism spectrum.
Using behavioral support procedures adapted from Nordahl, et al. (J Neurodev Disord 8:20-20, 2016), we completed non-sedated structural and functional MRI scans of 56 children ages 7-17, including LVCP children ( = 17, mean IQ = 54), children with autism and higher performance (HVCP, = 20, mean IQ = 106), and neurotypical children (NT, = 19, mean IQ = 111). Preparation included detailed intake questionnaires, video modeling, behavioral and anxiety reduction techniques, active noise-canceling headphones, and in-scan presentation of the Inscapes movie paradigm from Vanderwal et al. (Neuroimage 122:222-32, 2015). A high temporal resolution multiband echoplanar fMRI protocol analyzed motion-free time series data, extracted from concatenated volumes to mitigate the influence of motion artifact. All participants had > 200 volumes of motion-free fMRI scanning. Analyses were corrected for multiple comparisons.
LVCP showed decreased within-network connectivity in default, salience, auditory, and frontoparietal networks (LVCP < HVCP) and decreased interhemispheric connectivity (LVCP < HVCP=NT). Between-network connectivity was higher for LVCP than NT between default and dorsal attention and frontoparietal networks. Lower IQ was associated with decreased connectivity within the default network and increased connectivity between default and dorsal attention networks.
This study demonstrates that with moderate levels of support, including readily available techniques, information about brain similarities and differences in LVCP individuals can be further studied. This initial study suggested decreased network segmentation and integration in LVCP individuals. Further imaging studies of LVCP individuals with larger samples will add to understanding of origins and effects of autism on brain function and behavior.
自闭症谱系障碍的功能神经影像学研究报告了长程、内联网和半球间连接减少的模式。研究还报告了默认和注意力网络的皮质纹状体连接和网络间连接增加。过去的研究排除了自闭症和低语言和认知表现（LVCP）的个体，因此，自闭症影响更严重的个体的连接尚未得到研究。这是我们对自闭症谱系中大脑功能理解的一个关键差距。
使用 Nordahl 等人（J Neurodev Disord 8:20-20, 2016）改编的行为支持程序，我们对 56 名 7-17 岁的儿童进行了非镇静结构和功能 MRI 扫描，包括 LVCP 儿童（ = 17，平均智商 = 54）、自闭症和高表现（HVCP， = 20，平均智商 = 106）和神经典型儿童（NT， = 19，平均智商 = 111）。准备工作包括详细的摄入问卷、视频建模、行为和焦虑减轻技术、主动降噪耳机，以及在扫描中呈现 Vanderwal 等人的 Inscapes 电影范式（Neuroimage 122:222-32, 2015）。高时间分辨率多频带回波平面 fMRI 协议分析了从串联体积中提取的无运动时间序列数据，以减轻运动伪影的影响。所有参与者都有超过 200 个无运动 fMRI 扫描卷。分析结果经过多次比较校正。
LVCP 在默认、突显、听觉和额顶叶网络中表现出较低的内联网连接（LVCP < HVCP），并表现出较低的半球间连接（LVCP < HVCP=NT）。LVCP 与 NT 之间，默认网络与背侧注意力和额顶叶网络之间的连接强度更高。较低的智商与默认网络内连接减少和默认网络与背侧注意力网络之间连接增加有关。
这项研究表明，在适度的支持水平下，包括现成的技术，关于 LVCP 个体的大脑相似性和差异性的信息可以进一步研究。这项初步研究表明 LVCP 个体的网络分割和整合减少。进一步的成像研究将增加对自闭症对大脑功能和行为的起源和影响的理解。
