正常人不同刺激野ERP及其法医学价值研究

Study on different stimulative fields ERP in normal-vision subjects and its forensic value

目的研究正常人不同刺激野电生理反应及头皮分布,进一步探讨不同视野缺损时视觉信息处理的特征与差别。方法本研究分别对30名正常视功能被试进行不同刺激野刺激,同时记录其脑电反应。结果事件相关电位(ERP)早期成分显示:与上视野缺损相比,下视野缺损引起广泛脑区N1和枕颞部P1潜伏期显著延长;此外,上视野缺损较下视野缺损诱发出较小P1,而N1振幅表现为上下视野间相似。ERP晚期成分显示:与下视野缺损对比,上视野缺损引起广泛脑区N2和左半球中央顶区P3潜伏期显著延长,以及较小N2,而P3振幅在上下视野间无差异。结论ERP结果提示,下视野缺损主要引起ERP早期成分P1和N1潜伏期的延长,而上视野缺损主要引起ERP晚期成分N2和P3潜伏期的延长,以及P1和N2振幅的降低。

Objective To study the electrophysiological response and scalp distribution in health adults with different visual fields, and to investigate the character and difference of visual information processing with different visual field defect. Methods The electroencephalic responses in 30 subjects with normal visual function were recorded and analyzed after receiving different stimulative fields. Results The early event - related potential （ERP） components showed a longer P1 over the occipitotemporal areas and a longer N1 over the extensive encephalic region in lower visual field defect （LVFD） than in upper visual field defect （UVFD）. In addition, P1 was smaller in UVFD than in LVFD, but N1 was similar in size between UVFD and LVFD. The late components showed a longer N2 over the extensive encephalic region and a longer P3 over the centro - parietal region of left hemisphere in UVFD than in LVFD, as well as a smaller N2, but the amplitude of P3 was much similar between these two visual fields. Conclusion These ERP findings suggested that LVFD may principally cause prolonged latency of early ERP components P1 and N1, but UVFD can mainly evoke the prolonged latency of late components N2 and 173 as well as a smaller P1 and N2.