Keehn Brandon, Vogel-Farley Vanessa, Tager-Flusberg Helen, Nelson Charles A
Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana; Department of Psychological Sciences, Purdue University, West Lafayette, Indiana.
Autism Res. 2015 Apr;8(2):187-98. doi: 10.1002/aur.1438. Epub 2015 Mar 25.
Among the many experimental findings that tend to distinguish those with and without autism spectrum disorder (ASD) are face processing deficits, reduced hemispheric specialization, and atypical neurostructural and functional connectivity. To investigate the earliest manifestations of these features, we examined lateralization of event-related gamma-band coherence to faces during the first year of life in infants at high risk for autism (HRA; defined as having an older sibling with ASD) who were compared with low-risk comparison (LRC) infants, defined as having no family history of ASD. Participants included 49 HRA and 46 LRC infants who contributed a total of 127 data sets at 6 and 12 months. Electroencephalography was recorded while infants viewed images of familiar/unfamiliar faces. Event-related gamma-band (30-50 Hz) phase coherence between anterior-posterior electrode pairs for left and right hemispheres was computed. Developmental trajectories for lateralization of intra-hemispheric coherence were significantly different in HRA and LRC infants: by 12 months, HRA infants showed significantly greater leftward lateralization compared with LRC infants who showed rightward lateralization. Preliminary results indicate that infants who later met criteria for ASD were those that showed the greatest leftward lateralization. HRA infants demonstrate an aberrant pattern of leftward lateralization of intra-hemispheric coherence by the end of the first year of life, suggesting that the network specialized for face processing may develop atypically. Further, infants with the greatest leftward asymmetry at 12 months where those that later met criteria for ASD, providing support to the growing body of evidence that atypical hemispheric specialization may be an early neurobiological marker for ASD.
在众多有助于区分有无自闭症谱系障碍（ASD）的实验结果中，面部加工缺陷、半球特化减弱以及非典型的神经结构和功能连接是其特征。为了探究这些特征的最早表现，我们研究了自闭症高风险（HRA；定义为有一个患ASD的哥哥或姐姐）婴儿在出生后第一年观看面部时与事件相关的伽马波段相干性的偏侧化情况，并将其与低风险对照（LRC）婴儿进行比较，LRC婴儿定义为无ASD家族史。参与者包括49名HRA婴儿和46名LRC婴儿，他们在6个月和12个月时共提供了127个数据集。在婴儿观看熟悉/不熟悉面孔的图像时记录脑电图。计算左右半球前后电极对之间与事件相关的伽马波段（30 - 50赫兹）相位相干性。HRA和LRC婴儿半球内相干性偏侧化的发育轨迹显著不同：到12个月时，HRA婴儿与表现为向右偏侧化的LRC婴儿相比，向左偏侧化程度明显更高。初步结果表明，后来符合ASD标准的婴儿是那些向左偏侧化程度最大的婴儿。HRA婴儿在出生后第一年末表现出半球内相干性向左偏侧化的异常模式，这表明专门用于面部加工的神经网络可能发育异常。此外，12个月时向左不对称程度最大且后来符合ASD标准的婴儿，为越来越多的证据提供了支持，即非典型的半球特化可能是ASD的早期神经生物学标志物。
