Gross Eric, El-Baz Ayman S, Sokhadze Guela E, Sears Lonnie, Casanova Manuel F, Sokhadze Estate M
Department of Bioengineering, University of Louisville, Louisville, Kentucky, USA.
J Neurother. 2012 Jan 1;16(2):78-91. doi: 10.1080/10874208.2012.677631. Epub 2012 May 29.
Children diagnosed with an autism spectrum disorder (ASD) often lack the ability to recognize and properly respond to emotional stimuli. Emotional deficits also characterize children with attention deficit/hyperactivity disorder (ADHD), in addition to exhibiting limited attention span. These abnormalities may effect a difference in the induced EEG gamma wave burst (35-45 Hz) peaked approximately 300-400 milliseconds following an emotional stimulus. Because induced gamma oscillations are not fixed at a definite point in time post-stimulus, analysis of averaged EEG data with traditional methods may result in an attenuated gamma burst power. METHODS: We used a data alignment technique to improve the averaged data, making it a better representation of the individual induced EEG gamma oscillations. A study was designed to test the response of a subject to emotional stimuli, presented in the form of emotional facial expression images. In a four part experiment, the subjects were instructed to identify gender in the first two blocks of the test, followed by differentiating between basic emotions in the final two blocks (i.e. anger vs. disgust). EEG data was collected from ASD (n=10), ADHD (n=9), and control (n=11) subjects via a 128 channel EGI system, and processed through a continuous wavelet transform and bandpass filter to isolate the gamma frequencies. A custom MATLAB code was used to align the data from individual trials between 200-600 ms post-stimulus, EEG site, and condition by maximizing the Pearson product-moment correlation coefficient between trials. The gamma power for the 400 ms window of maximum induced gamma burst was then calculated and compared between subject groups. RESULTS AND CONCLUSION: Condition (anger/disgust recognition, gender recognition) × Alignment × Group (ADHD, ASD, Controls) interaction was significant at most of parietal topographies (e.g., P3-P4, P7-P8). These interactions were better manifested in the aligned data set. Our results show that alignment of the induced gamma oscillations improves sensitivity of this measure in differentiation of EEG responses to emotional facial stimuli in ADHD and ASD.
被诊断患有自闭症谱系障碍（ASD）的儿童通常缺乏识别和正确应对情绪刺激的能力。除了注意力持续时间有限外，注意力缺陷/多动障碍（ADHD）儿童也存在情绪缺陷。这些异常可能会导致在情绪刺激后约300 - 400毫秒达到峰值的诱发脑电图伽马波爆发（35 - 45赫兹）出现差异。由于诱发的伽马振荡在刺激后的特定时间点并不固定，使用传统方法分析平均脑电图数据可能会导致伽马爆发功率衰减。方法：我们使用数据对齐技术来改善平均数据，使其更好地代表个体诱发的脑电图伽马振荡。设计了一项研究来测试受试者对以情绪面部表情图像形式呈现的情绪刺激的反应。在一个四部分实验中，受试者被要求在前两个测试块中识别性别，然后在最后两个块中区分基本情绪（即愤怒与厌恶）。通过128通道EGI系统从ASD（n = 10）、ADHD（n = 9）和对照组（n = 11）受试者收集脑电图数据，并通过连续小波变换和带通滤波器进行处理，以分离伽马频率。使用自定义的MATLAB代码通过最大化试验之间的皮尔逊积矩相关系数，在刺激后200 - 600毫秒、脑电图部位和条件之间对齐来自各个试验的数据。然后计算最大诱发伽马爆发的400毫秒窗口的伽马功率，并在受试者组之间进行比较。结果与结论：在大多数顶叶地形图（例如，P3 - P4、P7 - P8）中，条件（愤怒/厌恶识别、性别识别）×对齐×组（ADHD、ASD、对照组）的交互作用显著。这些交互作用在对齐的数据集中表现得更好。我们的结果表明，诱发伽马振荡的对齐提高了该测量方法在区分ADHD和ASD中对情绪面部刺激的脑电图反应的敏感性。
