Harvard College Writing Program, Harvard University, Cambridge, Massachusetts, United States of America.
PLoS One. 2012;7(6):e39127. doi: 10.1371/journal.pone.0039127. Epub 2012 Jun 20.
Current research suggests that autism spectrum disorder (ASD) is characterized by asynchronous neural oscillations. However, it is unclear whether changes in neural oscillations represent an index of the disorder or are shared more broadly among both affected and unaffected family members. Additionally, it remains unclear how early these differences emerge in development and whether they remain constant or change over time. In this study we examined developmental trajectories in spectral power in infants at high- or low-risk for ASD. Spectral power was extracted from resting EEG recorded over frontal regions of the scalp when infants were 6, 9, 12, 18 and 24 months of age. We used multilevel modeling to assess change over time between risk groups in the delta, theta, low alpha, high alpha, beta, and gamma frequency bands. The results indicated that across all bands, spectral power was lower in high-risk infants as compared to low-risk infants at 6-months of age. Furthermore high-risk infants showed different trajectories of change in spectral power in the subsequent developmental window indicating that not only are the patterns of change different, but that group differences are dynamic within the first two years of life. These findings remained the same after removing data from a subset of participants who displayed ASD related behaviors at 24 or 36 months. These differences in the nature of the trajectories of EEG power represent important endophenotypes of ASD.
目前的研究表明,自闭症谱系障碍(ASD)的特征是神经振荡不同步。然而,目前尚不清楚神经振荡的变化是否代表该疾病的指标,或者是否在受影响和未受影响的家庭成员中更为广泛地共享。此外,目前尚不清楚这些差异在发育过程中何时出现,以及它们是否保持不变或随时间变化。在这项研究中,我们研究了自闭症高风险和低风险婴儿在发育过程中频谱功率的轨迹。当婴儿 6、9、12、18 和 24 个月大时,从头皮额区记录的静息 EEG 中提取频谱功率。我们使用多层次模型来评估风险组之间在 delta、theta、低 alpha、高 alpha、beta 和 gamma 频带中随时间的变化。结果表明,在所有频段中,高风险婴儿的频谱功率均低于低风险婴儿在 6 个月大时的频谱功率。此外,高风险婴儿在随后的发育窗口中表现出不同的频谱功率变化轨迹,这表明不仅变化模式不同,而且组间差异在生命的头两年内是动态的。在从 24 或 36 个月时表现出与 ASD 相关行为的参与者数据中删除数据后,这些发现仍然保持不变。这些 EEG 功率轨迹性质的差异代表了 ASD 的重要内表型。