Abnormalities in gamma-band responses to language stimuli in first-degree relatives of children with autism spectrum disorder: an MEG study.
Abnormalities in gamma-band responses to language stimuli in first-degree relatives of children with autism spectrum disorder: an MEG study.
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DOI：
10.1186/1471-244x-12-213
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发表时间：
2012-11-29
期刊：
影响因子：
4.4
通讯作者：
Rojas DC
中科院分区：
文献类型：
--
作者：
McFadden KL;Hepburn S;Winterrowd E;Schmidt GL;Rojas DC
在自闭症谱系障碍（ASD）患者及其一级亲属中，在简单的听觉刺激下，伽马范围（30-80 Hz）的同步神经振荡活动已被证明是异常的。在ASD先证者对语言刺激的反应中发现了伽马带异常，但尚未在一级亲属中进行研究。考虑到语言障碍是ASD的核心症状，并且可能是亲属中看到的广泛自闭症表型（BAP）的一部分，这一点特别有趣。在连续的单词识别任务中获得了23名自闭症儿童的父母和28名成人对照参与者的脑磁图记录。在对任务的反应中，测量了总和诱发的γ波段活动，以及试验间锁相因子（PLF）。由于其在语言处理中的作用，也测量了β -波段的活性。参与者完成了一系列语言测量来评估大脑活动和语言功能之间的关系，并评估了任务相关活动的偏侧性。pASD组的诱发γ和β活性增加，而对照组的诱发活性降低。此外，虽然两组都表现出总伽马能量的减少（在语言任务中常见），但这种减少在对照组中更为明显。与对照组相比，pASD组在音韵学方面的表现明显更差。在两组中，gamma/beta活动和语言测量之间存在显著但明显的关系。此外，虽然整体任务通常会引起左偏侧反应，但pASD在某些感兴趣的区域表现出比对照组更大的左偏侧反应。在自闭症谱系障碍中发现的语言振荡反应异常与先前在自闭症谱系障碍先证者中的发现一致。在ASD先证者的一级亲属中，伽玛带对语言刺激的反应以前没有被评估过，这些发现支持伽玛带活动作为ASD遗传的神经生理生物标志物。在目前的研究中，语言功能和神经活动之间可能存在的关系应该进一步研究，以评估振荡反应异常是否可能导致BAP的行为表现。
Synchronous neural oscillatory activity in the gamma range (30–80 Hz) has been shown to be abnormal in individuals with autism spectrum disorders (ASD) and their first-degree relatives in response to simple auditory stimuli. Gamma-band abnormalities in ASD probands have been seen in response to language stimuli, but this has not been investigated in first-degree relatives. This is of particular interest given that language impairments are a core symptom of ASD and may be part of the broad autism phenotype (BAP) seen in relatives. Magnetoencephalography recordings during a continuous word recognition task were obtained for 23 parents of a child with ASD (pASD) and 28 adult control participants. Total and evoked gamma-band activity, as well as inter-trial phase-locking factor (PLF), were measured in response to the task. Beta-band activity was also measured, due to its suggested role in language processing. Participants completed a series of language measures to assess the relationship between brain activity and language function, and lateralization of task-related activity was assessed. The pASD group showed increased evoked gamma and beta activity, while controls had decreased evoked activity. Additionally, while both groups showed a reduction in total gamma power (commonly seen in language tasks), this reduction was more prominent in the control group. The pASD group demonstrated significantly worse performance on a measure of phonology compared to controls. Significant but distinct relationships were found between gamma/beta activity and language measures within the two groups. In addition, while the overall task generally elicited left lateralized responses, pASD showed greater left lateralization than controls in some regions of interest. Abnormalities in oscillatory responses to language were seen in pASD that are consistent with previous findings in ASD probands. Gamma-band responses to language stimuli have not previously been assessed in first-degree relatives of ASD probands and these findings are supportive of gamma-band activity as a heritable, neurophysiological biomarker of ASD. The possible relationship seen between language function and neural activity in the current study should be investigated further to assess if oscillatory response abnormalities may contribute to behavioural manifestations of the BAP.