Sokhadze Estate, Baruth Joshua, Tasman Allan, Sears Lonnie, Mathai Grace, El-Baz Ayman, Casanova Manuel F
Department of Psychiatry and Behavioral Science, University of Louisville School of Medicine, Louisville, KY 40292, USA.
Appl Psychophysiol Biofeedback. 2009 Mar;34(1):37-51. doi: 10.1007/s10484-009-9074-5. Epub 2009 Feb 6.
To better understand visual processing abnormalities in autism we studied the attention orienting related frontal event potentials (ERP) and the sustained attention related centro-parietal ERPs in a three stimulus oddball experiment. The three stimulus oddball paradigm was aimed to test the hypothesis that individuals with autism abnormally orient their attention to novel distracters as compared to controls. A dense-array 128 channel EGI electroencephalographic (EEG) system was used on 11 high-functioning children and young adults with autism spectrum disorder (ASD) and 11 age-matched, typically developing control subjects. Patients with ASD showed slower reaction times but did not differ in response accuracy. At the anterior (frontal) topography the ASD group showed significantly higher amplitudes and longer latencies of early ERP components (e.g., P100, N100) to novel distracter stimuli in both hemispheres. The ASD group also showed prolonged latencies of late ERP components (e.g., P2a, N200, P3a) to novel distracter stimuli in both hemispheres. However, differences were more profound in the right hemisphere for both early and late ERP components. Our results indicate augmented and prolonged early frontal potentials and a delayed P3a component to novel stimuli, which suggest low selectivity in pre-processing and later-stage under-activation of integrative regions in the prefrontal cortices. Also, at the posterior (centro-parietal) topography the ASD group showed significantly prolonged N100 latencies and reduced amplitudes of the N2b component to target stimuli. In addition, the latency of the P3b component was prolonged to novel distracters in the ASD group. In general, the autistic group showed prolonged latencies to novel stimuli especially in the right hemisphere. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. We propose the potential application of ERP evaluations in a novelty task as outcome measurements in the biobehavioral treatment (e.g., EEG biofeedback, TMS) of autism.
为了更好地理解自闭症患者的视觉处理异常情况，我们在一项三刺激oddball实验中研究了与注意力定向相关的额叶事件相关电位（ERP）以及与持续注意力相关的中央顶叶ERP。三刺激oddball范式旨在检验这样一个假设：与对照组相比，自闭症患者会异常地将注意力导向新的干扰物。我们使用密集阵列128通道EGI脑电图（EEG）系统，对11名患有自闭症谱系障碍（ASD）的高功能儿童和青年以及11名年龄匹配、发育正常的对照受试者进行了研究。患有ASD的患者反应时间较慢，但反应准确性并无差异。在前部（额叶）地形图上，ASD组在两个半球中对新干扰物刺激的早期ERP成分（如P100、N100）显示出明显更高的波幅和更长的潜伏期。ASD组在两个半球中对新干扰物刺激的晚期ERP成分（如P2a、N200、P3a）也显示出潜伏期延长。然而，对于早期和晚期ERP成分，右半球的差异更为显著。我们的结果表明，早期额叶电位增强且持续时间延长，对新刺激的P3a成分延迟，这表明在预处理阶段选择性较低，前额叶皮质中整合区域在后期激活不足。此外，在后部（中央顶叶）地形图上，ASD组对目标刺激的N100潜伏期明显延长，N2b成分波幅降低。另外，ASD组中P3b成分对新干扰物的潜伏期延长。总体而言，自闭症组对新刺激的潜伏期延长，尤其是在右半球。这些结果表明，自闭症患者对成功区分目标和新刺激所需的信息进行了过度处理。我们建议将ERP评估潜在地应用于新奇任务中，作为自闭症生物行为治疗（如EEG生物反馈、经颅磁刺激）的结果测量指标。
